Methods for the combination of B7-H3 antibody drug conjugates with PD-1 x CTLA-4 bispecific molecules

Abstract

Part of this disclosure is directed to dosing regimens for administering a humanized anti-B7-H3 antibody conjugated to a duocarmycin moiety ("B7-H3-ADC") for the treatment of cancer, particularly cancers associated with expression of B7-H3. Part of this disclosure is directed to the use of the above-mentioned B7-H3-ADC in combination with a bispecific molecule capable of binding to PD-1 and CTLA-4 ("PD-1 x CTLA-4 bispecific molecule"). Part of this disclosure is directed to the use of the above-mentioned B7-H3-ADC in combination with lorigellimab for the treatment of cancer. Part of this disclosure is directed to the use of MGC018 in combination with lorigellimab for the treatment of cancer. Part of this disclosure is directed to the use of such molecules as described above, as well as pharmaceutical compositions and pharmaceutical kits that contain such molecules as described above and that facilitate the use of such dosing regimens in the treatment of cancer.

Description

[Technical field]

[0001] Part of this disclosure relates to dosing regimens for administering a humanized anti-B7-H3 antibody conjugated to a duocarmycin moiety ("B7-H3-ADC") for the treatment of cancer, including, for example, cancers associated with expression of B7-H3. Part of this disclosure relates to the use of the above-mentioned B7-H3-ADC in combination with a bispecific molecule capable of binding to PD-1 and CTLA-4 ("PD-1 x CTLA-4 bispecific molecule"). Part of this disclosure relates to the use of the above-mentioned B7-H3-ADC in combination with lorigellimab for the treatment of cancer. Part of this disclosure relates to the use of MGC018 in combination with lorigellimab for the treatment of cancer. Part of this disclosure is directed to the use of such molecules as described above, as well as pharmaceutical compositions and pharmaceutical kits that contain such molecules as described above and that facilitate the use of such dosing regimens in the treatment of cancer. [Background technology]

[0002] I.B7‐H3 B7-H3 is a member of the B7-CD28 superfamily and is expressed on antigen-presenting cells. B7-H3 is unique in that the major human form contains two extracellular tandem IgV-IgC domains (i.e., IgV-IgC-IgV-IgC) (Non-Patent Document 1). B7-H3 is not expressed on resting B or T cells, monocytes, or dendritic cells, but is induced on dendritic cells by IFN-γ and on monocytes by GM-CSF (Non-Patent Document 2). The mode of action of B7-H3 is complex, and the protein has been reported to mediate both T cell costimulation and co-inhibition (Non-Patent Documents 3, 4). B7-H3 binds to one or more unidentified receptors to mediate T cell co-inhibition. In addition, B7-H3 is an inhibitor of NK cells and osteoblasts by interacting with one or more unknown receptors (Non-Patent Document 3).

[0003] B7-H3 is expressed on a variety of cancers (e.g., neuroblastoma, gastric cancer, ovarian cancer, non-small cell lung cancer, etc., see, for example, Non-Patent Document 5) and on cultured cancer stem-like cells. Several independent studies have shown that human malignant tumor cells exhibit significantly elevated expression of B7-H3 protein, and that this significant expression is associated with increased disease severity (Non-Patent Documents 6, 7), suggesting that B7-H3 is exploited by tumors as an immune evasion pathway (Non-Patent Document 3).

[0004] The role of B7-H3 in inhibiting the immune system and its increased expression on human tumors suggests that this molecule may serve as a therapeutic target for the treatment of cancer. It has been proposed to use anti-B7-H3 antibodies and other molecules that modulate B7-H3 expression to treat tumors and / or upregulate immune responses (see Non-Patent Documents 8-10; also see Patent Documents 1-20).

[0005] II. Cell-Mediated Immune Response Immune responses are tightly controlled by costimulatory and co-inhibitory ligands and receptors that are often referred to as "immune checkpoints" (Non-Patent Documents 11, 12). These molecules provide a balanced network of positive and negative signals that regulate the immune response and provide protection against infections and cancer. Some cancer cells can escape the immune system by inducing a state of T cell exhaustion in which T cells are exposed to persistent antigen and / or inflammatory signals (Non-Patent Document 13). Immune checkpoint molecules involved in T cell exhaustion include Programmed Death-1 (PD-1) and Cytotoxic T-lymphocyte associated protein-4 (CTLA-4) (Non-Patent Document 14).

[0006] Bispecific molecules that bind both PD-1 and CTLA-4 can provide high flexibility in design and engineering for a variety of applications, providing enhanced avidity to multimeric antigens, cross-linking of different antigens, and directed targeting to specific cell types depending on the presence of both target antigens. For example, US Pat. Nos. 5,991,103, 5,991,104, 5,991,112, and 5,991,123 propose the use of PD-1×CTLA-4 bispecific molecules in the treatment of cancer and also describe PD-1×CTLA-4 bispecific molecules. In particular, US Pat. Nos. 5,991,103 and 5,991,123 describe tetravalent PD-1×CTLA-4 bispecific molecules. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] U.S. Patent No. 7,279,567 [Patent Document 2] U.S. Patent No. 7,527,969 [Patent Document 3] U.S. Patent No. 7,718,774 [Patent Document 4] U.S. Patent No. 8,779,098 [Patent Document 5] U.S. Patent No. 8,802,091 [Patent Document 6] U.S. Patent Publication No. 2002 / 0168762 [Patent Document 7] U.S. Patent Publication No. 2008 / 0081346 [Patent Document 8] U.S. Patent Publication No. 2008 / 0116219 [Patent Document 9] U.S. Patent Publication No. 2013 / 0078234 [Patent Document 10] U.S. Patent Publication No. 2015 / 0274838 [Patent Document 11] International Publication No. 2009 / 073533 [Patent Document 12] International Publication No. 2008 / 066691 [Patent Document 13] International Publication No. 2006 / 016276 [Patent Document 14] International Publication No. 2008 / 116219 [Patent Document 15] International Publication No. 2001 / 094413 [Patent Document 16] International Publication No. 2002 / 32375 [Patent Document 17] International Publication No. 2004 / 093894 [Patent Document 18] International Publication No. 2006 / 016276 [Patent Document 19] International Publication No. 2008 / 116219 [Patent Document 20] International Publication No. 2011 / 109400 [Patent Document 21] International Publication No. 2014 / 209804 [Patent Document 22] International Publication No. 2017 / 218707 [Patent Document 23] International Publication No. 2017 / 193032 [Patent Document 24] International Publication No. 2019 / 094637 [Patent Document 25] U.S. Patent Publication No. 2019 / 0185569 [Patent Document 26] International Publication No. 2017 / 106061 [Patent Document 27] International Publication No. 2022 / 026306 [Non-patent literature]

[0008] [Non-Patent Document 1] Collins, M. et al. (2005) “The B7 Family Of Immune-Regulatory Ligands,” Genome Biol. 6:223.1-223.7 [Non-Patent Document 2] Sharpe, AH et al. (2002) “The B7-CD28 Superfamily,” Nature Rev. Immunol. 2:116-126 [Non-licensed document 3] Hofmeyer, K. et al. (2008) "The Contrasting Role Of B7-H3," Proc. Natl. Acad. Sci. (USA) 105(30):10277-10278

Non-licensed Document 4

Non-licensed Document 5

Non-licensed Document 6

Non-licensed Document 7

[0009] Some of the disclosure relates to dosing regimens for administering B7-H3-ADC for the treatment of cancer, including, for example, cancers associated with expression of B7-H3. In certain embodiments, the disclosure can include administration of a single dose or split doses (i.e., two or more separate doses) of B7-H3-ADC. In certain embodiments, the disclosure relates to the use of the above-described B7-H3-ADC in combination with a PD-1 x CTLA-4 bispecific molecule for the treatment of cancer. A dosing regimen for administering B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule for the treatment of cancer can include administration at regular dosing intervals or at intermittent dosing intervals. In certain aspects, a dosing regimen for administering B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule for the treatment of cancer can include administration of a single dose or a split dose (i.e., two or more separate doses) of B7-H3-ADC. In certain aspects, administration of B7-H3-ADC and PD-1×CTLA-4 bispecific molecule can be simultaneous or sequential in any order. The present disclosure is directed in certain aspects to the use of such molecules, as well as pharmaceutical compositions and pharmaceutical kits that contain such molecules and facilitate the use of such dosing regimens in the treatment of cancer.

[0010] In particular, the disclosure provides a method of treating cancer in a subject in need thereof, the method comprising administering B7-H3-ADC for the treatment of cancer, including, for example, cancer associated with expression of B7-H3, in a dosing regimen that may include administration of split doses (i.e., two or more separate) of B7-H3-ADC. In particular, the disclosure provides a method of treating cancer in a subject in need thereof, the method comprising administering to the subject an anti-B7-H3 antibody-drug conjugate (B7-H3-ADC) and a PD-1 x CTLA-4 bispecific molecule, wherein the B7-H3-ADC has the formula: Ab‐(LM) m -(D) n where: The Ab binds to B7-H3 and: (i) in its variable light (VL) domain, the CDRL1 sequence RASESIYSYLA (SEQ ID NO: 22), the CDRL2 sequence NTKTLPE (SEQ ID NO: 23), and the CDRL3 sequence QHHYGTPPWT (SEQ ID NO: 24); and (ii) in its variable heavy (VH) domain, the CDRH1 sequence SYGMS (SEQ ID NO: 25), the CDRH2 sequence TINSGGSNTYY PDSLKG (SEQ ID NO: 26), and the CDRH3 sequence HDGGAMDY (SEQ ID NO: 27). a humanized B7-H3 antibody or a B7-H3-binding fragment thereof comprising: D is a cytotoxic duocarmycin moiety; LM comprises at least one bond or linker molecule that covalently bonds Ab and D; m is an integer from 0 to n, representing the number of bonds or linker molecules in the B7-H3-ADC, except that m is not 0 when LM is one bond; n is an integer from 1 to 10 and represents the number of the cytotoxic duocarmycin moieties covalently attached to the B7-H3-ADC molecule.

[0011] The present disclosure further provides that said Ab is: (i) a humanized variable light (VL) domain comprising the amino acid sequence of SEQ ID NO: 17, and (ii) a humanized variable heavy (VH) domain comprising the amino acid sequence of SEQ ID NO: 18 In accordance with an embodiment of the present invention, there is provided an embodiment of the method as described above, comprising:

[0012] The disclosure further provides embodiments of the methods as described above, wherein said Ab further comprises a human IgG1, IgG2, IgG3, or IgG4 Fc domain.

[0013] The disclosure further provides embodiments of the methods as described above, wherein said Ab further comprises a human IgG1 Fc domain.

[0014] The present disclosure further relates to a variant Fc domain comprising: (a) one or more amino acid modifications that reduce the affinity of the variant Fc domain for FcγR; and / or (b) one or more amino acid modifications that enhance the serum half-life of the variant Fc domain. In one embodiment, the variant Fc domain comprises:

[0015] The disclosure further provides embodiments of the methods as described above, wherein the modification that reduces the affinity of the variant Fc domain for FcγR comprises the substitutions L234A; L235A; or L234A and L235A, the numbering of which is that of the EU index as set forth in Kabat.

[0016] The disclosure further provides embodiments of the method as described above, wherein the modification that increases the serum half-life of the variant Fc domain comprises the substitutions M252Y; M252Y and S254T; M252Y and T256E; M252Y, S254T and T256E; or K288D and H435K, the numbering of which is that of the EU index as set forth in Kabat.

[0017] The present disclosure further provides embodiments of the methods as described above, wherein at least one of said LMs is a linker molecule.

[0018] The disclosure further provides an embodiment of the method as described above, wherein said LM linker molecule is a peptide linker.

[0019] The disclosure further provides embodiments of the methods as described above, wherein the peptide linker is a valine-citrulline dipeptide linker.

[0020] The disclosure further provides an embodiment of the method as described above, wherein the LM linker molecule further comprises a self-eliminating spacer between the cleavable linker and D.

[0021] The present disclosure further provides an embodiment of the method as described above, wherein the self-erasing spacer comprises a para-aminobenzyloxycarbonyl moiety.

[0022] The disclosure further provides embodiments of the methods as described above, wherein the LM linker molecule further comprises a maleimide linker moiety between the cleavable linker and Ab.

[0023] The present disclosure further relates to a method for producing said LM having the formula: [V‐(W) k -(X)1-A] Thus, the B7-H3-ADC has the following formula: Ab‐[V‐(W) k -(X)1-A]-D where: V is a cleavable linker; (W) k -(X)1-A is an elongated self-erasing spacer system that self-erases by l,(4+2n) erasure; W and X are each a 1,(4+2n)-electron cascade spacer, which may be the same or different; A is a group represented by the formula (Y) m where Y is an 1,(4+2n) electron cascade spacer, or a group of formula U, which is a cyclization elimination spacer; k, 1, and m are independently integers from 0 to 5, inclusive; n is an integer from 0 to 10, inclusive; however: A is (Y) m if k+l+m≧1; If k+l+m=l then n>l; If A is U, then k+1>=1; W, X and Y are independently represented by the following formula: [ka] or the following formula: [ka] wherein the compound is selected from compounds having the formula: Q is -R 5 C=CR 6 -, S, O, NR 5 , -R 5 C=N- or -N=CR 5 - is; P is NR 7 , O or S; a, b and c are independently integers from 0 to 5, inclusive; I, F and G are independently selected from the formula: [ka] wherein the compound is selected from compounds having the formula: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independent of each other, H, C 1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C 1-6 Alkoxy, hydroxy (OH), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2) and phosphate (OP(=O)(OR x )2), where: R x , R x 1 and R x 2 is independent, C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; The above-mentioned substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 or R 9 two or more of which are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures; U is a group represented by the formula: [ka] wherein the compound is selected from compounds having the formula: a, b and c are independently selected to be integers of 0 or 1; where a+b+c=2 or 3; R 1 and / or R 2 are independent of each other, H, C 1-6represents an alkyl group, said alkyl group optionally containing the following groups: hydroxy (OH), ether (OR x ), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2), and phosphate (OP(=O)(OR x )2) where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independent of each other, H, C 1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C 1-6 Alkoxy, hydroxy (OH), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2), and phosphate (OP(=O)(OR x )2), where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl group, the substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , or R 8 are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures.

[0024] The present disclosure further provides that said LM linker molecule is: (1) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; (2) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; (3) p-aminocinnamyloxycarbonyl; (4) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl; (5) p-amino-benzyloxycarbonyl-p-aminocinnamyloxycarbonyl; (6) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl; (7) p-aminophenylpentadienyloxycarbonyl; (8) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyloxycarbonyl; (9) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyloxycarbonyl; (10) p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyloxycarbonyl; (11) p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (12) p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (13) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (14) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (15) p-aminobenzyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)-carbonyl; (16) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (17) p-aminobenzyloxycarbonyl-p-aminobenzyl; (18) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyl; (19) p-aminocinnamyl; (20) p-aminocinnamyloxycarbonyl-p-aminobenzyl; (21) p-aminobenzyloxycarbonyl-p-aminocinnamyl; (22) p-amino-cinnamyloxycarbonyl-p-aminocinnamyl; (23) p-aminophenylpentadienyl; (24) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyl; (25) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyl; or (26) Provided is an embodiment of the process as described above, comprising p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyl.

[0025] The disclosure further provides an embodiment of the method as described above, wherein the LM linker molecule is conjugated to a side chain of an amino acid of the polypeptide chain of the Ab, linking the Ab to a molecule of the cytotoxic duocarmycin moiety D.

[0026] The disclosure further provides embodiments of the methods as described above, wherein the cytotoxic duocarmycin moiety D comprises a duocarmycin cytotoxin selected from the group consisting of duocarmycin A, duocarmycin B1, duocarmycin B2, duocarmycin C1, duocarmycin C2, duocarmycin D, duocarmycin SA, CC-1065, adozelesin, bizeresin, carzerusin (U-80244), seco-duocarmycin (seco-DUBA), and spiro-duocarmycin (spiro-DUBA or DUBA).

[0027] The disclosure further provides embodiments of the methods as described above, wherein the cytotoxic duocarmycin moiety D comprises seco-DUBA.

[0028] The disclosure further provides an embodiment of the method as described above, wherein the LM linker molecule is covalently attached to the Ab via a reduced interchain disulfide.

[0029] The present disclosure further provides that said Ab is: (i) a light chain comprising a variable light (VL) domain comprising the amino acid sequence of SEQ ID NO: 17 and a CLκ domain of SEQ ID NO: 1; and (ii) a heavy chain comprising a variable heavy (VH) domain comprising the amino acid sequence of SEQ ID NO: 18, a CH1 domain of SEQ ID NO: 3, a hinge domain of SEQ ID NO: 5, and an Fc domain comprising the CH2-CH3 domain of SEQ ID NO: 8. Including, The above D includes seco-DUBA; An embodiment of the method as described above is provided, wherein the LM comprises a linker molecule comprising a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

[0030] The present disclosure further provides that said Ab is: (i) a light chain comprising the amino acid sequence of SEQ ID NO: 19; and (ii) a heavy chain comprising the amino acid sequence of SEQ ID NO: 20 Including, The above D includes seco-DUBA; An embodiment of the method as described above is provided, wherein the LM comprises a linker molecule comprising a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

[0031] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a therapeutically or prophylactically effective dose of about 1 mg / kg to about 3 mg / kg every three weeks.

[0032] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a therapeutically or prophylactically effective dose of about 2 mg / kg to about 3 mg / kg every three weeks.

[0033] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a therapeutically or prophylactically effective dose of about 1 mg / kg to about 3 mg / kg every four weeks.

[0034] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a therapeutically or prophylactically effective dose of about 2 mg / kg to about 3 mg / kg every four weeks.

[0035] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered as a single dose.

[0036] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered as a split dose, in two or more separate administrations.

[0037] The disclosure further provides embodiments of the methods as described above, wherein said split dose consists of two separate administrations administered within about 7±2 days of each other.

[0038] The disclosure further provides embodiments of the methods as described above, wherein said split dose consists of two separate administrations administered within a three week cycle.

[0039] The disclosure further provides embodiments of the methods as described above, wherein said split dose consists of two separate administrations administered within a four week cycle.

[0040] The present disclosure further provides embodiments of the methods as described above, wherein, on the day when both the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule are administered, the B7-H3-ADC is administered prior to administration of the PD-1 x CTLA-4 bispecific molecule.

[0041] The disclosure further provides embodiments of the methods as described above, where on the day both the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule are administered, the PD-1 x CTLA-4 bispecific molecule is administered prior to administration of the B7-H3-ADC.

[0042] The disclosure further provides embodiments of the methods as described above, wherein the PD-1 x CTLA-4 bispecific molecule is administered at least about 15-30 minutes after administration of the B7-H3-ADC.

[0043] The disclosure further provides embodiments of the methods as described above, wherein the B7-H3-ADC is administered at least about 15-30 minutes after administration of the PD-1 x CTLA-4 bispecific molecule.

[0044] The disclosure further provides embodiments of the methods as described above, wherein the PD-1 x CTLA-4 bispecific molecule is administered at least about 15 minutes after administration of the B7-H3-ADC.

[0045] The disclosure further provides embodiments of the methods as described above, wherein the B7-H3-ADC bispecific molecule is administered at least about 15 minutes after administration of the PD-1 x CTLA-4 bispecific molecule.

[0046] The disclosure further provides embodiments of the methods as described above, wherein the PD-1 x CTLA-4 bispecific molecule is administered at least about 30 minutes after administration of the B7-H3-ADC.

[0047] The disclosure further provides embodiments of the methods as described above, wherein the B7-H3-ADC bispecific molecule is administered at least about 30 minutes after administration of the PD-1 x CTLA-4 bispecific molecule.

[0048] The disclosure further provides embodiments of the methods as described above, wherein the PD-1 x CTLA-4 bispecific molecule is selected from the group consisting of: lorigellimab, MEDI5752, budaliimab, and cadnilimab.

[0049] The disclosure further provides embodiments of the methods as described above, wherein the PD-1 x CTLA-4 bispecific molecule is lorigellimab.

[0050] The disclosure further provides embodiments of the methods as described above, wherein said lorigellimab is administered at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg every three weeks.

[0051] The disclosure further provides embodiments of the methods as described above, wherein said lorigellimab is administered at a dose of about 6 mg / kg every three weeks.

[0052] The disclosure further provides embodiments of the methods as described above, wherein said lorigellimab is administered at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg every four weeks.

[0053] The disclosure further provides embodiments of the methods as described above, wherein said lorigellimab is administered at a dose of about 6 mg / kg every four weeks.

[0054] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 1 mg / kg.

[0055] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 1.25 mg / kg.

[0056] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 1.5 mg / kg.

[0057] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 1.75 mg / kg.

[0058] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2 mg / kg.

[0059] The disclosure further provides an embodiment of the method as described above, wherein the B7-H3-ADC is administered at a dose of about 2.1 mg / kg.

[0060] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.2 mg / kg.

[0061] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.25 mg / kg.

[0062] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.3 mg / kg.

[0063] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.4 mg / kg.

[0064] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.5 mg / kg.

[0065] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.6 mg / kg.

[0066] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.7 mg / kg.

[0067] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 2.75 mg / kg.

[0068] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered at a dose of about 3 mg / kg.

[0069] The disclosure further provides embodiments of such methods, wherein the B7-H3-ADC is administered by intravenous (IV) infusion.

[0070] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of said B7-H3-ADC is for a period of at least about 60-120 minutes.

[0071] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of said B7-H3-ADC is for a period of at least about 60 minutes.

[0072] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of said B7-H3-ADC is for a period of at least about 75 minutes.

[0073] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of said B7-H3-ADC is for a period of at least about 120 minutes.

[0074] The disclosure further provides embodiments of the methods as described above, wherein the PD-1 x CTLA-4 bispecific molecule is administered by IV infusion.

[0075] The disclosure further provides embodiments of the methods as described above, wherein the IV infusion of the PD-1 x CTLA-4 bispecific molecule is for a period of at least about 30 to 120 minutes.

[0076] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of the PD-1 x CTLA-4 bispecific molecule is for a period of at least about 30 minutes.

[0077] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of the PD-1 x CTLA-4 bispecific molecule is for a period of at least about 45 minutes.

[0078] The disclosure further provides embodiments of the methods as described above, wherein said IV infusion of the PD-1 x CTLA-4 bispecific molecule is for a period of at least about 60 minutes.

[0079] The disclosure further relates to a method for treating cancer comprising administering to a patient a therapeutically effective amount of at least one of the following: adrenal cancer; AIDS-related cancer; alveolar soft part sarcoma; astrocytic tumor; anal cancer; squamous cell carcinoma of the anal canal (SCAC); bladder cancer; bone cancer; brain and spinal cord cancer; metastatic brain tumors; B-cell cancer; breast cancer; HER2 + Breast cancer;Triple negative breast cancer (TNBC);Carotid bulb tumor;Cervical cancer;Chondrosarcoma;Chordoma;Chromophobe renal cell carcinoma;Clear cell carcinoma;Colon cancer;Colorectal cancer (CRC);Non-high microsatellite instability colorectal cancer (non-MSI-H CRC);Cutaneous benign fibrous histiocytoma;Desmoplastic small round cell tumor;Ependymoma;Ewing's tumor;Extraskeletal myxoid chondrosarcoma;Fibrosal dysplasia ossificans;Fibrous dysplasia;Gallbladder or bile duct cancer;Gastrointestinal cancer;Gestational trophoblastic disease;Germ cell tumor;Head and neck cancer;Glioblastoma;Hematologic malignancies;Hepatocellular carcinoma;Pancreatic islet cell tumor;Kaposi's sarcoma;Kidney cancer;Leukemia;Acute myeloid leukemia;Liposarcoma / malignant liposarcoma;Dedifferentiated liposarcoma;Liver cancer;Lymphoma;Lung cancer;Non-small-cell lung cancer cancer:NSCLC);medulloblastoma;melanoma;cutaneous melanoma;meningioma;mesotheliomapharyngeal cancer;multiple endocrine neoplasia;multiple myeloma;myelodysplastic syndrome;myxofibrosarcoma;neuroblastoma;neuroendocrine tumors;ovarian cancer;pancreatic cancer;papillary thyroid cancer;parathyroid tumor;pediatric cancer;peripheral nerve sheath tumor;pheochromocytoma;pituitary tumor;prostate cancer;metastatic castration resistant prostate cancer (mCRPC);posterior uveal melanoma;renal cell cancer;renal cell carcinoma (RCC);kidney metastatic cancer;rhabdoid tumor;rhabdomyosarcoma;sarcoma;skin cancer;small round blue cell tumor of childhood;neuroblastoma;soft tissue sarcoma;undifferentiated pleomorphic sarcoma;squamous cell carcinoma;squamous cell cancer of the head and neck In one embodiment, the cancer is selected from the group consisting of: gastric cancer; synovial sarcoma; testicular cancer; thymic cancer; thymoma; thyroid cancer; thyroid metastatic cancer; and uterine cancer.

