Modification of Anti-PD-1 antibodies to treat cancer

Abstract

The subject matter described here relates to anti-PD-1 monoclonal antibodies with increased size that are capable of modulating T-cell activity. In certain embodiments the monoclonal antibody comprises an additional Fc domain or CD22 domain.

Description

Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 MODIFICATION OF ANTI-PD-1 ANTIBODIES TO TREAT CANCER

[0001] This application claims the benefit of and priority to US Provisional Serial No.: 63 / 588,373, filed October 6, 2023, and US Provisional Serial No.: 63 / 696,015 filed September 18, 2024, the contents of each of which is hereby incorporated by reference in its entirety.

[0002] This patent disclosure contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of the patent document or the patent disclosure as it appears in the U.S. Patent and Trademark Office patent file or records, but otherwise reserves any and all copyright rights. INCORPORATION BY REFERENCE

[0003] All documents cited herein are incorporated herein by reference in their entireties. GOVERNMENT SUPPORT

[0004] This invention was made with government support under grant numbers AI125640 and AI150597 awarded by the National Institutes of Health (NIH). The government has certain rights in the invention. TECHNICAL FIELD

[0005] The present invention relates generally to antibodies and expression systems for producing antibodies. More particularly, the present invention relates to anti-PD-1 monoclonal antibodies with increased size. BACKGROUND

[0006] Targeting immune checkpoint receptors on T cells is a common cancer treatment strategy. Frequently, this is accomplished through monoclonal antibodies targeting the ligand binding sites of inhibitory co-receptors. Blocking the immune checkpoint PD-1 binding to its ligands PD-L1 and PD-L2 prevents downstream signaling and enhances specific T functions. Since 2013, the FDA has approved nine monoclonal antibodies to inhibit PD-1 and PD-L1 signaling. This therapeutic approach improved the care of patients with cancers. However, many patients are unresponsive, and some develop immune-related adverse events (irAEs). There is a need for prophylactic and / or therapeutic agents with improved specificity and efficacy, and reduced side effects. - 1 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 SUMMARY OF THE INVENTION

[0007] In certain aspects, the present application provides a monoclonal antibody or a fragment thereof, comprising: a first arm comprising a first variable heavy chain domain and a first variable light chain domain, wherein a portion of the first arm is capable of binding to a portion of a PD-1 protein; and a second arm comprising a second variable heavy chain domain and a second variable light chain domain, wherein a portion of the second arm is capable of binding to a portion of the PD-1 protein, wherein the first and second arms each further comprise a fragment crystallizable (Fc) domain wherein the first and second arms each further comprise at least one additional domain.

[0008] In some embodiments, the first and second arms each further comprise a CH1 domain, a hinge domain, and a CL domain.

[0009] In some embodiments, the at least one additional domain comprises a second Fc domain. In some embodiments, the first and second arms each further comprise one additional domain comprising a second Fc domain. In some embodiments, the at least one additional domain comprises a CD22 domain, a human serum albumin (HSA), or an albumin binding domain (ABD).

[0010] In some embodiments, the first and second arms each further comprise one additional domain comprising a CD22 domain. In some embodiments, the CD22 domain comprises the SEQ ID NO: 8, or a fragment thereof. In some embodiments, the CD22 domain comprises SEQ ID NO: 9. In some embodiments, the CD22 domain comprises SEQ ID NO: 10. In some embodiments, the monoclonal antibody comprises an ABD domain, wherein the ABD domain comprises any one of SEQ ID NOs: 62-71, or a fragment thereof. In some embodiments, the monoclonal antibody comprises a HSA domain, wherein the HSA domain comprises any one of SEQ ID NOs: 51-60, or a fragment thereof.

[0011] In some embodiments, the first variable heavy chain domain of the first arm is encoded by a first polypeptide chain; the first variable light chain domain of the first arm is encoded by a second polypeptide chain; the second variable heavy chain domain of the second arm is encoded by a third polypeptide chain; the second variable light chain domain of the second arm is encoded by a fourth polypeptide chain; and the first variable heavy chain domain and first variable light chain domain form a first PD-1 binding site, and the second variable heavy chain domain and second variable light chain domain form a second PD-1 binding site. - 2 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0012] In some embodiments, the first and second PD-1 binding sites are the same.

[0013] In some embodiments, the first and third polypeptide chain each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain, and the second and fourth polypeptide chain each further encode a CL domain. In some embodiments, the first and third polypeptide chains comprise the same sequence, and the second and fourth polypeptide chains comprise the same sequence.

[0014] In some embodiments, the first variable heavy chain domain comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71 and the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0015] In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO: 3.

[0016] In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 2 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 11 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 12 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3.

[0017] In some embodiments, the first and second polypeptide chains are linked by one or more covalent disulfide bonds and the third and fourth polypeptide chains are linked by one or more covalent disulfide bonds.

[0018] In some embodiments, the first and third polypeptide chains are linked by one or more covalent disulfide bonds. - 3 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0019] In some embodiments, the monoclonal antibody is capable of localizing a PD-1 protein away from an immune synapse.

[0020] In some embodiments, the monoclonal antibody is capable of disrupting downstream signaling of a PD-1 mediated response in a T cell.

[0021] In some embodiments, the monoclonal antibody is capable of enhancing T cell function.

[0022] In some embodiments, the PD-1 protein is located on a T cell, and the monoclonal antibody is capable of preventing the PD-1 protein from binding to a PDL-1 protein or a PDL-2 protein on a tumor cell.

[0023] In some embodiments, the monoclonal antibody is capable of inducing a cytokine secretion in a T cell. In some embodiments, the cytokine secretion is a secretion of IL-2.

[0024] In some embodiments, the monoclonal antibody is larger than 140kD in size. In some embodiments, the monoclonal antibody is about 200kD in size. In some embodiments, the monoclonal antibody is between about 160kD and 230kD in size.

[0025] In certain aspects, the present application provides a pharmaceutical composition comprising: a monoclonal antibody as described above and a pharmaceutically acceptable carrier.

[0026] In certain aspects, the present application provides a method of preventing or treating cancer in a subject comprising administering to the subject an effective amount of the composition of the composition described above.

[0027] In some embodiments, the cancer is selected from colorectal cancer, lung cancer, bladder cancer, breast cancer, cervical cancer, kidney cancer, leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, prostate cancer, skin cancer (e.g., melanoma), head and neck cancer, endometrial cancer, colon cancer, rectal cancer, liver cancer, thyroids cancer, esophageal cancer, renal cell cancer, and a combination thereof.

[0028] In certain aspects, the present application provides a method of preventing or treating a viral infection in a subject comprising administering to the subject an effective amount of the composition described above. In some embodiments, the viral infection is HIV. - 4 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0029] In certain aspects, the present application provides a kit for generating a monoclonal antibody or fragment thereof, the kit comprising one or more vectors comprising a polynucleotide sequence encoding any of the monoclonal antibodies described above.

[0030] In certain aspects, the present application provides a kit for generating a monoclonal antibody or fragment thereof, the kit comprising: a first vector comprising a polynucleotide sequence encoding the first polypeptide chain of the monoclonal antibody with the first variable heavy chain domain of the first arm encoded by a first polypeptide chain; and a second vector comprising a polynucleotide sequence encoding the second polypeptide chain of the monoclonal antibody with the first variable light chain domain of the first arm encoded by a second polypeptide chain, the first variable heavy chain domain and first variable light chain domain form a first PD-1 binding site.

[0031] In some embodiments, the first and second PD-1 binding sites are the same. In some embodiments, the first and the third polypeptide chains each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain and the second and fourth polypeptide chain each further encode a CL domain. In some embodiments, the first and third polypeptide chains comprise the same sequence, and the second and fourth polypeptide chains comprise the same sequence. In some embodiments, the first variable heavy chain domain comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, wherein the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0032] In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 2 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 11 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the - 5 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 12 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3.

[0033] In some embodiments, the first vector and the second vector are the same vector. In some embodiments, the first vector and the second vector are two different vectors.

[0034] In certain aspects, the present application provides one or more host cells comprising: one or more vectors comprising a polynucleotide sequence encoding any of the monoclonal antibodies described above.

[0035] In certain aspects, the present application provides one or more host cells comprising: a first vector comprising a polynucleotide sequence encoding the first polypeptide chain of the monoclonal antibody with the first variable heavy chain domain of the first arm encoded by a first polypeptide chain; and a second vector comprising a polynucleotide sequence encoding the second polypeptide chain of the monoclonal antibody with the first variable light chain domain of the first arm encoded by a second polypeptide chain, the first variable heavy chain domain and first variable light chain domain form a first PD-1 binding site.

[0036] In some embodiments, the first and second PD-1 binding sites are the same. In some embodiments, the first and the third polypeptide chains each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain and the second and fourth polypeptide chain each further encode a CL domain. In some embodiments, the first and third polypeptide chains comprise the same sequence and the second and fourth polypeptide chains comprise the same sequence. In some embodiments, the first variable heavy chain domain comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, wherein the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0037] In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO: 3. In some embodiments, the first and - 6 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 2 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 11 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 12 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3.

[0038] In some embodiments, the first vector and the second vector are the same vector. In some embodiments, the first vector and the second vector are two different vectors.

[0039] In some embodiments, the one or more host cells are cultured under conditions suitable for an expression of the one or more vectors; and recovering the monoclonal antibody or fragment thereof. In some embodiments, the one or more host cells are cultured under conditions suitable for an expression of the first vector and the second vector; and recovering the monoclonal antibody or fragment thereof.

[0040] In certain aspects, the present application provides a composition comprising: one or more vectors comprising a polynucleotide sequence encoding any of the monoclonal antibodies described above.

[0041] In certain aspects, the present application provides a composition comprising: a first vector comprising a polynucleotide sequence encoding the first polypeptide chain of the monoclonal antibody with the first variable heavy chain domain of the first arm encoded by a first polypeptide chain; and a second vector comprising a polynucleotide sequence encoding the second polypeptide chain of the monoclonal antibody with the first variable light chain domain of the first arm encoded by a second polypeptide chain, the first variable heavy chain domain and first variable light chain domain form a first PD-1 binding site.

[0042] In some embodiments, the first and second PD-1 binding sites are the same. In some embodiments, the first and the third polypeptide chains each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain and the second and fourth polypeptide chain each further encode a CL domain. In some embodiments, the first and third polypeptide chains comprise the same sequence and the second and fourth polypeptide chains comprise the same sequence. In some embodiments, the first variable heavy chain domain - 7 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, wherein the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0043] In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 2 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 11 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3. In some embodiments, the first and third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 12 and the second and fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3.

[0044] In some embodiments, the first vector and the second vector are the same vector. In some embodiments, the first vector and the second vector are two different vectors.

[0045] In certain aspects, the present application provides a means for binding a portion of a PD-1 protein. In some embodiments, the means comprises a monoclonal antibody comprising a domain for increasing the size of the monoclonal antibody over 140kD. In some embodiments, the monoclonal antibody or a fragment thereof comprises: a first arm comprising a first variable heavy chain domain and a first variable light chain domain, wherein a portion of the first arm is capable of binding to the portion of the PD-1 protein; and a second arm comprising a second variable heavy chain domain and a second variable light chain domain, wherein a portion of the second arm is capable of binding to the portion of the PD-1 protein wherein the first and second arms each further comprise a fragment, crystallizable (Fc) domain wherein the first and second arms each further comprise the domain for increasing the size of the monoclonal antibody over 140kD. - 8 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0046] In some embodiments, the first and second arms each further comprise a CH1 domain, a hinge domain, and a CL domain.

[0047] In some embodiments, the domain for increasing the size of the monoclonal antibody over 140kD comprises a second Fc domain. In some embodiments, the domain for increasing the size of the monoclonal antibody over 140kD comprises a CD22 domain.

[0048] In some embodiments, the first and second arms each further comprise one additional domain comprising a CD22 domain, a human serum albumin (HSA), or an albumin binding domain (ABD). In some embodiments, the CD22 domain comprises the SEQ ID NO: 8, or a fragment thereof. In some embodiments, the CD22 domain comprises SEQ ID NO: 9. In some embodiments, the CD22 domain comprises SEQ ID NO: 10. In some embodiments, the monoclonal antibody comprises an ABD domain, wherein the ABD domain comprises any one of SEQ ID NOs: 62-71, or a fragment thereof. In some embodiments, the monoclonal antibody comprises a HSA domain, wherein the HSA domain comprises any one of SEQ ID NOs: 51-60, or a fragment thereof.

[0049] In some embodiments, the first variable heavy chain domain of the first arm is encoded by a first polypeptide chain; the first variable light chain domain of the first arm is encoded by a second polypeptide chain; the second variable heavy chain domain of the second arm is encoded by a third polypeptide chain; the second variable light chain domain of the second arm is encoded by a fourth polypeptide chain; and the first variable heavy chain domain and first variable light chain domain form a first PD-1 binding site and wherein the second variable heavy chain domain and second variable light chain domain form a second PD-1 binding site. In some embodiments, the first and second PD-1 binding sites are the same.

[0050] In some embodiments, the first and third polypeptide chain each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain for increasing the size of the monoclonal antibody over 140kD, and wherein the second and fourth polypeptide chain each further encode a CL domain. In some embodiments, the first and third polypeptide chains comprise the same sequence and the second and fourth polypeptide chains comprise the same sequence.

[0051] In some embodiments, the first variable heavy chain domain comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, - 9 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, wherein the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0052] In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO: 3. In some embodiments, the first arm and second arm each comprises an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO: 3.

[0053] In some embodiments, the monoclonal antibody is capable of localizing a PD-1 protein away from an immune synapse.

[0054] In some embodiments, the monoclonal antibody is capable of disrupting downstream signaling of a PD-1 mediated response in a T cell. In some embodiments, the monoclonal antibody is capable of enhancing T cell function.

[0055] In some embodiments, the PD-1 protein is located on a T cell, and wherein the monoclonal antibody is capable of preventing the PD-1 protein from binding to a PDL-1 protein or a PDL-2 protein on a tumor cell.

[0056] In some embodiments, the monoclonal antibody is capable of inducing a cytokine secretion in a T cell. In some embodiments, the cytokine secretion is a secretion of IL-2.

[0057] In some embodiments, the monoclonal antibody is between about 160kD and 200kD in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The patent or application file contains at least one drawing executed in color. To conform to the requirements for PCT patent applications, many of the figures presented herein are black and white representations of images originally created in color.

