Methods and compositions for treating autoimmune hemolytic anemia (AIHA)

Abstract

The present invention provides compositions and methods for treating and improving the symptoms of AIHA using antibodies or antigen-binding fragments thereof that specifically bind to human CD19. In particular, the disclosure provides methods, compositions, and uses of obexerimab for the treatment and prevention of relapse in human patients with autoimmune hemolytic anemia (AIHA). In one embodiment, the present invention provides a method for treating autoimmune hemolytic anemia (AIHA), the method comprising subcutaneous administration of obexerimab at a dose of 250 mg once weekly to a human patient. In some embodiments, the disclosure covers methods for treating warm AIHA (wAIHA) using CD19 antibodies such as obexerimab.

Description

Technical Field

[0001] Cross - References to Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 497,936, filed on April 24, 2023, which is hereby incorporated by reference in its entirety.

[0002] Sequence Listing This application includes a sequence listing submitted electronically in XML file format, which is hereby incorporated by reference in its entirety. The XML copy created on April 22, 2024, is named "ZEN - 010WO1_SequenceListing" and is 13,194 bytes.

Background Art

[0003] Autoimmune hemolytic anemia (AIHA) is a rare acquired autoimmune disorder in which autoantibodies directed against self - red blood cell (RBC) membrane antigens lead to accelerated RBC destruction. The destruction of RBCs by immune cells occurs faster than the production rate of new cells, and patients develop anemia, general fatigue, dizziness, fainting, malaise, chest pressure / pain, cognitive impairment, weakness, pale skin color (pallor of the face), palpitations, shortness of breath (dyspnea), the appearance of jaundice, and usually dark - colored urine (hemoglobinuria) that is abnormal and suggestive of hemolysis. Mouse models of AIHA show that reticulocytes are preferentially targeted by anti - RBC autoantibodies and that increased oxidative stress can induce autoantibody production. Although usually not fatal, most patients experience a decline in health - related quality of life. Current treatments used for AIHA include steroids, immunosuppressive agents, and splenectomy. Long - term use of steroids is associated with significant risks of infection, diabetes, and fractures. Defining therapies that utilize treatments for AIHA (e.g., wAIHA) and are tailored to the risks represents a new unmet need.

Summary of the Invention

Means for Solving the Problems

[0004] In particular, this disclosure provides methods, compositions, and uses of obexerimab for the treatment and prevention of relapse in human patients with autoimmune hemolytic anemia (AIHA). In one embodiment, the present invention provides a method for treating autoimmune hemolytic anemia (AIHA), the method comprising subcutaneous administration of obexerimab at a dose of 250 mg once weekly to a human patient. In some embodiments, this disclosure covers methods for treating warm AIHA (wAIHA) using a CD19 antibody such as obexerimab.

[0005] In one embodiment, the present invention provides a method for treating AIHA, which is classified as warm AIHA. In some embodiments, the patient does not have cold agglutinin syndrome, cold AIHA, mixed AIHA, or PCH.

[0006] In some embodiments, the present disclosure comprises a method for treating autoimmune hemolytic anemia (AIHA) comprising subcutaneously administering obexerimab at a dose of 250 mg once weekly to a human patient. In some embodiments, the patient has an Hgb level of ≥7 to <10 g / dL.

[0007] In some embodiments, the patient is diagnosed with warm autoimmune hemolytic anemia (wAIHA). In some embodiments, the patient has at least one sign or symptom of anemia. In some embodiments, the patient has also been unsuccessful with at least one previous wAIHA treatment regimen. In some embodiments, the previous wAIHA treatment regimen is glucocorticoid (GC) or immunosuppressive therapy.

[0008] In some embodiments, the method includes measuring Hgb and / or LDH levels. In some embodiments, failure of a previous wAIHA treatment regimen includes a reduction in Hgb of ≥1 g / dL. In some embodiments, failure of a previous wAIHA treatment regimen includes an increase in LDH of ≥1.5 × upper limit of normal (ULN). In some embodiments, obexerimab is administered concurrently with GC therapy. In some embodiments, GC therapy is administered at a dose of 20–60 mg / day of prednisone or an equivalent dose. In some embodiments, GC therapy is administered at a dose of 1–1.5 mg / kg / day of prednisone or an equivalent dose.

[0009] In some embodiments, the patient maintains an Hgb level of ≥7 g / dL after administration of obexerimab. In some embodiments, the patient maintains an Hgb level of ≥7 g / dL, ≥8 g / dL, ≥9 g / dL, or ≥10 g / dL. In some embodiments, the patient achieves an Hgb of ≥10 g / dL. In some embodiments, the patient achieves an Hgb increase of ≥2 g / dL compared to the Hgb level before treatment with obexerimab. In some embodiments, obexerimab is administered for a period of time sufficient to improve, stabilize, or reduce one or more symptoms of wAIHA compared to a control.

[0010] In some embodiments, patients achieve Hgb improvement after at least 4, 5, 6, 7, 8, 9, 10, 11, or 12 weeks of obexerimab administration. In some embodiments, patients achieve improvement in FACIT-F score compared to baseline (e.g., FACIT-F score before treatment with obexerimab). In some embodiments, patients achieve improvement in EQ-5D-5L index score from baseline (e.g., Q-5D-5L index score before treatment with obexerimab). In some embodiments, patients achieve one or more of the following: (a) a decrease in circulating absolute T cell count, B cell count, and NK cell count; (b) a decrease in Ig levels and ratios (e.g., IgG, IgM, IgA, IgE); (c) an increase in CD19 target receptor occupancy; (d) a decrease in reticulocyte count; (e) a decrease in LDH; (f) an increase in haptoglobin; (g) a decrease in indirect bilirubin (unconjugated bilirubin) after obexerimab administration. In some embodiments, the human patient is relapsed or refractory to rituximab. In some embodiments, the patient is ≥18 years old.

[0011] In some embodiments, the patient does not have cold autoimmune hemolytic amenorrhea (CAD). In some embodiments, the patient does not have mixed autoimmune hemolytic amenorrhea (AMENIA). In some embodiments, the patient does not have paroxysmal cold hemoglobinuria (PCH).

[0012] In some embodiments, obexerimab is administered as a liquid formulation containing 125 mg / mL of obexerimab, 2.35 mg / mL of sodium acetate trihydrate, 0.17 mg / mL of acetic acid, 30 mg / mL of L-proline, and 0.1 mg / mL of polysorbate 80 at pH 5.5. In some embodiments, obexerimab is administered as a 2 × 1 mL injection or a 1 × 2 mL injection. In some embodiments, obexerimab is administered using a pre-filled syringe or an autoinjector. [Brief explanation of the drawing]

[0013] [Figure 1-1] Figure 1 is a schematic diagram illustrating an exemplary clinical trial design for the treatment of wAIHA. [Figure 1-2] Same as above. [Modes for carrying out the invention]

[0014] The present invention provides a method for treating wAIHA-related disease by administering an anti-CD19 antibody to human patients aged 18 years or older who require treatment, in particular, at a therapeutically effective dose and administration interval sufficient to improve, stabilize, or reduce one or more symptoms of wAIHA-related disease compared to a control (e.g., at the start of treatment).

[0015] Various aspects of the present invention will be described in detail in the following sections. The use of these sections is not intended to limit the present invention. Each section may be applied to any aspect of the present invention. In this application, unless otherwise stated, the use of "or" means "and / or".

[0016] definition Several definitions are provided herein. These definitions are intended to encompass grammatical equivalents.

[0017] Antibodies: The term “antibody” as used herein means a protein consisting of one or more polypeptides substantially encoded by all or part of a recognized immunoglobulin gene. Recognized immunoglobulin genes include, for example in humans, kappa (K), lambda (l), and heavy chain loci, which together comprise a multitude of variable region genes and constant region genes mu (u), delta (d), gamma (y), sigma (s), and alpha (a) that encode IgM, IgD, IgG (IgG1, IgG2, IgG3, and IgG4), IgE, and IgA (IgGA1 and IgG2) isotypes, respectively. Antibodies as used herein are intended to include full-length antibodies and antibody fragments and may refer to naturally occurring antibodies of any organism, engineered antibodies, or antibodies recombinantly produced for experimental, therapeutic, or other purposes.

[0018] Baseline: The term "baseline" is defined as the value of a parameter before the start of treatment with a therapeutic agent. In some embodiments, the baseline is an initial measurement of a state that is obtained at an earlier time point and used for a comparison over time to look for changes. In some embodiments, the baseline is "time zero" before a test subject receives an experimental agent or intervention, or a negative control, and the safety and efficacy of a drug can be determined by monitoring changes in the baseline values.

[0019] CD32b + cells or FcγRIIb + Cells: As used herein, the term "CD32b + cells" or "FcγRIIb + cells" means any cell or cell type that expresses CD32b (FcγRIIb). Examples of CD32b+ cells include, but are not limited to, B cells, plasma cells, dendritic cells, macrophages, neutrophils, mast cells, basophils, or eosinophils.

[0020] CDC or complement-dependent cytotoxicity: As used herein, the term "CDC" or "complement-dependent cytotoxicity" means a reaction in which one or more complement protein components recognize a bound antibody on a target cell and subsequently cause lysis of the target cell.

[0021] Effector function: As used herein, the term "effector function" means a biochemical event resulting from the interaction of the Fc region of an antibody with an Fc receptor or ligand. Effector functions include FcγR-mediated effector functions such as ADCC and ADCP, as well as complement-mediated effector functions such as CDC. Furthermore, effector functions include FcγRIIb-mediated effector functions such as inhibitory functions (e.g., downregulating, reducing, inhibiting a B cell response, e.g., a humoral immune response, etc.).

[0022] Effector cell: As used herein, the term "effector cell" means a cell of the immune system that expresses one or more Fc receptors and / or complement receptors and mediates one or more effector functions. Effector cells include, but are not limited to, monocytes, macrophages, neutrophils, dendritic cells, eosinophils, mast cells, platelets, B cells, large granular lymphocytes, Langerhans cells, natural killer (NK) cells, and gd T cells. It may be derived from any organism including, but not limited to, humans, mice, rats, rabbits, and monkeys.

[0023] Fc or Fc region: As used herein, the term "Fc" or "Fc region" means a polypeptide that includes the constant region of an antibody excluding the first constant region immunoglobulin domain and, optionally, a part of the hinge. Thus, Fc refers to the last two constant region immunoglobulin domains of IgA, IgD, and IgG, and the last three constant region immunoglobulin domains of IgE and IgM, as well as the flexible hinge N-terminus to these domains. In the case of IgA and IgM, Fc may include the J chain. In the case of IgG, Fc includes the immunoglobulin domains Cgamma2 and Cgamma3 (Og2 and C3), and the hinge between Cgammal

Number

[0024] Fc gamma receptor, or FcγR: As used herein, the terms “Fc gamma receptor” or “FcγR” mean any member of the protein family that binds to the Fc region of an IgG antibody and is substantially encoded by the FcγR gene. In humans, this family includes, but is not limited to, FcγRI(CD64) including isoforms FcγRIa, FcγRIb, and FcγRIc; FcγRII(CD32) including isoforms FcγRIIa (including allotypes H131 and R131), FcγRIIb (including FcγRIIb-1 and FcγRIIb-2), and FcγRIIc; and FcγRIII(CD16) including isoforms FcγRIIIa (including allotypes V1 58 and F158) and FcγRIIIb (including allotypes FcγRIIIb-NA1 and FcγRIIIb-NA2) (Jefferis et al., 2002, Immunol Lett 82:57-65, the whole is incorporated by reference), as well as any undiscovered human FcγR or FcγR isoform or allotype. FcγR may be derived from any organism, including but not limited to humans, mice, rats, rabbits, and monkeys. Mouse FcγR includes, but is not limited to, FcγRI(CD64), FcγRII(CD32), FcγRIII(CD16), and FcγRIII-2(CD16-2), as well as any undiscovered mouse FcγR or FcγR isoform or allotype.