[0080] The disclosure further provides embodiments of the methods as described above, wherein the cancer is selected from the group consisting of: anal cancer, SCAC, breast cancer, TNBC, cervical cancer, colorectal cancer, non-microsatellite instability-high colorectal cancer (non-MSI-H CRC), head and neck cancer, kidney cancer, renal cell carcinoma, liver cancer, hepatocellular carcinoma, lung cancer, NSCLC, melanoma, cutaneous melanoma, posterior uveal melanoma, ovarian cancer, pancreatic cancer, prostate cancer, mCRPC, soft tissue sarcoma, dedifferentiated liposarcoma, myxofibrosarcoma, undifferentiated pleomorphic sarcoma, synovial sarcoma, epithelial cell carcinoma, and SCCHN.

[0081] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is prostate cancer.

[0082] The disclosure further provides embodiments of the methods as described above, wherein said prostate cancer is mCRPC.

[0083] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is liver cancer.

[0084] The present disclosure further provides embodiments of the methods as described above, wherein said liver cancer is hepatocellular carcinoma.

[0085] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is renal cancer.

[0086] The present disclosure further provides embodiments of the methods as described above, wherein said renal cancer is renal cell carcinoma.

[0087] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is ovarian cancer.

[0088] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is pancreatic cancer.

[0089] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is anal cancer.

[0090] The disclosure further provides embodiments of the methods as described above, wherein said anal cancer is SCAC.

[0091] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is an epithelial cell cancer.

[0092] The disclosure further provides embodiments of the methods as described above, wherein said epithelial cell cancer is SCCHN.

[0093] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is breast cancer.

[0094] The disclosure further provides embodiments of the methods as described above, wherein said breast cancer is TNBC.

[0095] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is melanoma.

[0096] The present disclosure further provides embodiments of the methods as described above, wherein said melanoma is cutaneous melanoma or posterior uveal melanoma.

[0097] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is lung cancer.

[0098] The present disclosure further provides embodiments of the methods as described above, wherein said lung cancer is NSCLC.

[0099] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is cervical cancer.

[0100] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is colorectal cancer.

[0101] The disclosure further provides embodiments of the methods as described above, wherein said colorectal cancer is non-MSI-H CRC.

[0102] The present disclosure further provides embodiments of the methods as described above, wherein said cancer is soft tissue sarcoma.

[0103] The disclosure further provides embodiments of the methods as described above, wherein said soft tissue sarcoma is dedifferentiated liposarcoma, myxofibrosarcoma, undifferentiated pleomorphic sarcoma, or synovial sarcoma.

[0104] The disclosure further provides embodiments of the methods as described above, wherein the cancer expresses B7-H3.

[0105] The disclosure further provides embodiments of the methods as described above, further comprising the step of administering a therapeutically or prophylactically effective amount of one or more additional therapeutic or chemotherapeutic agents.

[0106] The present disclosure further provides embodiments of the methods as described above, wherein the chemotherapeutic agent is a platinum-based chemotherapeutic agent.

[0107] The disclosure further provides embodiments of the methods as described above, wherein the chemotherapeutic agent is a taxane.

[0108] The present disclosure further provides embodiments of the methods as described above, wherein the subject in need thereof is a human. [Brief description of the drawings]

[0109] [Figure 1]FIG. 1A provides a schematic diagram of MGC018, showing the release mechanism of the active toxin (DUBA). MGC018 is an ADC composed of a humanized monoclonal IgG1 antibody covalently linked to a limited number of linker-drug moieties containing seco-duocarmycin derivatives. The humanized monoclonal IgG1 antibody recognizes human B7-H3. The linker-drug contains a cleavable linker and a prodrug, seco-duocarmycin-hydroxybenzamide-azaindole (seco-DUBA). After receptor-mediated internalization of MGC018, the linker is cleaved at the dipeptide valine-citrulline (vc) motif by lysosomal proteases. The prodrug (seco-DUBA) then spontaneously rearranges by cyclization to form the active toxin (DUBA), which binds to and alkylates DNA based on the drug's mechanism of action. FIG. 1B is a schematic diagram of an exemplary covalently linked tetravalent diabody, e.g., a PD-1 x CTLA-4 bispecific diabody, having four epitope-binding sites comprised of two pairs of polypeptide chains (i.e., four total polypeptide chains). One polypeptide of each pair has an E-coil Heterodimer-Promoting Domain, and the other polypeptide of each pair has a K-coil Heterodimer-Promoting Domain. As shown, cysteine ​​residues may be present in the linker and / or in the Heterodimer-Promoting Domain. One polypeptide of each pair has a linker that includes a cysteine ​​(which may include all or a portion of the hinge region), and a CH2 and / or CH3 Domain, such that the joined chains form all or a portion of an Fc region. VL and VH Domains that recognize the same epitope are shown using the same shading or fill pattern. The VL and VH Domains recognize different epitopes, and the resulting molecule has four epitope-binding sites and is bispecific and bivalent for each epitope that it binds. [Diagram 2]Figure 2 shows the results of a study comparing the efficacy of single and split doses of MGC018 in mediating in vivo cytotoxicity against Calu-6 lung cancer cells implanted subcutaneously in a CD-1 nude mouse model. Tumor growth curves are presented for mice treated intravenously with a single dose of 12 mg / kg MGC018 (QWx1, dotted arrow) or with split doses of MGC018 (0.3 mg / kg, 1 mg / kg, or 3 mg / kg) administered once weekly for 4 weeks (QWx4, solid arrow). Vehicle was used as a negative control and was administered only on day 21. [Diagram 3] Figures 3A-3F show the results of a study comparing the efficacy of single and split doses of MGC018 in mediating in vivo cytotoxicity against A375.S2 melanoma cells (Figures 3A and 3B), Calu-6 lung cancer cells (Figures 3C and 3D), or MDA-MD-468 triple-negative breast cancer cells (Figures 3E and 3F) implanted subcutaneously in a CES1c knockout mouse model. Tumor growth curves are presented for mice treated intravenously with a single dose of MGC018 (1 mg / kg or 3 mg / kg; QW x 1) (Figures 3A, 3C, and 3E) or with split doses of MGC018 (0.3 mg / kg or 1 mg / kg) administered once a week for 4 weeks (QW x 4) (Figures 3B, 3D, and 3F). Vehicle was used as a negative control and was administered only on the first dosing day. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0110] Some of the disclosure relates to dosing regimens for administering B7-H3-ADC for the treatment of cancer, including, for example, cancers associated with expression of B7-H3. In certain embodiments, the disclosure can include administration of a single dose or split doses (i.e., two or more separate doses) of B7-H3-ADC. In certain embodiments, the disclosure relates to the use of the above-described B7-H3-ADC in combination with a PD-1 x CTLA-4 bispecific molecule for the treatment of cancer. A dosing regimen for administering a B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule for the treatment of cancer can include administration at regular or intermittent dosing intervals. In certain embodiments, a dosing regimen for administering a B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule for the treatment of cancer can include administration of a single dose or a split dose (i.e., two or more separate doses) of B7-H3-ADC. In certain embodiments, administration of the B7-H3-ADC and the PD-1×CTLA-4 bispecific molecule can be simultaneous or sequential in any order. In certain embodiments, the B7-H3-ADC is MGC018. In certain embodiments, the PD-1×CTLA-4 bispecific molecule is lorigellimab. The present disclosure is directed in certain aspects to the use of such molecules, as well as pharmaceutical compositions and kits that contain such molecules and facilitate the use of such dosing regimens in the treatment of cancer.

[0111] I. Antibodies and Their Binding Domains The antibodies of the present disclosure are immunoglobulin molecules that can specifically bind to targets such as carbohydrates, polynucleotides, lipids, polypeptides, etc., by at least one antigen recognition site located in the variable domain of the immunoglobulin molecule. Thus, B7-H3-ADC includes antibodies that bind to B7-H3. As used herein, the terms "antibody" and "antibodies" include monoclonal antibodies, multispecific antibodies, human antibodies, humanized antibodies, synthetic antibodies, chimeric antibodies, polyclonal antibodies, camelized antibodies, single chain Fvs (scFvs), single chain antibodies, Fab fragments, F(ab') fragments, disulfide-linked bispecific Fvs (sdFvs), intrabodies, and epitope-binding fragments of any of the above. In particular, the term "antibody" includes immunoglobulin molecules and immunologically active fragments of immunoglobulin molecules, i.e., molecules that contain an epitope-binding site. Immunoglobulin molecules can be of any type (e.g., IgG, IgE, IgM, IgD, IgA, and IgY), class (e.g., IgG1, IgG2, IgG3, IgG4, IgA1, and IgA2), or subclass. Antibodies can "immunospecifically bind" to (or bind in an "immunospecific manner" to) polypeptides or protein or non-protein molecules because of the presence of a particular domain or portion or form (an "epitope") on such molecules. Epitope-containing molecules can have immunological activity, thereby eliciting an antibody production response in an animal. Such molecules are called "antigens."

[0112] As used herein, an antibody, diabody, or other epitope-binding molecule is said to "immunospecifically" bind to a region (i.e., epitope) of another molecule if it reacts or binds to the epitope more frequently, more rapidly, for longer, and / or with higher affinity than other epitopes. For example, an antibody that immunospecifically binds to a viral epitope is an antibody that binds to the viral epitope with higher affinity, higher avidity, more readily, and / or for longer than it immunospecifically binds to other viral or non-viral epitopes. It is understood by reading this definition that, for example, an antibody (or moiety or epitope) that immunospecifically binds to a first target may or may not specifically or preferentially bind to a second target. Thus, "immunospecific binding" does not necessarily require (but can include) exclusive binding. Generally, but not necessarily, references to binding refer to "immunospecific" binding. Two molecules are said to be capable of binding to one another in a "physiospecific" manner if such binding exhibits specificity in the binding of receptors to their respective ligands.

[0113] The term "monoclonal antibody" refers to a homogeneous population of antibodies, which are composed of amino acids (naturally occurring or non-naturally occurring) involved in the selective binding of an antigen. Monoclonal antibodies are highly specific, being directed against a single epitope (or antigenic site). The term "monoclonal antibody" encompasses intact and full-length monoclonal antibodies, as well as fragments thereof (Fab, Fab', F(ab')2, Fv, etc.), single chain (scFv) binding molecules, variants thereof, fusion proteins containing antibody portions, humanized monoclonal antibodies, chimeric monoclonal antibodies, and any other modified configuration of an immunoglobulin molecule that contains an antigen recognition site with the requisite specificity and ability to bind to the antigen. No limitation is intended as to the source of the antigen or the manner in which it is made (e.g., by hybridoma, phage selection, recombinant expression, transgenic animals, etc.). The term includes whole immunoglobulins, as well as fragments such as those described above in the definition of "antibody". Methods for producing monoclonal antibodies are known in the art. One method that may be employed is that of Kohler, G. et al. (1975) "Continuous Cultures Of Fused Cells Secreting Antibody Of Predefined Specificity," Nature 256:495-497, or a modification thereof. Typically, monoclonal antibodies are raised in mice, rats, or rabbits. The antibodies are generated by immunizing animals with an immunogenic amount of cells, cell extracts, or protein preparations containing the desired epitope. The immunogen can be, but is not limited to, primary cells, cultured cell lines, cancer cells, proteins, peptides, nucleic acids, or tissues. Alternatively, existing monoclonal antibodies and other equivalent antibodies that are immunospecific for the desired pathogenic epitope can be recombinantly sequenced and generated by any means known in the art. In one embodiment, such antibodies are sequenced and the polynucleotide sequence is then cloned into a vector for expression or propagation.The sequence encoding the antibody of interest is maintained in a vector in a host cell, which can then be expanded and frozen for future use. Such antibody polynucleotide sequences are used for genetic engineering to improve the affinity or other characteristics of the antibody by generating monospecific or multispecific (e.g., bispecific, trispecific and tetraspecific) molecules, as well as affinity-optimized chimeric, humanized and / or caninized antibodies. The general principle of humanizing an antibody involves replacing the non-human remainder of the antibody with human antibody sequences while retaining the base sequence of the antigen-binding portion of the antibody, and is known in the art. See, e.g., U.S. Pat. Nos. 4,816,567; 5,807,715; 5,866,692; 5,997,867; 6,054,297; 6,180,377; 6,331,415; and European Patent No. 519,596.

[0114] Natural antibodies (such as IgG antibodies) consist of two "light chains" complexed with two "heavy chains". Each light chain contains a variable domain ("VL") and a constant domain ("CL"). Each heavy chain contains a variable domain ("VH"), three constant domains ("CH1", "CH2" and "CH3"), and a "hinge" region ("H") located between the CH1 and CH2 domains. Thus, the basic structural unit of naturally occurring immunoglobulins (e.g., IgG) is a trimer having two light chains and two heavy chains, usually expressed as a glycoprotein of about 150,000 Da. The amino-terminal ("N-terminal") portion of each chain contains about 100-110 variable domains that play a major role in antigen recognition. The carboxy-terminal ("C-terminal") portion of each chain defines a constant region, with light chains having a single constant domain and heavy chains usually having three constant domains and one hinge domain. Thus, the structure of the light chain of an IgG molecule is n-VL-CL-c and the structure of the IgG heavy chain is n-VH-CH1-H-CH2-CH3-c, where n and c represent the N-terminus and C-terminus of the polypeptide, respectively.

[0115] A. Characterization of Antibody Variable Domains The variable domains of an IgG molecule consist of several complementarity determining regions ("CDRs") that contain the residues in contact with the epitope, and non-CDR segments called framework segments ("FRs"), which generally maintain the structure of the CDR loops and determine the position of the CDRs, thereby enabling such contacts (although certain framework residues may also contact the antigen). Thus, the VL and VH domains have the structure n-FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4-c. The amino acid sequences of the CDRs determine whether an antibody can bind to a particular epitope. The interaction of the antibody light chain with the antibody heavy chain, and in particular the interaction of these VL and VH domains, forms the epitope-binding site of the antibody.

[0116] Amino acids from the mature heavy and light variable domains of immunoglobulins are designated by the position of the amino acid within the chain. Kabat (Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, NH1, MD (1991)) describes numerous amino acid sequences for antibodies, identifies the amino acid consensus sequence for each subgroup, and assigns a residue number to each amino acid, with CDRs and FRs identified as defined by Kabat (CDRs defined by Chothia, C. & Lesk, AM ((1987) "Canonical structures for the hypervariable regions of immunoglobulins," J. Mol. Biol. 196:901-917) H(It should be understood that residue number 1 begins 5 residues earlier). The Kabat numbering scheme can be extended to antibodies not included in the Kabat compendium by aligning the antibody in question with one of the consensus sequences in Kabat, with reference to conserved amino acids. The above method for assigning residue numbers has become standard in the art and readily identifies amino acids at equivalent positions in different antibodies, including chimeric or humanized variants. For example, amino acid at position 50 of a human antibody light chain occupies the equivalent position as amino acid at position 50 of a mouse antibody light chain. Thus, the start and end positions of the CDRs within the VL and VH domains are well defined and can be ascertained by inspection of the sequences of the VL and VH domains (see, for example, Martin, CR (2010) "Protein Sequence and Structure Analysis of Antibody Variable Domains," In: Antibody Engineering Vol. 2 (Kontermann, R. and Dubel, S. (eds.), Springer-Verlag Berlin Heidelberg, Chapter 3 (pages 33-51)).

[0117] Polypeptides which are (or can function as) the first, second and third CDRs of the light chain of an antibody are referred to herein as CDRs L 1 domain, CDR L 2 Domains and CDRs L Similarly, polypeptides which are (or can function as) the first, second and third CDRs of an antibody heavy chain are referred to herein as CDR 3 domains, respectively. H 1 domain, CDR H 2 Domains and CDRs H 3 domains. Therefore, CDR L 1 domain, CDR L 2 domains, CDR L 3 domains, CDR H 1 domain, CDR H 2 domains and CDRsH The term three domains refers to polypeptides that, when incorporated into a protein, enable the protein to bind to a specific epitope, whether the protein is an antibody having a light and heavy chain or a diabody or a single-chain binding molecule (e.g., scFv, BiTe, etc.), or another type of protein. Thus, as used herein, the term "epitope-binding fragment" refers to a fragment of a molecule that can immunospecifically bind to an epitope. An epitope-binding fragment may contain one, two, three, four or five CDR domains of an antibody, or may contain all six CDR domains of an antibody, and may be capable of immunospecifically binding to such an epitope, but may exhibit an immunospecificity, affinity or selectivity for the epitope that is different from that of such an antibody. In general, an epitope-binding fragment will contain all six of the CDR domains of such an antibody. An epitope-binding fragment of an antibody may be a single polypeptide chain (e.g., scFv) or may comprise two or more polypeptide chains, each having an amino terminus and a carboxy terminus (e.g., diabodies, Fab fragments, Fab2 fragments, etc.). Unless specified, the order of domains of protein molecules described herein is in the "N-terminal to C-Terminal" direction.

[0118] The disclosure particularly encompasses single chain variable domain fragments (scFvs) comprising the humanized anti-B7-H3-VL and / or VH domains of the invention. Single chain variable domain fragments comprise the VL and VH domains linked together using a short "linker" peptide. Such linkers can be modified to provide additional functionality, such as allowing attachment of drugs or attachment to a robust support. Single chain variants can be produced recombinantly or synthetically. For synthetic production of scFvs, an automated synthesizer can be used. For recombinant production of scFvs, a suitable plasmid containing a polynucleotide encoding the scFv can be introduced into a suitable host cell, such as a eukaryotic cell, such as a yeast, plant, insect or mammalian cell, or a prokaryotic cell, such as E. coli. A polynucleotide encoding the scFv of interest can be produced by conventional manipulations, such as ligation of polynucleotides. The resulting scFv can be isolated using standard protein purification techniques known in the art.

[0119] B. Characterization of Antibody Constant Domains 1. Light chain constant domain As mentioned above, each light chain of an antibody contains a variable domain ("VL") and a constant domain ("CL").

[0120] A representative CL domain is the human IgG CLκ domain. The amino acid sequence of the human CLκ domain is (SEQ ID NO:1): RTVAAPSVFI FPPSDEQLKS GTASVVCLLN NFYPREAKVQ WKVDNALQSG NSQESVTEQD SKDSTYSLSS TLTLSKADYE KHKVYACEVT HQGLSSPVTK SFNRGEC It is.

[0121] Another representative CL domain is the human IgG CL domain. The amino acid sequence of the human CL domain is (SEQ ID NO:2): QPKAAPSVTL FPPSSEELQA NKATLVCLIS DFYPGAVTVA WKADSSPVKA GVETTPSKQS NNKYAASSYL SLTPEQWKSH RSYSCQVTHE GSTVEKTVAP TECS It is.

[0122] 2. Heavy Chain Constant Domain As mentioned above, the heavy chain of an antibody may comprise a CH1, a hinge domain, a CH2 and a CH3 constant domain. The CH1 domains of the two heavy chains of an antibody are complexed with the CL constant domain of the antibody light chain and are attached to the heavy chain CH2 domain via an intervening hinge domain.

[0123] An exemplary CH1 domain is the human IgG1 CH1 domain. The amino acid sequence of the human IgG1 CH1 domain is (SEQ ID NO:3): ASTKGPSVFP LAPSSKSTSG GTAALGCLVK DYFPEPVTVS WNSGALTSGV HTFPAVLQSS GLYSLSSVVT VPSSSLGTQT YICNVNHKPS NTKVDKRV It is.

[0124] Another representative CH1 domain is the human IgG4 CH1 domain. The amino acid sequence of the human IgG4 CH1 domain is (SEQ ID NO:4): ASTKGPSVFP LAPCSRSTSE STAALGCLVK DYFPEPVTVS WNSGALTSGV HTFPAVLQSS GLYSLSSVVT VPSSSLGTKT YTCNVDHKPS NTKVDKRV It is.

[0125] A representative hinge domain is the human IgG1 hinge domain, the amino acid sequence of which is (SEQ ID NO:5): EPKSCDKTHTCPPCP.

[0126] Another representative hinge domain is the human IgG4 hinge domain. The amino acid sequence of the human IgG4 hinge domain is (SEQ ID NO: 6): ESKYGPPCPSCP. The IgG4 hinge domain may include a stabilizing mutation, such as an S228P substitution. The amino acid sequence of the S228P stabilized human IgG4 hinge domain is (SEQ ID NO: 7): ESKYGPPCPPCP.

[0127] The CH2 and CH3 domains of the two heavy chains of an antibody interact to form the "Fc Domain", which is the domain recognized by cellular Fc receptors, including but not limited to Fcγ receptors (FcγR). As used herein, the term "Fc Domain" is used to define the C-terminal region of an IgG heavy chain. An Fc Domain is referred to as the Fc Domain of an IgG isotype, class or subclass if its amino acid sequence is most identical to that of a particular IgG isotype compared to other IgG isotypes. In addition to their known uses in diagnostics, antibodies have been shown to be useful as therapeutic agents.

[0128] The amino acid sequence of a representative human IgG1 CH2-CH3 domain is (SEQ ID NO:8): 231 240 250 260 270 280 APELLGGPSV FLFPPKPKDT LMISRTPEVT CVVVDVSHED PEVKFNWYVD 290 300 310 320 330 GVEVHNAKTK PREEQYNSTY RVVSVLTVLH QDWLNGKEYK CKVSNKALPA 340 350 360 370 380 PIEKTISKAK GQPREPQVYT LPPSREEMTK NQVSLTCLVK GFYPSDIAVE 390 400 410 420 430 WESNGQPENN YKTTPPVLDS DGSFFLYSKL TVDKSRWQQG NVFSCSVMHE 440 447 ALHNHYTQKS LSLSPG X where X is a lysine (K) or is absent, as numbered according to the EU index as set forth in Kabat.

[0129] The amino acid sequence of a representative human IgG4 CH2-CH3 domain is (SEQ ID NO:9): 231 240 250 260 270 280 APEFLGGPSV FLFPPKPKDT LMISRTPEVT CVVVDVSQED PEVQFNWYVD 290 300 310 320 330 GVEVHNAKTK PREEQFNSTY RVVSVLTVLH QDWLNGKEYK CKVSNKGLPS 340 350 360 370 380 SIEKTISKAK GQPREPQVYT LPPSQEEMTK NQVSLTCLVK GFYPSDIAVE 390 400 410 420 430 WESNGQPENN YKTTPPVLDS DGSFFLYSRL TVDKSRWQEG NVFSCSVMHE 440 447 ALHNHYTQKS LSLSLG X where X is a lysine (K) or is absent, as numbered according to the EU index as set forth in Kabat.

[0130] Throughout this specification, the numbering of residues in the constant region of the IgG heavy chain is based on that of Kabat et al., Sequences of Proteins of Immunological Interest, 5, which is expressly incorporated herein by reference. thThe numbering of the EU index is from the Ed. Public Health Service, NH1, MD (1991). The term "EU index as in Kabat" refers to the numbering of the constant domains of the human IgG1 EU antibody.

[0131] Polymorphisms have been observed at many different positions within antibody constant regions (e.g., Fc positions including but not limited to positions 270, 272, 312, 315, 356 and 358 according to the EU index numbering as set forth in Kabat), and therefore slight differences may exist between the sequences presented here and those of the prior art. Polymorphic forms of human immunoglobulins have been well characterized. Currently, 18 Gm allotypes are known: G1m(1,2,3,17) or G1m(a,x,f,z), G2m(23) or G2m(n), G3m(5,6,10,11,13,14,15,16,21,24,26,27,28) or G3m(b1,c3,b3,b0,b3,b4,s,t,g1,c5,u,v,g5) (Lefranc, et al., The human IgG subclasses: molecular analysis of structure, function and regulation. Pergamon, Oxford, pp. 43-78 (1990); Lefranc, G. et al., 1979, Hum. Genet.: 50, 199-211). In particular, it is believed that the antibodies of the present disclosure can incorporate any allotype, isoallotype, or haplotype of any immunoglobulin gene, and are not limited to the allotype, isoallotype, or haplotype of the sequences presented herein. Furthermore, depending on the expression system, the C-terminal amino acid residue of the CH3 domain (bold above) can be removed post-translationally. Thus, the C-terminal residue of the CH3 domain can be any amino acid residue. Specifically encompassed by the present disclosure are B7-H3-ADCs lacking the C-terminal residue of the CH3 domain. Also specifically encompassed by the present disclosure are structures that include a C-terminal lysine residue of the CH3 domain.

[0132] The present disclosure particularly encompasses B7-H3-ADCs that comprise anti-B7-H3 variable domains (i.e., VL and / or VH domains) that immunospecifically bind to an epitope of a human B7-H3 polypeptide. Such B7-H3-ADCs can immunospecifically bind to human B7-H3. As used herein, the B7-H3 variable domains are referred to as "anti-B7-H3-VL" and "anti-B7-H3-VH," respectively.