[0059] The following figures depict illustrative embodiments of the invention.

[0060] FIG.1 shows that anti-PD-1 Ab and Anti-PD-1-Fc Ab bind to PD-1. ELISA wells were coated with the recombinant ectodomain of PD-1 (2 ug / ml) overnight before incubation with different concentrations of the anti-PD-1 or anti-PD-1-Fc antibodies at room temperate. - 10 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 After 45 min, wells were washed, and the level of bound antibodies was detected with tagged secondary antibodies using a plate reader at an OD of 450. A representative experiment is shown (n=2).

[0061] FIG.2 shows that anti-PD-1-Fc Ab removes PD-1 away from the immune synapse. Jurkat T cells stably expressing GFP-PD-1 were cocultured with Raji B cells expressing mCherry-PD-L1. The Raji B cells were pretreated with SEE (50 ug / ml), and the Jurakt T cells were pretreated with specific antibodies (1 ug / ml or molar equivalent), as indicated, for 45 minutes. Live cocultured cells were imaged with confocal microscopy (Zeiss) for 30 minutes, and the number of the conjugates where PD-1 was enriched at the immune synapse was calculated using ImageJ. Representative images are shown on top, and the quantitation of four independent experiments is included (n=4, 50-70 cells per experiment, SEM, *p<0.05).

[0062] FIG.3 shows that anti-PD-1-Fc Ab and anti-PD-1-CD22 increases IL-2 secretion of PBMC assay. PBMC were isolated from healthy volunteers before being pretreated with the indicated antibodies (1 ug / ml or molar equivalent) and SEE (50 ug / ml). Cells were cultured at 37 degrees C overnight, and ELISA determined the levels of secreted IL-2 in the media (n=3, SEM, *p<0.001).

[0063] FIG.4 shows alternative antibody designs for anti-PD-1 antibodies. The figure is adapted from Figure 1 of Spiess C, Zhai Q, Carter PJ, Alternative molecular formats and therapeutic applications for bispecific antibodies, Mol Immunol., 2015 Oct;67(2 Pt A):95-106, the contents of which is hereby incorporated by reference in its entirety.

[0064] FIGs.5A-B show binding curves to human-PD-1-His-coated plates quantified by ELISA. FIG.5A shows binding curves for anti-PD-1 antibody clones 01, 02, 03, and 07, anti- human PD-1 antibody Penbio (pembrolizumab), anti-HEL-human IgG1 isotype control, and blank. FIG.5B shows binding curves for anti-PD-1 antibody clones 09, 51, 55, 79, and 80, anti- human PD-1 antibody Penbio (pembrolizumab), anti-HEL-human IgG1 isotype control, and blank. EC50 values were calculated with GraphPad Prism (v10.2.1).

[0065] FIG.6 shows binding of anti-PD-1 clones 01, 02, 03, 07, 09, 51, 55, 79, and 80 to cell-expressed PD-1 by flow cytometry.

[0066] FIG.7 shows anti-PD-1 clones 01, 02, 03, 07, 09, 51, 55, 79, and 80 blocking the binding of rhPD-L2 to cell-expressed PD-1. - 11 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0067] FIG.8 shows IL-2 concentrations determined by ELISA following addition of anti- PD-1 clones 01, 02, 03, 07, 09, 51, 55, 79, or 80 and SEE (Staphylococcal Enterotoxin E) in Jurkat-Raji co-culture compared to no SEE and no antibody control and SEE and no antibody control.

[0068] FIG.9 shows IL-2 concentrations determined by ELISA following addition of anti- PD-1 clones 01, 02, 03, 07, 09, 51, 55, 79, or 80 at different concentrations (10, 2, 0.5 or 0.1 µg / ml) and SEE (Staphylococcal Enterotoxin E) in Jurkat-Raji co-culture compared to no SEE and no antibody control and SEE and no antibody control.

[0069] FIG.10 shows concentrations of IL-2, IFNγ, IL-6, IL-4 and IL-1β determined by ELISA in PBMCs in the presence of anti-PD-1 clones 01, 02, 03, 07, 09, 51, 55, 79, or 80 and SEE (Staphylococcal Enterotoxin E).

[0070] FIG.11 shows the amino acid sequences for variable heavy chain and variable light chain portions of anti-PD-1 antibody clones 01, 02, 03, 07, 09, 51, 55, 79, and 80. Bolded and underlined amino acids indicates CDRs.

[0071] FIG.12 shows binding of Pembrolizumab (left) and HSA-Pembrolizumab (right) to cell-expressed PD-1 determined by flow cytometry.

[0072] FIG.13 shows IFNg (top) and IL-2 (bottom) concentrations determined by ELISA following addition of SEE (Staphylococcal Enterotoxin E), Pembrolizumab with SEE, HSA- Pembrolizumab with SEE, or no antibody and no SEE.

[0073] FIG.14 shows binding determined by ELISA of Pembrolizumab, ABD- Pembrolizumab, and Pembrolizumab-ABD to PD-1 (top), human serum albumin (HSA) (middle), and mouse serum albumin (MSA) (bottom).

[0074] FIG.15 shows IL-2 concentrations determined by ELISA following addition of SEE (Staphylococcal Enterotoxin E), Pembrolizumab with SEE, ABD-Pembrolizumab with SEE and MSA, Pembrolizumab-ABD with SEE and MSA, or no antibody and no SEE. DETAILED DESCRIPTION

[0075] Disclosed herein are novel monoclonal antibodies that in some embodiments are useful for preventing or treating disease (e.g., cancer) or infection (e.g., human immunodeficiency virus (HIV)). One approach to cancer treatment consists of using - 12 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 monoclonal antibodies to target immune checkpoint receptors on T cells, inhibiting the interaction between the PD-1 immune checkpoint and its ligands. However, a significant number of patients do not respond to this treatment, and some may experience immune-related adverse events. A limitation of existing technologies that may lead to these outcomes is that they fail to adequately consider the localization of PD-1 on the surface of immune cells within the immune synapse. Described herein is the modification of an FDA-approved anti-PD-1 antibody, pembrolizumab, through the addition of another Fc domain, a CD22 domain, human serum albumin (HSA), or an albumin binding domain (ABD) to the Fc tail of pembrolizumab. The modified antibodies have an increased size of at least about 200 kD compared to the pembrolizumab (~140kD). Unexpectedly, the modified antibodies removed the PD‐1 protein from the immune synapse. In comparison to canonical pembrolizumab, this technology exhibits superior inhibition of PD‐1 signaling, thereby improving cytokine secretion and primary T cell killing of tumor cells in vitro. As such, this approach offers a safer and more efficacious alternative to current immunotherapies for treating cancer patients. Also described herein is the modification of anti-PD-1 antibodies referred to as clones 01, 02.03, 07, 09, 51, 55, 79, and 80, through the addition of another Fc domain, a CD22 domain, human serum albumin (HSA), or an albumin binding domain (ABD) to the Fc tail of pembrolizumab. The modified antibodies have an increased size of at least about 160 kD compared to a monoclonal antibody without the additional domain (~140kD). In some embodiments, the modified antibodies have an increased size of at least about 200 kD compared to a monoclonal antibody without the additional domain (~140kD). In some embodiments, the modified antibodies comprising an ABD can bind to albumin in vivo, for example, albumin present in the serum which contributes to an increased size of the monoclonal antibody. T Cells and The Immune Synapse

[0076] T cells have surface receptors that can act as immune checkpoint receptors, such as PD-1. See Speiser DE, Ho PC, Verdeil G. Regulatory Circuits of T Cell Function in Cancer. Nat Rev Immunol.2016 Oct; 16(10): pp.599-611, incorporated by reference in its entirety herein. These receptors act as “checkpoints” to prevent excessive immune activation. However, cancer cells can exploit these checkpoint pathways to evade immune detection and attack. See Liu J, Chen Z, Li Y, Zhao W, Wu J and Zhang Z. PD-1 / PD-L1 Checkpoint Inhibitors in Tumor Immunotherapy. Front. Pharmacol.2021 Sep; pp.12: p.731798, incorporated by reference in its entirety herein. PD-1 is expressed on the surface of activated T cells while its ligands PD-L1 - 13 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 and PD-L2 are expressed on various cancer cells. See Liu, et al. (2021). The immune synapse is the interface between T cells and tumor cells. This interface, or microenvironment, includes the checkpoint receptors (e.g., PD-l, PDL-1, PDL-2) and other immune receptors and ligands needed for T cells to function. The immune synapse is organized into three compartments; every protein has a specific location. For example, with respect to proteins found on T cells, the T cell receptor (TCR) is localized to the center of the synapse, PD-1 and CD28 are located in the peripheral synapse, and LFA-1, CD43, and CD45 are found in the distal compartment of the synapse. See e.g., Delon J, Kaibuchi K, Germain RN. Exclusion of CD43 from the immunological synapse is mediated by phosphorylation-regulated relocation of the cytoskeletal adaptor moesin. Immunity.2001 Nov;15(5):691-701. doi: 10.1016 / s1074-7613(01)00231-x. PMID: 11728332. This organization is critical for the function of the synapse, where specific clusters of proteins are formed.

[0077] Cancer immunotherapy drugs work by blocking these checkpoint receptors on T cells, thereby unleashing the immune system to recognize and destroy cancer cells more effectively. He X, Xu C. Immune Checkpoint Signaling and Cancer Immunotherapy. Cell Res. 2020 Aug; 30(8): pp.660–669, incorporated by reference in its entirety herein. For example, PD-1 inhibitors prevent PD-1 on T cells from binding to its ligands PDL-1 and PDL-2 on tumor cells, thereby preventing the tumor cells from evading the T cell immune response. Seven monoclonal antibodies targeting PD-1 have been approved by the FDA for cancer treatment. However, some individuals do not respond to this treatment, and some experience immune- related adverse events (irAEs).

[0078] Without intending to be bound by any particular theory, the design of antibodies for the prevention or treatment of cancer is improved by taking into account the localization of PD-1 on the surface of the immune cells in the context of the immune synapse. Without intending to be bound by any particular theory, in addition to blocking ligand binding, it is hypothesized that changing the location of PD-1 within the different compartments of the immune synapse could serve as an alternative, efficient, and safer approach to treating cancer patients.

[0079] Described herein are improved versions of anti-PD-1 antibodies. Novel anti-PD-1-Fc antibodies, anti-PD-1-CD22, anti-PD-1-HSA, and anti-PD-1-ABD antibodies were designed and are described herein. Without intending to be bound by any particular theory, the rationale behind the design of the antibodies disclosed herein was that disruption of selected protein interactions through altered localization would serve as a strategy to affect T cell function better. - 14 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 The PD-1 pathway provides a clear example to demonstrate how changing the localization of a protein on the cell surface can impact T cell function. In some embodiments, an advantage of removing PD-1 from the synapse with antibodies is its ability to prevent PD-1 ligand- independent downstream tonic signaling.

[0080] In some embodiments, described herein are anti-PD-1-Fc antibodies, anti-PD-1- CD22 antibodies, anti-PD-1-HSA antibodies, and anti-PD-1-ABD antibodies that are capable of removing PD-1 from the immune synapse. In some embodiments, the anti-PD-1-Fc antibodies are created by adding an additional Fc domain to the Fc tail of an anti-PD-1 antibody (e.g., but not limited to, pembrolizumab or the anti-PD-1 antibodies referred to as clones 01, 02.03, 07, 09, 51, 55, 79, and 80). In some embodiments, the anti-PD-1-CD22 antibodies are created by adding a CD22 domain to the Fc tail of an anti-PD-1 antibody (e.g., but not limited to, pembrolizumab or the anti-PD-1 antibodies referred to as clones 01, 02.03, 07, 09, 51, 55, 79, and 80). The modified antibodies have an increased size of at least about 160 kD compared to the pembrolizumab (~140kD). In some embodiments, the anti-PD-1-Fc antibodies are created by adding HSA to the Fc tail of an anti-PD-1 antibody (e.g., but not limited to, pembrolizumab or the anti-PD-1 antibodies referred to as clones 01, 02.03, 07, 09, 51, 55, 79, and 80). In some embodiments, the anti-PD-1-Fc antibodies are created by adding ABD to the Fc tail of an anti- PD-1 antibody, the ABD non-covalently binds to HSA (e.g., but not limited to, pembrolizumab or the anti-PD-1 antibodies referred to as clones 01, 02.03, 07, 09, 51, 55, 79, and 80). In some embodiments, the modified antibodies have an increased size of at least about 160kD compared to an unmodified monoclonal antibody (~140kD). In some embodiments, the modified antibodies have an increased size of at least about 200kD compared to an unmodified monoclonal antibody (~140kD). In some embodiments, one or more of the anti-PD-1-Fc antibodies or the anti-PD-1-CD22 antibodies described herein function by removing the PD-1 localization from the immune synapse, disrupting downstream signaling and effector pathways, and / or enhancing T-cell function.In some embodiments, the use of anti-PD-1-Fc antibodies, anti-PD-1-CD22, anti-PD-1-HSA antibodies, and anti-PD-1-ABD antibodies antibodies disclosed herein have one or more of the following advantages over conventional anti-PD-1 antibodies: 1) they prevent PD-1 interaction with its ligands and 2) they localize PD-1 away from the synapse and prevent it from interacting with its downstream effectors. In some embodiments, using one or more of the innovative monoclonal antibodies describes herein offer a more potent and safer technology to treat cancer patients resistant to current immunotherapies. - 15 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0081] In some embodiments, an anti-PD-1-Fc, an anti-PD-1-CD22, an anti-PD-1-HSA, and / or an anti-PD-1-ABD antibody, as disclosed herein, is used to prevent or treat cancer in a subject. In some embodiments, the cancer is selected from colorectal cancer, lung cancer, bladder cancer, breast cancer, cervical cancer, kidney cancer, leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, prostate cancer, skin cancer (e.g., melanoma), head and neck cancer, endometrial cancer, colon cancer, rectal cancer, liver cancer, thyroids cancer, esophageal cancer, renal cell cancer, and a combination thereof. In some embodiments, an anti-PD-1-Fc, an anti- PD-1-CD22, an anti-PD-1-HSA, and / or an anti-PD-1-ABD antibody, as disclosed herein, is used to prevent or treat disease caused by any solid tumor that is not able to repair errors in its DNA that occur when the DNA is copied.