[0025] Modification: As used herein, “modification” means a change in the physical, chemical, or sequence properties of a protein, polypeptide, antibody, or immunoglobulin. Modifications as described herein include amino acid modifications (including amino acid substitutions) and glycoform modifications.

[0026] Target antigen: As used herein, the term “target antigen” means the molecule to which a given antibody’s variable region is bound, or the fusion partner of an Fc fusion. The target antigen may be a protein, carbohydrate, lipid, or other chemical substance. The antibody or Fc fusion is said to be “specific” to a given target antigen based on having affinity for the target antigen. In some embodiments, the target antigen of obexerimab is CD19.

[0027] Target cells: As used herein, the term “target cells” means cells that express a target antigen.

[0028] Obexerimab: As used herein, the term “obexerimab” refers to an Fc-modified humanized monoclonal antibody (mAb) that binds to the human B cell restriction surface antigen CD19 and has enhanced Fc binding to the Fcγ receptor IIb (FcγRIIb). The molecule is an IgG1 immunoglobulin with two amino acid substitutions in the constant portions of the kappa light chain and heavy chain. Obexerimab is a monoclonal antibody with a predicted mass of approximately 147,426 Da based on its amino acid sequence. The heavy and light chains of obexerimab are given by SEQ ID NOs: 10 and 9, respectively.

[0029] Rescue therapy: As used herein, the term “rescue therapy” refers to the use of therapy to treat suspected relapse of disease or exacerbation of disease symptoms. In some embodiments, rescue therapy is a different approved therapy. In some embodiments, rescue therapy is any therapy that may be used to alleviate symptoms associated with wAIHA. In some embodiments, rescue therapy for wAIHA is glucocorticoid (GC) rescue therapy. In some embodiments, rescue therapy for wAIHA is blood transfusion. Non-limiting examples of rescue therapy include splenectomy, blood transfusion, rituximab, and other anti-CD19 antibody therapies.

[0030] Obexerimab and its variants According to the present invention, obexerimab or its variants are used to treat human patients suffering from wAIHA. Obexerimab is a CD19-specific monoclonal antibody and has a light chain containing a variable region having the following: CDR1 containing RSSKSLQNVNGNTYLY (Sequence ID 2), CDR2 containing RMSNLNS (SEQ ID NO: 3), and CDR3 containing MQHLEYPIT (SEQ ID NO: 4), and Heavy chain including a variable region having the following: CDR1 containing SYVMH (SEQ ID NO: 5), CDR2 containing WIGYINPYNDGTKY (SEQ ID NO: 6), and CDR3 containing GTYYYGTRVFDY (Sequence ID 7), The heavy chain contains amino acid substitutions in the Fc region S267E and L328F compared to the following SEQ ID NO: 8: ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK (Sequence ID 8), The numbering follows the EU index, similar to Kabat.

[0031] In one embodiment, as shown in Table 1, obexerimab comprises a light chain containing the amino acid sequence of (SEQ ID NO: 9) and a heavy chain containing the amino acid sequence of (SEQ ID NO: 10). [Table 1-1] [Table 1-2]

[0032] In one embodiment, obexerimab includes a light chain variable region containing SEQ ID NO: 11 and a heavy chain variable region containing SEQ ID NO: 12.

[0033] Obexerimab acts by utilizing the modulation of B cell receptor (BCR) signaling by FcγRIIb1. Obexerimab binds to CD19 on the BCR complex, and its Fc is manipulated to increase its affinity for inhibitory FcγRIIb. Since CD19 is associated with the BCR, tethering obexerimab to FcγRIIb on the same cell balances the BCR complex for inhibition during antigen-induced BCR aggregation. Obexerimab utilizes the innate inhibitory mechanism of FcγRIIb, the only Fc receptor expressed by B cells, which acts as a negative regulator under conditions of antigen overload and immune complex formation (Chu et al., 2014). Obexerimab also does not mediate B cell killing and may therefore have an improved safety profile compared to B cell depletion antibodies.

[0034] variant In one embodiment, the obexerimab variant is a CD19-specific immunoglobulin comprising a light chain comprising a variable region having CDR1 containing SEQ ID NO: 2, CDR2 containing SEQ ID NO: 3, and CDR3 containing SEQ ID NO: 4, and a heavy chain comprising a variable region having CDR1 containing SEQ ID NO: 5, CDR2 containing SEQ ID NO: 6, and CDR3 containing SEQ ID NO: 7, wherein the heavy chain comprises amino acid substitutions S267E and L328F in the Fc region compared to SEQ ID NO: 8, and the numbering follows the EU index as in Kabat.

[0035] In some embodiments, the obexerimab variant comprises a heavy chain variable region (VH) and / or a light chain variable region (VL) including CDR1, CDR2, and CDR3, each of which differs from each of SEQ ID NOs. 2, SEQ ID NOs. 3, SEQ ID NOs. 4, SEQ ID NOs. 5, SEQ ID NOs. 6, and / or SEQ ID NOs. 7 by 1, 2, 3, 4, or 5 or fewer amino acid residues.

[0036] In some embodiments, the obexerimab variant includes a light chain variable region containing an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 11. In some embodiments, the obexerimab variant includes a heavy chain variable region containing an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 12. In some embodiments, the obexerimab variant includes a light chain variable region containing an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 11, and a heavy chain variable region containing an amino acid sequence that is at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 12, and further includes amino acid substitutions S267E and L328F in the Fc region compared to SEQ ID NO: 8, and the numbering follows the EU index.

[0037] In one embodiment, the obexerimab variant includes a light chain containing an amino acid sequence that is 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to SEQ ID NO: 9. In one embodiment, the obexerimab variant includes a heavy chain containing an amino acid sequence that is 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to SEQ ID NO: 10.

[0038] In some embodiments, the variant of obexerimab comprises a light chain containing an amino acid sequence that is 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 9, and a heavy chain containing an amino acid sequence that is 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 10, wherein the heavy chain of the variant contains amino acid substitutions S267E and L328F in the Fc region compared to SEQ ID NO: 8, and the numbering follows the EU index as in Kabat.

[0039] In one embodiment, a variant of obexerimab contains a light chain with an amino acid sequence that is 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 99% identical to SEQ ID NO: 9 and / or contains amino acid substitutions S267E and L328F in the Fc region compared to SEQ ID NO: 10, and the numbering follows the EU index as in Kabat.

[0040] In some embodiments, preferred variants of obexerimab are antibodies comprising the light chain of SEQ ID NO: 9 and the heavy chain of SEQ ID NO: 10, which bind to the same epitope on human CD19. Epitope binding may be determined by methods known in the art.

[0041] In some embodiments, suitable variants of obexerimab compete for binding to human CD19 as antibodies containing the light chain of SEQ ID NO: 9 and the heavy chain of SEQ ID NO: 10 under binning assays known in the art. As used herein, a binning assay refers to any method for locally mapping the epitopes to which an antibody binds. A standard method for characterizing such antibodies, also known as epitope binning, typically involves surface plasmon resonance (SPR) techniques. Using SPR, monoclonal antibody candidates are screened in pairs for binding to a target protein. Other standard methods include ELISA-based screening, which may require the synthesis of a set of duplicate peptides corresponding to the protein of interest.

[0042] In some embodiments, preferred variants of obexerimab bind to the extracellular domain of human CD19, and human CD19 contains the amino acid sequence of SEQ ID NO: 1. (Sequence ID 1)

[0043] Fc receptor binding properties The anti-CD19 antibodies disclosed herein (e.g., obexerimab) include Fc variants having enhanced Fc binding to inhibitory Fcγ receptor IIb (FcγRIIb). FcγRIIb, the sole FcR on B cells, functions as an antibody-sensing downregulator of humoral immunity, which is spontaneously associated by immune complexes. When sufficient antibody is produced against a given antigen, a specific immune complex is formed, co-engaging FcγRIIb with the B cell receptor (BCR) with high avidity, selectively suppressing only B cells that recognize the congener antigen. Furthermore, FcγRIIb modulates the activity of other B cell stimulants, including interleukin (IL)-4, LPS, and BAFF, which amplify BCR-driven proliferation and differentiation. By simultaneously binding to CD19 and FcγRIIb, obexerimab (and the variants described herein) mimic the action of antigen-antibody complexes and downregulate B cell activity.

[0044] The Fc variants disclosed herein can be optimized for various Fc receptor binding properties. An Fc variant that is manipulated or predicted to exhibit one or more optimized properties is referred to herein as an “optimized Fc variant.” Properties that can be optimized include, but are not limited to, enhanced or reduced affinity for FcγR. In one embodiment, the Fc variant disclosed herein is optimized to have enhanced affinity for the inhibitory receptor FcγRIIb. In other embodiments, the immunoglobulin disclosed herein provides enhanced affinity for FcγRIIb, but reduces affinity for one or more activated FcγRs, including, for example, FcγRI, FcγRIIa, FcγRIIIa, and / or FcγRIIIb. FcγR receptors can be expressed on cells of any organism, including, but not limited to, human, cynomolgus monkey, and mouse. The Fc variants disclosed herein can be optimized to have enhanced affinity for human FcγRIIb.

[0045] An Fc variant comprises one or more amino acid modifications to the parent Fc polypeptide, and the amino acid modifications provide one or more optimized properties. The Fc variants disclosed herein have different amino acid sequences from their parent due to at least one amino acid modification. Therefore, the Fc variants disclosed herein have at least one amino acid modification compared to their parent. Alternatively, the Fc variants disclosed herein may have two or more amino acid modifications compared to their parent, for example, about 2 to 50 amino acid modifications compared to their parent, for example, about 2 to 10 amino acid modifications, about 2 to about 5 amino acid modifications, etc. Therefore, the sequences of the Fc variants and the sequences of the parent Fc polypeptides are substantially homologous. For example, the variant Fc variant sequences herein have about 80% homology to the parent Fc variant sequences, for example, at least about 90% homology, at least about 95% homology, at least about 98% homology, at least about 99% homology, etc. The modifications disclosed herein include amino acid modifications, including insertions, deletions, and substitutions. The modifications disclosed herein also include glycoform modifications.

[0046] The modifications may be genetically synthesized using molecular biology, or they may be synthesized enzymatically or chemically.