[0133] II. Fc Domain Modifications The Fc domain of an Fc domain-containing molecule (e.g., an antibody or diabody) may be a complete Fc domain (e.g., a complete IgG Fc domain), or simply a fragment of an Fc domain. Optionally, the Fc domain of an Fc domain-containing molecule does not include the C-terminal lysine amino acid residue.

[0134] In classical immune function, the interaction of antibody-antigen complexes with cells of the immune system results in a wide range of responses, from effector functions such as antibody-dependent cellular cytotoxicity, mast cell degranulation and phagocytosis, to immunoregulatory signals such as modulation of lymphocyte proliferation and antibody secretion. All these interactions are initiated by binding to specialized cell surface receptors (single termed "Fc gamma receptor", "FcγR", collectively "FcγRs") found on the surface of multiple types of immune system cells (e.g., B lymphocytes, follicular dendritic cells, natural killer cells, macrophages, neutrophils, eosinophils, basophils and mast cells). The diversity of cellular responses triggered by antibodies and immune complexes is afforded by the structural heterogeneity of the three Fc receptors: FcγRI (CD64), FcγRII (CD32) and FcγRIII (CD16). FcγRI (CD64), FcγRIIA (CD32A) and FcγRIII (CD16) are activating (i.e. immune system enhancing) receptors; FcγRIIB (CD32B) is an inhibitory (i.e. immune system attenuating) receptor. Furthermore, interaction with the neonatal Fc receptor (FcRn) mediates the recycling of IgG molecules from endosomes to the cell surface and release into the blood. The amino acid sequences of a representative wild-type IgG1 (SEQ ID NO: 8) and a representative wild-type IgG4 (SEQ ID NO: 9) have been presented previously.

[0135] Modification of the Fc domain may lead to phenotypic changes, such as altered serum half-life, altered stability, altered susceptibility to cellular enzymes, or altered effector functions. Thus, in certain embodiments, the Fc domain of the Fc domain-containing molecule may be an engineered variable Fc domain. The Fc domain of the Fc domain-containing molecule may have the ability to bind to one or more Fc receptors (e.g., one or more FcγRs), but in particular the variant Fc domain has altered binding to FcγRIA (CD64), FcγRIIA (CD32A), FcγRIIB (CD32B), FcγRIIIA (CD16a) or FcγRIIIB (CD16b) (relative to the binding exhibited by the wild-type Fc domain), e.g., enhanced binding to certain activating receptors, and / or reduced or no ability to bind to one or more inhibitory receptors. Thus, the Fc domain of an Fc domain-containing molecule may comprise some or all of the CH2 domain and / or some or all of the CH3 domain of a complete Fc domain, or may comprise a variant CH2 and / or variant CH3 sequence (e.g., which may comprise one or more insertions and / or one or more deletions relative to the CH2 or CH3 domain of the complete Fc domain). Such an Fc domain may comprise non-Fc polypeptide portions, or may comprise a portion of a complete Fc domain that does not occur in nature, or may comprise a non-naturally occurring orientation of the CH2 and / or CH3 domain (e.g., two CH2 domains or two CH3 regions, or a CH3 domain linked to a CH2 domain in the N-terminal to C-terminal direction, etc.).

[0136] In certain embodiments, the Fc domain of the binding molecule has reduced (or substantially no) binding to FcγRIA (CD64), FcγRIIA (CD32A), FcγRIIB (CD32B), FcγRIIIA (CD16a) or FcγRIIIB (CD16b) (relative to the binding exhibited by a wild-type IgG1 Fc domain (SEQ ID NO: 8)). In certain embodiments, the binding molecule comprises an IgG Fc domain with reduced ADCC effector function. In such embodiments, the CH2-CH3 domain of the binding molecule comprises any one, two, three or four of the following substitutions: L234A, L235A, D265A, N297Q, and N297G. In another embodiment, the CH2-CH3 domain contains an N297Q substitution, an N297G substitution, an L234A and an L235A substitution, or a D265A substitution, since these mutations abolish FcR binding. Alternatively, the CH2-CH3 domain of a native Fc domain is utilized that has inherently low (or virtually no) binding to FcγRIIIA (CD16a) and / or naturally low effector function (relative to the binding and effector function exhibited by the wild-type IgG1 Fc domain (SEQ ID NO: 8)). In a specific embodiment, the binding molecule comprises an IgG4 Fc domain (SEQ ID NO: 9). When an IgG4 Fc domain is utilized, the present disclosure also encompasses the introduction of stabilizing mutations, such as the hinge domain S228P substitution described herein (see, e.g., SEQ ID NO: 7).

[0137] The serum half-life of a protein containing an Fc domain can be increased by increasing the binding affinity of the Fc domain for FcRn. As used herein, the term "half-life" refers to a pharmacokinetic property of a molecule that is a measure of the average survival time of the molecule after administration. Half-life can be expressed as the time required for fifty percent (50%) of a known amount of the molecule to be cleared from a subject's body (e.g., a human patient or other mammal) or a particular body cavity thereof, as measured in serum (i.e., circulating half-life) or other tissues. In general, an increase in half-life leads to an increase in the mean residence time (MRT) in the circulation of the administered molecule. Modifications that can increase the half-life of Fc domain-containing molecules are known in the art, and include, for example, M252Y, S254T, T256E, and combinations thereof. See, e.g., the modifications described in U.S. Patent Nos. 6,277,375; 7,083,784; 7,217,797; 8,088,376; U.S. Patent Publication Nos. 2002 / 0147311, 2007 / 0148164, and 2011 / 0081347.

[0138] In one embodiment, a non-limiting example of the PD-1 x CTLA-4 bispecific molecule lorigerlimab comprises a mutated IgG4 Fc Region, which comprises a substitution at position 252 with tyrosine, a substitution at position 254 with threonine, and a substitution at position 256 with glutamic acid (252Y, 254T, and 256E), the numbering of which is that of the EU index as set forth in Kabat.

[0139] The mutant IgG4 sequence for the CH2 and CH3 domains containing the M252Y / S254T / T256E substitutions is (SEQ ID NO: 14): APEFLGGPSV FLFPPKPKDT L Y I T R E PEVT CVVVDVSQED PEVQFNWYVD GVEVHNAKTK PREEQFNSTY RVVSVLTVLH QDWLNGKEYK CKVSNKGLPS SIEKTISKAK GQPREPQVYT LPPSQEEMTK NQVSLTCLVK GFYPSDIAVE WESNGQPENN YKTTPPVLDS DGSFFLYSRL TVDKSRWQEG NVFSCSVMHE ALHNHYTQKS LSLSLG X and X is a lysine (K) or is absent.

[0140] III. Anti-B7-H3 antibody mAb-A A representative anti-B7-H3 antibody, designated "mAb-A," was isolated from hybridoma cells generated by immunization with cells expressing human B7-H3, a B7-H3 polypeptide, or a peptide epitope thereof. Antibody mAb-A was humanized.

[0141] The antibody mAb-A was found to be cross-reactive to B7-H3 in cynomolgus monkeys. The amino acid sequences of the VL and VH domains of mAb-A are provided below. B7-H3-ADC contains all three CDRs of the VH domain of humanized monoclonal antibody mAb-A ("hmAb-A"). H , all three CDRs of the VL domain L , and optionally the entire VH and VL domains.

[0142] A. Mouse anti-B7-H3 antibody mAb-A The amino acid sequence of the VL domain of mouse anti-B7-H3 antibody mAb-A (SEQ ID NO: 15) is shown below (CDR L Residues are underlined): DIQMTQSPAS LSVSVGETVT ITC RASESIY SYLA WYQQKQ GKSPQLLVY N TKTLPE GVPS RFSGSGSGTQ FSLKINSLQP EDFGRYYC QH HYGTPPWT FG GGTNLEIK

[0143] The amino acid sequence of the VH domain of anti-B7-H3 mAb-A (SEQ ID NO: 16) is shown below (CDR H Residues are underlined): EVQQVESGGD LVKPGGSLKL SCAASGFTFS SYGMS WVRQT PDKRLEWVA T INSGGSNTYY PDSLKG RFTI SRDNAKNTLY LQMRSLKSED TAMYYCAR HD GGAMDY WGQGTSVTVSS

[0144] B. Humanized anti-B7-H3 antibody hmAb-A The variable domains of anti-B7-H3 antibody mAb-A were humanized to generate humanized mAb-A ("hmAb-A"). In some instances, alternative humanized variable domains may be generated to optimize binding activity and / or to remove antigenic epitopes and / or to remove potentially unstable amino acid residues.

[0145] The amino acid sequence of the VL domain of hmAb-A (SEQ ID NO: 17) is shown below (CDR L Residues are underlined): DIQMTQSPSS LSASVGDRVT ITC RASESIY SYLA WYQQKP GKAPKLLVY N TKTLPE GVPS RFSGSGSGTD FTLTISSLQP EDFATYYC QH HYGTPPWT FG QGTRLEIK

[0146] The amino acid sequence of the light chain of hmAb-A (SEQ ID NO: 19), including the VL domain and the CLκ domain of hmAb-A, is shown below: DIQMTQSPSS LSASVGDRVT ITCRASESIY SYLAWYQQKP GKAPKLLVYN TKTLPEGVPS RFSGSGSGTD FTLTISSLQP EDFATYYCQH HYGTPPWTFG QGTRLEIKRT VAAPSVFIFP PSDEQLKSGT ASVVCLLNNF YPREAKVQWK VDNALQSGNS QESVTEQDSK DSTYSLSSTL TLSKADYEKH KVYACEVTHQ GLSSPVTKSF NRGEC

[0147] In SEQ ID NO:19, amino acid residues 1-108 correspond to the VL domain of hmAb-A (SEQ ID NO:17), and amino acid residues 109-215 correspond to the light chain kappa constant region (SEQ ID NO:1).

[0148] The amino acid sequence of the VH domain of hmAb-A (SEQ ID NO: 18) is shown below (CDR H Residues are underlined): EVQLVESGGG LVKPGGSLRL SCAASGFTFS SYGMS WVRQA PGKGLEWVA T INSGGSNTYY PDSLKG RFTI SRDNAKNSLY LQMNSLRAED TAVYYCAR HD GGAMDY WGQG TTVTVSS

[0149] The amino acid sequence of the heavy chain (SEQ ID NO:20), including the VH domain and the IgG1 CH1-H-CH2-CH3 domain of hmAb-A, is shown below: EVQLVESGGG LVKPGGSLRL SCAASGFTFS SYGMSWVRQA PGKGLEWVAT INSGGSNTYY PDSLKGRFTI SRDNAKNSLY LQMNSLRAED TAVYYCARHD GGAMDYWGQG TTVTVSSAST KGPSVFPLAP SSKSTSGGTA ALGCLVKDYF PEPVTVSWNS GALTSGVHTF PAVLQSSGLY SLSSVVTVPS SSLGTQTYIC NVNHKPSNTK VDKRVEPKSC DKTHTCPPCP APELLGGPSV FLFPPKPKDT LMISRTPEVT CVVVDVSHED PEVKFNWYVD GVEVHNAKTK PREEQY N STY RVVSVLTVLH QDWLNGKEYK CKVSNKALPA PIEKTISKAK GQPREPQVYT LPPSREEMTK NQVSLTCLVK GFYPSDIAVE WESNGQPENN YKTTPPVLDS DGSFFLYSKL TVDKSRWQQG NVFSCSVMHE ALHNHYTQKS LSLSPG X X is a lysine (K) or is absent.

[0150] In SEQ ID NO:20, amino acids 1-117 correspond to the VH domain of hmAb-A (SEQ ID NO:18), amino acid residues 118-215 correspond to the IgG1 CH1 domain (SEQ ID NO:3), amino acid residues 216-230 correspond to the IgG1 hinge domain (SEQ ID NO:5), and amino acid residues 231-447 correspond to the IgG1 CH2-CH3 domain (SEQ ID NO:8). An N-linked glycosylation site is present at Kabat position 296 (shown underlined). The C-terminal residue "X" is either lysine (K) or absent.

[0151] IV. B7-H3-ADC The present disclosure relates to the above-mentioned anti-B7-H3 antibody hmAb-A conjugated to a cytotoxic drug "B7-H3-ADC". B7-H3-ADC as described above enhances the cytotoxicity of anti-B7-H3 therapy, particularly in the treatment of cancer. As described above, B7-H3-ADC has the following formula: Ab‐(LM)m -(D) n Represented by: The Ab is an antibody that binds to B7-H3 comprising a humanized variable heavy (VH) domain and a humanized variable light (VL) domain, or a B7-H3-binding fragment thereof; D is a cytotoxic duocarmycin moiety; LM is a linker or linker molecule covalently linking Ab and D; m is an integer from 0 to n, representing the number of bonds or linker molecules in the B7-H3-ADC, except that m is not 0 when LM is one bond; n is an integer from 1 to 10 and represents the number of said cytotoxic duocarmycin moieties covalently attached to said B7-H3-ADC.

[0152] In certain embodiments, B7-H3-ADC comprises a naturally occurring Fc domain of the IgG1 isotype. Such an Fc domain does not include the C-terminal lysine residue of the CH3 domain. In specific embodiments, B7-H3-ADC binds to tumor cells expressing B7-H3 and is internalized into the cells by receptor-mediated endocytosis. Once inside the lysosome, B7-H3-ADC can degrade, causing release of the cytotoxic duocarmycin moiety within the cell, resulting in cell death. As will be appreciated, the mechanism of action of this cell death can vary based on the class of cytotoxic drug used (e.g., disruption of cytokinesis with tubulin polymerization inhibitors such as maytansine and auristatin, DNA damage with DNA interacting agents such as calicheamicin and duocarmycin), etc. Adjacent cancer cells can also be killed when free drug is released into the tumor environment by dying cells in a process known as the bystander effect (Panowski, S. et al. (2014) "Site-Specific Antibody Drug Conjugates For Cancer Therapy," mAbs 6(1):34-45; Kovtun, YV et al. (2006) "Antibody-Drug Conjugates Designed To Eradicate Tumors With Homogeneous And Heterogeneous Expression Of The Target Antigen," Cancer Res. 66:3214-3221).

[0153] A. Linker Molecules of the Invention Thus, the present disclosure specifically contemplates B7-H3-ADCs as described above in which LM is a linker molecule and is absent (i.e., m=0), and B7-H3-ADCs having two or more linker molecules LM (i.e., m is an integer from 2 to n and n is an integer from 2 to 10), each linker molecule LM covalently linking a cytotoxic duocarmycin moiety D and Ab of the B7-H3-ADC.

[0154] The disclosure further provides a B7-H3-ADC in which Ab is covalently linked to two or more linker molecules LM, all of which are identical as described above. The cytotoxic duocarmycin moieties D covalently linked to Ab of the B7-H3-ADC as described above may all be identical or may comprise two, three, four, five or more individually distinct cytotoxic duocarmycin moieties D.

[0155] The disclosure further provides a B7-H3-ADC as described above, in which Ab is covalently linked to two or more linker molecules LM, and where such linker molecules may be individually different. The cytotoxic duocarmycin moieties D covalently linked to Ab of the B7-H3-ADC as described above may all be the same or may comprise two, three, four or five or more individually different cytotoxic duocarmycin moieties D.

[0156] Humanized VH and VL domains of antibodies that bind to human B7-H3, as well as human antibody constant domains that may be included in B7-H3-ADCs, have been presented. As described above, B7-H3-ADCs further comprise at least one cytotoxic duocarmycin moiety that is covalently linked to an atom of the side chain of an amino acid residue of the VH or VL domain and / or constant domain as described above, either directly or via a linker molecule inserted between the side chain atom and the duocarmycin moiety. The linker molecule may be a non-peptide molecule, or a molecule that includes a non-peptide portion and a peptide portion, or the linker molecule may be a molecule that consists only of amino acid residues. The amino acid residues of any such linker molecule may contain naturally occurring or non-naturally occurring amino acid residues, including D versions of naturally occurring amino acid residues, p-acetylphenylalanine, selenocysteine, and the like. Optionally, or in addition, specific residues having desired side chains (e.g., -CH-SH side chain, -CH-OH side chain, -CH(CH)-SH side chain, -CH-CH-S-CH side chain, -CH-C(O)-NH side chain, -CH-CH-C(O)-NH side chain, -CH-C(O)OH-side chain, CH-CH-C(O)OH-side chain, -CH-CH-CH-CH-NH side chain, -CH-CH-CH-NH-C(NH) side chain, imidazole side chain, benzyl side chain, phenol side chain, indole side chain, etc.) may be incorporated into B7-H3-ADC.

[0157] The linker molecule LM may be non-cleavable under physiological conditions and may comprise a hydrolytically stable moiety, such as, for example, a thioether linker or a hindered disulfide linker. A hydrolytically stable linker is generally stable in water and does not react with water at useful pH values, including, but not limited to, under physiological conditions over an extended period of time. In contrast, a hydrolytically unstable or degradable linker will degrade in water or in aqueous solutions, including, for example, blood.

[0158] Alternatively, the linker molecule LM may be cleavable or may contain a cleavable moiety. Examples of such cleavable moieties include acid-labile linkers (e.g., 4-(4'-acetylphenoxy)butanoic acid linkers that form hydrazine bonds), cleavable disulfide linkers (cleaved in the reducing intracellular environment), and protease-cleavable linkers. An acid-labile linker means that it is stable at pH levels encountered in blood, but becomes unstable and breaks down when it encounters the low pH environment in lysosomes. And a protease-cleavable linker means that it is stable in blood / plasma, but rapidly releases free drug in lysosomes in cancer cells upon cleavage by lysosomal enzymes (Panowski, S. et al. (2014) "Site-Specific Antibody Drug Conjugates For Cancer Therapy," mAbs 6(1):34-45). Alternatively, the linker molecule may be or contain an enzyme-cleavable substrate, such as a cleavable peptide (e.g., a valine-citrulline dipeptide para-aminobenzyl alcohol linker (cAC10-mc-vc-PABA) that is selectively cleaved by lysosomal enzymes).Suitable cleavable linkers are known in the art and are described, for example, in de Groot, Franciscus MH, et al. (2002) "Design, Synthesis, and Biological Evaluation of a Dual Tumor-Specific Motive Containing Integrin-Targeted Plasmin-Cleavable Doxorubicin Prodrug," Molecular Cancer Therapeutics, 1: 901-911; Dubowchik et al., (2002) "Doxorubicin Immunoconjugates Containing Bivalent, Lysosomally-Cleavable Dipeptide Linkages." Bioorganic & Medicinal Chemistry See Letters 12:1529-1532; U.S. Patent No. 5,547,667; U.S. Patent No. 6,214,345; U.S. Patent No. 7,585,491; U.S. Patent No. 7,754,681; U.S. Patent No. 8,080,250; U.S. Patent No. 8,461,117; and WO 02 / 083180.

[0159] Enzyme-labile or degradable linkers can be employed. Such linkers are degraded by one or more enzymes. By way of example only, PEG and related polymers can include one or more degradable linker molecules within the polymer backbone or within the linker group between the polymer backbone and one or more of the terminal functional groups of the polymer molecule. Such one or more degradable linker molecules include, but are not limited to, ester bonds formed by the reaction of PEG carboxylic acids or activated PEG carboxylic acids with alcohol groups on the bioactive agent, such ester groups typically hydrolyze under physiological conditions to release the bioactive agent. Other hydrolytically degradable linker molecules include, but are not limited to: carbonate linkages; imine linkages resulting from the reaction of an amine with an aldehyde; phosphate linkages formed by the reaction of an alcohol with a phosphate group; hydrazone linkages which are the reaction product of hydrazine with an aldehyde; acetal linkages which are the reaction product of an aldehyde with an alcohol; orthoester linkages which are the reaction product of formic acid with an alcohol; peptide linkages formed by an amine group, including but not limited to, at the terminus of a polymer, such as PEG, and a carboxyl group of a peptide; and oligonucleotide linkages formed by a phosphoramidite group, including but not limited to, at the terminus of a polymer, and a 5' hydroxyl group of an oligonucleotide.

[0160] In one embodiment, the linker molecule LM is a cleavable linker molecule V-(W) as disclosed in WO 02 / 083180. k -(X)1-A, which has the following formula: Ab‐[V‐(W) k -(X)1-A]-D 4, resulting in a B7-H3-ADC having: V is any cleavable moiety; (W) k -(X)1-A is an elongated self-erasing spacer system that self-erases by l,(4+2n) erasure; W and X are each a 1,(4+2n)-electron cascade spacer, which may be the same or different; A is a group represented by the formula (Y) m where Y is an 1,(4+2n) electron cascade spacer, or a group of formula U, which is a cyclization elimination spacer; k, 1, and m are independently integers from 0 to 5, inclusive; n is an integer from 0 to 10, inclusive; however: A is (Y) m if k+l+m≧1; If k+l+m=l then n>l; If A is U, then k+1>=1; W, X and Y are independently represented by the following formula: [ka] or the following formula: [ka] wherein the compound is selected from compounds having the formula: Q is -R 5 C=CR 6 -, S, O, NR 5 , -R 5 C=N- or -N=CR 5 - is; P is NR 7 , O or S; a, b and c are independently integers from 0 to 5, inclusive; I, F and G are independently selected from the formula: [ka] wherein the compound is selected from compounds having the formula: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independent of each other, H, C1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C 1-6 Alkoxy, hydroxy (OH), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2) and phosphate (OP(=O)(OR x )2), where: R x , R x 1 and R x 2 is independent, C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; The above-mentioned substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 or R 9 two or more of which are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures; U is a group represented by the formula: [ka] wherein the compound is selected from compounds having the formula: a, b and c are independently selected to be integers of 0 or 1; where a+b+c=2 or 3; R 1 and / or R 2 are independent of each other, H, C 1-6 represents an alkyl group, said alkyl group optionally containing the following groups: hydroxy (OH), ether (OR x ), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxy (S(=O)OH), sulfinate (S(=O)ORx), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2), and phosphate (OP(=O)(OR x )2) where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independent of each other, H, C 1-6 Alkyl, C 3-20Heterocyclyl, C 5-20 Aryl, C 1-6 Alkoxy, hydroxy (OH), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2), and phosphate (OP(=O)(OR x )2), where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl group, the substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , or R 8 Two or more of are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures.

[0161] In embodiments, the LM linker molecule includes: p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; p-aminocinnamyloxycarbonyl; p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl; p-amino-benzyloxycarbonyl-p-aminocinnamyloxycarbonyl; p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl; p-aminophenylpentadienyloxycarbonyl; p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyloxycarbonyl; p-aminophenylpentadienyloxycarbonyl-p-aminobenzyloxycarbonyl; p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyloxycarbonyl; p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; p-aminobenzyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)-carbonyl; p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; p-aminobenzyloxycarbonyl-p-aminobenzyl; p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyl; p-aminocinnamyl; p-aminocinnamyloxycarbonyl-p-aminobenzyl; p-aminobenzyloxycarbonyl-p-aminocinnamyl; p-amino-cinnamyloxycarbonyl-p-aminocinnamyl; p-aminophenylpentadienyl; p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyl; p-aminophenylpentadienyloxycarbonyl-p-aminobenzyl; and Examples thereof include p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyl.

[0162] In some embodiments, a B7-H3-ADC comprises 2, 3, 4, 5, 6, 7, 8, 9, or 10 cytotoxic duocarmycin moieties, which may be identical or, individually, may be identical to or different from another cytotoxic duocarmycin moiety of the B7-H3-ADC. In one embodiment, each such cytotoxic duocarmycin moiety is conjugated to the Ab of the B7-H3-ADC via a separate linker molecule. Alternatively, two or more cytotoxic duocarmycin moieties may be attached to the Ab of the B7-H3-ADC via the same linker molecule.