[0082] In some embodiments, an anti-PD-1-Fc, an anti-PD-1-CD22, an anti-PD-1-HSA, and / or an anti-PD-1-ABD antibody, as disclosed herein, is used to prevent or treat a viral infection. In some embodiments, the viral infection caused by HIV in a subject. Antibodies

[0083] There are five classes of human antibodies (i.e., IgA, IgD, IgE, IgG, and IgM) and each have various isotypes (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2). In some embodiments, the antibodies disclosed herein belong to the IgG class. IgG can be further divided into four subclasses: IgG1, IgG2, IgG3, and IgG4. Each subclass has a unique profile with respect to antigen binding, immune complex formation, complement activation, triggering of effector cells, half-life, and placental transport. E.g., see Gestur Vidarsson, et al., IgG Subclasses and Allotypes: From Structure to Effector Functions, 5 Frontiers in Immunology 520 (2014), incorporated by reference herein in its entirety. The term “immunoglobulin” (Ig) is used interchangeably with “antibody” herein.

[0084] The IgG immunoglobulin molecule consists of four polypeptide chains, two identical light (L) chains and two identical heavy (H) chains. The four chains are joined by disulfide bonds in a “Y” configuration wherein the light chains bracket the heavy chains starting at the mouth of the “Y” and continuing through the variable region to the dual ends of the “Y”. Each L chain is linked to an H chain by one covalent disulfide bond, while the two H chains are linked to each other by one or more disulfide bonds depending on the H chain isotype. Each H and L chain also has regularly spaced intrachain disulfide bridges. Each heavy chain consists of an N-terminal variable domain (VH) and three constant domains (CH1, CH2, CH3), with an - 16 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 additional “hinge region” between CH1 and CH2. Similarly, the light chains consist of an N- terminal variable domain (VL) and a constant domain (CL). The variable domains of the heavy chain and light chain may be referred to as “VH” and “VL”, respectively. These domains are generally the most variable parts of the antibody (relative to other antibodies of the same class) and contain the antigen binding sites. The VL is aligned with the VH and the CL is aligned with the first constant domain of the heavy chain (CH1). The pairing of a VH and VL together forms a single antigen-binding site. The part of the antibody formed by the lower hinge region and the CH2 / CH3 domains of the heavy chain is called “Fc” (“fragment crystalline”). See e.g., Basic and Clinical Immunology, 8th Edition, Daniel P. Sties, Abba I. Terr and Tristram G. Parsolw (eds), Appleton & Lange, Norwalk, CT, 1994, page 71 and Chapter 6, incorporated by reference herein in its entirety.

[0085] The variability in an antibody sequence is concentrated in three segments called complementarity determining regions (CDRs) (also called hypervariable regions (HVRs)) both in the light-chain and the heavy chain variable domains. The more highly conserved portions of variable domains are called the framework regions (FR). The variable domains of native heavy and light chains each comprise four FR regions, largely adopting a beta-sheet configuration, connected by three CDRs, which form loops connecting, and in some cases forming part of, the beta-sheet structure. The CDRs in each chain are held together in close proximity by the FR regions and, with the CDRs from the other chain, contribute to the formation of the antigen binding site of antibodies. See Kabat et al, Sequences of Immunological Interest, Fifth Edition, National Institute of Health, Bethesda, MD (1991), incorporated by reference in its entirety herein. The constant domains are not involved directly in the binding of antibody to an antigen, but exhibit various effector functions, such as participation of the antibody in antibody- dependent cellular toxicity.

[0086] By way of example, CDRs may be defined using the nomenclature described by Kabat et al. (1991, NIH Publication 91-3242, National Technical Information Service, Springfield, Va.), incorporated by reference in its entirety herein. Specifically, residues 31-35 (CDR-H1), 50-65 (CDR-H2), and 95-102 (CDR-H3) in the heavy chain variable region and residues 24-34 (CDR-L1), 50-56 (CDR-L2), and 89-97 (CDR-L3) in the light chain variable region.

[0087] The antibodies disclosed herein (e.g., monoclonal antibodies) includes, but is not limited to, full-length antibodies that are larger in size than 140kD and also includes other - 17 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 immunologically reactive / antigen-binding molecules that are larger in size than 140kD. The antibodies of the various embodiments disclosed herein can include one or more of synthetic antibodies, monoclonal antibodies, oligoclonal or polyclonal antibodies, multiclonal antibodies, recombinantly produced antibodies, monospecific antibodies, monovalent antibodies, human antibodies, humanized antibodies, chimeric antibodies, CDR-grafted antibodies, primatized antibodies, single-chain Fv-Fcs (scFv-Fc)), bivalent with four scFv (scFv-Fc-scFv), IgG-scFv, IgM, IgA, trispecific, IgG-dAb, CrossMab 2:1 or 2:2, DVD-IgG, IgG(L)-scFv2, DVD-IgG, IgG(H)-scFv, scFv-(H)IgG, IgG(L)-scFv, scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V, V(H)-IgG, IgG(L)-V, V(L)-IgG, KIH IgG-scFab, 2scFv-IgG, IgG-2scFv, scFv4-Ig, Zybody, DVI-IgG (four-in-one), scFv-KIH, and any other immunologically-reactive / antigen-binding molecules. In some embodiments, the antibody is a monoclonal antibody (see FIG.4).

[0088] In some embodiments, the monoclonal antibody comprises a first, second, third and fourth chain. In some embodiments, the first and third chains each comprise a VH domain and the second and fourth chains each comprise a VL domain. In some embodiments, the first and third chains each further comprises a CH1 domain, a hinge domain, a Fc domain, and at least one additional domain attached to the Fc domain. In some embodiments, the additional domain is another Fc domain. In some embodiment, the additional domain is a CD22 domain. In some embodiments, the additional domain is HSA. In some embodiments, the additional domain is an ABD. In some embodiments, the second and fourth chains each further comprises a CL domain. The pairing of the VH and VL of the first and second chains together forms a single antigen- binding site specific for an epitope on PD-1 and the pairing of the VH and VL of the third and fourth chains together forms a single antigen-binding site specific for the same epitope. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size than 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0089] However, the antibodies disclosed herein are not limited to full-length IgG like antibodies. Other immunologically reactive / antigen-binding molecules that are larger in size than 140kD (including but not limited to, single-chain Fv-Fcs (scFv-Fc), bivalent with four scFv (scFv-Fc-scFv), IgG-scFv, IgM, IgA, trispecific, IgG-dAb, CrossMab 2:1 or 2:2, DVD-IgG, - 18 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 IgG(L)-scFv2, DVD-IgG, IgG(H)-scFv, scFv-(H)IgG, IgG(L)-scFv, scFv-(L)IgG, IgG(L,H)-Fv, IgG(H)-V, V(H)-IgG, IgG(L)-V, V(L)-IgG, KIH IgG-scFab, 2scFv-IgG, IgG-2scFv, scFv4-Ig, Zybody, DVI-IgG (four-in-one), and scFv-KIH are also contemplated herein and a person of skill in the art can readily synthesize such molecules using the sequences and identified domains of the heavy and light chains of the anti-PD-1 antibodies disclosed here. For example, in some embodiments, the monoclonal antibody comprises a first and second chain that associate together. In some embodiments, the first chain and second chain each comprises an scFv with specificity for an epitope on PD-1 and the first and second chains each further comprise a Fc domain and at least one additional domain attached to the Fc domain. In some embodiments, the additional domain is another Fc domain. In some embodiment, the additional domain is a CD22 domain. An scFv comprises a variable heavy domain and variable light chain domain separated by a linker. In some embodiments, the linker is a glycine-serine linker. In some embodiments, the Fc domain of the first chain comprises knob mutations and the Fc domain of the second chain comprise hole mutations, or vice versa. In some embodiments the antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain, a linker, a variable light chain (VL) domain, an Fc domain, and at least one additional domain. In some embodiments, the additional domain is another Fc domain. In some embodiment, the additional domain is a CD22 domain. In some embodiments, the additional domain is HSA. In some embodiments, the additional domain is an ABD.

[0090] For example, in some embodiments, the monoclonal antibody comprises a first and second chain that associate together. In some embodiments, the first chain and second chain each comprise two scFvs with specificity for an epitope on PD-1 and the first and second chains each further comprise a Fc domain. An scFv comprises a variable heavy domain and variable light chain domain separated by a linker. In some embodiments, the linker is a glycine-serine linker. In some embodiments, the Fc domain of the first chain comprises knob mutations and the Fc domain of the second chain comprise hole mutations, or vice versa. In some embodiments the antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain, a first linker, a first variable light chain (VL) domain, an Fc domain, a second variable heavy chain (VH) domain, a second linker, and a second variable light chain (VL) domain. - 19 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0091] In some embodiments, the monoclonal antibodies disclosed herein contain various modifications, substitutions, additions, or deletions to the variable or binding regions of one or more arms of an anti-PD-1-Fc antibody or an anti-PD-1-CD22 antibody or an anti-PD-1-HSA antibody or an anti-PD-1-ABD antibody disclosed herein. In some embodiments, the monoclonal antibodies disclosed herein may contain substitutions or modifications of the constant region (i.e., the Fc domain). The antibodies disclosed herein may contain one or more additional amino acid residue substitutions, mutations and / or modifications, which result in a compound with preferred characteristics including, but not limited to: altered pharmacokinetics, increased serum half-life, increase binding affinity, reduced binding affinity, reduced immunogenicity, increased production, altered Fc ligand binding, enhanced or reduced ADCC or CDC activity, altered glycosylation and / or disulfide bonds and modified binding specificity. Amino Acid Sequences of Anti-PD-1-Fc Antibodies

[0092] In some embodiments, the anti-PD-1-Fc antibody comprises two polypeptide heavy chains each comprising a variable heavy chain (VH) domain, CH1 domain, a hinge domain, a first Fc domain (CH2-CH3), and a second Fc domain (CH2-CH3), and two polypeptide light chains comprising a variable light chain (VL) domain and a CL domain.

[0093] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0094] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 2. Underlined amino acids represent the VH domain. Underlined and bolded amino acids represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. QVQLVQSGVEVKKPGASVKVSCKASGYTFTNYYMYWVRQAPGQGLEWMGGINPSN GGTNFNEKFKNRVTLTTDSSTTTAYMELKSLQFDDTAVYYCARRDYRFDMGFDYWG QGTLVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAP EFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPRE EQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQE - 20 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 EMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQ EGNVFSCSVMHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDT LMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTV LHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTC LVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCS VMHEALHNHYTQKSLSLSLG (SEQ ID NO: 2). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 2. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0095] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 3. Underlined amino acids represent the VL domain. Underlined and bolded amino acids represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. DIVLTQSPATLSLSPGERATLSCRASKGVSTSGYSYLHWYQQKPGQAPRLLIYLASYLE SGVPARFSGSGSGTDFTLTISSLEPEDFAVYYCQHSRDLPLTFGGGTKVEIKRTVAAPSVF IFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTL TLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 3). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0096] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 2 and a second and fourth chains each comprises SEQ ID NO: 3. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0097] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, - 21 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 2. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 2 and SEQ ID NO: 3. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 2 and SEQ ID NO: 3.

[0098] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 2 or SEQ ID No: 3 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 2 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3 is substituted.

[0099] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 2, a linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a variable light chain (VL) domain of SEQ ID NO: 3, an Fc domain of SEQ ID NO: 2, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 2.

[0100] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO:2, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO:3, an Fc domain of SEQ ID NO:2, a second variable heavy chain (VH) domain of SEQ ID NO:2, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO:3. - 22 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0101] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0102] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 14. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVKLLESGGGLVQPGGSLKLSCAASGFDFSRYWMSWVRQAPGKGLEWIGEINPDSSTIK YTPSLKDKFIISRDNAKNTLCLQLSKVRSEDSALYYCARMGYRLFDSWGQGTTLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVT CVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNG KEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSD IAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHN HYTQKSLSLSLG (SEQ ID NO: 14). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 14. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0103] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 15. Underlined amino acids represent the VL domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. NIVMTQATPSVPVTPGESVSISCRSSKSLLHSDGDTYLYWFLQRPGQSPQLLIYRMSNLV SGVPDRFSGSGSGTAFTLRISRVEAEDVGVYYCMQHLEYPYTFGGGTKLEIKTVAAPSVF IFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTL - 23 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 TLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 15). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 15. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0104] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 14 and a second and fourth chains each comprises SEQ ID NO: 15. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0105] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 14. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 15. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 14 and SEQ ID NO: 15. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 14 and SEQ ID NO: 15.

[0106] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 14 or SEQ ID No: 15 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 14 is substituted. In some embodiments, one or more amino acids of an - 24 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 15 is substituted.

[0107] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 14, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 15, an Fc domain of SEQ ID NO: 14, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 14.

[0108] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO:14, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 15, an Fc domain of SEQ ID NO: 14, a second variable heavy chain (VH) domain of SEQ ID NO: 14, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 15.

[0109] An antibody comprising the VH and VL domains of SEQ ID NO: 14 and SEQ ID NO: 15 is represented by antibody “Clone 001” or “Clone 01” in embodiments described and depicted in this disclosure.

[0110] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0111] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 16. Underlined amino acids represent the VH domain. Underlined and bolded amino acids in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVQLQQSGTVLARPGASVKMSCKASGNTFTSYWMHWVKQRPGQGLEWIGAIYPGYSD TRYNQKFKGKATLTAVTSTSTAYMELSSLTNEDSAVYYCTKFIATVGGYFDVWGAGTT VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG - 25 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRT PEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDW LNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGF YPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHE ALHNHYTQKSLSLSLG (SEQ ID NO: 16). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 16. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0112] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 17. Underlined amino acids represent the VL domain. Underlined and bolded amino acids in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. QIVLTQSPAIMSSSLGERVTMTCTASSSVSSSYLHWYQQKPGSSPKLWIYSTSNLASGVP ARFSGSGSGTSYSLTISSMEAEDAATYYCHQYHRSPPIFTFGSGTKLEIKTVAAPSVFIFPP SDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSK ADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 17). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 17. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0113] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 16 and a second and fourth chains each comprises SEQ ID NO: 17. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0114] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, - 26 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 16. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 17. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 16 and SEQ ID NO: 17. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 16 and SEQ ID NO: 17.

[0115] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 16 or SEQ ID No: 17 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 16 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 17 is substituted.