[0047] The Fc variants disclosed herein are defined according to the amino acid modifications that constitute them. For example, S267E is an Fc variant having the substitution S267E on the parent Fc polypeptide. Similarly, S267E / L328F defines an Fc variant having the substitutions S267E and L328F on the parent Fc polypeptide. The identity of the WT amino acids does not need to be specified; in this case, the aforementioned variant is referred to as 267E / 328F. Note that the order in which substitutions are provided is arbitrary, i.e., for example, 267E / 328F is the same Fc variant as 328F / 267E. Unless otherwise stated, the locations considered herein are numbered according to the EU index described in Kabat (Kabat et al., 1991, Sequences of Proteins of Immunological Interest, 5th Ed., United States Public Health Service, National Institutes of Health, Bethesda, fully incorporated here by reference). Briefly, EU is the name of the first antibody molecule whose entire amino acid sequence has been determined (Edelman et al., 1969, Proc Natl Acad Sci USA 63:78-85, fully incorporated here by reference), and its amino acid sequence has become the standard numbering scheme for the heavy chain constant region. EU proteins have become the standard reference defining the numbering. Kabat et al. list EU sequences in a set of indices for aligning EU sequences with other antibody sequences as a tool necessary for aligning antibodies to the EU numbering scheme. Therefore, as will be understood by those skilled in the art, the standard way to refer to EU numbering is to refer to Kabat et al.'s sequence alignment to place EU in relation to other antibodies with variable domain lengths. Thus, as used herein, “EU index as Kabat” or “numbering follows EU index as Kabat” refers to the numbering of EU antibodies as described in Kabat.

[0048] In certain embodiments, the Fc variants disclosed herein are based on human IgG sequences, and therefore the human IgG sequence is used as a “base” sequence on which other sequences are compared, including but not limited to sequences from other organisms, such as rodent sequences and primate sequences. Immunoglobulins may also include sequences from other immunoglobulin classes such as IgA, IgE, IgGD, and IgGM. The Fc variants disclosed herein are manipulated in the context of one parent IgG, but the variants are intended to be manipulated in the context of another second parent IgG, or to be “transmitted” to them. This is typically done by determining “equivalent” or “corresponding” residues and substitutions between the first and second IgGs based on sequence or structural homology between the sequences of the first and second IgGs. To establish homology, the amino acid sequences of the first IgG outlined herein can be directly compared to the sequences of the second IgG. After the sequences are aligned, residues corresponding to specific amino acids in the primary sequence of the first immunoglobulin are defined using one or more homologous alignment programs known in the art (e.g., using interspecies-conserved residues) to allow insertions and deletions necessary to maintain the alignment (i.e., avoiding the removal of conserved residues by any deletions and insertions). Alignment of conserved residues may preserve 100% of these residues. However, alignment of more than 75% or even just 50% of conserved residues is also appropriate for defining equivalent residues. Equivalent residues may also be defined by determining the structural homology between the first and second IgG at the tertiary structure level of the structurally determined IgG. In this case, equivalent residues are defined as those in which the atomic coordinates (N on N, CA on CA, C on C, and O on O) of two or more back-chain atoms of a particular amino acid residue of the parent or precursor are within about 0.13 nm after alignment. In another embodiment, equivalent residues are within about 0.1 nm after alignment. Alignment is achieved after the best model has been oriented and positioned to yield the maximum overlap of atomic coordinates of the non-hydrogen protein atoms of the protein.Regardless of how equivalent or corresponding residues are determined, and regardless of the identity of the parent IgG from which the IgG is produced, the intention is that the Fc variant discovered as disclosed herein can be manipulated into any second parent IgG having significant sequence or structural homology to the Fc variant. Therefore, for example, if a variant antibody is produced where the parent antibody is human IgG1, the variant antibody may be manipulated by using the method described above or other methods for determining equivalent residues into another IgG1 parent antibody, human IgG2 parent antibody, human IgA parent antibody, mouse IgG2a or IgG2b parent antibody, etc., that binds to a different antigen. Again, as stated above, the context of the parent Fc variant does not affect the ability to transfer the Fc variant disclosed herein to another parent IgG.

[0049] As used herein, the terms “greater affinity” or “improved affinity,” or “enhanced affinity” or “better affinity” compared to the parent Fc polypeptide mean that the Fc variant binds to the Fc receptor with a significantly higher equilibrium binding constant (KA or Ka) or a lower equilibrium dissociation constant (KD or Kd) than the parent Fc polypeptide when the amounts of the variant and the parent polypeptide in the binding assay are essentially the same. For example, an Fc variant with improved Fc receptor binding affinity may show an improvement of about 5 to 1000 times, for example, about 10 to 500 times, compared to the parent Fc polypeptide, and the Fc receptor binding affinity is determined, for example, by a binding method disclosed herein, including, but not limited to, Biacore, as can be seen by those skilled in the art. Therefore, as used herein, “reduced affinity” compared to the parent Fc polypeptide means that the Fc variant binds to the Fc receptor with a significantly lower KA or higher KD than the parent Fc polypeptide. Greater or reduced affinity can also be defined in comparison to an absolute level of affinity. For example, according to the data herein, WT (natural) IgG1 binds to FcγRIIb with an affinity of about 1.5 mM, or about 1500 nM. Furthermore, some Fc variants described herein bind to FcγRIIb with an affinity about 10 times higher than WT IgG1. As disclosed herein, greater or enhanced affinity means having a KD of less than about 100 nM, for example, about 10 nM to about 100 nM, about 1 to about 100 nM, or less than about 1 nM.

[0050] In one embodiment, the Fc variant provides selectively enhanced affinity for FcγRIIb compared to one or more activating receptors. Selectively enhanced affinity means that the Fc variant has improved affinity for FcγRIIb to the activating receptor compared to the parent Fc polypeptide, but reduced affinity for the activating receptor compared to the parent Fc polypeptide, or that the Fc variant has improved affinity for both FcγRIIb and the activating receptor compared to the parent Fc polypeptide, but the improvement in affinity is greater for FcγRIIb than for the activating receptor. In an alternative embodiment, the Fc variant reduces or cleaves binding to one or more activating FcγRs, reduces or cleaves binding to one or more complement proteins, reduces or cleaves the function of one or more FcγR-mediated effector, and / or reduces or cleaves the function of one or more complement-mediated effector.

[0051] The existence of different polymorphic forms of FcγR provides yet another parameter that influences the therapeutic utility of the Fc variants disclosed herein. While the specificity and selectivity of a given Fc variant to different classes of FcγR significantly influences the ability of the Fc variant to target a given antigen for the treatment of a given disease, the specificity or selectivity of an Fc variant to different polymorphic forms of these receptors can in part determine which studies or preclinical experiments may be appropriate for testing, and ultimately which patient populations may or may not respond to treatment. Thus, the specificity or selectivity of an Fc variant to the Fc receptor polymorphisms disclosed herein, including but not limited to FcγRIIa, FcγRIIIa, etc., can be used to guide the selection of effective studies and preclinical experiments, clinical trial designs, patient selection, dose dependence, and / or other aspects of clinical trials.

[0052] The Fc variants disclosed herein may include, but are not limited to, complement proteins, FcRn, and Fc receptor homologs (FcRH), and may include modifications that modulate interactions with Fc receptors other than FcγR. Examples of FcRH include, but are not limited to, FcRFH, FcRH2, FcRH3, FcRH4, FcRH5, and FcRH6 (Davis et al., 2002, Immunol. Reviews 190:123-136).

[0053] A key parameter determining the most beneficial selectivity of a given Fc variant for treating a given disease is the context of the Fc variant. Therefore, the selectivity or specificity of a given Fc variant to the Fc receptor will provide different properties depending on whether the antibody, Fc fusion, or Fc variant is composed with a binding fusion partner. In one embodiment, the Fc receptor specificity of an Fc variant disclosed herein determines its therapeutic utility. The utility of a given Fc variant for a therapeutic purpose will depend on the epitope or morphology of the target antigen and the disease or indication being treated. For some targets and indications, a higher FcγRIIb affinity and reduced activated FcγR-mediated effector function may be beneficial. For other target antigens and therapeutic applications, increasing the affinity to FcγRIIb, or increasing the affinity to both FcγRIIb and the activating receptor, may be beneficial.

[0054] Pharmaceutical preparations and pharmaceutical compositions The present invention provides pharmaceutical compositions and formulations of anti-CD19 antibodies (e.g., obexerimab). The anti-CD19 antibody formulations disclosed herein are prepared for storage by mixing the antibody, having a desired purity, in the form of a lyophilized formulation or aqueous solution with any pharmaceutically acceptable carrier, excipient, or stabilizer (as fully incorporated by reference, Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed., 1980).

[0055] In some embodiments, the target pharmaceutical composition contains various concentrations of anti-CD19 antibody (e.g., obexerimab). In some embodiments, a suitable formulation may contain the target antibody at concentrations up to approximately 250 mg / ml (e.g., up to approximately 225 mg / ml, up to 200 mg / ml, up to 150 mg / ml, up to 140 mg / ml, up to 130 mg / ml, up to 125 mg / ml, up to 120 mg / ml, up to 115 mg / ml, up to 110 mg / ml, up to 105 mg / ml, up to 100 mg / ml, up to 90 mg / ml, up to 80 mg / ml, up to 70 mg / ml, up to 60 mg / ml, up to 50 mg / ml, up to 40 mg / ml, up to 30 mg / ml, up to 25 mg / ml, up to 20 mg / ml, up to 10 mg / ml).

[0056] In some embodiments, a suitable formulation may contain anti-CD19 antibody in a concentration ranging from about 10 to 300 mg / ml (for example, about 10 to 250 mg / ml, about 10 to 200 mg / ml, about 10 to 180 mg / ml, about 10 to 160 mg / ml, about 10 to 150 mg / ml, about 10 to 140 mg / ml, about 10 to 130 mg / ml, about 10 to 125 mg / ml, about 100 to 125 mg / ml, about 100 to 180 mg / ml, about 100 to 150 mg / ml, about 100 to 130 mg / ml, about 100 to 125 mg / ml, about 100 to 170 mg / ml, about 100 to 160 mg / ml, about 100 to 150 mg / ml, about 100 to 200 mg / ml, about 120 to 130 mg / ml).

[0057] In some embodiments, formulations suitable for subcutaneous administration may contain the target protein at concentrations of approximately 100 mg / ml, 115 mg / ml, 120 mg / ml, 125 mg / ml, 130 mg / ml, 135 mg / ml, 140 mg / ml, 145 mg / ml, 150 mg / ml, 200 mg / ml, or 300 mg / ml.

[0058] In some embodiments, isotonic solutions are used. In some embodiments, slightly hypertonic solutions (e.g., up to 300 mM (e.g., up to 250 mM, 200 mM, 175 mM, 150 mM, 125 mM) of sodium chloride in 5 mM sodium phosphate at pH 7.0) and sugar-containing solutions (e.g., up to 3% (e.g., up to 2.4%, 2.0%, 1.5%, 1.0%) of sucrose in 5 mM sodium phosphate at pH 7.0). In some embodiments, a preferred formulation composition is physiological saline (e.g., 150 mM NaCl in water).