[0163] The cytotoxic duocarmycin moiety may be conjugated to the Ab of B7-H3-ADC by means known in the art (see, e.g., Yao, H. et al. (2016) "Methods to Design and Synthesize Antibody-Drug Conjugates (ADC)," Intl. J. Molec. Sci. 17(194):1-16; Behrens, CR et al. (2014) "Methods For Site-Specific Drug Conjugation To Antibodies," mAbs 6(1):46-53; Bouchard, H. et al. (2014) "Antibody-Drug Conjugates - A New Wave Of Cancer Drugs," Bioorganic & Medicinal Chem. Lett 24:5357-5363). The linker molecule-cytotoxic duocarmycin moiety (LM-D) can be conjugated to the Ab of B7-H3-ADC using the thiol group of cysteine, the amino side groups of lysine, glutamine or arginine, or the carboxyl groups of glutamic or aspartic acid. Native antibodies contain multiple lysine conjugation sites, and therefore multiple conjugated molecules can be linked per antibody. In fact, peptide mapping has been determined in which conjugation occurs at approximately 20 different lysine residues in both the heavy and light chains (40 lysines per mAb). Thus, more than one million different ADC species can be generated. Cysteine ​​conjugation occurs after reduction of one to four interchain disulfide bonds, so this conjugation is limited to the eight exposed sulfhydryl groups in the native VL and VH domains. However, if desired, additional reactive (e.g., lysine, cysteine, selenocysteine, etc.) residues can be incorporated into the antibody (e.g., within the VL and / or VH domains and / or constant domains). For example, one or more native amino acid residues can be substituted with a cysteine ​​residue.Unnatural amino acids (e.g., p-acetylphenylalanine) may be genetically incorporated into antibodies using amber stop codon suppressor tRNA / aaRS pairs (see, e.g., Behrens CR, and Liu B. (2014) "Methods For Site-Specific Drug Conjugation To Antibodies," mAbs 6(1):46-53. doi:10.4161 / mabs.26632; Panowksi, S., et al. (2014) "Site-Specific Antibody Drug Conjugates For Cancer Therapy," mAbs, 6(1), 34-45, doi:10.4161 / mabs.27022; and WO 2008 / 070593). Alternatively, or in addition, an enzyme (e.g., glycotransferase) may be used to conjugate the linker molecule-cytotoxic duocarmycin moiety (LM-D) to the Ab of the B7-H3-ADC. The glycotransferase platform attaches a sugar moiety to a glycosylation site on the antibody (e.g., the N297 position of the Fc domain of a human IgG antibody), which can act as a linker molecule to conjugate the cytotoxic duocarmycin moiety (D) to the Ab of the B7-H3-ADC. Alternatively, a transglutaminase may be used to catalyze the formation of a covalent bond between a free amino group and a glutamine side chain.

[0164] An exemplary transglutaminase is the commercially available transglutaminase (mTG) from Streptoverticillium mobaraense (Pasternack, R. et al. (1998) "Bacterial Pro-Transglutaminase From Streptoverticillium mobaraense - Purification, Characterisation And Sequence Of The Zymogen," Eur. J. Biochem. 257(3):570-576; Yokoyama, K. et al. (2004) "Properties And Applications Of Microbial Transglutaminase," Appl. Microbiol. Biotechnol. 64:447-454). This enzyme does not recognize any naturally occurring glutamine residues in the Fc domain of glycosylated antibodies, but rather recognizes the tetrapeptide LLQL (SEQ ID NO:21), which can be incorporated into the VL and / or VH and / or constant domains (Jeger, S. et al. (2010) "Site-Specific And Stoichiometric Modification Of Antibodies By Bacterial Transglutaminase," Angew Chem. Int. Ed. Engl. 49:9995-9997). Such considerations are reviewed by Panowski, S. et al. (2014) "Site-Specific Antibody Drug Conjugates For Cancer Therapy," mAbs 6(1):34-45.

[0165] B. Duocarmycin moiety Duocarmycins are members of a series of related natural products originally isolated from microorganisms of the genus Streptomyces and are potent antitumor antibiotics (Dokter, W. et al. (2014) “Preclinical Profile of the HER2‐Targeting ADC SYD983 / SYD985: Introduction of a New Duocarmycin‐Based Linker‐Drug Platform,” Mol. Cancer Ther. 13(11):2618‐2629; Boger, DL et al. (1991). “Duocarmycins ‐ A New Class Of Sequence Selective DNA Minor Groove Alkylating Agents,” Chemtracts: Organic Chemistry 4 (5): 329‐349 (1991); Tercel et al. (2013) “The Cytotoxicity Of Duocarmycin Analogues Is Mediated Through Alkylation Of DNA, Not Aldehyde Dehydrogenase 1: A Comment,” Chem. Int. Ed. Engl. 52(21):5442‐5446; Boger, DL et al. (1995) “CC‐1065 And The Duocarmycins: Unraveling The Keys To A New Class Of Naturally Derived DNA Alkylating Agents,” Proc. Natl. Acad. Sci. (USA) 92(9):3642‐3649; Cacciari, B. et al. (2000) “CC‐1065 And The Duocarmycins: Recent Developments,” Expert Opinion on Therapeutic Patents 10(12):1853‐1871).

[0166] The naturally occurring duocarmycins include duocarmycin A, duocarmycin B1, duocarmycin B2, duocarmycin C1, duocarmycin C2, duocarmycin D, duocarmycin SA, and CC-1065 (WO 2010 / 062171; Martin, DG et al. (1980) "Structure Of CC-1065 (NSC 298223), A New Antitumor Antibiotic," J. Antibiotics 33:902-903; Boger, DL et al. (1995) "CC-1065 And The Duocarmycins: Unraveling The Keys To A New Class Of Naturally Derived DNA Alkylating Agents," Proc. Natl. Acad. Sci. (USA) 92:3642-3649). [ka]

[0167] Suitable synthetic duocarmycin analogs include adozelesin, bizelesin, carzeresin (U-80244), and spiroduocarmycin (spiro-DUBA) (Dokter, W. et al. (2014) "Preclinical Profile of the HER2-Targeting ADC SYD983 / SYD985: Introduction of a New Duocarmycin-Based Linker-Drug Platform," Mol. Cancer Ther. 13(11):2618-2629; Elgersma, RC et al. (2014) "Design, Synthesis, and Evaluation of Linker-Duocarmycin Payloads: Toward Selection of HER2-Targeting Antibody-Drug Conjugate SYD985," Mol. Pharmaceut. 12:1813-1835): [ka]

[0168] Further synthetic duocarmycin analogues include those disclosed in WO 2010 / 062171 and in particular those of the formula: [ka] or a pharma- ceutically acceptable salt, hydrate or solvate thereof, where DB is a DNA-binding moiety: [ka] wherein the group consisting of: R is a leaving group; R 2 , R 2' , R 3 , R 3' , R 4 , R 4' , R 12 and R 19are independently H, OH, SH, NH2, N3, NO2, NO, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, Ra, SR a , S(O)R a , S(O)2R a , S(O)OR a , S(O)2OR a , O.S.(O)R a , OS(O)2R a ,OS(O)OR a ,OS(O)2OR a , OR a , N.H.R. a , N(R a )R b , +N(R a )(R b )R c , P(O)(OR a )(OR b ), OP(O)(OR a )(OR b ), SiR a R b R c , C(O)R a , C(O)OR a , C(O)N(R a )R b , O.C.(O)R a , O.C.(O)O.R. a , O.C.(O)N(R a )R b , N(R a )C(O)R b , N(R a )C(O)OR b and N(R a )C(O)N(R b )R c is selected from, where R a , R b and R c are independently H and optionally substituted C 1-3 Alkyl or C 1-3 heteroalkyl, or R 3 +R 3' and / or R 4 +R 4' are independently: =O, =S, =NOR 18 , =C(R 18 )R18' and =NR 18 Selected from R 18 and R 18' are independently H and optionally substituted C 1-3 alkyl; R 2 , R 2' , R 3 , R 3' , R 4 , R 4' and R 12 two or more of are linked by one or more bonds to form one or more optionally substituted carbocyclic and / or heterocyclic rings; X 2 is O, C(R 14 )(R 14' ) and NR 14' is selected from, where R 14 and R 14' is R 7 and are independently selected or R 14' and R 7' is absent, which means that R 7' and R 14' A double bond is provided between the atoms designated to carry the R 5 , R 5' , R 6 , R 6' , R 7 and R 7' are independently H, OH, SH, NH2, N3, NO2, NO, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, R e , S.R. e , S(O)R e , S(O)2R e , S(O)OR e , S(O)2OR e , O.S.(O)R e , OS(O)2R e ,OS(O)OR e ,OS(O)2OR e , OR e , N.H.R. e , N(R e )R f , + N(R e )(Rf )R g , P(O)(OR e )(OR f ), OP(O)(OR e )(OR f ), SiR e R f R g , C(O)R e , C(O)OR e , C(O)N(R e )R f , O.C.(O)R e , O.C.(O)O.R. e , O.C.(O)N(R e )R f , N(R e )C(O)R f , N(R e )C(O)OR f , N(R e )C(O)N(R f )R g and a water-soluble group, R e , R f and R g are independently H and optionally substituted (CH2CH2O) ee CH2CH2X 13 R e1 , C 1-15 Alkyl, C 1-15 Heteroalkyl, C 3-15 Cycloalkyl, C 1-15 Heterocycloalkyl, C 5-15 Aryl or C 1-15 heteroaryl, where ee is selected from 1 to 1000; X 13 is O, S and NR f1 is selected from R f1 and R e1 are independently H and C 1-3 alkyl; R e , R f , and / or R g One or more of the optional substituents of R is optionally a water-soluble group; e , R f and R gtwo or more of are optionally joined by one or more bonds to form one or more optionally substituted carbocyclic and / or heterocyclic rings; Or R 5 +R 5' and / or R 6 +R 6' and / or R 7 +R 7' are independently: =O, =S, =NOR e3 , =C(R e3 )R e4 and =NR e3 , R e3 is selected from R e4 are independently H and optionally substituted C 1-3 alkyl or R 5' +R 6' and / or R 6' +R 7' and / or R 7' +R 14' is absent, which means that R 5' +R 6' and / or R 6' +R 7' and / or R 7' +R 14' A double bond is created between the atoms designated to carry each, R 5 , R 5' , R 6 , R 6' , R 7 , R 7' , R 14 and R 14' two or more of are optionally joined by one or more bonds to form one or more optionally substituted carbocyclic and / or heterocyclic rings; X 1 is selected from O, S and NR, where R is H and optionally substituted C 1-8 Alkyl or C 1-8 heteroalkyl, which is not linked to any other substituents; X 3 is O, S, C(R 15 )R 15' , ‐C(R 15 )(R 15' )‐C(R 15'')(R 15''' )-, -N(R 15 )‐N(R 15' )-, -C(R 15 )(R 15' )‐N(R 15" )-, -N(R 15" )‐C(R 15 )(R 15' )-, -C(R 15 )(R 15' )-O-, -O-C(R 15 )(R 15' )-, -C(R 15 )(R 15' )-S-, -S-C(R 15 )(R 15' )-, -C(R 15 )=C(R 15' )‐, =C(R 15 )‐C(R 15' )=, ‐N=C(R 15' )-, =N-C(R 15' ) = , -C(R 15 )=N-, =C(R 15 )‐N=, ‐N=N‐, =N‐N=, CR 15 , N, N.R. 15 or in DB1 and DB2, -X3- is -X 3a and X 3b - represents, where X 3a isX 34 Connected to X 34 and X 4 There is a double bond between 3b isX 11 where X 3a are independently H and optionally substituted (CH2CH2O) ee CH2CH2X 13 R e1 , C 1-8 Alkyl or C 1-8 heteroalkyl, which is not linked to any other substituents; X 4 is O, S, C(R 16 )R 16' , N.R. 16 , N and CR 16 Selected from; X 5is O, S, C(R 17 )R 17' , NOR 17 and N.R. 17 is selected from, where R 17 and R 17' are independently H and optionally substituted C 1-8 Alkyl or C 1-8 heteroalkyl, which is not linked to any other substituents; X 6 CR 11 , C.R. 11 (R 11' ), N, NR 11 , O and S; X 7 CR 8 , C.R. 8 (R 8' ), N, NR 8 , O and S; X 8 CR 9 , C.R. 9 (R 9' ), N, NR 9 , O and S; X 9 CR 10 , C.R. 10 (R 10' ), N, NR 10 , O and S; X 10 CR 20 , C.R. 20 (R 20' ), N, NR 20 , O and S; X 11 , C, CR 21 and N, or X 11 -X 3b CR 21 , C.R. 21 (R 21' ), N, NR 21 , O and S; X 12 , C, CR 22 and N; X 6* , X 7* , X 8*, X 9* , X 10* and X 11* are X 6 , X 7 , X 8 , X 9 , X 10 and X 11 have the same meaning as defined above with respect to, and may be independently selected; X 34 , C, CR 23 and N; DB6 and DB7 X 11* is connected to a ring atom of ring A, whereby rings A and B of DB6 and DB7 are directly connected by a single bond; A double bond drawn with a dash indicates that the indicated bond is a single bond or means that the double bonds may be optionally delocalized and non-cumulative; R 8 , R 8' , R 9 , R 9' , R 10 , R 10' , R 11 , R 11' , R 15 , R 15' , R 15" , R 15" , R 16 , R 16' , R 20 , R 20' , R 21 , R 21' , R 22 and R 23 are each independently H, OH, SH, NH2, N3, NO2, NO, CF3, CN, C(O)NH2, C(O)H, C(O)OH, halogen, R h , S.R. h , S(O)R h , S(O)2R h , S(O)OR h , S(O)2OR h , O.S.(O)R h , OS(O)2R h ,OS(O)OR h ,OS(O)2OR h , OR h, N.H.R. h , N(R h )R i , + N(R h )(R i )R j , P(O)(OR h )(OR i ), OP(O)(OR h )(OR i ), SiR h R i R j , C(O)R h , C(O)OR h , C(O)N(R h )R i , O.C.(O)R h , O.C.(O)O.R. h , O.C.(O)N(R h )R i , N(R h )C(O)R i , N(R h )C(O)OR i , N(R h )C(O)N(R i )R j and a water-soluble group; R h , R i and R j are independently H and optionally substituted (CH2CH2O) ee CH2CH2X 13 R e1 , C 1-15 Alkyl, C 1-15 Heteroalkyl, C 3-15 Cycloalkyl, C 1-15 Heterocycloalkyl, C 5-15 Aryl or C 1-15 heteroaryl; R h , R i and / or R j Optionally, one or more of the optional substituents of R is a water-soluble group; h , R i and R j two or more of are optionally joined by one or more bonds to form one or more optionally substituted carbocyclic and / or heterocyclic rings; Or, R8 +R 8' and / or R 9 +R 9' and / or R 10 +R 10' and / or R 11 +R 11' and / or R 15 +R 15' and / or R 15" +R 15'" and / or R 16 +R 16' and / or R 20 +R 20' and / or R 21 +R 21' are independently: =O, =S, =NOR h1 , =C(R hl )R h2 and =NR hl Selected from R hl and R h2 are independently H and optionally substituted C 1-3 alkyl; R 8 , R 8' , R 9 , R 9' , R 10 , R 10' , R 11 , R 11' , R 15 , R 15' , R 15" , R 15'" , R 16 , R 20 , R 20' , R 21 , R 21' , R 22 and R 23 two or more of are optionally joined by one or more bonds to form one or more optionally substituted carbocyclic and / or heterocyclic rings; R 8b and R 9b are independently selected and may not be linked to any other substituent, except that R 8 has the same meaning as; R 4 and R 4' One of them and R 16 and R 16'may be optionally linked by one or more bonds to one another to form one or more optionally substituted carbocyclic and / or heterocyclic rings; R 4 and R 4' One of them and R 16 and R 16' may be optionally linked to one of R 2 , R 2' , R 3 and R 3' One of them and R 5 and R 5' may be optionally linked by one or more bonds to one another to form one or more optionally substituted carbocyclic and / or heterocyclic rings; a and b are independently selected from 0 and 1; the DB portion does not include a DAI, DA2, DAI', or DA2' portion; Ring B of DB1 is a heterocycle; DB1X 3 Ga-X 3a and X 3b - and when ring B is aromatic, two adjacent substituents on said ring B are linked to form an optionally substituted carbocyclic or heterocyclic ring fused to said ring B; DB2 X 3 Ga-X 3a and X 3b - and when ring B is aromatic, two adjacent substituents on said ring B are linked to form: an optionally substituted heterocycle fused to said ring B; an optionally substituted non-aromatic carbocycle fused to said ring B; or a substituted aromatic carbocycle fused to said ring B and having attached thereto at least one substituent containing a hydroxy group, a primary amino group or a secondary amino group, wherein said primary or secondary amine is not a ring atom in an aromatic ring system or part of an amide; When ring A of DB2 is a 6-membered aromatic ring, the substituents on ring B are not linked to form a ring fused to ring B; two adjacent substituents on ring A of DB8 are linked to form an optionally substituted carbocyclic or heterocyclic ring which is fused to said ring A to form a bicyclic moiety to which no further rings are fused; Ring A of DB9, together with any rings fused to said ring A, contains at least two heteroatoms.

[0169] The above-mentioned linker molecules can be conjugated to cysteine ​​thiol groups using thiol-maleimide chemistry as shown above. In some embodiments, the cytotoxic duocarmycin moiety is a prodrug. For example, the prodrug vc-seco-DUBA can be conjugated to a self-eliminating moiety attached to a maleimide linker moiety via a cleavable peptide moiety. [ka]

[0170] The maleimide linker moiety of this molecule can be conjugated to the thiol group of a cysteine ​​residue in the VL and / or VH domains and / or constant domains of the Ab portion of B7-H3-ADC. Following proteolytic cleavage of the cleavable peptide moiety, spontaneous elimination of the self-eliminating moiety occurs, leading to the release of seco-duocarmycin (seco-DUBA), which spontaneously rearranges to form the active drug DUBA: [ka] (See Dokter, W. et al. (2014) “Preclinical Profile of the HER2‐Targeting ADC SYD983 / SYD985: Introduction of a New Duocarmycin‐Based Linker‐Drug Platform,” Mol. Cancer Ther. 13(11):2618‐2629)

[0171] A non-limiting method for the production of B7-H3-duocarmycin drug moiety conjugates employs the method of Elgersma, RC et al. (2014) "Design, Synthesis, and Evaluation of Linker-Duocarmycin Payloads: Toward Selection of HER2-Targeting Antibody-Drug Conjugate SYD985," Mol. Pharmaceut. 12:1813-1835, or the method of WO 2011 / 133039. Thus, a thiol-containing group on the VL or VH chain of an anti-B7-H3 antibody or antibody fragment is conjugated to seco-DUBA or other prodrug via a maleimide linker moiety-cleavable peptide moiety-self-eliminating moiety (Scheme 3A): [ka]

[0172] Although the present disclosure is exemplified with respect to DUBA prodrugs, other prodrugs may alternatively be employed, such as CC-1065, as shown in Scheme 3B. [ka]

[0173] After cleavage of the cleavable peptide moiety and elimination of the self-eliminating moiety, the prodrug moiety is believed to undergo Winstein spirocyclization to yield the active drug (e.g., from seco-DUBA (seco-duocarmycin, i.e., the prodrug) to DUBA (also referred to herein as spiro-DUBA or spiro-duocarmycin) as shown in Scheme 3C). [ka]

[0174] Seco-DUBAs are prepared from the corresponding DNA alkylating and DNA binding moieties (e.g., the 1,2,9,9a-tetrahydrocyclopropa-[c]benzo[e]indol-4-one scaffold as described in Elgersma, RC et al. (2014) “Design, Synthesis, and Evaluation of Linker-Duocarmycin Payloads: Toward Selection of HER2-Targeting Antibody-Drug Conjugate SYD985,” Mol. Pharmaceut. 12:1813-1835) (Boger, DL et al. (1989) “Total Synthesis and Evaluation of (±)-N-(tert-Butoxycarbonyl)-CBI, (±)-CBI-CDPI1, and (±)-CBI-CDPI2: CC-1065 Functional Agents Incorporating the Equivalent 1,2,9,9a‐Tetrahydrocyclopropa[1,2‐c]benz[1,2‐e]indol‐4‐one (CBI) Left‐Hand Subunit,” J. Am. Chem. Soc. 111:6461‐6463; Boger, DL et al. (1992) “DNA Alkylation Properties of Enhanced Functional Analogs of CC‐1065 Incorporating the 1,2,9,9a-Tetrahydrocyclopropa[1,2-c]benz[1,2-e]indol-4-one (CBI) Alkylation Subunit,” J. Am. Chem. Soc. 114:5487-5496).

[0175] Scheme 3D illustrates the present disclosure by showing the synthesis of a DNA-alkylating moiety for DUBA. o-Tolualdehyde (1) reacts with dimethyl succinate (2) to produce a mixture of acids (3a / 3b) by Stobbe condensation. Ring closure of this mixture of acids can be achieved with trifluoroacetic anhydride to give alcohol (4), which is then protected with benzyl chloride to give benzyl ether (5). Successful hydrolysis of the methyl ester group gives carboxylic acid (6), which undergoes Curtius rearrangement in a mixture of toluene and tert-butyl alcohol to give carbamate (7). Bromination with N-bromosuccinimide gives bromide (8). Alkylation of bromide (8) with (S)-glycidyl nosylate in the presence of potassium tert-butoxide gives epoxide (9). Reaction with n-butyllithium gives the desired compound (10) and the debrominated and rearranged derivative (11). When tetrahydrofuran is used as the solvent and the reaction temperature is maintained at -25 to -20°C, the yield of the desired compound (10) is relatively high. Under these conditions, the desired compound (10) and the debrominated and rearranged derivative (11) can be obtained in approximately a 1:1 ratio. Work-up with p-toluenesulfonic acid converts the debrominated and rearranged derivative (11) to (7), which aids in the recovery of the desired compound (10). Mesylation of the hydroxyl group in (10) followed by chloride displacement with lithium chloride affords the key intermediate (12). [ka]

[0176] Scheme 3E illustrates the present disclosure by showing the synthesis of a DNA-binding moiety for DUBA. The Chichibabin cyclization reaction can proceed between ethyl bromopyruvate (13) and 5-nitropyridin-2-amine (14), which gives the nitro compound (15). Reduction of the nitro group with zinc under acidic conditions gives the amine (16). Coupling with methoxymethyl (MOM)-protected 4-hydroxybenzoic acid (17), prepared from methyl 4-hydroxybenzoate by reaction with chloromethyl methyl ether followed by ester hydrolysis (see WO 2004 / 080979), gives the ethyl ester (18), which can be hydrolyzed with sodium hydroxide in aqueous 1,4-dioxane to give the acid (19). [ka]

[0177] Next, seco-DUBA (also referred to herein as seco-duocarmycin) is synthesized from DNA-alkylating unit 12 and DNA-binding moiety 19. The tert-butoxide carbonyl (Boc) protecting group is removed from 12 under acidic conditions to form amine 20. EDC-mediated coupling of amine 20 with compound 19 gives protected compound 21, which is then fully deprotected in two consecutive steps: Pd / C, NH4HCO2, MeOH / THF, 3 h, 90% to give 22, followed by HCl, 1,4-dioxane / water, 1 h, 95% to provide seco-DUBA 23 as the HCl salt (Scheme 3F). [ka]

[0178] Prodrugs of other drugs, such as CC-1065, can be synthesized, for example, as described in WO 2010 / 062171.

[0179] The prodrug moiety can be linked to the other parts of the ADC according to Scheme 3G. The maleimide linker building block was synthesized by starting with the condensation reaction of (24) with 2-(2-aminoethoxy)ethanol (25) to give the alcohol (26), which was then converted to the reactive carbonate (27) by reaction with 4-nitrophenyl chloroformate. The linker (29) was formed by coupling (27) to H-valine-citrulline-PABA (28) prepared according to Dubowchik, GM et al. (2002) “Cathepsin B-Labile Dipeptide Linkers For Lysosomal Release Of Doxorubicin From Internalizing Immunoconjugates: Model Studies Of Enzymatic Drug Release And Antigen-Specific In Vitro Anticancer Activity,” Bioconjugate Chem. 13:855-869, which was treated with bis(4-nitrophenyl) carbonate to give the activated linker (30). [ka]

[0180] As shown in Scheme 3H, seco-DUBA-MOM 22 was modified for conjugation in two steps. Sequential treatment of 22 with 4-nitrophenyl chloroformate and tert-butylmethyl(2-(methylamino)ethyl)carbamate 31 affords compound 32. Removal of the Boc and MOM protecting groups in 32 afforded 33 as the TFA salt. [ka]

[0181] The ADC was synthesized by reaction of the activated linker (30) with the cyclization spacer-duocarmycin construct (33) under slightly basic conditions, under which self-elimination of the cyclization spacer and the resulting formation of 3a was suppressed (Scheme 3I). [ka]

[0182] This process generates, on average, two free thiol groups per mAb, which results in a statistical distribution of B7-H3-ADCs with an average drug-to-antibody-ratio (DAR) of approximately 2 and low amounts of high molecular weight species and residual unconjugated duocarmycin moieties.

[0183] The order of the various steps of the synthesis may be varied as desired. As noted above, it is specifically contemplated that the methods used are those of Schemes 3A-3I.