[0116] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 16, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 17, an Fc domain of SEQ ID NO: 16, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 16.

[0117] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO:16, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 17, an Fc domain of SEQ ID NO: 16, a second variable heavy chain (VH) domain of SEQ ID NO: 16, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 17. - 27 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0118] An antibody comprising the VH and VL of SEQ ID NO: 16 and SEQ ID NO: 17 is represented by antibody “Clone 002” or “Clone 02” in embodiments described and depicted in this disclosure.

[0119] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0120] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 18. Underlined amino acids represent the VH domain. Underlined and bolded amino acids in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. QIQLVQSGPELKKPGETVKISCKASGYTFTDYSMHWVKQAPGKGLKWMGWIKIETGNP TYADDFKGRFAFSLETSASTAYLQINNLKNEDTATYFCARDYYGYYYYAMDYWGQGT SVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFP AVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFE GGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQF NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGN VFSCSVMHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMI SRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLH QDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLV KGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLG (SEQ ID NO: 18). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 18. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0121] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 19. Underlined amino acids represent the VL domain. Underlined and bolded amino acids in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. - 28 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 QIVLTQSPAIMSASLGERVTMTCTVSSSISSSYLHWYQQKPGSSPKLWIYSTSNLASGVP ARFSGSGSGTSYSLTISSMEAEDAATYYCHQYHRSPLTFGAGTKLELKTVAAPSVFIFPPS DEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKA DYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 19). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 19. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0122] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 18 and a second and fourth chains each comprises SEQ ID NO: 19. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0123] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 18. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 19. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 18 and SEQ ID NO: 19. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 18 and SEQ ID NO: 19.

[0124] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 18 or SEQ ID No: 19 is substituted. In some embodiments, - 29 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 18 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 19 is substituted.

[0125] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 18, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 19, an Fc domain of SEQ ID NO: 18, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 18.

[0126] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO:18, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 19, an Fc domain of SEQ ID NO: 18, a second variable heavy chain (VH) domain of SEQ ID NO: 18, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 19.

[0127] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0128] An antibody comprising the VH and VL of SEQ ID NO: 18 and SEQ ID NO: 19 is represented by antibody “Clone 003” or “Clone 03” in embodiments described and depicted in this disclosure.

[0129] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 20. Underlined amino acids represent the VH domain. Underlined and bolded amino acids in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVQLVESGGGLVQPGGSLRLSCAASGFTFSHYGMSWVRQTPDKRLELVATIDNNGGNT YYPDSVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARDAYYTYDYWYFDVWGA - 30 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 GTTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHT FPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPE FEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREE QFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEE MTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQE GNVFSCSVMHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTL MISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVL HQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCL VKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLG (SEQ ID NO: 20). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 20. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0130] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 21. Underlined amino acids represent the VL domain. Underlined and bolded amino acids in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. DIQMTQTTSSLSASLGDRVTISCSASQGISNYLNWYQQKPDGTVKLLIYYTSSLHSGVPS RFSGSGSGTDYSLTISNLEPEDIATYYCQQYHKLPWTFGGGTKLEIKTVAAPSVFIFPPSDE QLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADY EKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 21). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 21. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0131] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 20 and a second and fourth chains each comprises SEQ ID NO: 21. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD. - 31 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0132] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 20. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 21. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 20 and SEQ ID NO: 21. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 20 and SEQ ID NO: 21.

[0133] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 20 or SEQ ID No: 21 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 20 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 21 is substituted.

[0134] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 20, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 21, an Fc domain of SEQ ID NO: 20, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 20.

[0135] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO: 20, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 21, an Fc domain of SEQ ID NO: 20, a second variable heavy chain (VH) domain of SEQ - 32 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 ID NO: 20, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 21.

[0136] An antibody comprising the VH and VL SEQ ID NO: 20 and SEQ ID NO: 21 is represented by antibody “Clone 007” or “Clone 07” in embodiments described and depicted in this disclosure.

[0137] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0138] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 22. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVKLVESGGGLVQPGGSLKLSCAASGFTFSSYTMSWVRQTPEKRLEWVAYISYGGGDT YYPDTVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARQKVDGYFVAMDYWSQG TSVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTF PAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEF EGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQ FNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLM ISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLH QDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLV KGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLG (SEQ ID NO: 22). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 22. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo. - 33 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0139] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 23. Underlined amino acids represent the VL domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. VIVLTQSPASLAVSLGQRATISCRASERVDDYGISFMNWFQQKPGQPPKLLIYAASNQGS GVPARFSGSGSGTDFSLNIHPMEEDDTAMYFCQQNKEVPWTFGGGTKLEIKTVAAPSVFI FPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLT LSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 23). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 23. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0140] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 22 and a second and fourth chains each comprises SEQ ID NO: 23. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0141] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 22. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 23. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 22 and SEQ ID NO: 23. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, - 34 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 22 and SEQ ID NO: 23.

[0142] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 22 or SEQ ID No: 23 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 22 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 23 is substituted.

[0143] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 22, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 23, an Fc domain of SEQ ID NO: 22, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 22.

[0144] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO: 22, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 23, an Fc domain of SEQ ID NO: 22, a second variable heavy chain (VH) domain of SEQ ID NO: 22, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 23.

[0145] An antibody comprising the VH and VL of SEQ ID NO: 22 and SEQ ID NO: 23 is represented by antibody “Clone 009” or “Clone 09” in embodiments described and depicted in this disclosure.

[0146] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0147] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 24. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the - 35 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVKLVESGGGLVKPGGSLKLSCAASGFTFSSYGMSWVRQTPEKRLEWVATISGGGRYT YYPDSVKGRFTISRDNAKNILYLQMSSLRSEDTALYYCASPYDGYYGAMDYWGQGTS VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRT PEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDW LNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGF YPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHE ALHNHYTQKSLSLSLG (SEQ ID NO: 24). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 24. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0148] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 25. Underlined amino acids represent the VL domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. DIVLTQSPASLAVSLGQRATISCRASESVDNSGISFMNWFQQKPGQPPKLLIYAASNQGS GVPARFSGSGSGTDFSLNIHPMEEDDTAMYFCQQSKEVPWTFGGGTKLEIKTVAAPSVFI FPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLT LSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 25). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 25. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0149] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 24 and a second and fourth chains each comprises SEQ ID NO: 25. In some embodiments, the first and second chains are linked by one or more covalent disulfide - 36 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0150] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 24. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 25. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 24 and SEQ ID NO: 25. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 24 and SEQ ID NO: 25.

[0151] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 24 or SEQ ID No: 25 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 24 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 25 is substituted.

[0152] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 24, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 25, an Fc domain of SEQ ID NO: 24, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 24. - 37 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0153] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO: 24, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 25, an Fc domain of SEQ ID NO: 24, a second variable heavy chain (VH) domain of SEQ ID NO: 24, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 25.

[0154] An antibody comprising the VH and VL of SEQ ID NO: 24 and SEQ ID NO: 25 is represented by antibody “Clone 051” or “Clone 51” in embodiments described and depicted in this disclosure.

[0155] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0156] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 26. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVQLQQSGTVLARPGASVRMSCKASGYSFSTYWMHWVKQRPGQGLEWIGGIYPGNSD TNYNQKFKGKAKLTAVTSASTAYMDLSSLTNEDSAVYYCTGGYFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEV TCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLN GKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPS DIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALH - 38 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 NHYTQKSLSLSLG (SEQ ID NO: 26). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 26. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0157] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 27. Underlined amino acids represent the VL domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. DIKMTQSPSSLYASLGERVTITCKASQDINRYLTWFQQKPGKSPKTLIFRANRLVTGVPS RFIGSGSGQEYSLTISSLEYEDMGIYFCLQYDESPYTFGGGTKLEIKTVAAPSVFIFPPSDE QLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADY EKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 27). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 27. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0158] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 26 and a second and fourth chains each comprises SEQ ID NO: 27. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0159] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 26. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 27. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of - 39 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 26 and SEQ ID NO: 27. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 26 and SEQ ID NO: 27.

[0160] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 26 or SEQ ID No: 27 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 26 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 27 is substituted.

[0161] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 26, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 27, an Fc domain of SEQ ID NO: 26, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 26.

[0162] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO: 26, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 27, an Fc domain of SEQ ID NO: 26, a second variable heavy chain (VH) domain of SEQ ID NO: 26, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 27.

[0163] An antibody comprising the VH and VL of SEQ ID NO: 26 and SEQ ID NO: 27 is represented by antibody “Clone 055” or “Clone 55” in embodiments described and depicted in this disclosure.

[0164] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1). - 40 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0165] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 28. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. QIQLQQSGPEQVKPGASVKISCKASGYMFIDYYMNWVKQKPGQGLEWIGWIYPGSGST KDNENFKGKATLTVDTSSSTAYMQLSSLTSEDTAVYFCARYGPRFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEV TCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLN GKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPS DIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALH NHYTQKSLSLSLG (SEQ ID NO: 28). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 28. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0166] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 29. Underlined amino acids represent the VL domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. DIQMTQSPSSLSASLGERVNLTCRASQEISGYLSWLQQKPDGTIKRLIYVASTLDSGVPE RFSGSRSGSDYSLTISSLESEDFADYYCLQYASYPYTFGGGTKLEIKTVAAPSVFIFPPSDE QLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADY EKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 29). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 - 41 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 immediately followed by SEQ ID NO: 29. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0167] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 28 and a second and fourth chains each comprises SEQ ID NO: 29. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0168] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 28. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 29. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 28 and SEQ ID NO: 29. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 28 and SEQ ID NO: 29.

[0169] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 28 or SEQ ID No: 29 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 28 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 29 is substituted. - 42 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0170] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 28, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 29, an Fc domain of SEQ ID NO: 28, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 28.

[0171] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO: 28, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 29, an Fc domain of SEQ ID NO: 28, a second variable heavy chain (VH) domain of SEQ ID NO: 28, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 29.

[0172] An antibody comprising the VH and VL of SEQ ID NO: 28 and SEQ ID NO: 29 is represented by antibody “Clone 079” or “Clone 79” in embodiments described and depicted in this disclosure.

[0173] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1. MGWSCIILFLVATATGVHS (SEQ ID NO: 1).

[0174] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 30. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the additional Fc domain. EVKLLESGGGLVQPGGSLKLSCEVSGFDFSRDWMSWVRQAPGKGLEWIGQISPDSTSIN YKPSLKDKFIISRDNAKNTLYLQLSGVRSEDTALYHCARDTSGYPDYWGQGTSLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT - 43 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGSTGSKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVT CVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNG KEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSD IAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHN HYTQKSLSLSLG (SEQ ID NO: 30). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 30. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0175] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain (without the signal peptide) comprises SEQ ID NO: 31. Underlined amino acids represent the VL domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized amino acids represent the CL domain. DILLTQSPSSMSVSLGDTVSITCHASQDISRNIGWLRQKPGKSFKGLIYHGTNLEDGVPSR FSGSGSGADYSLTISSLESEDFADYYCVQYAQFPYTFGGGTKLEIKTVAAPSVFIFPPSDE QLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADY EKHKVYACEVTHQGLSSPVTKSFNRGEC (SEQ ID NO: 31). In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0176] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 30 and a second and fourth chains each comprises SEQ ID NO: 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0177] In some embodiments, the signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1-Fc antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, - 44 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 30. In some embodiments, the anti-PD-1-Fc antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 31. In some embodiments, the anti-PD-1-Fc antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 30 and SEQ ID NO: 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 30 and SEQ ID NO: 31.

[0178] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 30 or SEQ ID No: 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 30 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 31 is substituted.

[0179] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 30, a linker (e.g., GGGGSGGGGSGGGGS), a variable light chain (VL) domain of SEQ ID NO: 31, an Fc domain of SEQ ID NO: 30, and at least one additional domain. In some embodiments, the additional domain is another Fc domain of SEQ ID NO: 30.

[0180] In some embodiments the monoclonal antibody is a scFv-Fc-scFv antibody comprising a first and second chain that associate together, each chain comprising a first variable heavy chain (VH) domain of SEQ ID NO: 30, a first linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a first variable light chain (VL) domain of SEQ ID NO: 31, an Fc domain of SEQ ID NO: 30, a second variable heavy chain (VH) domain of SEQ ID NO: 30, a second linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), and a second variable light chain (VL) domain of SEQ ID NO: 31. - 45 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0181] An antibody comprising the VH and VL of SEQ ID NO: 30 and SEQ ID NO: 31 is represented by antibody “Clone 080” or “Clone 80” in embodiments described and depicted in this disclosure. Nucleic Acid Sequences of Anti-PD-1-Fc Antibodies

[0182] A person skilled in the art can identify the nucleic acid sequences encoding the features identified in the corresponding amino acid sequences (e.g., CDRs, variable heavy domain, variable light domain, CH1 domain, hinge domain, Fc domain, and any additional FC domain) by translating the nucleic acid sequences into amino acid sequences. In some embodiments, the nucleic acid sequences may be codon optimized.

[0183] In some embodiments, the nucleic acid sequence of the anti-PD-1-Fc antibody comprises a nucleic acid sequence encoding a signal peptide comprising SEQ ID NO: 5. ATGGGCTGGAGCTGCATTATCCTGTTCCTGGTGGCCACAGCCACCGGCGTGCACAG C (SEQ ID NO: 5).

[0184] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 2, 14, 16, 18, 20, 22, 24, 26, 28, or 30.