[0059] Many therapeutic agents, particularly the antibodies of the present invention, require a controlled pH and specific excipients to maintain their solubility and stability in the pharmaceutical composition of the present invention.

[0060] The pH of the pharmaceutical composition is an additional factor that can alter the solubility of the anti-CD19 antibody (e.g., obexerimab) in the aqueous pharmaceutical composition. In some embodiments, the pharmaceutical composition of the present invention contains one or more buffers. In some embodiments, the composition according to the present invention contains a sufficient amount of buffer to maintain the optimal pH of the composition at about 4.0–8.0, about 5.0–7.5, about 5.5–7.0, about 6.0–7.0, and about 6.0–7.5. In other embodiments, the buffer contains sodium phosphate in a maximum of about 50 mM (e.g., up to about 45 mM, 40 mM, 35 mM, 30 mM, 25 mM, 20 mM, 15 mM, 10 mM, 5 mM). Suitable buffers include, for example, acetates, succinates, citrates, phosphates, other organic acids, and tris(hydroxymethyl)aminomethane ("Tris").

[0061] Suitable buffer concentrations may range from about 1 mM to about 100 mM, or from about 3 mM to about 20 mM, depending on the desired isotonicity of the buffer and formulation. In some embodiments, suitable buffers are available at concentrations of about 1 mM, 5 mM, 10 mM, 15 mM, 20 mM, 25 mM, 30 mM, 35 mM, 40 mM, 45 mM, 50 mM, 55 mM, 60 mM, 65 mM, 70 mM, 75 mM, 80 mM, 85 mM, 90 mM, 95 mM, or 100 mM.

[0062] In some embodiments, the formulation contains an isotonic agent to maintain the formulation's isotonicity. Exemplary isotonic agents include, but are not limited to, glycine, sorbitol, mannitol, sodium chloride, and arginine. In some embodiments, a preferred isotonic agent may be present in the formulation at a concentration of about 0.01 to 5% by weight (e.g., 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, 2.5, 3.0, 4.0, or 5.0% by weight).

[0063] In some embodiments, the formulation may contain a stabilizer to protect the antibody. Typically, preferred stabilizers are non-reducing sugars such as sucrose, raffinose, and trehalose, or amino acids such as glycine, arginine, and methionine. The amount of stabilizer in the formulation is generally such that the formulation is isotonic. However, hypertonic formulations may also be preferred. Furthermore, the amount of stabilizer should not be too low so that an unacceptable amount of antibody degradation / aggregation occurs. Exemplary stabilizer concentrations in the formulation may range from about 1 mM to about 400 mM (e.g., about 30 mM to about 300 mM, and about 50 mM to about 100 mM), or alternatively, 0.1% to 15% by weight (e.g., 1% to 10% by weight, 5% to 15% by weight, 5% to 10% by weight). In some embodiments, the mass ratio of stabilizer to therapeutic agent is about 1:1. In other embodiments, the mass ratio of the stabilizer to the therapeutic agent is approximately 0.1:1, 0.2:1, 0.25:1, 0.4:1, 0.5:1, 1:1, 2:1, 2.6:1, 3:1, 4:1, 5:1, 10:1, or 20:1. In some embodiments suitable for freeze-drying, the stabilizer is also a lyoprotectant.

[0064] The pharmaceutical compositions, formulations, and related methods of the present invention are useful for delivering anti-CD19 antibodies (e.g., subcutaneously) and treating related diseases. The pharmaceutical compositions of the present invention are particularly useful for delivering anti-CD19 antibodies (e.g., obexerimab) to patients suffering from wAIHA.

[0065] In some embodiments, it is desirable to add a surfactant to the formulation. Exemplary surfactants include nonionic surfactants such as polysorbate (e.g., polysorbate 20 or 80); poloxamer (e.g., poloxamer 188); triton; sodium dodecyl sulfate (SDS); sodium lauryl sulfate; sodium octyl glycoside; lauryl-, myristyl-, linoleyl-, or stearyl-sulfobetaine; lauryl-, myristyl-, linoleyl-, or stearyl-sarcosine; linoleyl-, myristyl-, or cetyl-betaine; lauroamidopropyl-, cocamidopropyl-, linoleamidopropyl-, myristamidopropyl-, palmidopropyl-, or isostearamidopropyl-betaine (e.g., lauroamidopropyl); myristarnidopropyl-, palmidopropyl-, or isostearamidopropyl-dimethylamine; sodium cocoyl methyl taurate, or disodium oleyl methyl taurate; and the MONAQUAT™ series (Mona Examples include surfactants (Paterson Industries, Inc., NJ), polyethyl glycol, polypropyl glycol, and copolymers of ethylene and propylene glycol (e.g., Pluronics® PF68). Typically, the amount of surfactant added is such that it reduces protein aggregation and minimizes particle or foam formation. For example, the surfactant may be present in the formulation at a concentration of about 0.001–0.5% (e.g., about 0.005–0.05%, or 0.005–0.01%). In particular, the surfactant may be present in the formulation at concentrations such as approximately 0.005%, 0.01%, 0.02%, 0.1%, 0.2%, 0.3%, 0.4%, or 0.5%.

[0066] In some embodiments, a preferred formulation may further include one or more extenders, particularly for lyophilization and formylation. An "extender" is a compound that adds mass to the lyophilized mixture and contributes to the physical structure of the lyophilized cake. For example, an extender can improve the appearance of the lyophilized cake (e.g., an essentially homogeneous lyophilized cake). Preferred extenders include, but are not limited to, sodium chloride, lactose, mannitol, glycine, sucrose, trehalose, and hydroxyethyl starch. Exemplary concentrations of extenders are about 1% to about 10% (e.g., 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, and 10.0%).

[0067] The formulations according to the present invention can be evaluated based on product quality analysis, reconstitution time (if lyophilized), reconstitution quality (if lyophilized), molecular weight, moisture content, and glass transition temperature. Typically, protein quality and product analysis include product degradation rate analysis using methods including, but not limited to, size exclusion HPLC (SE-HPLC), cation exchange HPLC (CEX-HPLC), X-ray diffraction (XRD), modulated differential scanning calorimetry (mDSC), reversed-phase HPLC (RP-HPLC), multi-angle light scattering (MALS), fluorescence, ultraviolet absorption, turbidimetry, capillary electrophoresis (CE), SDS-PAGE, and combinations thereof. In some embodiments, evaluation of the product according to the present invention may include a step of evaluating its appearance (either liquid or cake appearance).

[0068] In general, formulations (lyophilized or aqueous) can be stored for long periods at room temperature. Storage temperatures can typically range from 0°C to 45°C (e.g., 4°C, 20°C, 25°C, 45°C, etc.). Formulations may be stored for periods ranging from several months to several years. Storage times are generally 24 months, 12 months, 6 months, 4.5 months, 3 months, 2 months, or 1 month. Formulations can be stored directly in the containers used for administration, eliminating the need for transfer.

[0069] The formulation can be stored directly in a lyophilized container (if lyophilized), which also serves as a reconstitution container, eliminating the need for transfer. Alternatively, the lyophilized product formulation may be measured into smaller increments for storage. Storage should generally avoid situations that could lead to protein degradation, including but not limited to exposure to sunlight, UV radiation, other forms of electromagnetic radiation, excessive heat or cold, rapid thermal shock, and mechanical shock.

[0070] In some embodiments, the formulations according to the present invention are in liquid or aqueous form. In some embodiments, the formulations according to the present invention are lyophilized. Such lyophilized formulations may be reconstituted by adding one or more diluents to them before administration to a patient. Suitable diluents include, but are not limited to, sterile water, bacteriostatic water for injection, and sterile saline. Preferably, upon reconstitution, the antibodies contained therein are stable, soluble, and tolerable upon administration to a patient.

[0071] The pharmaceutical compositions of the present invention are characterized by their tolerability. As used herein, the terms “tolerable” and “tolerability” refer to the ability of the pharmaceutical compositions of the present invention to not cause adverse reactions in patients to whom such compositions are administered, or, alternatively, to not cause serious adverse reactions in patients to whom such compositions are administered. In some embodiments, the pharmaceutical compositions of the present invention are well accepted by patients to whom such compositions are administered.

[0072] Acceptable carriers, excipients, or stabilizers are non-toxic to the recipient at the dose and concentration used and include buffers such as phosphates, citrates, acetates, and other organic acids; antioxidants including ascorbic acid and methionine; preservatives (such as octadecyldimethylbenzylammonium chloride, hexamethonium chloride, benzalkonium chloride, benzethonium chloride, phenol, butyl or benzyl alcohol, alkylparabens such as methyl or propylparaben, catechol, resorcinol, cyclohexanol, 3-pentanol, and m-cresol); low molecular weight (less than approximately 10 residues) polypeptides; proteins such as serum albumin, gelatin, or immunoglobulins; polyvinyl This product contains hydrophilic polymers such as lupyrolidone, amino acids such as glycine, glutamine, asparagine, histidine, arginine, or lysine, monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrin, chelating agents such as EDTA, sugars such as sucrose, mannitol, trehalose, or sorbitol, sweeteners and other flavoring agents, fillers such as microcrystalline cellulose, lactose, corn, and other starches, binders, additives, colorants, salt-forming counterions such as sodium, metal complexes (e.g., Zn protein complexes), and / or nonionic surfactants such as TWEEN®, PLURONICS®, or polyethylene glycol (PEG).

[0073] In some embodiments, the antibody-containing pharmaceutical compositions disclosed herein may be in a water-soluble form, such as existing as a pharmaceutically acceptable salt, meaning that they contain both an acid and a base addition salt. A "pharmaceutically acceptable acid addition salt" means a salt that retains the biological efficacy of a free base and is not biologically or otherwise undesirable, and is formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, and phosphoric acid, and organic acids such as acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, and salicylic acid.

[0074] Examples of "pharmaceutically acceptable base addition salts" include those derived from inorganic bases such as sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, and aluminum salts. Some embodiments include at least one of ammonium salts, potassium salts, sodium salts, calcium salts, and magnesium salts. Examples of pharmaceutically acceptable salts derived from organic non-toxic bases include salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, and basic ion exchange resins such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, and ethanolamine.

[0075] Formulations used for in vivo administration (e.g., subcutaneous administration) may be sterile. In some embodiments, the formulations are sterilized by filtration through a sterile filtration membrane.