[0184] C.MGC018 In a particular embodiment, the B7-H3-ADC is MGC018. MGC018 comprises the light and heavy chains of anti-B7-H3 hmAb-A conjugated with a seco-DUBA payload. The amino acid sequences of the Ab, the cytotoxic duocarmycin moiety D, and the linker molecule LM in MGC018 are shown below: AB is: (i) a light chain comprising the amino acid sequence of SEQ ID NO: 19; and (ii) a heavy chain comprising the amino acid sequence of SEQ ID NO: 20 Includes; D contains seco‐DUBA; LM comprises a linker molecule that includes a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

[0185] V.PD-1×CTLA-4 bispecific molecule PD-1 x CTLA-4 bispecific molecules include bispecific molecules (e.g., bispecific antibodies, bispecific diabodies, etc.), chimeric or humanized antibodies, and such bispecific binding molecules with variant Fc regions. PD-1 x CTLA-4 bispecific molecules that can be used in the methods of the present disclosure are disclosed, for example, in: WO 2014 / 209804; WO 2017 / 218707; WO 2017 / 193032; WO 2019 / 094637; and U.S. Patent Publication No. 2019 / 0185569. Variants of such PD-1 x CTLA-4 bispecific molecules can be readily generated, for example, by incorporating alternative VH / VL domains, such as those provided herein. In a specific embodiment, the PD-1 x CTLA-4 bispecific molecule is lorigellimab (also known as MGD019) (the amino acid sequence of lorigellimab is provided herein and also in WHO Drug Information, 2021, Recommended INN: List 125, 35(2):466-468). Additional PD-1 x CTLA-4 bispecific molecules include budalimab (CAS Registry Number 2329669-72-7, also known as XmAb20717 and XmAb® 717; Xencor, Inc.; the amino acid sequence of budalimab is provided herein and in WHO Drug Information, 2020, Recommended INN: List 123, 34(2):413-415); kadonilimab (CAS Registry Number 2394841-59-7, also known as AK104; Akeso Biopharma, Inc.; the amino acid sequence of kadonilimab is provided herein and in WHO Drug Information, 2020, Recommended INN: List 124,34(4):947-949); and MEDI5752 (Medimmune, Inc.; the amino acid sequence of MEDI5752 is provided in WO 2017 / 193032).

[0186] A. Lorigellimab In a particular embodiment, the PD-1 x CTLA-4 bispecific molecule is lorigellimab. Lorigellimab is a bispecific, four-chain, Fc Region-containing diabody with two binding sites specific for PD-1, two binding sites specific for CTLA-4, a mutated IgG4 Fc Region engineered to extend half-life, and a cysteine-containing E / K-coil heterodimer-promoting domain. The amino acid sequence of lorigellimab is shown below.

[0187] The first and third polypeptide chains of lorigellimab are composed, in the N-terminal to C-terminal direction, of: N-terminus; a VL domain of a monoclonal antibody capable of binding to PD-1 (VL PD‐1 ) (SEQ ID NO:30; bold underlined in SEQ ID NO:28 below); an intervening linker peptide (Linker 1: GGGSGGGG (SEQ ID NO:10)); a VH domain of a monoclonal antibody capable of binding to CTLA-4 (VH CTLA‐4 ) (SEQ ID NO:33; bold double underlined in SEQ ID NO:28 below); a cysteine-containing intervening linker peptide (Linker 2: GGCGGG (SEQ ID NO:11)); a cysteine-containing heterodimer-promoting (E-coil) domain (EVAACEK-EVAALEK-EVAALEK-EVAALEK (SEQ ID NO:12)); an intervening linker peptide (Linker 3) comprising a stabilized IgG4 hinge region (SEQ ID NO:7); a mutated IgG4 CH2-CH3 domain comprising substitutions M252Y / S254T / T256E and no C-terminal residues (SEQ ID NO:14); and a C-terminus.

[0188] The amino acid sequence of the first and third polypeptide chains of lorigellimab is (SEQ ID NO:28): The image is JPEG2025506142000025.jpg59147.

[0189] The second and fourth polypeptide chains of lorigellimab are composed, in the N-terminal to C-terminal direction, of: N-terminus; a VL domain of a monoclonal antibody capable of binding to CTLA-4 (VL CTLA‐4) (SEQ ID NO:32; bold underlined in SEQ ID NO:29 below); an intervening linker peptide (Linker 1: GGGSGGGG (SEQ ID NO:10)); a VH domain of a monoclonal antibody capable of binding to PD-1 (VH PD‐1 ) (SEQ ID NO:31; bold double underlined in SEQ ID NO:29 below); a cysteine-containing intervening linker peptide (Linker 2: GGCGGG (SEQ ID NO:11)); a cysteine-containing heterodimer-promoting (K-coil) domain (KVAACKE-KVAALKE-KVAALKE-KVAALKE (SEQ ID NO:13)); and a C-terminus.

[0190] The amino acid sequence of the second and fourth polypeptide chains of lorigellimab is (SEQ ID NO:29): The image is JPEG2025506142000026.jpg37148.

[0191] B. Budalimab In a specific embodiment, the PD-1 x CTLA-4 bispecific molecule is budalimb, the amino acid sequence of which is shown below.

[0192] The amino acid sequence of the first chain (heavy chain; anti-CTLA-4) of budalimb is (SEQ ID NO:34): EVQLVESGGG LVKPGGSLRL SCAASGFTFS SYTMHWVRQA PGKGLEWVSF ISYDGNNKYY ADSVKGRFTI SRDNAKNSLY LQMNSLRAED TAVYYCARTG WLGPFDYWGQ GTLVTVSSAS TKGPSVFPLA PSSKSTSGGT AALGCLVKDY FPEPVTVSWN SGALTSGVHT FPAVLQSSGL YSLSSVVTVP SSSLGTQTYI CNVNHKPSDT KVDKKVEPKS CDKTHTCPPC PAPPVAGPSV FLFPPKPKDT LMISRTPEVT CVVVDVKHED PEVKFNWYVD GVEVHNAKTK PREEEYNSTY RVVSVLTVLH QDWLNGKEYK CKVSNKALPA PIEKTISKAK GQPREPQVYT LPPSREEMTK NQVSLTCDVS GFYPSDIAVE WESDGQPENN YKTTPPVLDS DGSFFLYSKL TVDKSRWEQG DVFSCSVLHE ALHSHYTQKS LSLSPGK It is.

[0193] The amino acid sequence of the second chain (light chain; anti-CTLA-4) of budalimb is (SEQ ID NO:35): EIVLTQSPGT LSLSPGERAT LSCRASQSVS SSYLAWYQQK PGQAPRLLIY GAFSRATGIP DRFSGSGSGT DFTLTISRLE PEDFAVYYCQ QYGSSPWTFG QGTKVEIKRT VAAPSVFIFP PSDEQLKSGT ASVVCLLNNF YPREAKVQWK VDNALQSGNS QESVTEQDSK DSTYSLSSTL TLSKADYEKH KVYACEVTHQ GLSSPVTKSF NRGEC It is.

[0194] The amino acid sequence of the third chain of budalimab (scFv-h-CH2-CH3; anti-PD-1) is (SEQ ID NO:36): EIVLTQSPAT LSASPGERVT LTCRASQSVG NDVAWYQQKP GQAPRLLINY ASHRYTGVPD RFTGSGYGTE FTLTISSVQS EDFGVYYCQQ DFSSPRTFGG GTKVEIKGKP GSGKPGSGKP GSGKPGSEVQ LVESGGGLVK PGGSLRLSCV ASGFTFSNYW MNWVRQAPGK GLEWVAEIRL YSNNYATHYA ESVKGRFTIS RDDSKSTLYL QMNNLKTEDT GVYYCTRYYG NYGGYFDVWG RGTLVTVSSE PKSSDKTHTC PPCPAPPVAG PSVFLFPPKP KDTLMISRTP EVTCVVVDVK HEDPEVKFNW YVDGVEVHNA KTKPREEQYN STYRVVSVLT VLHQDWLNGK EYKCKVSNKA LPAPIEKTIS KAKGQPREPQ VYTLPPSREQ MTKNQVKLTC LVKGFYPSDI AVEWESNGQP ENNYKTTPPV LDSDGSFFLY SKLTVDKSRW QQGNVFSCSV LHEALHSHYT QKSLSLSPGK It is.

[0195] C. Kadonilimab In a specific embodiment, the PD-1 x CTLA-4 bispecific molecule is kadonilimab, the amino acid sequence of which is shown below.

[0196] The amino acid sequence of the first chain (heavy chain; anti-PD-1 and anti-CTLA-4 (scFv)) of kadonilimab is (SEQ ID NO:37): EVQLVESGGG LVQPGGSLRL SCAASGFAFS SYDMSWVRQA PGKGLDWVAT ISGGGRYTYY PDSVKGRFTI SRDNSKNNLY LQMNSLRAED TALYYCANRY GEAWFAYWGQ GTLVTVSSAS TKGPSVFPLA PSSKSTSGGT AALGCLVKDY FPEPVTVSWN SGALTSGVHT FPAVLQSSGL YSLSSVVTVP SSSLGTQTYI CNVNHKPSNT KVDKKVEPKS CDKTHTCPPC PAPEAAGAPS VFLFPPKPKD TLMISRTPEV TCVVVDVSHE DPEVKFNWYV DGVEVHNAKT KPREEQYNST YRVVSVLTVL HQDWLNGKEY KCKVSNKALP APIEKTISKA KGQPREPQVY TLPPSRDELT KNQVSLTCLV KGFYPSDIAV EWESNGQPEN NYKTTPPVLD SDGSFFLYSK LTVDKSRWQQ GNVFSCSVMH EALHNHYTQK SLLSPGKGG GGSGGGGSGG GGSGGGGSQV QLVESGAEVK KPGASVKVSC KASGYSFTGY TMNWVRQAPG QCLEWIGLIN PYNNITNYAQ KFQGRVTFTV DTSISTAYME LSRLRSDDTG VYFCARLDYR SYWGQGTLVT VSAGGGGSGG GGSGGGGSGG GGSQAVVTQE PSLTVSPGGT VTLTCGSSTG AVTTSNFPNW VQQKPGQAPR SLIGGTNNKA SWTPARFSGS LLGGKAALTI SGAQPEDEAE YYCALWYSNH WVFGCGTKLT VLR It is.

[0197] The amino acid sequence of the second chain (light chain; anti-PD-1) of kadonilimab is (SEQ ID NO:38): DIQMTQSPSS MSASVGDRVT FTCRASQDIN TYLSWFQQKP GKSPKTLIYR ANRLVSGVPS RFSGSGSGQD YTLTISSLQP EDMATYYCLQ YDEFPLTFGA GTKLELKRTV AAPSVFIFPP SDEQLKSGTA SVVCLLNNFY PREAKVQWKV DNALQSGNSQ ESVTEQDSKD STYSLSSTLT LSKADYEKHK VYACEVTHQG LSSPVTKSFN RGEC It is.

[0198] VI. Manufacturing method The binding molecules of the present disclosure (e.g., anti-B7-H3 antibody hmAb-A and PD-1 x CTLA-4 bispecific molecules) can be made recombinantly and expressed using any method known in the art for producing recombinant proteins. For example, nucleic acids encoding the polypeptide chains of such binding molecules can be constructed, introduced into an expression vector, and expressed in a suitable host cell. The binding molecules can be recombinantly produced in bacterial cells (e.g., E. coli cells) or eukaryotic cells (e.g., CHO, 293E, COS, NS0 cells). Additionally, the binding molecules can be expressed in yeast cells, such as Pichia or Saccharomyces.

[0199] To produce the binding molecules (e.g., anti-B7-H3 antibody hmAb-A and PD-1 x CTLA-4 bispecific molecule), one or more polynucleotides encoding the molecules may be constructed, introduced into an expression vector, and expressed in a suitable host cell. Standard molecular biology techniques are used to prepare recombinant expression vectors, transfect host cells, select transformants, culture host cells, and recover the molecules (e.g., Green, MR et al., (2012), Molecular Cloning, A Laboratory Manual, 4th Ed., Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, and Ausubel et al. eds., 1998, Current Protocols in Molecular Biology, John Wiley & Sons, NY). One or more expression vectors must have characteristics that allow the vector to replicate in the host cell. The vector must also have promoter and signal sequences necessary for expression in the host cell. Such sequences are known in the art. In addition to one or more nucleic acid sequences encoding such binding molecules, recombinant expression vectors may carry additional sequences, such as sequences that regulate replication of the vector in host cells (e.g., origins of replication), and selectable marker genes. Suitable methods that can be used to recombinantly express the binding molecules in plants (e.g., tobacco) or transgenic animals have been previously disclosed (see, e.g., Peeters et al. (2001) "Production Of Antibodies And Antibody Fragments In Plants," Vaccine 19:2756; U.S. Patent No. 5,849,992; and Pollock et al. (1999) "Transgenic Milk As A Method For The Production Of Recombinant Antibodies," J. Immunol Methods 231:147-157).

[0200] After the binding molecule is recombinantly expressed, it may be purified from inside or outside the host cell (e.g., from the culture medium) by any method known in the art for purifying polypeptides or polyproteins. Isolation and purification methods commonly used for antibody purification (e.g., antigen selectivity-based antibody purification schemes) may be used to isolate and purify the molecule, and are not limited to any particular method, such as column chromatography, filtration, ultrafiltration, salting out, solvent precipitation, solvent extraction, distillation, immunoprecipitation, SDS-polyacrylamide gel electrophoresis, isoelectric focusing, dialysis, and recrystallization. Examples of chromatography include ion exchange chromatography, affinity chromatography (optionally after Protein A selection (wherein the PD-1 x CTLA-4 bispecific molecule comprises an Fc region)) specifically by affinity for a particular antigen, sizing column chromatography, hydrophobic chromatography, gel filtration chromatography, reverse phase chromatography, and adsorption chromatography (Marshak et al. (1996) Strategies for Protein Purification and Characterization: A Laboratory Course Manual. (Eds.), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY).

[0201] VII. Pharmaceutical Compositions The B7-H3-ADC and PD-1×CTLA-4 binding molecules of the present disclosure can be formulated as compositions. Such compositions include bulk drug compositions (e.g., compositions that are not pure or sterile) that can be used to manufacture pharmaceutical compositions, and pharmaceutical compositions (i.e., compositions that are suitable for administration to a subject or patient) that can be used to prepare unit dosage forms. Such compositions include prophylactically or therapeutically effective amounts of B7-H3-ADC, PD-1×CTLA-4 binding molecules, or combinations thereof, and one or more pharma- ceutically acceptable carriers, and may optionally further include one or more additional therapeutic agents. The pharmaceutical compositions can be supplied, for example, as aqueous solutions, or lyophilized powders or water-free concentrates that are specifically adapted for or to be reconstituted with a pharma- ceutically acceptable carrier.

[0202] As used herein, the term "pharmaceutical acceptable carrier" means a diluent, solvent, dispersion medium, antibacterial and antifungal agent, excipient, or vehicle approved by a federal or state regulatory agency or listed in the United States Pharmacopeia or other generally recognized pharmacopeia as suitable for administration to animals, and more particularly to humans. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal fats, vegetable oils, or synthetic origin. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid carriers, particularly for injectable solutions. The compositions can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents, if desired. These compositions can take the form of solutions, suspensions, emulsions, tablets, pills, capsules, powders, sustained-release formulations, and the like.

[0203] In general, the components of the composition are supplied separately or mixed in the dosage form, as lyophilized powders or water-free concentrates, or as aqueous solutions in airtight containers such as vials, ampoules, or sachets labeled with the amount of active agent. If the composition is to be administered by injection, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline. If the composition is to be administered by injection, an ampoule of sterile water for injection, saline, or other diluent can be provided so that the components can be mixed prior to administration.

[0204] VIII. Medical Kits The disclosure also provides a pharmaceutical pack or kit comprising one or more containers containing one or more pharmaceutical compositions and instructional materials (e.g., cautions, package inserts, instructions, etc.). Additionally, one or more other prophylactic or therapeutic agents useful for treating a disease can also be included in the pharmaceutical kit. The containers of such pharmaceutical kits can include one or more airtight vials, ampoules, sachets, etc., which are labeled with the amount of active agent contained therein. If the composition is to be administered by injection, the container can be an infusion bottle, bag containing a sterile pharmaceutical grade solution (e.g., water, saline, buffer, etc.). If the composition is to be administered by injection, the pharmaceutical kit can contain an ampoule of sterile water for injection, saline, or other diluent to facilitate mixing of the components of the pharmaceutical kit for administration to a subject (e.g., a human patient or other mammal). In certain embodiments, the pharmaceutical pack or kit comprises a B7-H3-ADC pharmaceutical composition and instructional materials. In other embodiments, the pharmaceutical pack or kit comprises a B7-H3-ADC pharmaceutical composition, a PD-1 x CTLA-4 bispecific molecule composition, and instructional materials.

[0205] In one embodiment, the B7-H3-ADC and / or PD-1 x CTLA-4 bispecific molecules of such kits are supplied as lyophilized sterile powders or water-free concentrates in airtight containers and can be reconstituted, for example, with water, saline, or other diluents, to a concentration suitable for administration to a subject. In another embodiment, the B7-H3-ADC and / or PD-1 x CTLA-4 bispecific molecules of such kits are supplied as aqueous solutions in airtight containers and can be diluted, for example, with water, saline, or other diluents, to a concentration suitable for administration to a subject. The kits can further include, in one or more containers, one or more other prophylactic and / or therapeutic agents that can be used to treat cancer; and / or the kits can further include one or more cytotoxic antibodies that bind to one or more cancer antigens associated with cancer. In certain embodiments, the other prophylactic or therapeutic agents are chemotherapeutic agents. In other embodiments, the prophylactic or therapeutic agents are biotherapeutic agents or hormonal therapeutic agents.

[0206] The instructional material included in the pharmaceutical kit can be, for example, of a content and format prescribed by a government agency regulating the manufacture, use, or sale of pharmaceuticals or biological products, and can indicate approval by such agency of the manufacture, sale, or use of the pharmaceutical composition for administration to and / or treatment of humans. The instructional material can provide, for example, information regarding the dosages contained in the pharmaceutical composition, the manner in which the pharmaceutical composition can be prepared (e.g., reconstituted), and the manner in which the pharmaceutical composition can be administered, etc. Such instructions can further provide information related to the dosage and administration of one or more pharmaceutical compositions not provided in the kit.

[0207] Thus, for example, instructional materials included in a pharmaceutical kit may instruct to administer one or more of the pharmaceutical compositions provided in combination with additional agents, which may be provided separately in the same pharmaceutical kit. Such instructional materials may include administering B7-H3-ADC in a dose range of about 1 mg / kg to about 2 mg / kg, about 2 mg / kg to about 3 mg / kg, about 1 mg / kg to about 1.25 mg / kg, about 1.25 mg / kg to about 1.5 mg / kg, about 1.5 mg / kg to about 1.75 mg / kg, about 2 mg / kg to about 2.25 mg / kg, about 2.25 mg / kg to about 2.5 mg / kg, about 2.5 mg / kg to about 2.75 mg / kg, about 2.75 mg / kg, or about 2.75 mg / kg. The instructional material may instruct the patient to administer the B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg, about 1 mg / kg, about 1.25 mg / kg, about 1.5 mg / kg, about 1.75 mg / kg, about 2 mg / kg, about 2.1 mg / kg, about 2.2 mg / kg, about 2.25 mg / kg, about 2.3 mg / kg, about 2.4 mg / kg, about 2.5 mg / kg, about 2.6 mg / kg, about 2.7 mg / kg, about 2.75 mg / kg, or about 3 mg / kg. Such instructional material may instruct the patient to administer the B7-H3-ADC about every 2 weeks, about every 3 weeks, about every 4 weeks, or more or less frequently. Such instructional material may instruct the patient to administer the B7-H3-ADC pharmaceutical composition at a single dose, or at two or more doses (e.g., 2 doses, 4 doses, 6 doses, 12 doses, 24 doses, etc.). Such instructional materials may instruct that the B7-H3-ADC pharmaceutical compositions provided include split doses to be provided as two or more separate administrations administered within about 7±2 days of each other (e.g., 1 mg / kg administered on days 1-3 and 1 mg / kg administered on days 5-7 to provide a dose of 2 mg / kg per week.) Such instructional materials may instruct that the B7-H3-ADC pharmaceutical compositions provided include split doses to be provided as two or more separate administrations administered within a three or four week cycle.

[0208] Such instructional materials may instruct to also administer a PD-1 x CTLA-4 bispecific molecule pharmaceutical composition. Such instructional materials may instruct that the PD-1 x CTLA-4 bispecific molecule pharmaceutical composition comprises lorigellimab to be administered at a dose of about 1 mg / kg to about 6 mg / kg, about 1 mg / kg to about 3 mg / kg, about 3 mg / kg to about 6 mg / kg, about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg. Such instructional materials may instruct that the PD-1 x CTLA-4 bispecific molecule pharmaceutical composition comprises budalimbab to be administered at a dose of about 1 mg / kg to about 15 mg / kg, about 4 mg / kg to about 15 mg / kg, about 6 mg / kg to about 10 mg / kg, about 10 mg / kg to about 15 mg / kg, about 4 mg / kg, about 6 mg / kg, about 10 mg / kg, or about 15 mg / kg. Such instructional materials may instruct the PD-1 x CTLA-4 bispecific molecule pharmaceutical composition to comprise cadonilimab to be administered at a dose of about 1 mg / kg to about 15 mg / kg, about 4 mg / kg to about 15 mg / kg, about 4 mg / kg to about 6 mg / kg, about 6 mg / kg to about 15 mg / kg, about 4 mg / kg, about 6 mg / kg, about 10 mg / kg, or about 15 mg / kg. Such instructional materials may instruct the pharmaceutical composition to comprise cadonilimab to be administered as a fixed dose of about 450 mg. Such instructional materials may instruct the PD-1 x CTLA-4 bispecific molecule pharmaceutical composition to comprise MEDI5752 to be administered at a dose of about 1 mg / kg to about 15 mg / kg, about 4 mg / kg to about 15 mg / kg, about 4 mg / kg to about 10 mg / kg, or about 6 mg / kg to about 15 mg / kg. Such instructional materials may instruct that the PD-1 x CTLA-4 bispecific molecule pharmaceutical composition provided comprises, or is to be reconstituted to comprise, a single dose or two or more doses (e.g., 2 doses, 4 doses, 6 doses, 12 doses, 24 doses, etc.) Such instructional materials may instruct to administer the PD-1 x CTLA-4 bispecific molecule pharmaceutical composition about every 2 weeks, about every 3 weeks, about every 4 weeks, or more or less frequently.

[0209] The instructional material included in the pharmaceutical kit may combine any set of information described above (e.g., the instructional material may instruct that B7-H3-ADC is administered at a dose of about 1 mg / kg, and that said dose is administered about once a week for about 1 week, about 2 weeks, or about 3 weeks; the instructional material may instruct that B7-H3-ADC is administered at a dose of about 2 mg / kg, and that said dose is administered about every 3 weeks; the instructional material may instruct that B7-H3-ADC is administered at a dose of about 2.5 mg / kg, and that said dose is administered about every 3 weeks; the instructional material may instruct that B7-H3-ADC is administered at a dose of about 3 mg / kg, and that said dose is administered about every 3 weeks; the instructional material may instruct that B7-H3-ADC is administered at a dose of about 3 mg / kg, and that said dose is administered about every 3 weeks; the instructional material may instruct that the 7-H3-ADC is administered at a dose of about 2 mg / kg, and that said dose is administered about every 4 weeks; the instructional material may instruct that the B7-H3-ADC is administered at a dose of about 2.5 mg / kg, and that said dose is administered about every 4 weeks; the instructional material may instruct that the B7-H3-ADC is administered at a dose of about 3 mg / kg, and that said dose is administered about every 4 weeks; and / or the instructional material may instruct that the PD-1 x CTLA-4 bispecific molecule (e.g., lorigellimab) is administered at a dose of about 1 mg / kg, about 3 mg / kg, about 4 mg / kg, about 6 mg / kg, about 10 mg / kg, or about 15 mg / kg, and that said dose is administered about every 2 weeks, about every 3 weeks, or about every 4 weeks). Such instructional materials may instruct on the mode of administration of the included pharmaceutical composition, e.g., to administer the pharmaceutical composition by intravenous (IV) infusion. Instructional materials included with the pharmaceutical kit may instruct on the duration or timing of the administration, e.g., to administer the included pharmaceutical composition by intravenous (IV) infusion over a period of about 30 minutes, about a period of about 45 minutes, about a period of about 60 minutes, about a period of about 75 minutes, a period of 30-60 minutes, a period of 60-120 minutes, etc.