[0185] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-Fc antibody heavy chain comprises SEQ ID NO: 6. CAGGTGCAGCTGGTGCAGTCCGGCGTGGAGGTGAAGAAGCCAGGCGCCTCCGTGAA GGTGTCTTGCAAGGCCAGCGGCTACACATTCACCAACTACTATATGTATTGGGTGCG GCAGGCACCTGGACAGGGCCTGGAGTGGATGGGAGGCATCAACCCATCCAATGGC GGCACAAACTTCAATGAGAAGTTTAAGAATCGGGTGACCCTGACCACAGATAGCTC CACCACAACCGCCTACATGGAGCTGAAGTCTCTGCAGTTTGACGATACAGCCGTGT ACTATTGCGCCCGGAGAGACTACAGATTCGATATGGGCTTTGACTATTGGGGCCAG GGCACACTGGTGACCGTGTCTAGCGCCAGCACCAAGGGTCCTAGCGTGTTCCCTCTG GCCCCATGCTCAAGAAGCACTTCCGAGTCTACCGCCGCTCTGGGGTGTCTGGTGAA GGACTACTTCCCCGAACCTGTCACCGTGAGCTGGAACTCCGGGGCCCTGACTTCCGG TGTCCACACCTTTCCCGCTGTGCTGCAGTCTAGTGGCCTGTACTCTCTGAGCAGCGT GGTCACTGTGCCTTCCTCTAGTCTGGGAACTAAGACCTATACATGCAACGTGGACCA TAAACCATCCAATACCAAGGTCGATAAACGCGTGGAGTCTAAGTACGGACCACCAT GCCCTCCATGTCCAGCACCAGAGTTCGAAGGCGGACCTTCCGTGTTCCTGTTTCCCC CTAAGCCAAAAGACACCCTGATGATCTCCCGAACACCAGAGGTCACTTGCGTGGTC - 46 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 GTGGACGTGTCTCAGGAGGACCCCGAAGTCCAGTTCAACTGGTATGTGGATGGCGT CGAAGTGCACAATGCTAAGACCAAACCAAGAGAGGAACAGTTTAATAGTACTTACC GCGTCGTGTCAGTCCTGACCGTGCTGCATCAGGATTGGCTGAACGGCAAGGAGTAT AAGTGCAAAGTGAGCAATAAGGGACTGCCCTCAAGCATCGAGAAAACAATTAGCA AGGCTAAAGGACAGCCCAGGGAGCCTCAGGTGTACACTCTGCCACCCAGTCAGGAG GAAATGACCAAGAACCAGGTCAGCCTGACCTGTCTGGTGAAAGGGTTCTATCCCTC TGACATTGCAGTGGAGTGGGAAAGTAATGGTCAGCCTGAGAACAATTACAAGACTA CCCCTCCAGTGCTGGACTCTGATGGAAGTTTCTTTCTGTATAGCAGACTGACAGTGG ATAAATCCAGGTGGCAGGAGGGGAACGTCTTTAGTTGCTCAGTGATGCACGAAGCC CTGCACAATCATTATACTCAGAAGAGCCTGTCCCTGTCTCTGGGCAGCACCGGTTCT AAGTACGGACCACCATGCCCTCCATGTCCAGCACCAGAGTTCGAAGGCGGACCTTC CGTGTTCCTGTTTCCCCCTAAGCCAAAAGACACCCTGATGATCTCCCGAACACCAGA GGTCACTTGCGTGGTCGTGGACGTGTCTCAGGAGGACCCCGAAGTCCAGTTCAACT GGTATGTGGATGGCGTCGAAGTGCACAATGCTAAGACCAAACCAAGAGAGGAACA GTTTAATAGTACTTACCGCGTCGTGTCAGTCCTGACCGTGCTGCATCAGGATTGGCT GAACGGCAAGGAGTATAAGTGCAAAGTGAGCAATAAGGGACTGCCCTCAAGCATC GAGAAAACAATTAGCAAGGCTAAAGGACAGCCCAGGGAGCCTCAGGTGTACACTC TGCCACCCAGTCAGGAGGAAATGACCAAGAACCAGGTCAGCCTGACCTGTCTGGTG AAAGGGTTCTATCCCTCTGACATTGCAGTGGAGTGGGAAAGTAATGGTCAGCCTGA GAACAATTACAAGACTACCCCTCCAGTGCTGGACTCTGATGGAAGTTTCTTTCTGTA TAGCAGACTGACAGTGGATAAATCCAGGTGGCAGGAGGGGAACGTCTTTAGTTGCT CAGTGATGCACGAAGCCCTGCACAATCATTATACTCAGAAGAGCCTGTCCCTGTCTC TGGGC (SEQ ID NO: 6). In some embodiments, the nucleic acid sequence encoding the anti- PD-1-Fc antibody heavy chain comprises SEQ ID NO: 5 immediately followed by SEQ ID NO: 6. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the respective CDRs, VH domain, CH1 domain, hinge domain, Fc domain and additional Fc domain in SEQ ID NO:6 can be determined from the amino acid sequence of SEQ ID NO: 2 as identified herein by a person of skill in the art.

[0186] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-Fc antibody heavy chain encodes an amino acid sequence comprising SEQ ID NO: 2, 14, 16, 18, 20, 22, 24, 26, 28, or 30. - 47 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0187] In some embodiments, the amino acid sequence of the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0188] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 7. GACATCGTGCTGACACAGTCTCCAGCCACCCTGAGCCTGTCCCCAGGAGAGAGGGC CACACTGTCCTGTCGCGCCTCTAAGGGCGTGTCTACCAGCGGCTACAGCTATCTGCA CTGGTACCAGCAGAAGCCAGGACAGGCACCTAGGCTGCTGATCTACCTGGCAAGCT ATCTGGAGTCCGGAGTGCCAGCAAGATTCTCCGGATCTGGAAGCGGAACCGACTTC ACCCTGACCATCTCCTCTCTGGAGCCCGAGGATTTCGCCGTGTACTATTGTCAGCAC AGCAGGGACCTGCCTCTGACATTTGGCGGCGGCACCAAGGTGGAGATCAAGCGCAC AGTGGCCGCTCCCAGCGTGTTCATCTTCCCACCTAGCGACGAGCAGCTGAAGTCCG GCACAGCCTCTGTCGTGTGCCTGCTGAACAACTTCTACCCCCGCGAGGCCAAGGTGC AGTGGAAGGTGGACAATGCCCTGCAGAGCGGCAACAGCCAGGAAAGCGTGACCGA GCAGGACAGCAAGGACTCCACCTACAGCCTGAGCAGCACCCTGACCCTGAGCAAGG CCGACTACGAGAAGCACAAGGTGTACGCCTGCGAAGTGACCCACCAGGGCCTGTCT AGCCCCGTGACCAAGAGCTTCAACCGGGGCGAGTGT (SEQ ID NO: 7). In some embodiments, the nucleic acid sequence encoding the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 5 immediately followed by SEQ ID NO: 7. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the respective CDRs, VL domain and CL domain in SEQ ID NO:7 can be determined from the amino acid sequence of SEQ ID NO: 3 as identified herein by a person of skill in the art.

[0189] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-Fc antibody light chain encodes an amino acid sequence comprising SEQ ID NO: 23, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0190] In some embodiments, the nucleic acid sequence encoding a signal peptide of the anti-PD-1-Fc antibody heavy or light chain comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 5. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-Fc heavy chain (without the signal peptide) comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 6. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-Fc light chain (without the signal peptide) comprise a - 48 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 7. In some embodiments, the nucleic acid sequence encodes CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 2 and SEQ ID NO:3. In some embodiments, the nucleic acid sequence encoding framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 6 and SEQ ID NO: 7.

[0191] In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more CDRs of SEQ ID NO: 6 or SEQ ID NO: 7 is substituted. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 6 is substituted. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 7 is substituted.

[0192] In some embodiments, the nucleic acid sequence encoding an anti-PD-1-Fc heavy chain (without the signal peptide) comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 2, 14, 16, 18, 20, 22, 24, 26, 28, or 30. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-Fc light chain (without the signal peptide) comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the nucleic acid sequence encodes CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1- Fc antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 2, 3, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31. In some embodiments, the nucleic acid sequence encoding framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-Fc antibody comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 2, 3, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or 31. - 49 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0193] In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more CDRs of SEQ ID NO: 2, 3, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, or 31 is substituted. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 2, 14, 16, 18, 20, 22, 24, 26, 28, or 30 is substituted. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0194] In some embodiments, the nucleic acid sequence comprises a nucleic acid sequence encoding the scFv-Fc and scFv-Fc-scFv described herein. Amino Acid Sequences of Anti-PD-1-CD22 Antibodies

[0195] In some embodiments, the anti-PD-1-CD22 antibody comprises two polypeptide heavy chains each comprising a variable heavy chain (VH) domain, CH1 domain, a hinge domain, a first Fc domain (CH2-CH3), and a CD22 domain and two polypeptide light chains comprising a variable light chain (VL) domain and a CL domain.

[0196] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1.

[0197] In some embodiments, the amino acid sequence of the CD22 domain comprises the extracellular domain of CD22 (SEQ ID NO: 8): DSSKWVFEHPETLYAWEGACVWIPCTYRALDGDLESFILFHNPEYNKNTSKFDGTRLYE STKDGKVPSEQKRVQFLGDKNKNCTLSIHPVHLNDSGQLGLRMESKTEKWMERIHLNV SERPFPPHIQLPPEIQESQEVTLTCLLNFSCYGYPIQLQWLLEGVPMRQAAVTSTSLTIKS VFTRSELKFSPQWSHHGKIVTCQLQDADGKFLSNDTVQLNVKHTPKLEIKVTPSDAIVR EGDSVTMTCEVSSSNPEYTTVSWLKDGTSLKKQNTFTLNLREVTKDQSGKYCCQVSND VGPGRSEEVFLQVQYAPEPSTVQILHSPAVEGSQVEFLCMSLANPLPTNYTWYHNGKE MQGRTEEKVHIPKILPWHAGTYSCVAENILGTGQRGPGAELDVQYPPKKVTTVIQNPMP IREGDTVTLSCNYNSSNPSVTRYEWKPHGAWEEPSLGVLKIQNVGWDNTTIACAACNS WCSWASPVALNVQYAPRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWEKNG RLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPGDQV MEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTN SVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 8). - 50 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0198] In some embodiments, the amino acid sequence of the CD22 domain comprises amino acids 505-687 of CD22 (SEQ ID NO: 9): RDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWEKNGRLLGKESQLNFDSISPED AGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPGDQVMEGKSATLTCESDANPP VSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYS PETIGRR (SEQ ID NO: 9).

[0199] In some embodiments, the amino acid sequence of the CD22 domain comprises amino acids 593-687 of CD22 (SEQ ID NO: 10): LRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQ HSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 10).

[0200] In some embodiments, the amino acid sequence of the CD22 domain comprises any fragment of SEQ ID NO: 8 as long as the CD22 domain increases the monoclonal antibody size to at least 150kD, at least 160kD, at least 170kD, at least 180kD, at least 190kD, or at least 200kD. In some embodiments, the amino acid sequence of the CD22 domain comprises any fragment of SEQ ID NO: 8 as long as the CD22 domain increases the monoclonal antibody size to at least about 200kD. In some embodiments, the amino acid sequence of the CD22 domain comprises any fragment of SEQ ID NO: 8 as long as the CD22 domain increases the monoclonal antibody size to about 200kD.

[0201] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 11. Underlined amino acids represent the VH domain. Underlined and bolded amino acids represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. QVQLVQSGVEVKKPGASVKVSCKASGYTFTNYYMYWVRQAPGQGLEWMGGINPSN GGTNFNEKFKNRVTLTTDSSTTTAYMELKSLQFDDTAVYYCARRDYRFDMGFDYWG QGTLVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAP EFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPRE EQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQE - 51 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 EMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQ EGNVFSCSVMHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEV QFFWEKNGRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLR VSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHS GAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 11). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 11. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0202] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 12. Underlined amino acids represent the VH domain. Underlined and bolded amino acids represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. QVQLVQSGVEVKKPGASVKVSCKASGYTFTNYYMYWVRQAPGQGLEWMGGINPSN GGTNFNEKFKNRVTLTTDSSTTTAYMELKSLQFDDTAVYYCARRDYRFDMGFDYWG QGTLVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAP EFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPRE EQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQE EMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQ EGNVFSCSVMHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHY TWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIG RR (SEQ ID NO: 12). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 12. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0203] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 11 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 12 except the double underlined portion is replaced with - 52 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0204] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0205] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 11 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0206] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 12 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0207] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 11 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some - 53 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0208] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 12 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0209] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 11. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 12. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 11 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 12 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 11, 12,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of - 54 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 the variable light chain domain of the anti-PD-1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31.

[0210] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0211] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 2, 14, 16, 18, 20, 22, 24, 26, 28, or 30, a linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a variable light chain (VL) domain of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31, an Fc domain of SEQ ID NO: 2, and at least one additional domain. In some embodiments, the additional domain is a CD22 domain of SEQ ID NOs: 8, 9, or 10. In some embodiments, the amino acid sequence of the CD22 domain comprises any fragment of SEQ ID NO: 8 as long as the CD22 domain increases the antibody size to at least 150kD, at least 160kD, at least 170kD, at least 180kD, at least 190kD, or at least 200kD. In some embodiments, the amino acid sequence of the CD22 domain comprises any fragment of SEQ ID NO: 8 as long as the CD22 domain increases the antibody size to at least about 200kD. In some embodiments, the amino acid sequence of the CD22 domain comprises any fragment of SEQ ID NO: 8 as long as the CD22 domain increases the antibody size to about 200kD.