[0076] In some embodiments, the anti-CD19 antibody (e.g., obexerimab) disclosed herein is formulated for subcutaneous (SC) administration. In some embodiments, the anti-CD19 antibody (e.g., obexerimab) formulation for SC administration comprises one or more buffers, one or more isotonic modifiers, one or more solvents, and one or more surfactants. Non-limiting examples of buffers include phosphates, citrates, acetates, glutamates, carbonates, tartrates, triethanolamine (TRIS), glycylglycine, histidine, glycine, lysine, arginine, and other organic acids. More specifically, non-limiting examples of buffers include sodium HEPES, MES, potassium phosphate, potassium thiocyanate, sterilizers, TAE, TBE, ammonium sulfate / HEPES, BuffAR, sodium acetate, sodium carbonate, sodium citrate, sodium dihydrogen phosphate, disodium hydrogen phosphate, and sodium phosphate. Furthermore, the buffers may be in various hydrate forms. For example, the buffer may be monohydrate, dihydrate, trihydrate, tetrahydrate, pentahydrate, hexahydrate, heptahydrate, octahydrate, nunahydrate, decahydrate, elevenhydrate, and dodecahydrate. Occasionally, the hydrate may be a fraction such as hemihydrate or 1.5-hydrate (sequihydrate). Non-limiting examples of tonic modifiers include sodium chloride, acetic acid, L-proline, dextrose, mannitol, potassium chloride, glycerin, and glycerol. Non-limiting examples of solvents include water, propylene glycol, polyethylene glycol, ethanol, dimethyl sulfoxide, N-methyl-2-pyrrolidone, Glycoflor, Solketal®, glycerol formal, acetone, tetrahydrofurfuryl alcohol, diglym, dimethyl isosorbide, and ethyl lactate.Non-limiting examples of solvents include polysorbates (e.g., polysorbate-20, polysorbate-80), polyoxyethylene sorbitan monooleate (Tween® 80), sorbitan monooleate polyoxyethylene sorbitan monolaurate (Tween® 20), sorbitan trioleate (Span 85), lecithin, and polyoxyethylene polyoxypropylene copolymers (Pluronics®, Pluronic® F-68).

[0077] The amounts of anti-CD19 antibody (e.g., obexerimab), buffer, isotonic modifier, solvent, and surfactant may vary. In some embodiments, the anti-CD19 antibody (e.g., obexerimab) is formulated at a concentration of 125 mg / mL of obexerimab, 2.35 mg / mL of sodium acetate trihydrate, 0.17 mg / mL of acetic acid (density 1.053 g / mL), 30 mg / mL of L-proline, and 0.1 mg / mL of polysorbate 80, at a pH of 5.5. In some embodiments, the anti-CD19 antibody (e.g., obexerimab) is formulated at a concentration of 80-200 mg / mL of obexerimab, 1.5-3 mg / mL of sodium acetate trihydrate, 0.1-0.2 mg / mL of acetic acid (density 1.053 g / mL), 10-50 mg / mL of L-proline, and 0.05-0.2 mg / mL of polysorbate 80, with a pH of 5.0-6.0. In some embodiments, the anti-CD19 antibody (e.g., obexerimab) is formulated at a concentration of 122-127 mg / mL of obexerimab, 2.0-2.5 mg / mL of sodium acetate trihydrate, 0.15-0.19 mg / mL of acetic acid (density 1.053 g / mL), 25-35 mg / mL of L-proline, and 0.05-0.15 mg / mL of polysorbate 80, with a pH of 5.0-6.0.

[0078] In certain embodiments, the subcutaneous (SC) formulation comprises an anti-CD19 antibody (e.g., obexerimab), one or more buffers, one or more isotonic modifiers, one or more solvents, and one or more surfactants. In some embodiments, the buffer may be a sodium acetate buffer. For example, the buffer may be sodium acetate trihydrate. In one embodiment, the isotonic modifier may be acetic acid, L-proline, or a combination thereof. In another embodiment, the solvent is water.

[0079] In some embodiments, the surfactant is polysorbate. In some embodiments, the polysorbate is polysorbate-80. In some embodiments, the SC formulation comprises an anti-CD19 antibody (e.g., obexerimab), sodium acetate trihydrate, acetic acid and L-proline, water, and polysorbate-80.

[0080] In some embodiments, the subcutaneous (SC) formulation comprises an anti-CD19 antibody (e.g., obexerimab) in an amount of about 1 mg to about 500 mg per mL, or about 50 mg to about 250 mg per mL, or about 100 mg to about 250 mg per mL; sodium acetate trihydrate in an amount of about 1 to about 10 mg per mL, or about 1 to about 5 mg per mL, or about 1 to about 2.5 mg per mL; acetic acid and L-proline in an amount of about 5 to about 50 mg per mL, or about 10 to about 50 mg per mL, or about 20 to about 40 mg per mL; up to about 1 mL of water; and polysorbate-80 in an amount of about 0.01 mg to about 1 mg per mL, or about 0.01 to about 0.5 mg / mL, or about 0.05 to about 0.2 mg / mL. Specifically, the SC formulation contains approximately 100 mg to 250 mg / ml of anti-CD19 antibody (e.g., obexerimab), approximately 1 to 2.5 mg / ml of sodium acetate trihydrate, approximately 20 to 40 mg / ml of acetic acid and L-proline, up to approximately 1 mg / ml of water, and approximately 0.05 to 0.2 mg / ml of polysorbate-80.

[0081] In some embodiments, the subcutaneous formulation comprises obexerimab, a buffer, and an isotonic modifier. In some embodiments, the subcutaneous formulation comprises 100 mg / mL to 250 mg / mL of obexerimab, acetate buffer, and proline. In some embodiments, the subcutaneous formulation comprises 125 mg / mL of obexerimab, acetate buffer, and proline. In some embodiments, the subcutaneous formulation comprises 100 mg / mL to 250 mg / mL of obexerimab, 5 to 40 mM acetate buffer, and 1% to 5% (w / v) of proline. In some embodiments, the subcutaneous formulation contains 125 mg / mL of obexerimab, 20 mM acetate buffer, and 3% (w / v) of proline at pH 5 to 6. In some embodiments, the subcutaneous formulation contains 125 mg / mL of obexerimab, 20 mM acetate buffer, and 3% (w / v) proline at pH 5.5.

[0082] In some embodiments, the subcutaneous formulation comprises obexerimab, a buffer, an isotonic modifier, and a surfactant.

[0083] In some embodiments, the subcutaneous formulation comprises 100 mg / mL to 250 mg / mL of obexerimab, acetate buffer, proline, and polysorbate 80.

[0084] In some embodiments, the subcutaneous formulation comprises 100 mg / mL to 250 mg / mL of obexerimab, 5 to 40 mM acetate buffer, 1% to 5% (w / v) proline, and 0.002% to 0.02% (w / v) polysorbate 80.

[0085] In some embodiments, the subcutaneous formulation contains 125 mg / mL of obexerimab, 20 mM acetate buffer, 3% (w / v) proline, and 0.01% (w / v) polysorbate 80 at pH 5-6.

[0086] In some embodiments, the subcutaneous formulation contains 125 mg / mL of obexerimab, 20 mM acetate buffer, 3% (w / v) proline, and 0.01% (w / v) polysorbate 80 at pH 5.5.

[0087] In some embodiments, the subcutaneous formulation has any one of the features listed in Table 2 of this specification. For example, in some embodiments, the subcutaneous formulation contains 125 mg / mL of obexerimab, 2.35 mg / mL of sodium acetate trihydrate, 0.17 mg / mL of acetic acid (density 1.053 g / mL), 30 mg / mL of L-proline, and 0.1 mg / mL of polysorbate 80. In some embodiments, the subcutaneous formulation has a pH of 5.5.

[0088] In some embodiments, the subcutaneous formulation has a unit dose intensity / dose level of 125.0 (±10%) mg / mL of obexerimab.

[0089] The anti-CD19 antibodies (e.g., obexerimab) disclosed herein may also be formulated as immunoliposomes. Liposomes are vesicles containing various types of lipids, phospholipids, and / or surfactants useful for the delivery of anti-CD19 antibodies (e.g., obexerimab) to mammals. Liposomes containing anti-CD19 antibodies (e.g., obexerimab) are prepared by methods known in the art. Liposomes with enhanced circulation time are disclosed in U.S. Patent No. 5,013,556, which is fully incorporated by reference. In some embodiments, the anti-CD19 antibody (e.g., obexerimab) is formulated in liposomes produced by reverse-phase evaporation using a lipid composition containing phosphatidylcholine, cholesterol, and PEG-derivativeized phosphatidylethanolamine (PEG-PE). The liposomes are extruded through a filter with a defined pore size to obtain liposomes having a desired diameter.

[0090] In some embodiments, an anti-CD19 antibody (e.g., obexerimab) is encapsulated in microcapsules prepared by methods including, but not limited to, coacervation techniques, interfacial polymerization (e.g., using hydroxymethylcellulose or gelatin microcapsules, or poly-(methylmethacylate) microcapsules), colloidal drug delivery systems (e.g., liposomes, albumin microspheres, microemulsions, nanoparticles, and nanocapsules), and macroemulsions. Such techniques are disclosed in Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed., 1980, and are fully incorporated by reference.

[0091] In some embodiments, sustained-release preparations of anti-CD19 antibodies (e.g., obexerimab) may be prepared. Suitable examples of sustained-release preparations include a semipermeable matrix of a solid hydrophobic polymer, the matrix of which may be in the form of a molded article, such as a film, or microcapsules. Examples of sustained-release matrices include polyesters, hydrogels (e.g., poly(2-hydroxyethyl methacrylate) or poly(vinyl alcohol)), polylactides (US3,773,919, the whole being incorporated by reference), L-glutamic acid and gamma-ethyl-L-glutamate copolymers, non-degradable ethylene vinyl acetate, degradable lactate-glycolic acid copolymers such as Lupron Depot® (an injectable microsphere composed of lactate-glycolic acid copolymer and leuprolide acetate), poly-D-(-)-3-hydroxybutyrate, and ProLease® (commercially available from Alkermes), which is a microsphere-based delivery system composed of desirable bioactive molecules incorporated into a poly-DL-lactide-co-glycolide (PLG) substrate.

[0092] injection container The present invention provides a container for injecting pharmaceutical compositions and formulations of an anti-CD19 antibody (e.g., obexerimab). In one embodiment, the container contains a liquid pharmaceutical composition comprising obexerimab. Suitable containers include, but are not limited to, syringes, autoinjectors, vials, injection bottles, ampoules, carpoules, syringes with needle protection systems, and carpoules in injection pens.

[0093] In some embodiments, the container containing the liquid pharmaceutical composition is a pre-filled syringe, a vial, or an autoinjector. In some embodiments, the container is a pre-filled syringe. In some embodiments, the container is an autoinjector. In some embodiments, the autoinjector administers a fixed injection dose volume of 2.0 mL. In some embodiments, the autoinjector administers a fixed injection dose volume of 2.0 mL using a 27-gauge needle. In some embodiments, the autoinjector is suitable for administering an effective amount of the obexerimab composition (e.g., any formulation described herein) to a patient once a week.

[0094] In some embodiments, the container is a. Obexerimab at 122-127 mg / mL, b. At pH 5.0-6.0, 2.0-2.5 mg / mL of sodium acetate trihydrate, c. Acetic acid at 0.15~0.19 mg / mL (density 1.053 g / mL), d. L-proline at 25-35 mg / mL, A pre-filled syringe or auto-injector containing a liquid pharmaceutical composition comprising e.05~0.15 mg / mL of polysorbate 80.