[0210] The instructional material included in the pharmaceutical kit may provide instructions regarding the appropriate or desired use of one or more of the included pharmaceutical compositions, for example, to administer the pharmaceutical composition for the treatment of cancer, including: adrenal cancer; AIDS-related cancer; alveolar soft part sarcoma; astrocytic tumor; anal cancer; squamous cell carcinoma of the anal canal (SCAC); bladder cancer; bone cancer; brain and spinal cord cancer; metastatic brain tumors; B-cell cancer; breast cancer; HER2 + Breast cancer;Triple-negative breast cancer (TNBC);Carotid bulb tumor;Cervical cancer;Chondrosarcoma;Chordoma;Chromophobe renal cell carcinoma;Clear cell carcinoma;Colon cancer;Colorectal cancer (CRC);Non-high microsatellite instability colorectal cancer (non-MSI-H CRC);Cutaneous benign fibrous histiocytoma;Desmoplastic small round cell tumor;Ependymoma;Ewing's tumor;Extraskeletal myxoid chondrosarcoma;Fibrosal dysplasia ossificans;Fibrous dysplasia;Gallbladder or bile duct cancer;Gastrointestinal cancer;Gestational trophoblastic disease;Germ cell tumor;Head and neck cancer;Glioblastoma;Hematologic malignancies;Hepatocellular carcinoma;Pancreatic islet cell tumor;Kaposi's sarcoma;Kidney cancer;Leukemia;Acute myeloid leukemia;Liposarcoma / malignant liposarcoma;Dedifferentiated liposarcoma;Liver cancer;Lymphoma tumors;lung cancer;non-small cell lung cancer (NSCLC);medulloblastoma;melanoma;cutaneous melanoma;meningioma;mesothelioma;pharyngeal carcinoma;multiple endocrine neoplasia;multiple myeloma;myelodysplastic syndrome;myxofibrosarcoma;neuroblastoma;neuroendocrine tumors;ovarian cancer;pancreatic cancer;papillary thyroid cancer;parathyroid tumors;pediatric cancer;peripheral nerve sheath tumors;pheochromocytoma;pituitary tumors;prostate cancer;metastatic castration-resistant prostate cancer (mCRPC);posterior uveal melanoma;renal cell carcinoma (renal cell cancer); renal cell carcinoma (RCC); renal metastatic carcinoma; rhabdoid tumor; rhabdomyosarcoma; sarcoma; skin cancer; small round blue cell tumor of childhood; neuroblastoma; soft tissue sarcoma; undifferentiated pleomorphic sarcoma; squamous cell carcinoma; squamous cell carcinoma of the head and neck (SCCHN); gastric cancer; synovial sarcoma; testicular cancer; thymic carcinoma; thymoma; thyroid cancer; thyroid metastatic cancer; and uterine cancer. In certain embodiments, the cancer is a B7-H3 expressing cancer.

[0211] IX. Uses of the B7-H3-ADCs of the Invention B7-H3-ADC and PD-1×CTLA-4 bispecific molecules can be used to treat or prevent a variety of disorders, including cancer, including cancers that express B7-H3. Accordingly, the present disclosure provides a method of treating cancer, the method comprising administering to a subject in need thereof a B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule. In certain aspects, the present disclosure provides a method of treating cancer, the method comprising administering to a subject in need thereof MGC018 in combination with lorigellimab. In certain aspects, the present disclosure provides a method of treating cancer, the method comprising administering to a subject in need thereof MGC018 in combination with budalimb. In certain aspects, the present disclosure provides a method of treating cancer, the method comprising administering to a subject in need thereof MGC018 in combination with cadnilimab. In certain aspects, the present disclosure provides methods of treating cancer, comprising administering MGC018 in combination with MEDI5752 to a subject in need thereof. As used herein, the term "subject" refers to a human (i.e., a human patient) or other mammal. Non-limiting dosing regimens for administering such therapy to a subject in need thereof are provided herein.

[0212] Cancers that can be treated using B7-H3-ADC in combination with PD-1 x CTLA-4 bispecific molecules include: adrenal cancer; AIDS-related cancer; alveolar soft part sarcoma; astrocytic tumor; anal cancer; squamous cell carcinoma of the anal canal (SCAC); bladder cancer; bone cancer; brain and spinal cord cancer; metastatic brain tumors; B-cell cancer; breast cancer; HER2 +Breast cancer;Triple-negative breast cancer (TNBC);Carotid bulb tumor;Cervical cancer;Chondrosarcoma;Chordoma;Chromophobe renal cell carcinoma;Clear cell carcinoma;Colon cancer;Colorectal cancer (CRC);Non-high microsatellite instability colorectal cancer (non-MSI-H CRC);Cutaneous benign fibrous histiocytoma;Desmoplastic small round cell tumor;Ependymoma;Ewing's tumor;Extraskeletal myxoid chondrosarcoma;Fibrosal dysplasia ossificans;Fibrous dysplasia;Gallbladder or bile duct cancer;Gastrointestinal cancer;Gestational trophoblastic disease;Germ cell tumor;Head and neck cancer;Glioblastoma;Hematologic malignancies;Hepatocellular carcinoma;Pancreatic islet cell tumor;Kaposi's sarcoma;Kidney cancer;Leukemia;Acute myeloid leukemia;Liposarcoma / malignant liposarcoma;Dedifferentiated liposarcoma;Liver cancer;Lymphoma tumors;lung cancer;non-small cell lung cancer (NSCLC);medulloblastoma;melanoma;cutaneous melanoma;meningioma;mesothelioma;pharyngeal carcinoma;multiple endocrine neoplasia;multiple myeloma;myelodysplastic syndrome;myxofibrosarcoma;neuroblastoma;neuroendocrine tumors;ovarian cancer;pancreatic cancer;papillary thyroid cancer;parathyroid tumors;pediatric cancer;peripheral nerve sheath tumors;pheochromocytoma;pituitary tumors;prostate cancer;metastatic castration-resistant prostate cancer (mCRPC);posterior uveal melanoma;renal cell carcinoma (renal cell cancer); renal cell carcinoma (RCC); renal metastatic carcinoma; rhabdoid tumor; rhabdomyosarcoma; sarcoma; skin cancer; small round blue cell tumor of childhood; neuroblastoma; soft tissue sarcoma; undifferentiated pleomorphic sarcoma; squamous cell carcinoma; squamous cell carcinoma of the head and neck (SCCHN); gastric cancer; synovial sarcoma; testicular cancer; thymic carcinoma; thymoma; thyroid cancer; thyroid metastatic carcinoma; and uterine cancer. In certain embodiments, the cancer expresses B7-H3.

[0213] In certain embodiments, B7-H3-ADC can be combined with PD-1 x CTLA-4 bispecific molecules in the treatment of: anal cancer (including SCAC), breast cancer (including HER2+ breast cancer and / or TNBC), cervical cancer (including HPV-associated cervical cancer and cervical squamous cell carcinoma), colorectal cancer (including non-microsatellite instability-high colorectal cancer (non-MSI-H CRC)), head and neck cancer (including HPV-associated head and neck cancer and SCCHN), kidney cancer (including renal cancer and renal cell carcinoma), liver cancer (including hepatocellular carcinoma), lung cancer (including NSCLC), melanoma (including cutaneous melanoma and posterior uveal melanoma), ovarian cancer, pancreatic cancer, prostate cancer (including mCRPC), soft tissue sarcoma (including dedifferentiated liposarcoma, myxofibrosarcoma, undifferentiated pleomorphic sarcoma, and synovial sarcoma), and epithelial cell carcinoma. In certain embodiments, the cancer expresses B7-H3.

[0214] In certain embodiments, B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule of the present disclosure is administered as a first-line therapy for the treatment of cancer. In certain embodiments, B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule of the present disclosure is administered after one or more prior lines of therapy. In certain embodiments, B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule of the present disclosure can be employed as an adjuvant therapy at or after surgical removal of a tumor to delay, inhibit, or prevent the development of metastasis. B7-H3-ADC in combination with a PD-1×CTLA-4 bispecific molecule of the present disclosure can be administered prior to surgery (e.g., as a neoadjuvant therapy) to reduce the size of the tumor to allow or simplify surgery, to conserve tissue during surgery, and / or to reduce any resulting cosmetic damage.

[0215] The present disclosure specifically encompasses administering B7-H3-ADC in combination with PD-1×CTLA-4 bispecific molecules, and further in combination with one or more other therapies known to those of skill in the art for the treatment or prevention of cancer, including, but not limited to, current standard and experimental chemotherapy, hormonal therapy, biological therapy, immunotherapy, radiation therapy, or surgery. In some embodiments, B7-H3-ADC in combination with PD-1×CTLA-4 bispecific molecules may be administered in combination with a therapeutically or prophylactically effective amount of one or more therapeutic or chemotherapeutic agents known to those of skill in the art for the treatment and / or prevention of cancer, particularly B7-H3-expressing cancers. Therapeutic and chemotherapeutic agents commonly used to treat B7-H3-expressing cancers include, but are not limited to, platinum-based chemotherapy agents (particularly carboplatin, oxaliplatin, and carboplatin), taxanes (particularly docetaxel and paclitaxel), hormonal therapy agents (particularly abiraterone and enzalutamide), anthracyclines (particularly daunorubicin, doxorubicin, and epirubicin), capecitabine, carboplatin, cyclophosphamide, leucovorin, methotrexate, radium-223, sipuleucel-T, 5-fluorouracil (5-FU), and immune checkpoint inhibitors (such as retifanlimab and tebotelimab).

[0216] As used herein, the term "combination" refers to the use of two or more therapeutic agents. The use of the term "combination" does not restrict the order in which the therapeutic agents should be administered to a subject (e.g., a human patient or other mammal) with a disorder, nor does it imply that the agents are administered simultaneously. The term "combination" means that the B7-H3-ADC, the PD-1×CTLA-4 bispecific molecule, and any other agent are administered sequentially to a human patient or other mammal within a time interval such that the combination of the B7-H3-ADC, the PD-1×CTLA-4 bispecific molecule, and the other agent provides a greater benefit than if the agents were administered in another manner. For example, each therapeutic agent (e.g., a chemotherapeutic agent, a radiotherapeutic agent, a hormonal therapeutic agent, or a biotherapeutic agent) may be administered sequentially in any order, at the same time or at different times, but if not administered simultaneously, they should be administered sufficiently close in time to provide the desired therapeutic or prophylactic effect. Each therapeutic agent can be administered separately in any suitable form and by any suitable route, e.g., one by the oral route and one by the parenteral route, etc. Provided herein are non-limiting dosing regimens for administering a B7-H3-ADC in combination with a PD-1 x CTLA-4 bispecific molecule to a subject in need thereof.

[0217] X. Method and Dosage of Administration The binding molecules (e.g., B7-H3-ADC and / or PD-1 x CTLA-4 bispecific molecules) of the disclosure can be administered to a subject, e.g., a subject in need thereof, e.g., a human patient, in a variety of ways. For many applications, the route of administration is one of: intravenous injection or infusion (IV), subcutaneous injection (SC), intraperitoneal (IP), or intramuscular injection. Intra-articular delivery can also be used. Other modes of parenteral administration can also be used. Examples of such modes include: intra-arterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, transtracheal, subcuticular, intra-articular, subcapsular, subarachnoid, intraspinal, and epidural and intrasternal injection.

[0218] The molecules (e.g., B7-H3-ADC, and / or PD-1 x CTLA-4 bispecific molecule) can be administered as a weight-based dose (e.g., 3.5 mg / kg). The dose can also be selected to reduce or avoid the production of antibodies against the administered molecule. The dosing regimen is adjusted to provide a desired response, e.g., a therapeutic response or a combined therapeutic effect. Generally, multiple doses of B7-H3-ADC and PD-1 x CTLA-4 bispecific molecule (and optionally additional agents) can be used to provide a subject with a bioavailable amount of the agent. As used herein, the term "dose" refers to a specified amount of drug treatment administered at one time. The term "dosage" refers to the administration of a particular amount, number, and frequency of doses over a specified period of time, and thus the term "dosage" includes chronological characteristics such as duration and periodicity.

[0219] As used herein, the term "weight-based dose" refers to a discrete amount of a molecule administered per unit of patient weight, e.g., milligrams of drug per kilogram of subject weight (mg / kg body weight; abbreviated herein as "mg / kg"). As used herein, the term "flat dose" refers to a dose that is independent of patient weight and includes physically discrete units of a molecule suitable as a single dose to a subject to be treated, each unit containing a predetermined amount of drug. Typically, a significant (10% or more) change in body weight from a baseline or established plateau body weight will generally prompt a recalculation of the dose. Single or multiple doses may be administered. A composition comprising a B7-H3-ADC and / or PD-1 x CTLA-4 bispecific molecule may be administered by infusion to a subject in need thereof.

[0220] As used herein, the term "fractionated dose" refers to two or more separate administrations of a molecule administered to achieve a particular desired dose. A fractionated dose provides that the desired dose is divided into two or more separate administrations. Between such two or more administrations, the dose may be divided equally and / or unequally. A fractionated dose can be two or more separate administrations within about 7±2 days. In certain embodiments, a fractionated dose can be two or more separate administrations within a cycle (e.g., a three-week or four-week cycle). As an example, which should not be construed as limiting, if the desired dose is 2 mg / kg, a subject may be administered a dose of 1 mg / kg as a first administration (in week 1) and a dose of 1 mg / kg as a second administration (in one of weeks 2-4); the 1 mg / kg dose may be split into two separate administrations of 0.5 mg / kg within about 7±2 days; the 1 mg / kg dose may be split into two separate administrations of 0.25 mg / kg and 0.75 mg / kg within about 7±2 days; the 1.5 mg / kg dose may be split into three separate administrations of 0.5 mg / kg within about 7±2 days; or the 1.5 mg / kg dose may be split into three separate administrations of 0.25 mg / kg, 0.25 mg / kg, and 1.0 mg / kg within about 7±2 days. In one embodiment, B7-H3-ADC is administered in split doses of 1 mg / kg on days 1-3 and 1 mg / kg on days 5-7 to achieve a dose of 2 mg / kg. In another embodiment, B7-H3-ADC is administered in split doses of 1.5 mg / kg on days 1-3 and 1.5 mg / kg on days 5-7 to achieve a dose of 3 mg / kg. In one embodiment, for a desired dose of 2 mg / kg in a 3 week cycle, 1 mg / kg can be administered in week 1, 1 mg / kg can be administered in week 2, and no administration is performed in week 3 of the 3 week cycle. In another embodiment, for a desired dose of 2 mg / kg in a 4 week cycle, 1 mg / kg can be administered in week 1, 1 mg / kg can be administered in week 2, and no administration is performed in weeks 3 and 4 of the 4 week cycle.In another embodiment, for a desired dose of 3 mg / kg in a three week cycle, 1 mg / kg can be administered each week of the three week cycle. In another embodiment, for a desired dose of 3 mg / kg in a four week cycle, 1 mg / kg can be administered in weeks 1-3 of the four week cycle, with no administration in week 4.

[0221] In certain embodiments, B7-H3-ADC is administered to a subject in need thereof at a dose of about 1 mg / kg to about 2 mg / kg, about 2 mg / kg to about 3 mg / kg, about 1 mg / kg to about 1.25 mg / kg, about 1.25 mg / kg to about 1.5 mg / kg, about 1.5 mg / kg to about 1.75 mg / kg, about 2 mg / kg to about 2.25 mg / kg, about 2.25 mg / kg to about 2.5 mg / kg, or about 2.5 mg / kg to about 2.75 mg / kg. , about 2.75 mg / kg to about 3 mg / kg, about 1 mg / kg, about 1.25 mg / kg, about 1.5 mg / kg, about 1.75 mg / kg, about 2 mg / kg, about 2.1 mg / kg, about 2.2 mg / kg, about 2.25 mg / kg, about 2.3 mg / kg, about 2.4 mg / kg, about 2.5 mg / kg, about 2.6 mg / kg, about 2.7 mg / kg, about 2.75 mg / kg, or about 3 mg / kg, based on body weight. In certain embodiments, B7-H3-ADC will be administered about once a week, about once every two weeks, about once every three weeks, about once every four weeks, or more or less frequently. In certain embodiments, the dose of B7-H3-ADC is provided as a single dose. In certain embodiments, the dose of B7-H3-ADC is provided as a split dose of two or more separate administrations. In a specific embodiment, the B7-H3-ADC administered is MGC018.

[0222] In certain embodiments, the PD-1 x CTLA-4 bispecific molecule is lorigellimab and is administered to a subject in need thereof at a weight-based dose of about 1 mg / kg to about 15 mg / kg. In certain embodiments, the PD-1 x CTLA-4 bispecific molecule is lorigellimab, budaliimab, kadonilimab, or MEDI5752. In certain embodiments, lorigellimab is administered to a subject in need thereof at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg. In certain embodiments, lorigellimab is administered to a subject in need thereof at a dose of about 1 mg / kg. In certain embodiments, lorigellimab is administered to a subject in need thereof at a dose of about 3 mg / kg. In certain embodiments, lorigellimab is administered to a subject in need thereof at a dose of about 6 mg / kg. In certain embodiments, lorigellimab will be administered about every 2 weeks, about every 3 weeks, about every 4 weeks, or more or less frequently. In certain embodiments, lorigellimab will be administered to a subject in need thereof at a dose of about 6 mg / kg every 3 weeks. In certain embodiments, lorigellimab will be administered to a subject in need thereof at a dose of about 6 mg / kg every 4 weeks. In certain embodiments, budalimab will be administered to a subject in need thereof at a dose of about 10 mg / kg, or about 15 mg / kg. In certain embodiments, budalimab will be administered to a subject in need thereof at a dose of about 10 mg / kg. In certain embodiments, budalimab will be administered to a subject in need thereof at a dose of about 15 mg / kg. In certain embodiments, budalimab will be administered to a subject in need thereof at a dose of about 2 weeks, about every 3 weeks, about every 4 weeks, or more or less frequently. In certain embodiments, budaliimab is administered to a subject in need thereof at a dose of about 10 mg / kg every two weeks. In certain embodiments, budaliimab is administered to a subject in need thereof at a dose of about 15 mg / kg every two weeks. In certain embodiments, cadnilimab is administered to a subject in need thereof at a dose of about 6 mg / kg, or about 15 mg / kg. In certain embodiments, cadnilimab is administered to a subject in need thereof at a dose of about 6 mg / kg.In certain embodiments, cadonilimab is administered to a subject in need thereof at a dose of about 15 mg / kg. In certain embodiments, cadonilimab will be administered about every 2 weeks, about every 3 weeks, about every 4 weeks, or more or less frequently. In certain embodiments, cadonilimab is administered to a subject in need thereof at a dose of about 6 mg / kg every 2 weeks. In certain embodiments, cadonilimab is administered to a subject in need thereof at a dose of about 15 mg / kg every 3 weeks.

[0223] With respect to weight-based doses, the term "about" is intended to refer to a range of ±10% of the stated dose, so that, for example, a dose of about 1 mg / kg would be 0.09 mg / kg to 1.01 mg / kg.

[0224] As used herein, the term "dosing interval" refers to the time interval between doses, which may be regular or intermittent. A dosage of a molecule (e.g., a dose of B7-H3-ADC and / or a dose of a PD-1 x CTLA-4 bispecific molecule) may be administered at periodic dosing intervals over a period (a course of treatment) sufficient to encompass at least 2 doses, at least 4 doses, at least 6 doses, at least 12 doses, or at least 24 doses. For example, a dosage may be administered, for example, once or twice daily, or about 1-4 times per week, or, in particular, once per week ("Q1W"), once every 2 weeks ("Q2W"), once every 3 weeks ("Q3W"), once every 4 weeks ("Q4W"), etc. The desired dose may be provided in a single administration or as a divided dose of two or more separate administrations within a given cycle (e.g., a 3-week or 4-week cycle). Such periodic administration may continue for a period of time, e.g., about 1-52 weeks or more than 52 weeks. Such a course of treatment may be divided into multiple increments, e.g., 2-8 weeks, about 3-7 weeks, about 3 weeks, about 4 weeks, about 6 weeks, or about 8 weeks, each of which is referred to herein as a "cycle," during which a set number of doses are administered. The dose and / or frequency of administration may be the same or different during each cycle. Factors that may affect the dosing and timing required for effective treatment of a subject include, for example, the severity, formulation, route of delivery, previous treatments, overall health, and / or age of the subject's disease or disorder, as well as the presence of other diseases in the subject's body. Furthermore, treatment of a subject with a therapeutically effective amount of a compound may include a single treatment, or a series of multiple treatments.

[0225] A "dosing regimen" is the administration of a dosage in which a patient is administered a predetermined dose (or set of a plurality of such doses) at a predetermined frequency (or set of a plurality of such frequencies) with one or more predetermined periodicities. In certain embodiments, the dosing regimen involves administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every three weeks. In certain embodiments, the dosing regimen involves administration of B7-H3-ADC at a weight-based dose of about 1 mg / kg to about 2 mg / kg every three weeks. In certain embodiments, the dosing regimen involves administration of B7-H3-ADC at a dose of about 2 mg / kg to about 3 mg / kg every three weeks. In certain embodiments, the dosing regimen involves administration of B7-H3-ADC at a dose of about 1 mg / kg every three weeks. In certain embodiments, the dosing regimen involves administration of B7-H3-ADC at a dose of about 1.25 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.5 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.75 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every three weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.4 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.5 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.6 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every three weeks.In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every three weeks.

[0226] In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg to about 2 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg to about 3 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.25 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.5 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.75 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.3 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.4 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.5 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.6 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every 4 weeks. In certain embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every 4 weeks.

[0227] In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every 3 weeks or every 4 weeks and lorigellimab at a dose of about 1 mg / kg to about 6 mg / kg every 2 weeks, every 3 weeks, or every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every 3 weeks or every 4 weeks and budalimb at a dose of about 6 mg / kg to about 15 mg / kg every 2 weeks, every 3 weeks, or every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every 3 weeks or every 4 weeks and cadnilimab at a dose of about 6 mg / kg to about 15 mg / kg every 2 weeks, every 3 weeks, or every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every 3 or 4 weeks and MEDI5752 at a dose of about 1 mg / kg to about 15 mg / kg every 2 weeks, every 3 weeks, or every 4 weeks.

[0228] In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every three weeks and lorigellimab at a dose of about 1 mg / kg to about 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 2 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to about 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2 mg / kg to about 3 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to about 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to about 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1.25 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1.5 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1.75 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks.In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.3 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.4 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.5 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.6 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every three weeks.

[0229] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0230] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.25 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.25 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0231] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.5 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.5 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0232] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.75 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.75 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0233] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0234] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0235] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0236] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0237] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.3 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.3 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0238] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.4 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.4 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0239] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.5 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.5 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0240] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.6 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.6 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0241] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0242] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0243] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every three weeks and lorigellimab at a dose of about 3 mg / kg every three weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every three weeks and lorigellimab at a dose of about 6 mg / kg every three weeks.

[0244] In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 3 mg / kg every 4 weeks and lorigellimab at a dose of about 1 mg / kg to about 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg to about 2 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to about 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2 mg / kg to about 3 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to about 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to about 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1.25 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1.5 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 1.75 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks.In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.3 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.4 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.5 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen includes administration of B7-H3-ADC at a dose of about 2.6 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks. In some embodiments, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg to 6 mg / kg every 4 weeks.

[0245] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0246] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.25 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.25 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0247] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.5 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.5 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0248] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.75 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 1.75 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0249] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0250] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.1 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0251] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.2 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0252] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.25 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0253] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.3 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.3 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0254] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.4 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.4 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0255] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.5 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.5 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0256] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.6 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.6 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0257] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.7 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0258] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 2.75 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0259] In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every 4 weeks and lorigellimab at a dose of about 3 mg / kg every 4 weeks. In one embodiment, the dosing regimen comprises administration of B7-H3-ADC at a dose of about 3 mg / kg every 4 weeks and lorigellimab at a dose of about 6 mg / kg every 4 weeks.

[0260] In the above-mentioned embodiments, administration is contemplated at a predetermined frequency or periodicity, or within 1-3 days of the scheduled dosing interval, such as every 3 weeks (± 3 days), such that administration occurs 1-3 days before, 1-3 days after, or on the day of the scheduled dosing. Specifically, in the above-mentioned embodiments, it is contemplated that the B7-H3-ADC and PD-1 x CTLA-4 bispecific molecule are administered by IV infusion within a 24 hour period. In certain embodiments, the B7-H3-ADC and PD-1 x CTLA-4 bispecific molecule are administered by IV infusion according to any of the above-mentioned dosing regimens for a duration (i.e., course of treatment) of at least 1 month or more, at least 3 months or more, or at least 6 months or more, or at least 12 months or more. Durations of treatment of at least 6 months or more, or at least 12 months or more, or until remission of the disease or unmanageable toxicity is observed are specifically contemplated. In certain embodiments, treatment is continued for a period of time following remission of the disease.

[0261] In certain embodiments, the B7-H3-ADC and PD-1 x CTLA-4 bispecific molecule are administered by IV infusion. The molecules are thus diluted (separately or together) in an infusion bag containing a suitable diluent, such as 0.9% sodium chloride or dextrose 5% in water (D5W). Infusion or allergic reactions may occur, and pre-medication to prevent such infusion reactions is recommended, and anaphylaxis precautions should be observed during antibody administration. In certain embodiments, the IV infusion can be administered to the subject over a period of about 30 minutes to about 24 hours. In certain embodiments, the IV infusion is delivered over a period of about 30-45 minutes, about 30-60 minutes, about 60-75 minutes, about 30-120 minutes, or longer or shorter periods, provided the subject does not exhibit signs or symptoms of an adverse infusion reaction. In one embodiment, the B7-H3-ADC is administered by IV infusion over a period of about 60-75 minutes. In one embodiment, B7-H3-ADC is administered by IV infusion over a period of about 60 minutes. In one embodiment, B7-H3-ADC is administered by IV infusion over a period of about 75 minutes. In another embodiment, the PD-1 x CTLA-4 bispecific molecule is administered by IV infusion over a period of about 30-45 minutes. In another embodiment, lorigellimab is administered by IV infusion over a period of about 30 minutes. In another embodiment, lorigellimab is administered by IV infusion over a period of about 45 minutes.