[0212] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 32. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. - 55 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 EVKLLESGGGLVQPGGSLKLSCAASGFDFSRYWMSWVRQAPGKGLEWIGEINPDSSTIK YTPSLKDKFIISRDNAKNTLCLQLSKVRSEDSALYYCARMGYRLFDSWGQGTTLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWEKNGR LLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPGDQV MEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTN SVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 32). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 32. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0213] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 33. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLLESGGGLVQPGGSLKLSCAASGFDFSRYWMSWVRQAPGKGLEWIGEINPDSSTIK YTPSLKDKFIISRDNAKNTLCLQLSKVRSEDSALYYCARMGYRLFDSWGQGTTLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQ SLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 33). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 33. In some - 56 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0214] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 32 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 33 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0215] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0216] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 32 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0217] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 33 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD. - 57 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0218] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 32 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0219] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 33 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0220] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 32. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 33. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 32 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 33 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence - 58 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 32 and 33 and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 32 and 33 and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0221] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 32, 33, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 32 or SEQ ID NO: 33 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0222] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 34. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVQLQQSGTVLARPGASVKMSCKASGNTFTSYWMHWVKQRPGQGLEWIGAIYPGYSD TRYNQKFKGKATLTAVTSTSTAYMELSSLTNEDSAVYYCTKFIATVGGYFDVWGAGTT VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWE KNGRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPG - 59 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 DQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWC QGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 34). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 34. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0223] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 35. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVQLQQSGTVLARPGASVKMSCKASGNTFTSYWMHWVKQRPGQGLEWIGAIYPGYSD TRYNQKFKGKATLTAVTSTSTAYMELSSLTNEDSAVYYCTKFIATVGGYFDVWGAGTT VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDW NNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 35). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 35. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0224] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 34 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 35 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. - 60 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0225] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0226] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 34 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0227] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 35 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0228] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 34 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD. - 61 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0229] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 35 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0230] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 34. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 35. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 34 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 35 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 34 and 35, and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 34 and 35, and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. - 62 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0231] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 34, 35, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 34 or SEQ ID NO: 35 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0232] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 36. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. QIQLVQSGPELKKPGETVKISCKASGYTFTDYSMHWVKQAPGKGLKWMGWIKIETGNP TYADDFKGRFAFSLETSASTAYLQINNLKNEDTATYFCARDYYGYYYYAMDYWGQGT SVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFP AVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFE GGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQF NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGN VFSCSVMHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFF WEKNGRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSM SPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAY WCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 36). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 36. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0233] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 37. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized - 63 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. QIQLVQSGPELKKPGETVKISCKASGYTFTDYSMHWVKQAPGKGLKWMGWIKIETGNP TYADDFKGRFAFSLETSASTAYLQINNLKNEDTATYFCARDYYGYYYYAMDYWGQGT SVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFP AVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFE GGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQF NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGN VFSCSVMHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWF DWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 37). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 37. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0234] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 36 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 37 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0235] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0236] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 36 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are - 64 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0237] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 37 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0238] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 36 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0239] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 37 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD. - 65 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0240] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 36. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 37. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 36 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 37 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 36 and 37, and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 36 and 37, and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0241] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 36, 37, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 36 or SEQ ID NO: 37 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0242] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 38. Underlined amino acids represent the VH domain. - 66 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVQLVESGGGLVQPGGSLRLSCAASGFTFSHYGMSWVRQTPDKRLELVATIDNNGGNT YYPDSVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARDAYYTYDYWYFDVWGA GTTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHT FPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPE FEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREE QFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEE MTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQE GNVFSCSVMHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEV QFFWEKNGRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLR VSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHS GAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 38). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 38. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0243] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 39. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVQLVESGGGLVQPGGSLRLSCAASGFTFSHYGMSWVRQTPDKRLELVATIDNNGGNT YYPDSVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARDAYYTYDYWYFDVWGA GTTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHT FPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPE FEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREE QFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEE - 67 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 MTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQE GNVFSCSVMHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYT WFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGR R (SEQ ID NO: 39). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 39. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0244] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 38 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 39 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0245] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0246] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 38 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0247] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 39 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are - 68 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0248] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 38 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0249] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 39 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0250] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 38. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 39. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % - 69 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 identical to SEQ ID NO: 38 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 39 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 38 and 39, and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 38 and 39, and SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0251] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 38, 39, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 38 or SEQ ID NO: 39 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0252] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 40. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLVESGGGLVQPGGSLKLSCAASGFTFSSYTMSWVRQTPEKRLEWVAYISYGGGDT YYPDTVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARQKVDGYFVAMDYWSQG TSVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTF PAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEF - 70 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 EGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQ FNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQF FWEKNGRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVS MSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGA YWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 40). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 40. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0253] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 41. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLVESGGGLVQPGGSLKLSCAASGFTFSSYTMSWVRQTPEKRLEWVAYISYGGGDT YYPDTVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARQKVDGYFVAMDYWSQG TSVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTF PAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEF EGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQ FNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYT WFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGR R (SEQ ID NO: 41). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 41. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0254] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 40 except the - 71 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 41 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0255] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0256] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 40 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0257] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 41 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0258] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 40 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent - 72 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0259] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 41 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0260] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 40. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 41. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 40 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 41 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, - 73 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 40, 41, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD- 1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 40, 41, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0261] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 40, 41, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 40 or SEQ ID NO: 41 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0262] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 42. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLVESGGGLVKPGGSLKLSCAASGFTFSSYGMSWVRQTPEKRLEWVATISGGGRYT YYPDSVKGRFTISRDNAKNILYLQMSSLRSEDTALYYCASPYDGYYGAMDYWGQGTS VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWE KNGRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPG DQVMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWC QGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 42). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 - 74 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 immediately followed by SEQ ID NO: 42. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0263] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 43. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLVESGGGLVKPGGSLKLSCAASGFTFSSYGMSWVRQTPEKRLEWVATISGGGRYT YYPDSVKGRFTISRDNAKNILYLQMSSLRSEDTALYYCASPYDGYYGAMDYWGQGTS VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDW NNQSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 43). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 43. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0264] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 42 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 43 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0265] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, - 75 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0266] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 42 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0267] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 43 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0268] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 42 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0269] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 43 except the double underlined portion is replaced with SEQ ID - 76 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0270] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 42. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 43. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 42 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 43 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 42, 43, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD- 1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 42, 43, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. - 77 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0271] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 42, 43, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 42 or SEQ ID NO: 43 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0272] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 44. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVQLQQSGTVLARPGASVRMSCKASGYSFSTYWMHWVKQRPGQGLEWIGGIYPGNSD TNYNQKFKGKAKLTAVTSASTAYMDLSSLTNEDSAVYYCTGGYFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWEKN GRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPGDQ VMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGT NSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 44). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 44. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0273] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 45. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized - 78 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVQLQQSGTVLARPGASVRMSCKASGYSFSTYWMHWVKQRPGQGLEWIGGIYPGNSD TNYNQKFKGKAKLTAVTSASTAYMDLSSLTNEDSAVYYCTGGYFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNN QSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 45). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 45. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0274] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 44 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 45 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0275] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0276] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 44 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are - 79 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0277] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 45 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0278] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 44 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0279] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 45 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD. - 80 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0280] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 44. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 45. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 44 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 45 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 44, 45, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD- 1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 44, 45, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0281] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 44, 45, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 44 or SEQ ID NO: 45 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0282] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 46. Underlined amino acids represent the VH domain. - 81 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. QIQLQQSGPEQVKPGASVKISCKASGYMFIDYYMNWVKQKPGQGLEWIGWIYPGSGST KDNENFKGKATLTVDTSSSTAYMQLSSLTSEDTAVYFCARYGPRFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWEKN GRLLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPGDQ VMEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGT NSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 46). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 46. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0283] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 47. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. QIQLQQSGPEQVKPGASVKISCKASGYMFIDYYMNWVKQKPGQGLEWIGWIYPGSGST KDNENFKGKATLTVDTSSSTAYMQLSSLTSEDTAVYFCARYGPRFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL - 82 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNN QSLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 47). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 47. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0284] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 46 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 47 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0285] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0286] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 46 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0287] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 47 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are - 83 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0288] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 46 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0289] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 47 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0290] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 46. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 47. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % - 84 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 identical to SEQ ID NO: 46 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 47 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 46, 47, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD- 1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 46, 47, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0291] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 46, 47, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 46 or SEQ ID NO: 47 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0292] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 48. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLLESGGGLVQPGGSLKLSCEVSGFDFSRDWMSWVRQAPGKGLEWIGQISPDSTSIN YKPSLKDKFIISRDNAKNTLYLQLSGVRSEDTALYHCARDTSGYPDYWGQGTSLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL - 85 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGRDVRVRKIKPLSEIHSGNSVSLQCDFSSSHPKEVQFFWEKNGR LLGKESQLNFDSISPEDAGSYSCWVNNSIGQTASKAWTLEVLYAPRRLRVSMSPGDQV MEGKSATLTCESDANPPVSHYTWFDWNNQSLPYHSQKLRLEPVKVQHSGAYWCQGTN SVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 48). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 48. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0293] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 49. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the CD22 domain. EVKLLESGGGLVQPGGSLKLSCEVSGFDFSRDWMSWVRQAPGKGLEWIGQISPDSTSIN YKPSLKDKFIISRDNAKNTLYLQLSGVRSEDTALYHCARDTSGYPDYWGQGTSLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGLRVSMSPGDQVMEGKSATLTCESDANPPVSHYTWFDWNNQ SLPYHSQKLRLEPVKVQHSGAYWCQGTNSVGKGRSPLSTLTVYYSPETIGRR (SEQ ID NO: 49). In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 49. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0294] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 48 except the - 86 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 49 except the double underlined portion is replaced with SEQ ID NO: 8. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0295] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-Fc antibody. In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0296] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 48 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0297] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 49 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0298] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 48 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent - 87 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0299] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 49 except the double underlined portion is replaced with SEQ ID NO: 8 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0300] In some embodiments, the signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 48. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 49. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 48 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 49 with the double underlined portion replaced with SEQ ID NO: 8. In some embodiments, the anti-PD-1-CD22 antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-CD22 antibody comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, - 88 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 48, 49, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD- 1-CD22 antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 48, 49, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0301] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 48, 49, 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 48 or SEQ ID NO: 49 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. Nucleic Acid Sequences of Anti-PD-1-CD22 Antibodies

[0302] A person skilled in the art can identify the nucleic acid sequences encoding the features identified in the corresponding amino acid sequences (e.g., CDRs, variable heavy domain, variable light domain, CH1 domain, hinge domain, Fc domain, and CD22 domain) by translating the nucleic acid sequences into amino acid sequences. In some embodiments, the nucleic acid sequences may be codon optimized.

[0303] In some embodiments, the nucleic acid sequence of the anti-PD-1-CD22 antibody comprises a nucleic acid sequence encoding a signal peptide comprising SEQ ID NO: 5.

[0304] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-CD22 antibody heavy chain comprises one of SEQ ID NO: 11, 12, or 32-49. In some embodiments, the nucleic acid sequence encoding the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 5 immediately followed by one of SEQ ID NO: 11, 12, or 32-49. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the respective CDRs, VH domain and CH domain in SEQ ID NO: 11, 12, or 32-49 can be determined from the amino acid sequence of SEQ ID NO: 11, 12, or 32-49 as identified herein by a person of skill in the art.

[0305] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 11, 32, 34, 36, 38, 40, 42, 44, 46, or 48. - 89 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0306] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-CD22 antibody heavy chain comprises a nucleic acid sequence encoding SEQ ID NO: 11, 32, 34, 36, 38, 40, 42, 44, 46, or 48. In some embodiments, the nucleic acid sequence encoding the anti- PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 5 immediately followed by a nucleic acid sequence encoding SEQ ID NO: 11, 32, 34, 36, 38, 40, 42, 44, 46, or 48. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the anti-PD-1-CD22 antibody heavy chain and respective CDRs, VH domain, CH1 domain, hinge domain, Fc domain and CD22 domain can be determined from the amino acid sequence of SEQ ID NO: 11, 32, 34, 36, 38, 40, 42, 44, 46, or 48 by a person of skill in the art.

[0307] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 12, 33, 35, 37, 39, 41, 43, 45, 47, or 49.

[0308] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-CD22 antibody heavy chain comprises a nucleic acid sequence encoding SEQ ID NO: 12, 33, 35, 37, 39, 41, 43, 45, 47, or 49. In some embodiments, the nucleic acid sequence encoding the anti- PD-1-CD22 antibody heavy chain comprises SEQ ID NO: 5 immediately followed by a nucleic acid sequence encoding SEQ ID NO: 12, 33, 35, 37, 39, 41, 43, 45, 47, or 49. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the anti-PD-1-CD22 antibody heavy chain and respective CDRs, VH domain, CH1 domain, hinge domain, Fc domain and CD22 domain can be determined from the amino acid sequence of SEQ ID NO: 12, 33, 35, 37, 39, 41, 43, 45, 47, or 49 by a person of skill in the art.

[0309] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 7 provided above for anti-PD-1-Fc. In some embodiments, the nucleic acid sequence encoding the anti-PD-1-Fc antibody light chain comprises SEQ ID NO: 5 immediately followed by SEQ ID NO: 7. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the respective CDRs, VL domain and CL domain in SEQ ID NO: 7 can be determined from the amino acid sequence of SEQ ID NO: 3 as identified herein by a person of skill in the art. - 90 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0310] In some embodiments, the amino acid sequence of the anti-PD-1-CD22 antibody light chain comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0311] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-CD22 antibody light chain comprises a nucleic acid sequence encoding SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the nucleic acid sequence encoding the anti-PD-1- CD22 antibody light chain comprises SEQ ID NO: 5 immediately followed by a nucleic acid sequence encoding SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the anti-PD-1-CD22 antibody light chain and respective CDRs, VL domain, and CL1 domain can be determined from the amino acid sequence of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 by a person of skill in the art.

[0312] In some embodiments, the nucleic acid sequence encoding a signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 5. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-CD22 heavy chain (without the signal peptide) comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 11, 12, or 32-49. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-CD22 light chain (without the signal peptide) comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 7.

[0313] In some embodiments, the nucleic acid sequence encoding a signal peptide of the anti-PD-1-CD22 antibody heavy or light chain comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-CD22 heavy chain (without the signal peptide) comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 11, 12, or 32-49. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-CD22 light chain (without the signal peptide) comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. - 91 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024

[0314] In some embodiments, the nucleic acid sequence encodes CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-CD22 antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 2, 3, 11, 12, 14-49. In some embodiments, the nucleic acid sequence encoding framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-CD22 antibody comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 2, 3, 11, 12, 14-49. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more CDRs of SEQ ID NO: 2, 3, 11, 12, 14-49 is substituted. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32-49 is substituted. In some embodiments, one or more nucleic acids of a nucleic acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0315] In some embodiments, the nucleic acid sequence comprises a nucleic acid sequence encoding the scFv-Fc described herein. Amino Acid Sequences of Anti-PD-1-HSA Antibodies

[0316] In some embodiments, the anti-PD-1-HSA antibody comprises two polypeptide heavy chains each comprising a variable heavy chain (VH) domain, CH1 domain, a hinge domain, a first Fc domain (CH2-CH3), and a HSA domain and two polypeptide light chains comprising a variable light chain (VL) domain and a CL domain.

[0317] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises a signal peptide comprising SEQ ID NO: 1.

[0318] In some embodiments, the amino acid sequence of the HSA domain comprises Human Serum Albumin (SEQ ID NO: 50): DAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHVKLVNEVTEFAKTCVADES AENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQEPERNECFLQHKDDNPNLPRLV RPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPELLFFAKRYKAAFTECCQAADK AACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFKAWAVARLSQRFPKAEFAEVS KLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISSKLKECCEKPLLEKSHCIA - 92 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 EVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGMFLYEYARRHPDYSVVLLLR LAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIKQNCELFEQLGEYKFQNAL LVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMPCAEDYLSVVLNQLCVLHE KTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFNAETFTFHADICTLSEKERQIKK QTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDKETCFAEEGKKLVAASQA ALGL (SEQ ID NO: 50).