[0095] In some embodiments, the pre-filled syringe or autoinjector contains a liquid pharmaceutical composition, which is pH 5.5 and contains approximately 125 mg / mL of obexerimab, 2.35 mg / mL of sodium acetate trihydrate, 0.17 mg / mL of acetic acid, 30 mg / mL of L-proline, and 0.1 mg / mL of polysorbate 80.

[0096] In some embodiments, the pre-filled syringe or autoinjector contains a liquid pharmaceutical composition having a unit dose strength of 125.0 (±10%) mg / mL of obexerimab.

[0097] In some embodiments, the pre-filled syringe or autoinjector contains a liquid pharmaceutical composition at pH 5.5, comprising approximately 125 mg / mL of obexerimab, 20 mM acetate buffer, 3% (w / v) proline, and 0.01% (w / v) polysorbate 80.

[0098] In some embodiments, a pre-filled syringe or autoinjector facilitates subcutaneous or intradermal delivery of the pharmaceutical composition. In some embodiments, the method for treating AIHA (e.g., wAIHA) described herein includes administering a formulation containing obexerimab into the patient's bloodstream after single or multiple subcutaneous injections into the patient's abdomen using a pre-filled syringe or autoinjector.

[0099] In some embodiments, a method for treating AIHA (e.g., wAIHA) includes administering a fixed injection dose of 2.0 mL once weekly. In some embodiments, a method for treating AIHA (e.g., wAIHA) includes administering 2.0 mL of 125 mg / mL obexerimab, 20 mM acetate buffer, 3% (w / v) proline, and 0.01% (w / v) polysorbate 80 once weekly at pH 5.5.

[0100] In some embodiments, the composition in the pre-filled syringe is stable for at least 3 months when stored at 2-8°C. In some embodiments, the composition in the pre-filled syringe is stable for at least 6 months when stored at 2-8°C. In some embodiments, the composition in the pre-filled syringe is stable for at least 6 months when stored at 2-8°C. In some embodiments, the composition in the pre-filled syringe is stable for at least 1 year when stored at 2-8°C. In some embodiments, the composition in the pre-filled syringe is stable for at least 2 years when stored at 2-8°C.

[0101] Autoimmune hemolytic anemia (AIHA) This specification provides a method for treating AIHA, including the administration of obexerimab. Hemolytic anemia occurs when red blood cells (RBCs) undergo hemolysis before they can recover. Severe anemia is considered to be Hgb <10.0 g / dL. Autoimmune hemolytic anemia (AIHA) is an acquired hematological disorder caused by increased peripheral erythrocyte destruction mediated by autoantibodies against erythrocyte (RBC) antigens. Autoimmune hemolytic anemia (AIHA) can occur with or without complement activation. In fact, the identification of antibodies against RBC antigens is crucial in the diagnosis of AIHA. For example, RBCs are first evaluated for the presence of both immunoglobulins and C3 using multispecific antiserum. The underlying etiology of such autoantibodies remains unknown. Known associations with autoimmune hemolytic anemia (AIHA) include lymphoproliferative neoplasms, autoimmune conditions, drug use, and viral infections. The clinical presentation is heterogeneous, ranging from mild / compensated anemia to life-threatening anemia, depending on the thermal amplitude, isotype, complement fixation ability, and bone marrow compensation of the antibodies. Steroids, immunosuppressants, and splenectomy are central to treatment. One of the many clinical challenges to treating AIHA is treatment resistance or relapse of AIHA. In atypical settings, AIHA occurs after autologous and allogeneic hematopoietic stem cell transplantation. These cases are generally severe, resistant to standard treatment, and have a high mortality rate. AIHA can be primary / idiopathic or secondary to infections, autoimmune diseases, malignancies, particularly lymphoproliferative disorders, and drugs, further complicating their clinical presentation and management. Regarding new drugs, false-positive Coombs test (direct antiglobulin test, DAT) after daratumumab, along with passenger lymphocytosis after solid organ transplantation, is added to the list of diagnostic challenges. AIHA is also increasingly being described in the context of solid tumor therapy using immune checkpoint molecule inhibitors.

[0102] Warm autoimmune hemolytic anemia (wAIHA) Warm-reactive autoantibodies are encountered relatively frequently in tertiary care hospitals. WAIHA is characterized by evidence of RBC hemolysis and DAT positivity for IgG and, in some cases, complement. Symptoms of anemia, as well as jaundice, are predominant, although they vary depending on the degree of compensatory increase in RBC production, and the latter is often exacerbated by the co-occurrence of Gilbert's syndrome. Rarely, the antibody may be IgA, and even less commonly, IgM, which may account for about 5% of patients with "Coombs-negative" wAIHA.

[0103] Over 95% of wAIHA patients have IgG antibodies that bind to RBC antigens regardless of temperature. These antibodies bind to two major RBC antigens: Rh protein and glyfolin. While we don't want to be bound by theory, autoantibodies that bind to Rh protein are less likely to activate complement due to their presence on RBCs, while autoantibodies that bind to glyfolin may activate complement. Once bound to antibodies, RBCs can meet diverse fates. Most bind to splenic macrophages via FcγRIII receptors, resulting in either phagocytosis of the entire RBC or removal of a significant portion of RBC membrane-producing spherocytes (also known as miniature spherocytes). Unlike normal RBCs, spherocytes are immutable and are destroyed upon entering Billroth's cords of the spleen. This may explain some of the increased LDH and decreased haptoglobin. Approximately one-third of wAIHA patients have additionally RBC-bound complement, and these C3b-coated RBCs are then removed by C3b receptors on hepatic Kupffer cells. In some of these RBCs, C3b is inactivated to C3d, thereby preventing their subsequent destruction and allowing the population of antibody / complement-coated RBCs to persist.

[0104] In summary, wAIHA can be defined by: (1) evidence of hemolysis, (2) IgG antibodies (warm antibodies) that bind to protein antigens on the surface of RBCs at core body temperature, as indicated by a positive Coombs test for IgG in 95% of patients, and (3) spherocytes in peripheral blood smears.

[0105] Patients with wAIHA present with typical symptoms of anemia, including shortness of breath with exercise, general fatigue, dizziness, syncope, malaise, chest tightness / pain, and cognitive impairment. Most patients experience a reduced quality of health. Some wAIHA patients have mild anemia and increased mean corpuscular volume and are referred to hematology to assess the possibility of myelodysplastic syndrome. The increased mean corpuscular volume is associated with an increased number of reticulocytes (generally larger than more mature RBCs) and is not due to primary myelopathy.

[0106] In some embodiments, the patient has primary wAIHA. In some embodiments, the patient has secondary wAIHA. In some embodiments, the patient has secondary wAIHA due to autoimmune disorder. In some embodiments, secondary wAIHA is caused by systemic lupus erythematosus, rheumatoid arthritis, or immune system deficiency (immunodeficiency). In some embodiments, the patient has secondary wAIHA due to lymphoproliferative disorder, B-cell lymphoma, or chronic lymphocytic leukemia (CLL). In some embodiments, the patient has secondary wAIHA due to infection or drug use such as methyldopa or carbamazepine.

[0107] Cold autoimmune hemolytic anemia (cAIHA) Cold-reactive autoimmune hemolytic anemia (cAIHA), or cold agglutinin disease (CAD), is a rare form of hemolytic anemia. Cold AIHA is typically a primary lymphoproliferative disorder involving myeloid B cell clones that produce pathogenic IgM. More rarely, secondary cold AIHA (cAIHA) can develop from malignancies, infections, or other autoimmune disorders. Cold autoimmune hemolytic anemia (cAIHA) is caused by IgM autoantibodies in which the κ light chain binds to the erythrocyte I (or i) antigen at temperatures below 37°C. The pathogenic antibodies are cold agglutinins, most commonly immunoglobulin M (IgM) subtypes with I antigen specificity. Cold agglutinins fix complement (C1q) below core body temperature and dissociate from erythrocytes as they migrate to the core, leading to activation of the classical complement pathway and deposition of C3b on the surface of RBCs. Complement-coated red blood cells undergo extravascular hemolysis via the C3b receptor of the hepatic mononuclear phagocytic system. If large amounts of complement are produced, the formation of membrane-invasive complexes leads to intravascular hemolysis. This process is generally limited by the presence of complement regulatory proteins (CD55 and CD59) on the red blood cell surface.

[0108] In patients with cAIHA, DAT is positive for the presence of C3d. Hemolysis is also observed, accompanied by increased reticulocyte count and positive hemolytic markers. Mean corpuscular volume is elevated, either reflecting reticulocyte plaque or erroneously elevated due to RBC agglutination. RBC agglutination is evident in peripheral blood smears.

[0109] Cold AIHA is generally primary, but can also be secondary to another disorder. In adults, CAD is a clonal disorder driven by low-grade B-cell proliferation in the absence of an apparent malignancy. The proliferating B cells produce IgM, which drives hemolysis through complement activation. CAD is more common than cold agglutinin syndrome (CAS), which is defined as cold hemolytic anemia that occurs secondary to another disorder such as an autoimmune disease, infection, or malignancy.

[0110] In one embodiment, the present invention provides a method for treating cold-reactive autoimmune hemolytic anemia (cAIHA), comprising administering obexerimab according to the method disclosed herein. The terms cold-reactive autoimmune hemolytic anemia (cAIHA) and cold agglutinin disease (CAD) are used interchangeably in this disclosure.

[0111] mixed AIHA Mixed autoimmune hemolytic anemia (AIHA) is defined by the presence of both warm and cold autoantibodies. Mixed AIHA, diagnosed by detecting autoantibodies using monospecific direct antiglobulin testing that shows patterns of IgG and complement C3d and the presence of cold agglutinins, accounts for less than 10% of all cases. Such variants of AIHA may be idiopathic or secondary to lymphoproliferative disorders or systemic lupus erythematosus (SLE). Patients with mixed AIHA often follow a chronic course and experience periodic severe exacerbations. Hemoglobin levels may drop to less than 5 g / dL. Hematological screening shows panagglutination with IgG. DAT is positive for IgG and C3d.

[0112] In one embodiment, the present invention provides a method for treating mixed AIHA, comprising administering obexerimab according to the method disclosed herein.

[0113] Paroxysmal cold hemoglobinuria (PCH) Paroxysmal cold hemoglobinuria (PCH) is a rare form of cold autoimmune hemolytic anemia first discovered in the early 20th century in adults with tertiary syphilis. Initially described as a chronic, relapsing disease in adults with tertiary syphilis, today, the acute form of PCH in children is most commonly documented, with a median age of 5 years. PCH accounts for 30–40% of all pediatric cases of autoimmune hemolytic anemia. Certain viruses are thought to be involved in the acute onset of PCH in children, including measles, mumps, varicella, cytomegalovirus, EBV, influenza, parvovirus B19, coxsackievirus, and adenovirus.

[0114] The diagnosis of PCH is confirmed by the presence of DL antibodies, which are biphasic polyclonal IgG that bind most commonly to the p antigen, on the surface of RBCs in cold extremities. The antibody fixes the first two components of the complement cascade and then dissociates upon rewarming, resulting in complement-mediated intravascular hemolysis. Due to this biphasic nature, the DAT is negative for IgG and positive for anti-C3. In the differential diagnosis of PCH, cold agglutinin disease has the same DAT results but the DL test is negative (named after Julius Donath and Karl Landsteiner, who discovered this test). Furthermore, IgM is positive and peripheral blood smears show RBC agglutination.