[0262] In any of the above embodiments, the B7-H3-ADC and the PD-1×CTLA-4 bispecific molecule are administered simultaneously, sequentially, alternating, or at different times by IV infusion. In certain embodiments, on days when both B7-H3-ADC and the PD-1×CTLA-4 bispecific molecule are administered, the B7-H3-ADC is administered prior to administration of the PD-1×CTLA-4 bispecific molecule. In certain embodiments, on days when both B7-H3-ADC and the PD-1×CTLA-4 bispecific molecule are administered, the PD-1×CTLA-4 bispecific molecule is administered prior to administration of the B7-H3-ADC. In some embodiments, on days when both B7-H3-ADC and the PD-1×CTLA-4 bispecific molecule are administered, the B7-H3-ADC is administered prior to administration of the PD-1×CTLA-4 bispecific molecule. In one embodiment, the PD-1 x CTLA-4 bispecific molecule is administered at least about 15-60 minutes after administration of B7-H3-ADC. In one embodiment, the PD-1 x CTLA-4 bispecific molecule is administered at least about 15-30 minutes after administration of B7-H3-ADC. In one embodiment, the PD-1 x CTLA-4 bispecific molecule is administered at least about 15 minutes after administration of B7-H3-ADC. In one embodiment, the PD-1 x CTLA-4 bispecific molecule is administered at least about 30 minutes after administration of B7-H3-ADC.

[0263] XI. EMBODIMENTS OF THE DISCLOSURE This disclosure relates in part to the following non-limiting embodiments (E1-E74).

[0264] E1. A method of treating cancer in a subject in need thereof, said method comprising administering to said subject an anti-B7-H3 antibody-drug conjugate (B7-H3-ADC) and a PD-1 x CTLA-4 bispecific molecule, said B7-H3-ADC having the following formula: Ab‐(LM) m -(D) n where: The Ab binds to B7-H3 and: (i) in its variable light (VL) domain, the CDRL1 sequence RASESIYSYLA (SEQ ID NO: 22), the CDRL2 sequence NTKTLPE (SEQ ID NO: 23), and the CDRL3 sequence QHHYGTPPWT (SEQ ID NO: 24); and (ii) in its variable heavy (VH) domain, the CDRH1 sequence SYGMS (SEQ ID NO: 25), the CDRH2 sequence TINSGGSNTYY PDSLKG (SEQ ID NO: 26), and the CDRH3 sequence HDGGAMDY (SEQ ID NO: 27). a humanized B7-H3 antibody or a B7-H3-binding fragment thereof comprising: D is a cytotoxic duocarmycin moiety; LM comprises at least one bond or linker molecule that covalently bonds Ab and D; m is an integer from 0 to n, representing the number of bonds or linker molecules in the B7-H3-ADC, except that m is not 0 when LM is one bond; The method, wherein n is an integer from 1 to 10 and represents the number of said cytotoxic duocarmycin moieties covalently attached to said B7-H3-ADC.

[0265] E2. The above Ab is: (i) a humanized variable light (VL) domain comprising the amino acid sequence of SEQ ID NO: 17, and (ii) a humanized variable heavy (VH) domain comprising the amino acid sequence of SEQ ID NO: 18 The method according to E1, comprising:

[0266] E3. The method of E1 or E2, wherein the Ab further comprises a human IgG1, IgG2, IgG3, or IgG4 Fc domain.

[0267] E4. The Fc domain is a variant Fc domain: (a) one or more amino acid modifications that reduce the affinity of the variant Fc domain for FcγR; and / or (b) one or more amino acid modifications that enhance the serum half-life of the variant Fc domain. The method of claim 1, wherein E3 is a mutant Fc domain comprising:

[0268] E5. The method of any one of E1-E4, wherein at least one of said LMs is a linker molecule.

[0269] E6. The method of any one of E1-E5, wherein the LM linker molecule is a peptide linker.

[0270] E7. The method of E6, wherein the peptide linker is a valine-citrulline dipeptide linker.

[0271] E8. The method of any one of E1-E7, wherein the LM linker molecule further comprises a self-erasing spacer between the cleavable linker and D.

[0272] E9. The method of E8, wherein said self-erasing spacer comprises a para-aminobenzyloxycarbonyl moiety.

[0273] E10. The method of any one of E1-E9, wherein the LM linker molecule further comprises a maleimide linker moiety between the cleavable linker and Ab.

[0274] E11. The above LM has the formula: [V‐(W) k -(X)1-A] Thus, the B7-H3-ADC has the following formula: Ab‐[V‐(W) k -(X)1-A]-D where: V is a cleavable linker; (W) k -(X)1-A is an elongated self-erasing spacer system that self-erases by l,(4+2n) erasure; W and X are each a 1,(4+2n)-electron cascade spacer, which may be the same or different; A is a group represented by the formula (Y) mwhere Y is an 1,(4+2n) electron cascade spacer, or a group of formula U, which is a cyclization elimination spacer; k, 1, and m are independently integers from 0 to 5, inclusive; n is an integer from 0 to 10, inclusive; however: A is (Y) m if k+l+m≧1; If k+l+m=l then n>l; If A is U, then k+1>=1; W, X and Y are independently selected from the group consisting of the following formulas: [ka] or the following formula: [ka] wherein the compound is selected from compounds having the formula: Q is -R 5 C=CR 6 -, S, O, NR 5 , -R 5 C=N- or -N=CR 5 - is; P is NR 7 , O or S; a, b and c are independently integers from 0 to 5, inclusive; I, F and G are independently selected from the formula: [ka] wherein the compound is selected from compounds having the formula: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independent of each other, H, C 1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C 1-6Alkoxy, hydroxy (OH), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2) and phosphate (OP(=O)(OR x )2), where: R x , R x 1 and R x 2 is independent, C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; The above-mentioned substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 or R 9 two or more of which are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures; U is a group represented by the formula: [ka] wherein the compound is selected from compounds having the formula: a, b and c are independently selected to be integers of 0 or 1; where a+b+c=2 or 3; R 1 and / or R 2 are independent of each other, H, C 1-6 represents an alkyl group, said alkyl group optionally containing the following groups: hydroxy (OH), ether (OR x ), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2), and phosphate (OP(=O)(OR x )2) where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independent of each other, H, C 1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C1-6 Alkoxy, hydroxy (OH), amino (NH2), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro(NO2), halogen, CF3, CN, CONH2, SO2Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O)2OH), sulfonate (S(=O)2OR x ), sulfonyl (S(=O)2R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(=O)(OH)2), and phosphate (OP(=O)(OR x )2), where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl group, the substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , or R 8 The method of any one of E1-E10, wherein two or more of are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures.

[0275] E12. The LM linker molecule is: (1) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; (2) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; (3) p-aminocinnamyloxycarbonyl; (4) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl; (5) p-amino-benzyloxycarbonyl-p-aminocinnamyloxycarbonyl; (6) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl; (7) p-aminophenylpentadienyloxycarbonyl; (8) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyloxycarbonyl; (9) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyloxycarbonyl; (10) p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyloxycarbonyl; (11) p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (12) p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (13) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (14) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (15) p-aminobenzyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)-carbonyl; (16) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (17) p-aminobenzyloxycarbonyl-p-aminobenzyl; (18) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyl; (19) p-aminocinnamyl; (20) p-aminocinnamyloxycarbonyl-p-aminobenzyl; (21) p-aminobenzyloxycarbonyl-p-aminocinnamyl; (22) p-amino-cinnamyloxycarbonyl-p-aminocinnamyl; (23) p-aminophenylpentadienyl; (24) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyl; (25) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyl; or (26) The method according to E11, comprising p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyl.

[0276] E13. The method of any one of E1-E12, wherein the LM linker molecule is conjugated to a side chain of an amino acid of a polypeptide chain of the Ab, linking the Ab to a molecule of the cytotoxic duocarmycin moiety D.

[0277] E14. The method of any one of E1-E13, wherein the cytotoxic duocarmycin moiety D comprises a duocarmycin cytotoxin selected from the group consisting of duocarmycin A, duocarmycin B1, duocarmycin B2, duocarmycin C1, duocarmycin C2, duocarmycin D, duocarmycin SA, CC-1065, adozelesin, bizeresin, carzerusin (U-80244), seco-duocarmycin (seco-DUBA), and spiro-duocarmycin (spiro-DUBA).

[0278] E15. The method of E14, wherein said cytotoxic duocarmycin moiety D comprises seco-DUBA.

[0279] E16. The method of any one of E1-E15, wherein said LM linker molecule is covalently bound to said Ab via a reduced interchain disulfide.

[0280] E17. The above Ab is: (i) a light chain comprising the amino acid sequence of SEQ ID NO: 19; and (ii) a heavy chain comprising the amino acid sequence of SEQ ID NO: 20 Including, D above includes seco-DUBA; The method of any one of E1-E16, wherein the LM comprises a linker molecule comprising a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

[0281] E18. The above B7-H3-ADC: a) about 1 mg / kg to about 3 mg / kg every 3 weeks; or b) 2 mg / kg to 3 mg / kg every 3 weeks The method according to any one of E1 to E17, wherein the compound is administered at a therapeutically or prophylactically effective dose.

[0282] E19. The above B7-H3-ADC: a) about 1 mg / kg to about 3 mg / kg every 4 weeks; or b) 2 mg / kg to 3 mg / kg every 4 weeks The method according to any one of E1 to E17, wherein the compound is administered at a therapeutically or prophylactically effective dose.

[0283] E20. The method of any one of E1-E19, wherein said dose of said B7-H3-ADC is administered as a single dose.

[0284] E21. The method of any one of E1-E19, wherein said dose of said B7-H3-ADC is administered as a split dose, in two or more separate administrations.

[0285] E22. The method of any one of E1-E19 and E21, wherein said split dose consists of two separate administrations administered within a three week cycle or a four week cycle.

[0286] E23.(a) on the day that both the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule are administered, the B7-H3-ADC is administered prior to administration of the PD-1 x CTLA-4 bispecific molecule; or (b) The method of any one of E1-E22, wherein, on the day when both the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule are administered, the PD-1 x CTLA-4 bispecific molecule is administered prior to administration of the B7-H3-ADC.

[0287] E24.(a) the PD-1 x CTLA-4 bispecific molecule is administered at least about 15-30 minutes after administration of the B7-H3-ADC; or (b) the method of any one of E1-E22, wherein the B7-H3-ADC is administered at least about 15-30 minutes after administration of the PD-1 x CTLA-4 bispecific molecule.

[0288] E25. The method of any one of E1-E24, wherein the PD-1 x CTLA-4 bispecific molecule is selected from the group consisting of: lorigellimab, MEDI5752, budaliimab, and cadnilimab.

[0289] E26. The method of any one of E1-E25, wherein the PD-1 x CTLA-4 bispecific molecule is lorigellimab.

[0290] E27. The method of E26, wherein said lorigellimab is administered at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg every three weeks.

[0291] E28. The method of E27, wherein said lorigellimab is administered at a dose of about 6 mg / kg every three weeks.

[0292] E29. The method of E26, wherein said lorigellimab is administered at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg every 4 weeks.

[0293] E30. The method of E29, wherein said lorigellimab is administered at a dose of about 6 mg / kg every 4 weeks.

[0294] E31. The method of any one of E1-E30, wherein the B7-H3-ADC is administered at a dose of about 1 mg / kg.

[0295] E32. The method of any one of E1-E30, wherein the B7-H3-ADC is administered at a dose of about 1.25 mg / kg.

[0296] E33. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 1.5 mg / kg.

[0297] E34. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 1.75 mg / kg.

[0298] E35. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2 mg / kg.

[0299] E36. The method of any one of E1-E30, wherein the B7-H3-ADC is administered at a dose of about 2.1 mg / kg.

[0300] E37. The method of any one of E1-E30, wherein the B7-H3-ADC is administered at a dose of about 2.2 mg / kg.

[0301] E38. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2.25 mg / kg.

[0302] E39. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2.3 mg / kg.

[0303] E40. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2.4 mg / kg.

[0304] E41. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2.5 mg / kg.

[0305] E42. The method of any one of E1-E30, wherein the B7-H3-ADC is administered at a dose of about 2.6 mg / kg.

[0306] E43. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2.7 mg / kg.

[0307] E44. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 2.75 mg / kg.

[0308] E45. The method of any one of E1-E30, wherein said B7-H3-ADC is administered at a dose of about 3 mg / kg.

[0309] E46. The method of any one of E1-E45, wherein said B7-H3-ADC is administered by intravenous (IV) infusion.

[0310] E47. The method of E46, wherein said IV infusion of said B7-H3-ADC is for a period of at least about 60-120 minutes.

[0311] E48. The method of E47, wherein said IV infusion of said B7-H3-ADC is for a period of at least about 60 minutes.

[0312] E49. The method of any one of E1-E48, wherein the PD-1 x CTLA-4 bispecific molecule is administered by IV infusion.

[0313] E50. The method of E49, wherein said IV infusion of said PD-1 x CTLA-4 bispecific molecule is for a period of at least about 30-120 minutes.

[0314] E51. The method of E50, wherein said IV infusion of said PD-1 x CTLA-4 bispecific molecule is over a period of at least about 30 minutes.

[0315] E52. The above cancers are: adrenal cancer; AIDS-related cancer; alveolar soft part sarcoma; astrocytic tumor; anal cancer; squamous cell carcinoma of the anal canal (SCAC); bladder cancer; bone cancer; brain and spinal cord cancer; metastatic brain tumors; B-cell cancer; breast cancer; HER2 + Breast cancer;Triple-negative breast cancer (TNBC);Carotid bulb tumor;Cervical cancer;Chondrosarcoma;Chordoma;Chromophobe renal cell carcinoma;Clear cell carcinoma;Colon cancer;Colorectal cancer (CRC);Non-high microsatellite instability colorectal cancer (non-MSI-H CRC);Cutaneous benign fibrous histiocytoma;Desmoplastic small round cell tumor;Ependymoma;Ewing's tumor;Extraskeletal myxoid chondrosarcoma;Fibrosal dysplasia ossificans;Fibrous dysplasia;Gallbladder or bile duct cancer;Gastrointestinal cancer;Gestational trophoblastic disease;Germ cell tumor;Head and neck cancer;Glioblastoma;Hematologic malignancies;Hepatocellular carcinoma;Pancreatic islet cell tumor;Kaposi's sarcoma;Kidney cancer;Leukemia;Acute myeloid leukemia;Liposarcoma / malignant liposarcoma;Dedifferentiated liposarcoma;Liver cancer;Lymphoma tumors;lung cancer;non-small cell lung cancer (NSCLC);medulloblastoma;melanoma;cutaneous melanoma;meningioma;mesothelioma;pharyngeal carcinoma;multiple endocrine neoplasia;multiple myeloma;myelodysplastic syndrome;myxofibrosarcoma;neuroblastoma;neuroendocrine tumors;ovarian cancer;pancreatic cancer;papillary thyroid cancer;parathyroid tumors;pediatric cancer;peripheral nerve sheath tumors;pheochromocytoma;pituitary tumors;prostate cancer;metastatic castration-resistant prostate cancer (mCRPC);posterior uveal melanoma;renal cell carcinoma (renal The method according to any one of E1 to E51, wherein the cancer is selected from the group consisting of: renal cell cancer); renal cell carcinoma (RCC); renal metastatic carcinoma; rhabdoid tumor; rhabdomyosarcoma; sarcoma; skin cancer; small round blue cell tumor of childhood; neuroblastoma; soft tissue sarcoma; undifferentiated pleomorphic sarcoma; squamous cell carcinoma; squamous cell carcinoma of the head and neck (SCCHN); gastric cancer; synovial sarcoma; testicular cancer; thymic carcinoma; thymoma; thyroid cancer; thyroid metastatic carcinoma; and uterine cancer.

[0316] E53. The method of E52, wherein the cancer is selected from the group consisting of: anal cancer, SCAC, breast cancer, TNBC, cervical cancer, colorectal cancer, non-microsatellite instability-high colorectal cancer (non-MSI-H CRC), head and neck cancer, kidney cancer, renal cell carcinoma, liver cancer, hepatocellular carcinoma, lung cancer, NSCLC, melanoma, cutaneous melanoma, posterior uveal melanoma, ovarian cancer, pancreatic cancer, prostate cancer, mCRPC, soft tissue sarcoma, dedifferentiated liposarcoma, myxofibrosarcoma, undifferentiated pleomorphic sarcoma, synovial sarcoma, epithelial cell carcinoma, and SCCHN.

[0317] E54. The method according to any one of E1 to E53, wherein the cancer is prostate cancer.

[0318] E55. The method according to any one of E46 to E54, wherein the prostate cancer is mCRPC.

[0319] E56. The method according to any one of E1 to E53, wherein the cancer is liver cancer.

[0320] E57. The method of any one of E52, E53, and E56, wherein said liver cancer is hepatocellular carcinoma.

[0321] E58. The method according to any one of E1 to E53, wherein said cancer is renal cancer.

[0322] E59. The method of any one of E52, E53, and E58, wherein said kidney cancer is renal cell carcinoma.

[0323] E60. The method according to any one of E1 to E53, wherein said cancer is ovarian cancer.

[0324] E61. The method according to any one of E1 to E53, wherein said cancer is pancreatic cancer.

[0325] E62. The method according to any one of E1-E53, wherein said cancer is anal cancer.

[0326] E63. The method of any one of E52, E53, and E62, wherein said anal cancer is SCAC.

[0327] E64. The method according to any one of E1 to E53, wherein the cancer is an epithelial cell cancer.

[0328] E65. The method of any one of E52, E53, and E64, wherein said epithelial cell cancer is SCCHN.

[0329] E66. The method according to any one of E1-E53, wherein said cancer is breast cancer.

[0330] E67. The method of any one of E52, E53, and E66, wherein said breast cancer is TNBC.

[0331] E68. The method according to any one of E1-E53, wherein said cancer is melanoma.

[0332] E69. The method of any one of E52, E53, and E68, wherein said melanoma is cutaneous melanoma or posterior uveal melanoma.

[0333] E70. The method according to any one of E1 to E53, wherein said cancer is lung cancer.

[0334] E71. The method of any one of E52, E53, and E70, wherein said lung cancer is NSCLC.

[0335] E72. The method according to any one of E1-E53, wherein said cancer is cervical cancer.

[0336] E73. The method of any one of E1-E53, wherein said cancer is colorectal cancer.

[0337] E74. The method of any one of E52, E53, and E73, wherein said colorectal cancer is non-MSI-H colorectal cancer.

[0338] E75. The method of any one of E1-E53, wherein said cancer is soft tissue sarcoma.

[0339] E76. The method of any one of E52, E53, and E75, wherein said soft tissue sarcoma is dedifferentiated liposarcoma, myxofibrosarcoma, undifferentiated pleomorphic sarcoma, or synovial sarcoma.

[0340] E77. The method of any one of E1-E76, wherein said cancer expresses B7-H3.

[0341] E78. The method of any one of E1-E77, further comprising administering a therapeutically or prophylactically effective amount of one or more additional therapeutic or chemotherapeutic agents.

[0342] E79. The method of E78, wherein said chemotherapeutic agent is a platinum-based chemotherapeutic agent.

[0343] E80. The method of E79, wherein said chemotherapeutic agent is a taxane.

[0344] E81. The method of any one of E1-E80, wherein the subject in need of treatment is a human. EXAMPLES

[0345] Having generally described the present invention above, the present invention will be more readily understood by reference to the following examples, which illustrate various methods relating to the compositions in the diagnostic or therapeutic methods of the present invention. These examples are intended to illustrate the scope of the present invention, but are in no way intended to limit the scope of the present invention.

[0346] Example 1 In vivo efficacy of single or divided doses of MGC018 in CD-1 nude mice Although the animal studies presented herein utilized MGC018, it will be understood in light of the teachings herein that similar studies can be designed using any of the B7-H3-ADCs described herein.

[0347] To demonstrate the antitumor activity of MGC018 in a split / repeated dose study, MGC018 was evaluated for in vivo toxicity in an immunodeficient CD-1 nude (homozygous) mouse model using a xenograft tumor model derived from the human Calu-6 lung cancer cell line. 6 Tumor cells (suspended in 1:1 medium and MATRIGEL®) were implanted subcutaneously into the flanks of female CD-1 nude mice (homozygous; Charles River Laboratories). Tumors reached a volume of approximately 100–235 mm on day 21. 3 (Average 172mm 3 Mice were randomized when tumors reached 100% CI 0.01 to 0.25 and administered MGC018 or control vehicle intravenously. In these studies, mice received a single dose of MGC018 (12 mg / kg, QW x 1) or divided doses of MGC018 (0.3 mg / kg, 1 mg / kg, or 3 mg / kg) once a week for 4 weeks (QW x 4W). Vehicle was administered as a control on day 21. Tumors were measured twice weekly by orthogonal measurements using electronic calipers and tumor volume was calculated as (length x width x height) / 2. Tumor volume (relative to control) was determined ("T / C"). If tumor volume in treated animals was ≤ 5 mm during the study period, 3 A finding that the tumor volume decreased to 50% or more from the date of dosing at any time during the study was considered to represent a Complete Regression ("CR"). A Partial Regression ("PR") was defined as a tumor volume that decreased by 50% or more from the date of dosing at any time during the study. Antitumor activity was assessed according to the following National Cancer Institute (NCI) criteria: T / C ≤ 42% is the lowest level of antitumor activity, and T / C values ​​> 42% are inactive. T / C < 10% is considered to be highly active.

[0348] The results of this study on subcutaneously implanted Calu-6 cells are presented in Table 1 and Figure 2. The results of this study show that split doses of MGC018 at all concentrations tested (0.3 mg / kg, 1 mg / kg, and 3 mg / kg; QW x 4W) produced antitumor activity against Calu-6 cells that was nearly equivalent to a single dose of MGC018 (12 mg / kg, QW x 1).

[0349] [Table 1]

[0350] Example 2 In vivo efficacy of single or divided doses of MGC018 in CES1c knockout mice To further demonstrate the antitumor activity of MGC018 in split / repeated dose studies, MGC018 was evaluated for in vivo toxicity in an immunodeficient SCID CES1c-KO mouse model using xenograft tumor models derived from the human A375.S2 melanoma cell line, the human Calu-6 lung cancer cell line, and the human MDA-MB-468 triple-negative breast cancer cell line.

[0351] 2.1 Study of A375.S2 melanoma cells In short, about 5 × 10 6 A375.S2 tumor cells (suspended in 1:1 medium and MATRIGEL®) were implanted subcutaneously into the flank of female SCID CES1c-KO mice (Charles River Laboratories). On day 22, tumor volumes were approximately 70–255 mm. 3 (Average 124mm 3Mice were randomized when tumors reached 0.01 mm2 and administered MGC018 or control vehicle intravenously. In these studies, mice received a single dose of MGC018 (1 mg / kg or 3 mg / kg, QW x 1) or divided doses of MGC018 (0.3 mg / kg or 1 mg / kg) once a week for 4 weeks (QW x 4W). Vehicle was administered on day 22 as a control. Tumors were measured twice weekly by orthogonal measurements using electronic calipers and tumor volume was calculated as (length x width x height) / 2. Tumor volume (relative to control) was determined ("T / C"). If tumor volume in treated animals was ≤ 5 mm2 during the study period, 3 A finding that the tumor volume decreased to 50% or more from the date of dosing at any time during the study was considered to represent a Complete Regression ("CR"). A Partial Regression ("PR") was defined as a tumor volume that decreased by 50% or more from the date of dosing at any time during the study. Antitumor activity was assessed according to the following National Cancer Institute (NCI) criteria: T / C ≤ 42% is the lowest level of antitumor activity, and T / C values ​​> 42% are inactive. T / C < 10% is considered to be highly active.

[0352] The results of this study on subcutaneously implanted A375.S2 cells are presented in Table 2 and Figures 3A-3B. The results of this study show that split doses of MGC018 at both concentrations tested (0.3 mg / kg and 1 mg / kg; QW x 4W) provide nearly equivalent antitumor activity against A375.S2 cells as a single dose of MGC018 (1 mg / kg or 3 mg / kg, QW x 1).