[0319] In some embodiments, the amino acid sequence of the HSA domain comprises any fragment of SEQ ID NO: 50 as long as the HSA domain increases the monoclonal antibody size to at least 150kD, at least 160kD, at least 170kD, at least 180kD, at least 190kD, or at least 200kD. In some embodiments, the amino acid sequence of the HSA domain comprises any fragment of SEQ ID NO: 50 as long as the HSA domain increases the monoclonal antibody size to at least about 200kD. In some embodiments, the amino acid sequence of the HSA domain comprises any fragment of SEQ ID NO: 50 as long as the HSA domain increases the monoclonal antibody size to about 200kD.

[0320] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 51. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. QVQLVQSGVEVKKPGASVKVSCKASGYTFTNYYMYWVRQAPGQGLEWMGGINPSN GGTNFNEKFKNRVTLTTDSSTTTAYMELKSLQFDDTAVYYCARRDYRFDMGFDYWG QGTLVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVH TFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAP EFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPRE EQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQE EMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQ EGNVFSCSVMHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQ QCPFEDHVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADC CAKQEPERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPY FYAPELLFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKF - 93 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 GERAFKAWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYI CENQDSISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAK DVFLGMFLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLV EEPQNLIKQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCK HPEAKRMPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETY VPKEFNAETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVE KCCKADDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 51). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 51. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0321] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0322] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 51 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0323] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 51. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 94 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 51, 15, 17, 19, 21, 23, 25, 27, 29, and 31. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 51, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0324] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 51, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 51 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0325] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 52. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. EVKLLESGGGLVQPGGSLKLSCAASGFDFSRYWMSWVRQAPGKGLEWIGEINPDSSTIK YTPSLKDKFIISRDNAKNTLCLQLSKVRSEDSALYYCARMGYRLFDSWGQGTTLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHVK LVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQEPERN ECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPELLFFA KRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFKAWA - 95 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 VARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISSK LKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGMFLY EYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIKQ NCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMPC AEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFNAETF TFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDKE TCFAEEGKKLVAASQAALGL (SEQ ID NO: 52). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 52. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0326] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0327] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 52 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0328] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 52. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 96 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 52. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 52.

[0329] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 52 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 52 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0330] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 53. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. VQLQQSGTVLARPGASVKMSCKASGNTFTSYWMHWVKQRPGQGLEWIGAIYPGYSDT RYNQKFKGKATLTAVTSTSTAYMELSSLTNEDSAVYYCTKFIATVGGYFDVWGAGTTV TVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAV LQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGG PSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNST YRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFED HVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQE PERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPEL LFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFK - 97 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 AWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDS ISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGM FLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLI KQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKR MPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFN AETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKA DDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 53). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 53. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0331] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0332] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 53 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0333] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 53. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 98 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 53. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 53.

[0334] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 53 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 53 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0335] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 54. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. QIQLVQSGPELKKPGETVKISCKASGYTFTDYSMHWVKQAPGKGLKWMGWIKIETGNP TYADDFKGRFAFSLETSASTAYLQINNLKNEDTATYFCARDYYGYYYYAMDYWGQGT SVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFP AVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFE GGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQF NSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMT KNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGN VFSCSVMHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCP FEDHVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCA KQEPERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFY APELLFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGE - 99 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 RAFKAWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICE NQDSISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDV FLGMFLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEE PQNLIKQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPE AKRMPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPK EFNAETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKC CKADDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 54). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 54. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0336] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0337] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 54 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0338] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 54. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 100 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 54. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 54.

[0339] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 54 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 54 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0340] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 55. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. VQLVESGGGLVQPGGSLRLSCAASGFTFSHYGMSWVRQTPDKRLELVATIDNNGGNTY YPDSVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARDAYYTYDYWYFDVWGAG TTVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTF PAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEF EGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQ FNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQC PFEDHVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCA KQEPERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFY APELLFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGE - 101 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 RAFKAWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICE NQDSISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDV FLGMFLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEE PQNLIKQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPE AKRMPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPK EFNAETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKC CKADDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 55). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 55. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0341] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0342] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 55 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0343] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 55. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 102 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 55. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 55.

[0344] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 55 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 55 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0345] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 56. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. EVKLVESGGGLVQPGGSLKLSCAASGFTFSSYTMSWVRQTPEKRLEWVAYISYGGGDT YYPDTVKGRFTISRDNAKNTLYLQMSSLKSEDTAMYYCARQKVDGYFVAMDYWSQG TSVTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTF PAVLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEF EGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQ FNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEM TKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG NVFSCSVMHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQC PFEDHVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCA KQEPERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFY APELLFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGE - 103 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 RAFKAWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICE NQDSISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDV FLGMFLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEE PQNLIKQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPE AKRMPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPK EFNAETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKC CKADDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 56). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 56. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0346] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0347] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 56 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0348] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 56. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 104 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 56. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 56.

[0349] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 56 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 56 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0350] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 57. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. EVKLVESGGGLVKPGGSLKLSCAASGFTFSSYGMSWVRQTPEKRLEWVATISGGGRYT YYPDSVKGRFTISRDNAKNILYLQMSSLRSEDTALYYCASPYDGYYGAMDYWGQGTS VTVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPA VLQSSGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEG GPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNS TYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKN QVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFS CSVMHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFED HVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQE PERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPEL LFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFK - 105 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 AWAVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDS ISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGM FLYEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLI KQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKR MPCAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFN AETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKA DDKETCFAEEGKKLVAASQAALGL (SEQ ID NO: 57). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 57. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0351] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0352] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 57 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0353] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 57. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 106 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 57. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 57.

[0354] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 57 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 57 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0355] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 58. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. EVQLQQSGTVLARPGASVRMSCKASGYSFSTYWMHWVKQRPGQGLEWIGGIYPGNSD TNYNQKFKGKAKLTAVTSASTAYMDLSSLTNEDSAVYYCTGGYFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHV KLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQEPER NECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPELLFF AKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFKAW - 107 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 AVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISS KLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGMFL YEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIK QNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMP CAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFNAET FTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDK ETCFAEEGKKLVAASQAALGL (SEQ ID NO: 58). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 58. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0356] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0357] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 58 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0358] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 58. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 108 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 58. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 58.

[0359] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 58 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 58 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0360] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 59. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. QIQLQQSGPEQVKPGASVKISCKASGYMFIDYYMNWVKQKPGQGLEWIGWIYPGSGST KDNENFKGKATLTVDTSSSTAYMQLSSLTSEDTAVYFCARYGPRFFDVWGAGTTVTVS SASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQS SGLYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSV FLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRV VSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSL TCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHV KLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQEPER NECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPELLFF AKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFKAW - 109 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 AVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISS KLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGMFL YEYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIK QNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMP CAEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFNAET FTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDK ETCFAEEGKKLVAASQAALGL (SEQ ID NO: 59). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 59. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0361] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0362] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 59 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0363] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 59. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 110 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 59. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 59.

[0364] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 59 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 59 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0365] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 60. Underlined amino acids represent the VH domain. Underlined and bolded amino acids shown in Figure 11 represent the respective complementarity determining regions (CDRs). Italicized and bold amino acids represent the CH1 domain. Italicized and underlined amino acids represent the hinge domain. Italicized amino acids represent the Fc domain. Double underlined amino acids represent the HSA domain. EVKLLESGGGLVQPGGSLKLSCEVSGFDFSRDWMSWVRQAPGKGLEWIGQISPDSTSIN YKPSLKDKFIISRDNAKNTLYLQLSGVRSEDTALYHCARDTSGYPDYWGQGTSLTVSSA STKGPSVFPLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSG LYSLSSVVTVPSSSLGTKTYTCNVDHKPSNTKVDKRVESKYGPPCPPCPAPEFEGGPSVFL FPPKPKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHNAKTKPREEQFNSTYRVVS VLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLT CLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVM HEALHNHYTQKSLSLSLGDAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHVK LVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQEPERN ECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPELLFFA KRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQRLKCASLQKFGERAFKAWA - 111 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 VARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISSK LKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVESKDVCKNYAEAKDVFLGMFLY EYARRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIKQ NCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMPC AEDYLSVVLNQLCVLHEKTPVSDRVTKCCTESLVNRRPCFSALEVDETYVPKEFNAETF TFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDKE TCFAEEGKKLVAASQAALGL (SEQ ID NO: 60). In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 60. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo.

[0366] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain (without the signal peptide) comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as provided above for the anti-PD1-HSA antibody. In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 1 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo.

[0367] In some embodiments, the monoclonal antibody comprises a first and third chain each comprises SEQ ID NO: 60 and a second and fourth chains each comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the first and second chains are linked by one or more covalent disulfide bonds and the third and fourth chains are linked by one or more covalent disulfide bonds. In some embodiments, the first and third chains are linked by one or more disulfide bonds. In some embodiments, the monoclonal antibody is larger in size that 140kD. In some embodiments, the monoclonal antibody is at least about 200kD. In some embodiments, the monoclonal antibody is about 200kD.

[0368] In some embodiments, the signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the anti-PD-1- HSA antibody heavy chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 60. In some embodiments, the anti-PD-1-HSA antibody light chain comprises an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the anti-PD-1-HSA antibody - 112 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 comprises an amino acid sequence comprising the CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 60. In some embodiments, the framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, and 60.

[0369] In some embodiments, one or more amino acids of an amino acid sequence encoding one or more CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, 31, or 60 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable heavy chain CDRs of SEQ ID NO: 60 is substituted. In some embodiments, one or more amino acids of an amino acid sequence encoding one or more variable light chain CDRs of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 is substituted.

[0370] In some embodiments the monoclonal antibody is a scFv-Fc antibody comprising a first and second chain that associate together, each chain comprising a variable heavy chain (VH) domain of SEQ ID NO: 2, 14, 16, 18, 20, 22, 24, 26, 28, or 30, a linker (e.g., GGGGSGGGGSGGGGS (SEQ ID NO: 13)), a variable light chain (VL) domain of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31, an Fc domain of SEQ ID NO: 2, and at least one additional domain. In some embodiments, the additional domain is an HSA domain of SEQ ID NO: 50. In some embodiments, the amino acid sequence of the HSA domain comprises any fragment of SEQ ID NO: 50 as long as the HSA domain increases the antibody size to at least 150kD, at least 160kD, at least 170kD, at least 180kD, at least 190kD, or at least 200kD. In some embodiments, the amino acid sequence of the HSA domain comprises any fragment of SEQ ID NO: 50 as long as the HSA domain increases the antibody size to at least about 200kD. In some embodiments, the amino acid sequence of the HSA domain comprises any fragment of SEQ ID NO: 50 as long as the HSA domain increases the antibody size to about 200kD. Nucleic Acid Sequences of Anti-PD-1-HSA Antibodies

[0371] A person skilled in the art can identify the nucleic acid sequences encoding the features identified in the corresponding amino acid sequences (e.g., CDRs, variable heavy domain, variable light domain, CH1 domain, hinge domain, Fc domain, and HSA domain) by - 113 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 translating the nucleic acid sequences into amino acid sequences. In some embodiments, the nucleic acid sequences may be codon optimized.

[0372] In some embodiments, the nucleic acid sequence of the anti-PD-1-HSA antibody comprises a nucleic acid sequence encoding a signal peptide comprising SEQ ID NO: 5.

[0373] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody heavy chain comprises any of SEQ ID NOs: 51-60 provided above for anti-PD-1-HSA. In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 5 immediately followed by the nucleic acid that encodes for any of SEQ ID NO: 51-60. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the respective CDRs, VH domain and CH domain in SEQ ID NOs: 51-60 can be determined from the amino acid sequence of SEQ ID NOs: 51-60 as identified herein by a person of skill in the art.

[0374] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises one of SEQ ID NOs: 51-60.

[0375] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody heavy chain comprises a nucleic acid sequence encoding one of SEQ ID NOs: 51-60. In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 5 immediately followed by a nucleic acid sequence encoding any of SEQ ID NOs: 51-60. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the anti-PD-1-HSA antibody heavy chain and respective CDRs, VH domain, CH1 domain, hinge domain, Fc domain and HSA domain can be determined from the amino acid sequence of SEQ ID NOS: 51-60 by a person of skill in the art.

[0376] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody heavy chain comprises any of SEQ ID NOs: 51-60.

[0377] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody heavy chain comprises a nucleic acid sequence encoding any of SEQ ID NOs: 51-60. In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody heavy chain comprises SEQ ID NO: 5 immediately followed by a nucleic acid sequence encoding any - 114 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 of SEQ ID NOs: 51-60. In some embodiments, the signal peptide is cleaved during post- translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the anti-PD-1-HSA antibody heavy chain and respective CDRs, VH domain, CH1 domain, hinge domain, Fc domain and HSA domain can be determined from the amino acid sequence of any of SEQ ID NOs: 51-60 by a person of skill in the art.

[0378] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 5 immediately followed by SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the respective CDRs, VL domain and CL domain in SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 can be determined from the amino acid sequence of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 as identified herein by a person of skill in the art.

[0379] In some embodiments, the amino acid sequence of the anti-PD-1-HSA antibody light chain comprises SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0380] In some embodiments, the nucleic acid sequence encoding the anti-PD-1-HSA antibody light chain comprises a nucleic acid sequence encoding SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the nucleic acid sequence encoding the anti-PD-1- HSA antibody light chain comprises SEQ ID NO: 5 immediately followed by a nucleic acid sequence encoding SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31. In some embodiments, the signal peptide is cleaved during post-translational modifications that occur in vitro or in vivo. Nucleic acid sequences encoding the anti-PD-1-HSA antibody light chain and respective CDRs, VL domain, and CL1 domain can be determined from the amino acid sequence of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31 by a person of skill in the art.

[0381] In some embodiments, the nucleic acid sequence encoding a signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 5. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-HSA heavy chain (without the signal peptide) comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to one of SEQ ID NOs: 51-60. In some - 115 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 embodiments, the nucleic acid sequence encoding an anti-PD-1-HSA light chain (without the signal peptide) comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to one of SEQ ID NOs: 51-60.