[0115] The DL test can be performed either directly using whole blood or indirectly using isolated serum. In the direct test, two blood samples are collected and immediately incubated at 37°C. The test sample is cooled to 0°C for 1 hour, then reheated to 37°C for 30 minutes, while the control sample is maintained at 37°C throughout the procedure. The supernatant serum of the cooled sample shows signs of hemolysis and will test positive.

[0116] Given the spontaneous healing nature of acute PCH, management primarily involves avoiding cold. In addition to warming all ingested fluids or intravenous fluids, keeping the patient warm can prevent continuous hemolysis. Depending on the severity of the anemia, blood transfusions may be given, ideally with warmed blood lacking the p antigen. For chronic PCH, avoiding cold remains central to treatment. Glucocorticoids have historically been used for refractory anemia, but there is insufficient evidence to demonstrate any benefit.

[0117] In one embodiment, the present invention provides a method for treating PCH, comprising administering obexerimab according to the method disclosed herein.

[0118] Human patient population This disclosure provides a method for selecting patients for treatment with obexerimab.

[0119] In some embodiments, patients are selected based on a confirmed diagnosis of wAIHA.

[0120] In some embodiments, patients having an Hgb level of ≥7 g / dL are selected.

[0121] In some embodiments, patients with an Hgb level of 7 g / dL or higher are selected. In some embodiments, patients with an Hgb level of 8 g / dL or higher are selected. In some embodiments, patients with an Hgb level of 9 g / dL or higher are selected. In some embodiments, patients with an Hgb level of 10 g / dL or higher are selected.

[0122] In some embodiments, eligible human patients have an Hgb level of 11 g / dL or less than 11 g / dL. In some embodiments, eligible human patients have an Hgb level of 10 g / dL or less than 10 g / dL. In some embodiments, eligible human patients have an Hgb level of 9 g / dL or less than 9 g / dL. In some embodiments, eligible human patients have an Hgb level of 8 g / dL or less than 8 g / dL. In some embodiments, eligible human patients have an Hgb level of 7 g / dL or less than 7 g / dL.

[0123] Eligible human patients for the study are those diagnosed with wAIHA with an Hgb level of 10 g / dL or less than 10 g / dL. In some embodiments, patients selected for treatment have at least one sign or symptom of anemia, such signs or symptoms include, but are not limited to, fatigue, weakness, pallor, chest pain, or shortness of breath (at rest or exertion), headache, dizziness, or lightheadedness, tachycardia, or tachypnea.

[0124] In some embodiments, the patient was also unsuccessful with at least one previous wAIHA treatment regimen (GC or immunosuppressive therapy). In some embodiments, a patient was considered unsuccessful with therapy if, during the course of the disease, Hgb decreased by ≥1 g / dL and LDH increased by ≥1.5 × upper limit of normal (ULN). In some embodiments, failure is assessed after a minimum of 4 weeks of GC therapy. In some embodiments, failure is assessed after a minimum of 3 months of immunosuppressive therapy.

[0125] In some embodiments, the patient has been unsuccessful with up to two previous wAIHA therapies. In some embodiments, if the patient maintains an Hgb level of ≥7 g / dL, the previous unsuccessful therapy may be considered concurrent therapy. In some embodiments, if the patient maintains an Hgb level of ≥8 g / dL, the previous unsuccessful therapy may be considered concurrent therapy. In some embodiments, if the patient maintains an Hgb level of ≥9 g / dL, the previous unsuccessful therapy may be considered concurrent therapy. In some embodiments, if the patient maintains an Hgb level of <10 g / dL on therapy, the previous unsuccessful therapy may be considered concurrent therapy.

[0126] In some embodiments, patients undergoing GC treatment need to receive a stable dose of prednisone or prednisolone not exceeding 20 mg / day for four weeks prior to initiating treatment with obexerimab.

[0127] In some embodiments, patients receiving immunosuppressants are administered a stable dose for 12 weeks and continue with the same stable dose of immunosuppressants. Exemplary immunosuppressants include azathioprine, mycophenolate mofetil / mycophenolate, cyclosporine, and cyclophosphamide.

[0128] In some embodiments, the prior therapy is GC therapy and / or an increase in background long-term GC therapy.

[0129] In some embodiments, eligible patients receive GC treatment for at least two weeks. In some embodiments, eligible patients according to the present invention are required to receive GC treatment for at least three weeks. In some embodiments, eligible patients according to the present invention are required to receive GC treatment for more than three weeks. In some embodiments, eligible patients according to the present invention are required to receive GC treatment for up to six weeks. In some embodiments, GC treatment is administered at a dose of 30-50 mg / day of prednisone or an equivalent dose. In some embodiments, GC treatment is administered at a dose of 10-70 mg / day of prednisone or an equivalent dose. In some embodiments, GC treatment is administered at a dose of 20-60 mg / day of prednisone or an equivalent dose.

[0130] In some embodiments, in eligible patients according to the present invention, GC therapy is administered in conjunction with obexerimab. In some embodiments, GC therapy is tapered before initiation of obexerimab therapy. An exemplary tapering protocol involves administering 0.6–1.0 mg / kg of corticosteroids daily for 2–4 weeks, followed by gradual tapering. In some exemplary embodiments, GC is completely tapered within 8–12 weeks until discontinuation. In some embodiments, tapering takes less than 8 weeks. In some embodiments, tapering takes more than 12 weeks. In some exemplary embodiments, GC therapy can be continued at a low to moderate dose of 2.5–10.0 mg daily for up to several years.

[0131] In some embodiments, eligible patients according to the present invention may have plasmablast levels greater than 100 cells / mL, greater than 200 cells / mL, greater than 300 cells / mL, greater than 400 cells / mL, greater than 500 cells / mL, greater than 600 cells / mL, greater than 700 cells / mL, greater than 800 cells / mL, greater than 900 cells / mL, greater than 1000 cells / mL, greater than 2000 cells / mL, greater than 3000 cells / mL, greater than 4000 cells / mL, or greater than 5000 cells / mL.

[0132] In some embodiments, obexerimab is administered every 7 days. In some embodiments, obexerimab is administered at the research facility for the first 5 weeks, and then every 2 weeks (Q2W) at required visits (e.g., day 1 [week 0] and weeks 1, 2, 3, 4, 6, 8, 10, 12). In some embodiments, all patients are observed for at least 2 hours after the first SC dose of obexerimab during which a safety assessment is performed. For subsequent SC doses, patients may be discharged from the clinic after obexerimab administration if deemed safe, and are instructed to administer obexerimab at home. In some embodiments, blood collection for PK, PD, and anti-drug antibody (ADA) sampling is performed 24 hours and 72 hours after day 1.

[0133] Treatment of AIHA with Obexerimab This specification provides a method for treating AIHA (e.g., wAIHA) by administering obexerimab. In some embodiments, treatment with obexerimab generates a sustained Hgb response without requiring long-term steroid use associated with significant toxicity and complications. Obexerimab (XmAb5871) is a humanized anti-CD19 monoclonal antibody having an Fc moiety engineered to increase its affinity for FcγRIIb, the sole receptor on B cells.

[0134] In some embodiments, administration of obexerimab in a subcutaneous (SC) formulation minimizes the risk of acute administration-related reactions.

[0135] In some embodiments, the patient is an adult human patient (e.g., a human patient ≥18 years of age).

[0136] In some embodiments, the patient has been diagnosed with wAIHA for at least three months.

[0137] In some embodiments, the patient is receiving treatment for wAIHA at the time of initiating treatment that includes administration of obexerimab.

[0138] In some embodiments, the patient has not received treatment for wAIHA at the time of initiating treatment, which includes administration of obexerimab.

[0139] In some embodiments, the patient has previously received treatment for wAIHA before initiating treatment that includes administration of obexerimab.

[0140] In some embodiments, the patient is diagnosed with primary or secondary wAIHA (e.g., documented as positive for anti-IgG or anti-IgA specific DAT). In some embodiments, the patient is diagnosed with primary wAIHA. In some embodiments, the patient is diagnosed with secondary wAIHA.

[0141] In some embodiments, the patient has received at least one prior wAIHA treatment regimen (e.g., one or more treatment regimens including the administration of steroids, rituximab, azathioprine, cyclophosphamide, cyclosporine, mycophenolate mofetil, danazol, vincristine, or erythropoiesis-promoting agents), or the patient has previously undergone a splenectomy or any combination thereof.

[0142] In some embodiments, patients receive a steroid (e.g., prednisone / prednisolone) in combination with treatment including administration of obexerimab as described herein. In some embodiments, the dose of the steroid (e.g., prednisone / prednisolone) shall not exceed 20 mg / day and shall be stable for at least 4 weeks prior to randomization and / or remain stable during treatment (e.g., during the dose-checking induction (run-in) period (SRP) and / or the randomization control period (RCP)).

[0143] In some embodiments, patients receive immunosuppressants in combination with treatment including administration of obexerimab as described herein. In embodiments, the immunosuppressant is selected from the group consisting of azathioprine, mycophenolate mofetil / mycophenolate, cyclosporine, and cyclophosphamide, and any combination thereof. In some embodiments, patients are at a stable dose throughout the treatment period (e.g., at least 12 weeks prior to randomization and / or throughout the SRP and / or RCP).

[0144] In some embodiments, the patient has an Hgb of ≥7 g / dL to <10 g / dL at the initiation of treatment, which includes administration of obexerimab as described herein.

[0145] In some embodiments, the patient has at least one sign or symptom of anemia at the time of initiation of treatment, which includes administration of obexerimab as described herein.

[0146] In some embodiments, the patient has a blood pressure of ≥50,000 mm at the initiation of treatment, which includes administration of obexerimab as described herein. 3 It has a platelet count of [number].

[0147] In some embodiments, the patient has a blood pressure of ≥1,000 mm at the initiation of treatment, which includes administration of obexerimab as described herein. 3 It has a neutrophil count.

[0148] In some embodiments, the patient has normal serum albumin and serum calcium concentrations at the initiation of treatment, which includes administration of obexerimab as described herein.

[0149] In some embodiments, the patient has a serum total IgG of ≥600 mg / dL at the initiation of treatment, which includes administration of obexerimab as described herein.

[0150] In some embodiments, the patient has a creatine kinase level of <2 × ULN at the initiation of treatment, which includes administration of obexerimab as described herein.

[0151] In some embodiments, patients who have previously undergone splenectomy are at least four months after the procedure at the time of initiation of treatment, including administration of obexerimab as described herein. In embodiments, patients are vaccinated according to a country-specific immunization schedule.

[0152] In some embodiments, the patient has an autoimmune disorder. In embodiments, the autoimmune disorder is systemic lupus erythematosus or rheumatoid arthritis. In embodiments, the autoimmune disorder is lymphoproliferative disorder (LPD). In embodiments, the patient with the autoimmune disorder has a stable condition with respect to the autoimmune disorder (e.g., the patient has not had any changes in disease-related concomitant medications and / or the severity of the disease is stable (e.g., for at least 4 months)).