[0353] [Table 2]

[0354] 2.2 Study of Calu-6 lung cancer cells In short, about 5 × 10 6Tumor cells (suspended in 1:1 medium and MATRIGEL®) were implanted subcutaneously into the flank of female SCID CES1c-KO mice (Charles River Laboratories). On day 16, tumor volumes were approximately 50-180 mm. 3 (Average 105mm 3 Mice were randomized when tumors reached 0.01 mm2 and administered MGC018 or control vehicle intravenously. In these studies, mice received a single dose of MGC018 (1 mg / kg or 3 mg / kg, QW x 1) or split doses of MGC018 (0.3 mg / kg or 1 mg / kg) once a week for 4 weeks (QW x 4W). Vehicle was administered on day 16 as a control. Tumors were measured twice weekly by orthogonal measurements using electronic calipers and tumor volume was calculated as (length x width x height) / 2. Tumor volume (relative to control) was determined ("T / C"). If tumor volume in treated animals was ≤ 5 mm2 during the study period, 3 A finding that the tumor volume decreased to 50% or more from the date of dosing at any time during the study was considered to represent a Complete Regression ("CR"). A Partial Regression ("PR") was defined as a tumor volume that decreased by 50% or more from the date of dosing at any time during the study. Antitumor activity was assessed according to the following National Cancer Institute (NCI) criteria: T / C ≤ 42% is the lowest level of antitumor activity, and T / C values ​​> 42% are inactive. T / C < 10% is considered to be highly active.

[0355] The results of this study on subcutaneously implanted Calu-6 cells are presented in Table 3 and Figures 3C-3D. The results of this study show that split doses of MGC018 at both concentrations tested (0.3 mg / kg and 1 mg / kg; QW x 4W) provided nearly equivalent antitumor activity against Calu-6 cells as a single dose of MGC018 (1 mg / kg or 3 mg / kg, QW x 1).

[0356] [Table 3]

[0357] 2.3 Study of MDA-MB-468 triple-negative breast cancer cells In short, about 5 × 10 6 Tumor cells (suspended in 1:1 medium and MATRIGEL®) were implanted subcutaneously into the flank of female SCID CES1c-KO mice (Charles River Laboratories). Tumors reached a volume of approximately 45-135 mm on day 54. 3 (Average 73mm 3 Mice were randomized when tumors reached 0.01 mm2 and administered MGC018 or control vehicle intravenously. In these studies, mice received a single dose of MGC018 (1 mg / kg or 3 mg / kg, QW x 1) or divided doses of MGC018 (0.3 mg / kg or 1 mg / kg) once a week for 4 weeks (QW x 4W). Vehicle was administered as a control on day 54. Tumors were measured twice weekly by orthogonal measurements using electronic calipers and tumor volume was calculated as (length x width x height) / 2. Tumor volume (relative to control) was determined ("T / C"). If tumor volume in treated animals was ≤ 5 mm2 during the study period, mice were randomized. 3 A finding that the tumor volume decreased to 50% or more from the date of dosing at any time during the study was considered to represent a Complete Regression ("CR"). A Partial Regression ("PR") was defined as a tumor volume that decreased by 50% or more from the date of dosing at any time during the study. Antitumor activity was assessed according to the following National Cancer Institute (NCI) criteria: T / C ≤ 42% is the lowest level of antitumor activity, and T / C values ​​> 42% are inactive. T / C < 10% is considered to be highly active.

[0358] The results of this study on subcutaneously implanted MDA-MB-468 cells are presented in Table 4 and Figures 3E-3F. The results of this study show that split doses of MGC018 at both concentrations tested (0.3 mg / kg and 1 mg / kg; QW x 4W) provide nearly equivalent antitumor activity against MDA-MB-468 cells as a single dose of MGC018 (1 mg / kg or 3 mg / kg, QW x 1).

[0359] [Table 4]

[0360] Example 3 Predicted pharmacokinetics of single and divided doses of MGC018 in human subjects To analyze the pharmacokinetics of single and split doses of MGC018, population pharmacokinetic (PPK) modeling was performed on clinical PK data from a dose escalation study of MGC018. The initial model was based on 52 patients (516 ADC observations, 495 payload observations) and was subsequently updated using data from a total of 122 patients. MGC018 concentration values ​​below the quantification limit (BQL) were excluded from the analysis but were retained (commented out) in the dataset.

[0361] PPK analysis was performed by nonlinear mixed-effects modeling (FOCEI) method including INTERACTION option using NONMEM software version 7.5.0 (ICON Development Solutions). A quasi-steady-state (QSS) approximation of the target-mediated drug disposition (TMDD) model was used to describe the observed ADC data. All clearances and parameters were relatively scaled. Model fit was assessed using goodness-of-fit plots and diagnostics (including standard error of estimates). Due to the small sample size (52 subjects), formal covariate analysis was not attempted, but the dependence of model parameters on weight, dose, and sex was investigated using diagnostic plots or by including them in the model. The ability of the model to describe the strong covariate relationships identified by the model was tested by stratifying the diagnostic plots and model evaluation procedures by the covariates of interest. Specifically, diagnostic and predictive check procedures were stratified by dose (cohort).

[0362] 3.1 Results Among the models evaluated, the clearance (CL), central volume (V C ), peripheral volume (V P A linear two-compartment model with separate random effects for the central and delayed compartments (CL), intercompartmental clearance (Q), and proportional residual variance best described the observed ADC data, and these led to further development of a composite ADC free payload model. The free payload is determined by the free payload clearance (CL) due to input (from the ADC) to both the central and delayed compartments. TOX ) and volume (V TOX ) is described by a one-compartment model with random effects for the parameters, and the retardation rate constant K tr , C.L. TOX , and V TOXThe final model (Model 151) was selected based on diagnostics and goodness of fit and used to estimate MGC018 PK parameters. According to this model, elimination from the ADC was directed to the free payload compartment, the delayed free payload compartment, and the central free payload compartment. Approximately equal proportions of the ADC elimination were directed to each of these compartments. The delayed rate constant was estimated to be 0.128 1 / day (corresponding to a half-life of 5.4 days), and the free payload elimination rate constant, K TOX =CL TOX / V TOX is K TOX = 52.5 1 / day (corresponding to a half-life of approximately 20 min). The kinetics of the free payload was therefore defined by the kinetics of the ADC and the delay between ADC elimination and input into the free payload central compartment.

[0363] For a typical subject weighing 75 kg, the clearance, central volume, intercompartmental clearance, and peripheral volume were CL = 1.68 L / day, V = 3.72 L, Q = 0.0549 L / day, and V p = 0.700 L. The peripheral half-life and distribution half-life were therefore estimated to be t 1 / 2 term = 9.18 days, and t 1 / 2 dist = 1.48 days. Of the model parameters, only the central and peripheral volumes of the ADC increased with weight (coefficient 0.41), but this dependence was poorly estimated (RSE = 41%).

[0364] Model-predicted MGC018 exposure parameters are summarized in Table 5 and are based on simulation of concentration-time courses at various doses, including a split-dose regimen, 1 mg / kg weekly for 3 weeks (QW for 3W), and 1 mg / kg in weeks 1 and 2 with no dose in weeks 3 and 4 (2Q4W). For doses above 1 mg / kg, ADC, AUC and C max Values ​​increased approximately dose-proportionally.

[0365] [Table 5]

[0366] In summary, as shown in Table 5, a split dosing schedule of 1 mg / kg administered weekly for 3 weeks in a 28-day (4-week) cycle showed a significantly improved C-reactive status compared with 3 mg / kg administered once every 3 weeks. max Although the AUC was lower, the AUC was comparable. Furthermore, a split dosing schedule of 1 mg / kg administered weekly in weeks 1 and 2 of a 4-week cycle showed a significantly higher C than a 2 mg / kg administered once every 4 weeks schedule. max Although the AUCs are lower, the split dosing regimens (QW for 3W and 2Q4W) are suitable alternatives to single doses of MGC018 3 mg / kg Q3W or 2 mg / kg Q4W, respectively.

[0367] Example 4 A dose escalation study of MGC018 in combination with lorigellimab A Phase I clinical study will be conducted to determine patient tolerability of B7-H3-ADC in combination with lorigellimab. Although the following protocol details the use of MGC018 in combination with lorigellimab, it will be understood in light of the teachings herein that similar combination protocols can be designed with any of the B7-H3-ADC and any of the PD-1 x CTLA-4 bispecific molecules described herein.

[0368] A dose escalation study will be conducted to determine the Maximum Tolerated Dose (MTD) or (if MTD is not defined) Maximum Administered Dose (MAD) of escalating doses of MGC018 administered in combination with lorigellimab at a dose of 6 mg / kg. Dose escalation will follow a conventional 3+3 design, i.e.: consecutive cohorts of 3 to 6 participants will each be evaluated in sequential escalating dose cohorts (Table 6).

[0369] [Table 6]

[0370] If the MTD of MGC018 and / or lorigellimab is determined to be exceeded in cohort 1, a dose reduction cohort (cohort-1) can be utilized to evaluate a lower dose of MGC018 (0.5 mg / kg). Additionally, reduction of lorigellimab to intermediate dose levels (3 mg / kg or 1 mg / kg) can be considered.

[0371] Both MGC018 and lorigellimab are administered as a single dose once every 3 weeks. Both MGC018 and lorigellimab are administered on the same day, with MGC018 administered first followed by lorigellimab. Each treatment cycle is defined as 3 weeks, with MGC018 and lorigellimab administered on day 1 (±3 days). MGC018 is administered IV over approximately 60 minutes. Lorigellimab is administered IV over approximately 30 minutes. Tumor assessments can be performed every 6 weeks (±7 days) for the first 6 months of treatment, and then every 12 weeks (±21 days) until progressive disease (PD). PPK modeling (as in Example 3) can be performed on clinical PK data from dose escalation studies of MGC018 and / or lorigellimab to assist in determining the MTD or (if no MTD is defined) the MAD. Additionally, intermediate doses of MGC018 and / or lorigellimab can be identified using the modeling described above, and cohorts at these intermediate doses can be included. For example, administration of MGC018 at intermediate doses can be between 2.0 mg / kg and 2.7 mg / kg.

[0372] The dose escalation study will be followed by a cohort expansion phase with MGC018 established in the dose escalation study to further define the safety and preliminary anti-tumor efficacy of the combination in various cancers (Table 7).

[0373] [Table 7]

[0374] Dose escalation studies and cohort expansion phases can be applied to add additional cohorts in which MGC018 and / or lorigellimab are administered as a single dose every 4 weeks (e.g., as shown in Table 8). MGC018 and lorigellimab can be administered on the same day, with MGC018 administered first followed by lorigellimab, or with lorigellimab administered first followed by MGC018. Each treatment cycle can be defined as 4 weeks, with MGC018 and lorigellimab administered on day 1 (± 3 days). MGC018 is administered IV over approximately 60 minutes. Lorigellimab is administered IV over approximately 30 minutes. As discussed above, additional cohorts may be introduced, for example, based on PPK modeling data.

[0375] [Table 8]

[0376] All publications and patents mentioned in this specification are incorporated by reference into this application as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference in its entirety. Although the present disclosure has been described with reference to specific embodiments thereof: it will be understood that further modifications are possible; and that the present application is intended to cover any changes, uses, or adaptations of the present disclosure that essentially follow the principles of the present disclosure and include departures from the present disclosure as may be within known or customary practice within the art to which the present disclosure pertains, and as may conform to the essential features previously described.

Claims

Claim 1: An anti-B7-H3 antibody-drug conjugate (B7-H3-ADC) and PD-1 x CTLA-4 bispecific molecule for use in treating cancer in a subject in need thereof, comprising: administering to the subject the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule; The B7-H3-ADC has the following formula: Ab‐(LM) m -(D) n Contains, where: The Ab binds to B7-H3 and: (i) in its variable light (VL) domain, the CDRL1 sequence RASESIYSYLA (SEQ ID NO:22), the CDRL2 sequence NTKTLPE (SEQ ID NO:23), and the CDRL3 sequence QHHYGTPPWT (SEQ ID NO:24); and (ii) in its variable heavy chain (VH) domain, the CDRH1 sequence SYGMS (SEQ ID NO:25), the CDRH2 sequence TINSGGSNTYY PDSLKG (SEQ ID NO:26), and the CDRH3 sequence HDGGAMDY (SEQ ID NO:27). a humanized B7-H3 antibody or a B7-H3-binding fragment thereof comprising: D is a cytotoxic duocarmycin moiety; LM comprises at least one bond or linker molecule covalently linking Ab and D; m is an integer from 0 to n, representing the number of bonds or linker molecules in said B7-H3-ADC, except that m is not 0 when LM is a single bond; n is an integer from 1 to 10 and represents the number of cytotoxic duocarmycin moieties covalently attached to the B7-H3-ADC; Anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule.

2. The Ab is: (i) a humanized variable light (VL) domain comprising the amino acid sequence of SEQ ID NO: 17; and (ii) a humanized variable heavy (VH) domain comprising the amino acid sequence of SEQ ID NO:

18.

2. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1, comprising:

3. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein the Ab further comprises a human IgG1, IgG2, IgG3, or IgG4 Fc domain.

4. The Fc domain is a variant Fc domain comprising: (a) one or more amino acid modifications that reduce the affinity of said variant Fc domain for an FcγR; and / or (b) one or more amino acid modifications that increase the serum half-life of the variant Fc domain.

4. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 3, wherein the variant Fc domain comprises:

5. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein at least one of said LMs is a linker molecule, and said linker molecule is a peptide linker.

6. 6. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 5, wherein said peptide linker is a valine-citrulline dipeptide linker.

7. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein said linker molecule further comprises a self-eliminating spacer between the cleavable linker and D.

8. 8. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 7, wherein said self-eliminating spacer comprises a para-aminobenzyloxycarbonyl moiety.

9. The LM has the following formula: [V‐(W) k ‐(X) 1 ‐A] Thus, the B7-H3-ADC has the following formula: Ab‐[V‐(W) k ‐(X) 1 ‐A]‐D where: V is a cleavable linker; (W) k -(X) 1 -A is an elongated self-erasing spacer system that self-erases by l,(4+2n) erasure; W and X are each a 1, (4+2n) electron cascade spacer, and may be the same or different; A is a group represented by the formula (Y) m where Y is a 1, (4+2n) electron cascade spacer, or a group of formula U, which is a cyclization elimination spacer; k, 1 and m are independently integers from 0 to 5, inclusive; n is an integer from 0 to 10 (inclusive); however: A is (Y) m then k+l+m≧1; If k+l+m=l, then n>l; If A is U, then k+1≧1; W, X and Y independently represent the following formula: 【Chemistry 1】 or the following formula: 【Chemistry 2】 wherein the compound is selected from compounds having the formula: Q is -R 5 C=CR 6 -, S, O, NR 5 , -R 5 C=N- or -N=CR 5 - and; P is NR 7 , O or S; a, b, and c are independently integers from 0 to 5, inclusive; I, F and G independently represent a group of the formula: 【Transformation 3】 wherein the compound is selected from compounds having the formula: R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independently H, C 1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C 1-6 Alkoxy, hydroxy (OH), amino (NH 2 ), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro (NO 2 ), halogens, CF 3 , C.N., C.O.N.H. 2 , S.O. 2 Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O) 2 OH), sulfonates (S(=O) 2 OR x ), sulfonyl (S(=O) 2 R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(═O)(OH) 2 ) and phosphate (OP(=O)(OR x ) 2 ), where: R x , R x 1 and R x 2 is independent, C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; The substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 or R 9 two or more of which are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures; U is a group of the formula: 【Chemistry 4】 wherein the compound is selected from compounds having the formula: a, b, and c are independently selected to be integers of 0 or 1; provided that a+b+c=2 or 3; R 1 and / or R 2 are independently H, C 1-6 represents an alkyl, which may optionally be selected from the following groups: hydroxy (OH), ether (OR x ), amino (NH 2 ), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro (NO 2 ), halogens, CF 3 , C.N., C.O.N.H. 2 , S.O. 2 Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O) 2 OH), sulfonates (S(=O) 2 OR x ), sulfonyl (S(=O) 2 R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(═O)(OH) 2 ), and phosphate (OP(=O)(OR x ) 2 ) where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups; R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independently H, C 1-6 Alkyl, C 3-20 Heterocyclyl, C 5-20 Aryl, C 1-6 Alkoxy, hydroxy (OH), amino (NH 2 ), monosubstituted amino (NR x H), disubstituted amino (NR x 1 R x 2 ), nitro (NO 2 ), halogens, CF 3 , C.N., C.O.N.H. 2 , S.O. 2 Me, CONHMe, cyclic C 1-5 Alkylamino, imidazolyl, C 1-6 Alkylpiperazinyl, morpholino, thiol (SH), thioether (SR x ), tetrazole, carboxy (COOH), carboxylate (COOR x ), sulfoxy (S(=O) 2 OH), sulfonates (S(=O) 2 OR x ), sulfonyl (S(=O) 2 R x ), sulfoxide (S(=O)OH), sulfinate (S(=O)OR x ), sulfinyl (S(=O)R x ), phosphonooxy (OP(═O)(OH) 2 ), and phosphate (OP(=O)(OR x ) 2 ), where R x , R x 1 and R x 2 is C 1-6 Alkyl group, C 3-20 Heterocyclyl group or C 5-20 aryl groups, and the substituent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , or R 8 are optionally connected to each other to form one or more aliphatic or aromatic cyclic structures.

10. The LM comprises: (1) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; (2) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl; (3) p-aminocinnamyloxycarbonyl; (4) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl; (5) p-amino-benzyloxycarbonyl-p-aminocinnamyloxycarbonyl; (6) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl; (7) p-aminophenylpentadienyloxycarbonyl; (8) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyloxycarbonyl; (9) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyloxycarbonyl; (10) p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyloxycarbonyl; (11) p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (12) p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (13) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (14) p-aminocinnamyloxycarbonyl-p-aminobenzyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (15) p-aminobenzyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)-carbonyl; (16) p-aminocinnamyloxycarbonyl-p-aminocinnamyloxycarbonyl(methylamino)ethyl(methylamino)carbonyl; (17) p-aminobenzyloxycarbonyl-p-aminobenzyl; (18) p-aminobenzyloxycarbonyl-p-aminobenzyloxycarbonyl-p-aminobenzyl; (19) p-aminocinnamyl; (20) p-aminocinnamyloxycarbonyl-p-aminobenzyl; (21) p-aminobenzyloxycarbonyl-p-aminocinnamyl; (22) p-amino-cinnamyloxycarbonyl-p-aminocinnamyl; (23) p-aminophenylpentadienyl; (24) p-aminophenylpentadienyloxycarbonyl-p-aminocinnamyl; (25) p-aminophenylpentadienyloxycarbonyl-p-aminobenzyl; or (26) The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 9, comprising p-aminophenylpentadienyloxycarbonyl-p-aminophenylpentadienyl.

11. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein said linker molecule is conjugated to a side chain of an amino acid in a polypeptide chain of said Ab, linking said Ab to said cytotoxic duocarmycin moiety D molecule.

12. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein said cytotoxic duocarmycin moiety D comprises a duocarmycin cytotoxin selected from the group consisting of duocarmycin A, duocarmycin B1, duocarmycin B2, duocarmycin C1, duocarmycin C2, duocarmycin D, duocarmycin SA, CC-1065, adozelesin, bizelesin, carzelesin (U-80244), seco-duocarmycin (seco-DUBA), and spiro-duocarmycin (spiro-DUBA).

13. The Ab is: (i) a light chain comprising the amino acid sequence of SEQ ID NO: 19; and (ii) a heavy chain comprising the amino acid sequence of SEQ ID NO: 20 Including, wherein D comprises seco-DUBA; 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein the LM comprises a linker molecule comprising a maleimide linker moiety, a valine-citrulline dipeptide linker, and a para-aminobenzyloxycarbonyl moiety.

14. The B7-H3-ADC comprises: a) about 1 mg / kg to about 3 mg / kg every three weeks; or b) about 2 mg / kg to about 3 mg / kg every three weeks 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2, wherein the anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule are administered at a therapeutically or prophylactically effective dose of

15. The B7-H3-ADC comprises: a) about 1 mg / kg to about 3 mg / kg every 4 weeks; or b) about 2 mg / kg to about 3 mg / kg every 4 weeks 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2, wherein the anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule are administered at a therapeutically or prophylactically effective dose of

16. The dose of the B7-H3-ADC is (a) administered as a single dose, or (b) administered as a divided dose, in two or more separate administrations; 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2.

17. 17. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 16, wherein said split-dose consists of two separate administrations administered within a four-week cycle.

18. (a) on the day that both the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule are administered, the B7-H3-ADC is administered prior to administration of the PD-1 x CTLA-4 bispecific molecule; or (b) The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein, on the day both the B7-H3-ADC and the PD-1 x CTLA-4 bispecific molecule are administered, the PD-1 x CTLA-4 bispecific molecule is administered prior to administration of the B7-H3-ADC.

19. (a) the PD-1 x CTLA-4 bispecific molecule is administered at least about 15-30 minutes after administration of the B7-H3-ADC; or (b) the anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 18, wherein the B7-H3-ADC is administered at least about 15-30 minutes after administration of the PD-1 x CTLA-4 bispecific molecule.

20. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein said PD-1 x CTLA-4 bispecific molecule is selected from the group consisting of: lorigellimab, MEDI5752, budalimab, and cadnilimab.

21. wherein the PD-1 x CTLA-4 bispecific molecule is lorigellimab, and the lorigellimab is (a) administered at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg every three weeks; or (b) the anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 20, administered at a dose of about 1 mg / kg, about 3 mg / kg, or about 6 mg / kg every four weeks.

22. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein the B7-H3-ADC is administered at a dose of about 1 mg / kg, about 1.25 mg / kg, about 1.5 mg / kg, about 1.75 mg / kg, about 2 mg / kg, about 2.1 mg / kg, about 2.2 mg / kg, about 2.25 mg / kg, about 2.3 mg / kg, about 2.4 mg / kg, about 2.5 mg / kg, about 2.6 mg / kg, about 2.7 mg / kg, about 2.75 mg / kg, or about 3 mg / kg.

23. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2, wherein the B7-H3-ADC is administered by intravenous (IV) infusion.

24. 24. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 23, wherein said IV infusion of said B7-H3-ADC is over a period of at least about 60-120 minutes.

25. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, wherein the PD-1 x CTLA-4 bispecific molecule is administered by IV infusion.

26. 26. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 25, wherein said IV infusion of said PD-1 x CTLA-4 bispecific molecule is over a period of at least about 30-120 minutes.

27. The cancers include: adrenal cancer; AIDS-related cancer; alveolar soft part sarcoma; astrocytic tumor; anal cancer; squamous cell carcinoma of the anal canal (SCAC); bladder cancer; bone cancer; brain and spinal cord cancer; metastatic brain tumor; B-cell cancer; breast cancer; HER2 + Breast cancer; Triple-negative breast cancer (TNBC); Carotid artery tumor; Cervical cancer; Chondrosarcoma; Chordoma; Chromophobe renal cell carcinoma; Clear cell carcinoma; Colon cancer; Colorectal cancer (CRC); Non-high microsatellite instability colorectal cancer (non-MSI-H CRC); Cutaneous benign fibrous histiocytoma; Desmoplastic small round cell tumor; Ependymoma; Ewing's tumor; Extraskeletal myxoid chondrosarcoma; Fibroplasia imperfecta osseous; Fibrous dysplasia; Gallbladder or bile duct cancer; Gastrointestinal cancer; Gestational trophoblastic disease; Germ cell tumor; Head and neck cancer; Glioblastoma; Hematologic malignancies; Hepatocellular carcinoma; Islet cell tumor; Kaposi's sarcoma; Kidney cancer; Leukemia; Acute myeloid leukemia; Liposarcoma / malignant liposarcoma; Dedifferentiated liposarcoma; Liver cancer; Lymphoid tumor; lung cancer; non-small cell lung cancer (NSCLC); medulloblastoma; melanoma; cutaneous melanoma; meningioma; mesothelioma; pharyngeal carcinoma; multiple endocrine neoplasia; multiple myeloma; myelodysplastic syndrome; myxofibrosarcoma; neuroblastoma; neuroendocrine tumor; ovarian cancer; pancreatic cancer; papillary thyroid carcinoma; parathyroid tumor; pediatric cancer; peripheral nerve sheath tumor; pheochromocytoma; pituitary tumor; prostate cancer; metastatic castration-resistant prostate cancer (mCRPC); posterior uveal melanoma; renal cell carcinoma 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2, wherein the anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule is selected from the group consisting of: renal cell carcinoma (RCC); renal cell carcinoma (RCC); renal metastatic carcinoma; rhabdoid tumor; rhabdomyosarcoma; sarcoma; skin cancer; small round blue cell tumor of childhood; neuroblastoma; soft tissue sarcoma; undifferentiated pleomorphic sarcoma; squamous cell carcinoma; squamous cell carcinoma of the head and neck (SCCHN); gastric cancer; synovial sarcoma; testicular cancer; thymic carcinoma; thymoma; thyroid cancer; thyroid metastatic carcinoma; and uterine cancer.

28. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2, wherein the cancer expresses B7-H3.

29. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to Claim 1 or 2, further comprising the step of administering a therapeutically or prophylactically effective amount of one or more additional therapeutic or chemotherapeutic agents, wherein said chemotherapeutic agent is a platinum-based chemotherapeutic agent.

30. 3. The anti-B7-H3 antibody-drug conjugate and PD-1 x CTLA-4 bispecific molecule for use according to claim 1 or 2, wherein the subject in need of treatment is a human.

Images