[0382] In some embodiments, the nucleic acid sequence encoding a signal peptide of the anti-PD-1-HSA antibody heavy or light chain comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 1. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-HSA heavy chain (without the signal peptide) comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to one of SEQ ID NOs: 51-60. In some embodiments, the nucleic acid sequence encoding an anti-PD-1-HSA light chain (without the signal peptide) comprise a nucleic acid sequence encoding an amino acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

[0383] In some embodiments, the nucleic acid sequence encodes CDRs of the variable heavy chain domain and the CDRs of the variable light chain domain of the anti-PD-1-HSA antibody, wherein the CDR sequences are indicated above (in bold and underline) in SEQ ID NOS: 51-60. In some embodiments, the nucleic acid sequence encoding framework regions (FRs) of the variable heavy chain domain and the FRs of the variable light chain domain of the anti-PD-1-HSA antibody comprise a nucleic acid sequence 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99 % identical to the FRs of one of SEQ ID NOs: 51-60. In some embodi...

Claims

Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 What is claimed is:

1. A monoclonal antibody or a fragment thereof, comprising: a first arm comprising a first variable heavy chain domain and a first variable light chain domain, wherein a portion of the first arm is capable of binding to a portion of a PD-1 protein; and a second arm comprising a second variable heavy chain domain and a second variable light chain domain, wherein a portion of the second arm is capable of binding to a portion of the PD-1 protein, wherein the first arm and the second arm each further comprise a first fragment crystallizable (Fc) domain, wherein the first arm and the second arm each further comprise at least one additional domain.

2. The monoclonal antibody of claim 1, wherein the first arm and the second arm each further comprise a CH1 domain, a hinge domain, and a CL domain.

3. The monoclonal antibody of any of claims 1-2, wherein the at least one additional domain of the first arm and the second arm comprises a second Fc domain.

4. The monoclonal antibody of claim 3, wherein the at least one additional domain of the first arm and the second arm comprises an albumin binding domain (ABD).

5. The monoclonal antibody of any of claims 1-2, wherein the at least one additional domain of the first arm and the second arm comprises a CD22 domain.

6. The monoclonal antibody of claim 5, wherein the at least one additional domain of the first arm and the second arm comprises a human serum albumin (HSA) domain.

7. The monoclonal antibody of claim 5, wherein the CD22 domain comprises SEQ ID NO: 8, SEQ ID NO: 9, or SEQ ID NO: 10, or a fragment thereof. - 173 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 8. The monoclonal antibody of claim 4, wherein the ABD domain comprises any one of SEQ ID NOs: 62-71, or a fragment thereof.

9. The monoclonal antibody of claim 6, wherein the HSA domain comprises any one of SEQ ID NOs: 51-60, or a fragment thereof.

10. The monoclonal antibody of any of claims 1-7, wherein: the first variable heavy chain domain of the first arm is encoded by a first polypeptide chain, the first variable light chain domain of the first arm is encoded by a second polypeptide chain, the second variable heavy chain domain of the second arm is encoded by a third polypeptide chain, the second variable light chain domain of the second arm is encoded by a fourth polypeptide chain, the first variable heavy chain domain and the first variable light chain domain form a first PD-1 binding site, and the second variable heavy chain domain and the second variable light chain domain form a second PD-1 binding site.

11. The monoclonal antibody of claim 10, wherein the first PD-1 binding site and the second PD-1 binding site are the same.

12. The monoclonal antibody of claim 10, wherein the first polypeptide chain and the third polypeptide chain each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain, and wherein the second polypeptide chain and the fourth polypeptide chain each further encode a CL domain.

13. The monoclonal antibody of claim 12, wherein the first polypeptide chain and the third polypeptide chain comprise the same sequence, and wherein the second polypeptide chain and the fourth polypeptide chain comprise the same sequence. - 174 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 14. The monoclonal antibody of any of claims 1-13, wherein the first variable heavy chain domain comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, wherein the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

15. The monoclonal antibody of any of claims 1-13, wherein the first arm and the second arm each comprise an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO:

3.

16. The monoclonal antibody of any of claims 1-13, wherein the first arm and second arm each comprise an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO:

3.

17. The monoclonal antibody of any of claims 1-13, wherein the first arm and the second arm each comprise an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO:

3.

18. The monoclonal antibody of claim 10, wherein the first polypeptide chain and the third polypeptide chain each comprise an amino acid sequence comprising SEQ ID NO: 2 and the second polypeptide chain and the fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO:

3.

19. The monoclonal antibody of claim 10, wherein the first polypeptide chain and the third polypeptide chain each comprise an amino acid sequence comprising SEQ ID NO: 11 and the second polypeptide chain and the fourth polypeptide chain each comprise an amino acid sequence comprising SEQ ID NO:

3.

20. The monoclonal antibody of claim 10, wherein the first polypeptide chain and the third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 12 and the second polypeptide chain and the fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO:

3. - 175 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 21. The monoclonal antibody of claim 10, wherein the first polypeptide chain and the third polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, and the second polypeptide chain and the fourth polypeptide chain each comprises an amino acid sequence comprising SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

22. The monoclonal antibody of any of claims 10-21, wherein the first polypeptide chain and the second polypeptide chain are linked by one or more covalent disulfide bonds and the third polypeptide chain and the fourth polypeptide chain are linked by one or more covalent disulfide bonds.

23. The monoclonal antibody of any of claims 10-22, wherein the first polypeptide chain and the third polypeptide chain are linked by one or more covalent disulfide bonds.

24. The monoclonal antibody of any of claims 1-23, wherein the monoclonal antibody is capable of localizing the PD-1 protein away from an immune synapse.

25. The monoclonal antibody of claim 24, wherein the monoclonal antibody is capable of disrupting a downstream signaling of a PD-1 mediated response in a T cell.

26. The monoclonal antibody of claim 25, wherein the monoclonal antibody is capable of enhancing a T cell function.

27. The monoclonal antibody of claim 26, wherein the PD-1 protein is located on a T cell, and wherein the monoclonal antibody is capable of preventing the PD-1 protein from binding to a PDL-1 protein or a PDL-2 protein on a tumor cell.

28. The monoclonal antibody of claim 27, wherein the monoclonal antibody is capable of inducing a cytokine secretion in a T cell.

29. The monoclonal antibody of claim 28, wherein the cytokine secretion is a secretion of IL-2. - 176 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 30. The monoclonal antibody of claim 29, wherein the monoclonal antibody is larger than 140kD in size.

31. The monoclonal antibody of claim 29, wherein the monoclonal antibody is about 160kD to about 230kD in size.

32. A pharmaceutical composition comprising: the monoclonal antibody of any of claims 1-31; and a pharmaceutically acceptable carrier.

33. A method of preventing or treating cancer in a subject comprising administering to the subject an effective amount of the composition of claim 32.

34. The method of claim 33, wherein the cancer is selected from colorectal cancer, lung cancer, bladder cancer, breast cancer, cervical cancer, kidney cancer, leukemia, Hodgkin lymphoma, non-Hodgkin lymphoma, prostate cancer, skin cancer (e.g., melanoma), head and neck cancer, endometrial cancer, colon cancer, rectal cancer, liver cancer, thyroids cancer, esophageal cancer, renal cell cancer, and a combination thereof.

35. A method of preventing or treating a viral infection in a subject comprising administering to the subject an effective amount of the composition of claim 32.

36. The method of claim 35, wherein the viral infection is HIV.

37. A kit for generating a monoclonal antibody or fragment thereof, the kit comprising one or more vectors comprising a polynucleotide sequence encoding any of the monoclonal antibodies of any of claims 1-31.

38. A kit for generating a monoclonal antibody or fragment thereof, the kit comprising: a first vector comprising a polynucleotide sequence encoding the first polypeptide chain of the monoclonal antibody of any of claims 10-21; and a second vector comprising a polynucleotide sequence encoding the second polypeptide chain of the monoclonal antibody of any of claims 10-21. - 177 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 39. The kit of claim 38, wherein the first vector and the second vector are the same vector.

40. The kit of claim 38, wherein the first vector and the second vector are two different vectors.

41. One or more host cells comprising: one or more vectors comprising a polynucleotide sequence encoding any of the monoclonal antibodies of any of claims 1-31.

42. One or more host cells comprising: a first vector comprising a polynucleotide sequence encoding the first polypeptide chain of the monoclonal antibody of any of claims 10-21; and a second vector comprising a polynucleotide sequence encoding the second polypeptide chain of the monoclonal antibody of any of claims 10-21.

43. The one or more host cells of claim 42, wherein the first vector and the second vector are the same vector.

44. The one or more host cells of claim 42, wherein the first vector and the second vector are two different vectors.

45. A method of making a monoclonal antibody or fragment thereof comprising: culturing the one or more host cells of claim 42 under conditions suitable for an expression of the one or more vectors; and recovering the monoclonal antibody or fragment thereof.

46. A method of making a monoclonal antibody or fragment thereof comprising: culturing the one or more host cells of any of claims 42-44 under conditions suitable for an expression of the first vector and the second vector; and recovering the monoclonal antibody or fragment thereof.

47. A composition comprising: one or more vectors comprising a polynucleotide sequence encoding any of the monoclonal antibodies of any of claims 1-31. - 178 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 48. A composition comprising: a first vector comprising a polynucleotide sequence encoding the first polypeptide chain of the monoclonal antibody of any of claims 10-21; and a second vector comprising a polynucleotide sequence encoding the second polypeptide chain of the monoclonal antibody of any of claims 10-21.

49. The composition of claim 48, wherein the first vector and the second vector are the same vector.

50. The composition of claim 48, wherein the first vector and the second vector are two different vectors.

51. A means for binding a portion of a PD-1 protein.

52. The means of claim 51, wherein the means comprises a monoclonal antibody comprising a domain for increasing a size of the monoclonal antibody over 140kD.

53. The means of claim 52, wherein the monoclonal antibody or a fragment thereof comprises: a first arm comprising a first variable heavy chain domain and a first variable light chain domain, wherein a portion of the first arm is capable of binding to the portion of the PD-1 protein; and a second arm comprising a second variable heavy chain domain and a second variable light chain domain, wherein a portion of the second arm is capable of binding to the portion of the PD-1 protein, wherein the first arm and the second arm each further comprise a fragment, crystallizable (Fc) domain, wherein the first and second arms each further comprise the domain for increasing the size of the monoclonal antibody over 140kD.

54. The means of claim 53, wherein the first arm and the second arm each further comprise a CH1 domain, a hinge domain, and a CL domain. - 179 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 55. The means of any of claims 53-54, wherein the domain for increasing the size of the monoclonal antibody over 140kD comprises a second Fc domain.

56. The means of claim 53, wherein the domain for increasing the size of the monoclonal antibody over 140kD comprises a CD22 domain, an albumin binding domain (ABD), or a human serum albumin (HAS) domain.

57. The means of claim 56, wherein the CD22 domain comprises SEQ ID NO: 8, SEQ ID NO: 9, or SEQ ID NO: 10, or a fragment thereof.

58. The means of claim 56, wherein the ABD domain comprises any one of SEQ ID NOs: 62-71, or a fragment thereof.

59. The means of claim 56, wherein the HSA domain comprises any one of SEQ ID NOs: 51-60, or a fragment thereof.

60. The means of any of claims 53-59, wherein: the first variable heavy chain domain of the first arm is encoded by a first polypeptide chain, the first variable light chain domain of the first arm is encoded by a second polypeptide chain, the second variable heavy chain domain of the second arm is encoded by a third polypeptide chain, the second variable light chain domain of the second arm is encoded by a fourth polypeptide chain, the first variable heavy chain domain and the first variable light chain domain form a first PD-1 binding site, and the second variable heavy chain domain and the second variable light chain domain form a second PD-1 binding site.

61. The means of claim 60, wherein the first PD-1 binding site and the second PD-1 binding site are the same. - 180 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 62. The means of claim 61, wherein the first polypeptide chain and the third polypeptide chain each further encode a hinge domain, a CH1 domain, the Fc domain, and the at least one additional domain for increasing the size of the monoclonal antibody over 140kD, and wherein the second polypeptide chain and the fourth polypeptide chain each further encode a CL domain.

63. The means of claim 62, wherein the first polypeptide chain and the third polypeptide chain comprise the same sequence, and the second polypeptide chain and the fourth polypeptide chain comprise the same sequence.

64. The means of any of claims 53-63, wherein the first variable heavy chain domain comprises an amino acid sequence of the variable heavy chain portion of SEQ ID NO: 2, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 67, 68, 69, 70, or 71, and wherein the first variable light chain domain comprises an amino acid sequence of the variable light chain portion of SEQ ID NO: 3, 15, 17, 19, 21, 23, 25, 27, 29, or 31.

65. The means of and of claims 53-64, wherein the first arm and the second arm each comprise an amino acid sequence comprising SEQ ID NO: 2 and SEQ ID NO:

3.

66. The means of any of claims 53-64, wherein the first arm and the second arm each comprise an amino acid sequence comprising SEQ ID NO: 11 and SEQ ID NO:

3.

67. The means of any of claims 53-64, wherein the first arm and the second arm each comprise an amino acid sequence comprising SEQ ID NO: 12 and SEQ ID NO:

3.

68. The means of any of claims 51-67, wherein the monoclonal antibody is capable of localizing a PD-1 protein away from an immune synapse.

69. The means of claim 68, wherein the monoclonal antibody is capable of disrupting a downstream signaling of a PD-1 mediated response in a T cell.

70. The means of claim 69, wherein the monoclonal antibody is capable of enhancing T cell function. - 181 - ActiveUS 206353837Attorney Docket No.0019240-01323WO1 Date of Electronic Deposit: October 4, 2024 71. The means of claim 70, wherein the PD-1 protein is located on a T cell, and wherein the monoclonal antibody is capable of preventing the PD-1 protein from binding to a PDL-1 protein or a PDL-2 protein on a tumor cell.

72. The means of claim 71, wherein the monoclonal antibody is capable of inducing a cytokine secretion in a T cell.

73. The means of claim 72, wherein the cytokine secretion is a secretion of IL-2.

74. The means of claim 73, wherein the monoclonal antibody is about 160kD to about 220kD in size. - 182 - ActiveUS 206353837

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