[0153] In some embodiments, the patient has lymphoproliferative disorder (LPD). In embodiments, the patient with LPD has a stable condition with respect to LPD (e.g., the patient has not changed any concomitant disease-related medications and / or the severity of the disease is stable (e.g., for at least 4 months)).

[0154] In some embodiments, the patient does not have cold antibody AIHA, cold agglutinin syndrome, mixed type (i.e., warm and cold) AIHA, or paroxysmal cold hemoglobinuria.

[0155] In some embodiments, the patient has no other relevant cause of hereditary or acquired hemolytic anemia.

[0156] In some embodiments, the patient does not have secondary wAIHA that is not caused by an autoimmune disorder (e.g., LPD).

[0157] In some embodiments, the patient has not received a blood transfusion within two weeks prior to the initiation of treatment, including the administration of obexerimab as described herein.

[0158] In some embodiments, the patient has not received a B-cell depletion agent, a B-cell target agent, or other bioimmunomodulator within six months prior to the initiation of treatment, including administration of obexerimab as described herein.

[0159] In some embodiments, the patient has received a B-cell depletion agent, a B-cell targeting agent, or other biological immunomodulatory agent within 6 to 12 months prior to the initiation of treatment, including administration of obexerimab as described herein. In some embodiments, the patient has a B-cell count within the clinical laboratory reference range at the initiation of treatment with obexerimab.

[0160] In some embodiments, the patient has not received IV Ig or epoetin alfa within 6 weeks prior to the initiation of treatment, including administration of obexerimab as described herein.

[0161] In some embodiments, the patient is not receiving more than two concomitant medications for the treatment of wAIHA at the time of treatment initiation, including administration of obexerimab as described herein. In some embodiments, concomitant medications exclude vitamins or other supplements.

[0162] In some embodiments, at the time of initiation of treatment including administration of obexerimab as described herein, the patient has not received any other investigational drug treatment or direct medical intervention in another clinical trial within 12 weeks or within <5 half-lives of the investigational drug treatment (whichever is shorter).

[0163] In some embodiments, the patient has not received a live vaccine or live therapeutic infectious agent within six weeks prior to the initiation of treatment, including the administration of obexerimab as described herein.

[0164] In some embodiments, the patient shows no evidence of active tuberculosis (TB) or is not at high risk of TB. In some embodiments, the criteria used to assess the patient are selected from the following: • A history of active or latent TB (unless the completion of treatment is documented). Unless treatment is documented, if the interferon-gamma (IFNγ) release assay result is positive, inconclusive, or ineffective at screening (patients with inconclusive test results may repeat the test once), • Symptoms and signs that may indicate active TB, and / or Chest X-ray, computed tomography scan, or magnetic resonance imaging suggestive of a possible diagnosis of TB.

[0165] In some embodiments, the patient has no history or evidence of a clinically unstable / uncontrollable disorder, condition, or disease (including, but not limited to, cardiopulmonary, tumor, renal, hepatic, metabolic, hematological, psychiatric, or active infection).

[0166] In some embodiments, the patient does not have a known allergy to monoclonal antibody therapy.

[0167] In some embodiments, the patient does not have a known hypersensitivity to dextran or any component of dextran.

[0168] In some embodiments, the patient does not have an active infection (e.g., pneumonia, biliary tract infection, diverticulitis, Clostridium difficile infection) requiring parenteral or oral antiinfective agents and / or hospitalization, and / or has been assessed as severe / clinically critical within eight (8) weeks prior to the initiation of treatment including administration of obexerimab as described herein.

[0169] In some embodiments, patients do not have a chronic infection (e.g., bronchiectasis, chronic osteomyelitis, chronic pyelonephritis) or require chronic treatment with anti-infective agents (e.g., antibiotics, antivirals) before initiating treatment including administration of obexerimab as described herein.

[0170] In some embodiments, the patient has a family history of congenital or hereditary immunodeficiency unless it is confirmed that the patient is not diagnosed with or suspected of having a clinical immunodeficiency syndrome unrelated to the treatment of wAIHA, or that such syndrome was not present in the patient prior to the initiation of treatment, including administration of obexerimab as described herein.

[0171] In some embodiments, the patient does not have acute hepatitis B infection (positive for hepatitis B surface antigen), active hepatitis C virus (HCV), or HIV infection prior to initiating treatment including administration of obexerimab as described herein.

[0172] In some embodiments, the patient does not test positive for active hepatitis B through pre-treatment detection of hepatitis B surface antigens, including administration of obexerimab as described herein.

[0173] In some embodiments, the patient does not have any of the following prior to initiating treatment including administration of obexerimab as described herein: · Hepatitis B surface antigen, • Hepatitis B surface antibody, or • Hepatitis B core antibodies.

[0174] In some embodiments, the patient has no prior history of HCV prior to the initiation of treatment, including administration of obexerimab as described herein. In embodiments, the patient has recorded negative HCV ribonucleic acid levels in serum at least 12 weeks after completion of HCV therapy prior to the initiation of treatment, including administration of obexerimab as described herein.

[0175] Table 2 shows exemplary dosing regimens and formulations of obexerimab. [Table 2]

[0176] In some embodiments, obexerimab is administered subcutaneously as 2 × 1 ml injections at a concentration of 125 mg / ml at a dose of 250 mg per week. In some embodiments, obexerimab is administered subcutaneously as 1 × 2 ml injections at a concentration of 125 mg / ml at a dose of 250 mg per week. In some embodiments, obexerimab is administered subcutaneously at a dose of 200 mg per week. In some embodiments, obexerimab is administered subcutaneously at a dose of 150 mg per week. In some embodiments, obexerimab is administered subcutaneously at a dose of 100 mg per week. In some embodiments, obexerimab is administered as a single injection. In some embodiments, obexerimab is administered as more than two injections, for example, as three injections or four or more injections. In some embodiments, the concentration of obexerimab is 100 mg / ml. In some embodiments, the concentration of obexerimab is 50 mg / ml. In some embodiments, obexerimab is administered subcutaneously as a 2 × 1 ml injection at a concentration of 100 mg / ml. In some embodiments, obexerimab is administered subcutaneously as a 2 × 1 ml injection at a concentration of 125 mg / ml.

[0177] In one embodiment, the present invention provides a method for treating wAIHA, the method comprising subcutaneous administration of obexerimab to human patients aged 18 years or older at a dose of 250 mg per week.

[0178] In some embodiments, the method includes subcutaneous administration of obexerimab at a dose of 125 mg twice weekly. In some embodiments, the method includes subcutaneous administration of obexerimab at a dose of 125 mg twice weekly. In some embodiments, the method includes subcutaneous administration of obexerimab at a dose of 125 mg every three days. In some embodiments, the method includes subcutaneous administration of obexerimab at a dose of 250 mg every seven days.

[0179] In some embodiments, obexerimab can be administered subcutaneously to human patients aged 18 years or older at a dose of 200 mg once weekly. In some embodiments, obexerimab can be administered subcutaneously to human patients aged 18 years or older at a dose of 125 mg twice weekly. In some embodiments, obexerimab is administered subcutaneously to human patients aged 18 years or older at a dose of 100 mg twice weekly. In some embodiments, obexerimab is administered subcutaneously to human patients aged 18 years or older at a dose of 300 mg once weekly. In some embodiments, obexerimab is administered subcutaneously to human patients aged 18 years or older at a dose of 150 mg twice weekly.

[0180] In some embodiments, obexerimab is administered as a liquid formulation containing 125 mg / mL of obexerimab. In some embodiments, obexerimab is administered as 2 × 1 mL injections. In some embodiments, obexerimab is administered as 2 × 1 mL injections for a total dose of 250 mg. In some embodiments, obexerimab injections are administered simultaneously. In some embodiments, obexerimab injections are administered within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 20 minutes from each other. In some embodiments, obexerimab injections are administered within 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours from each other.

[0181] In some embodiments, obexerimab is administered as a liquid formulation containing 125 mg / mL of obexerimab as a 4 × 0.5 mL injection. In some embodiments, obexerimab is administered as a liquid formulation containing 125 mg / mL of obexerimab as a 4 × 0.5 mL injection, for a total dose of 250 mg. In some embodiments, obexerimab injections are administered simultaneously. In some embodiments, obexerimab injections are administered within 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 20 minutes from each other. In some embodiments, obexerimab injections are administered within 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours from each other.

[0182] In some embodiments, obexerimab is administered as a single injection in a liquid formulation. In some embodiments, obexerimab is administered as a single injection in a liquid formulation with a total dose of 250 mg.

[0183] In some embodiments, obexerimab is administered in doses of approximately 100–500 mg per week. In some embodiments, obexerimab is administered in doses of approximately 100–200 mg per week, 100–300 mg per week, 100–400 mg per week, 200–400 mg per week, 100–300 mg per week, 200–350 mg per week, 150–300 mg per week, 125–275 mg per week, 225–275 mg per week, 230–260 mg per week, 240–260 mg per week, or 245–255 mg per week. In some embodiments, obexerimab is administered in doses of approximately 100 mg per week, 150 mg per week, 200 mg per week, 250 mg per week, 300 mg per week, 350 mg per week, 400 mg per week, 450 mg per week, or 500 mg per week.

[0184] In some embodiments, the weekly dose may be injected all at once throughout the week, or divided into two or more injections. In some embodiments, the weekly dose is divided into two, three, four, five, six injections, or one injection per day. In some embodiments, the weekly dose is divided equally. In some embodiments, the weekly dose is divided unevenly. In some embodiments, the weekly dose is divided to be administered every other day, every two days, or every three days.

[0185] In some embodiments, preferred doses are in the range of 20-40 mg per day, 25-40 mg per day, or 30-40 mg per day. In some embodiments, preferred dose is 35 mg per day.

[0186] In some embodiments, obexerimab is administered in doses of 500 mg every two weeks. In some embodiments, the two-week dose may be injected all at once or divided into two or more injections. In some embodiments, the dose may be divided into two, three, four, five, or six or more injections.

[0187] In some embodiments, the patient receives 1000 mg of obexerimab once a month. In some embodiments, the monthly dose of 1000 mg may be injected all at once or divided into four or more injections. In some embodiments, the dose may be divided into four, five, six, seven, or eight or more injections.

[0188] In some embodiments, obexerimab is administered to the patient over a period of at least 1–24, 4–24, 8–24, 12–24, 16–24, or 20–24 weeks (e.g., weekly subcutaneous administration of obexerimab).

[0189] In some embodiments, obexerimab is administered to the patient for at least about 4 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 4 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 8 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 8 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 12 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 12 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 16 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 16 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 20 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for at least about 24 weeks (e.g., weekly subcutaneous administration of obexerimab). In some embodiments, obexerimab is administered to the patient for approximately 24 weeks (e.g., once-weekly subcutaneous administration of obexerimab).

[0190] Table 3 shows exemplary benefits that can be obtained using the methods described herein. In some embodiments, the methods described herein can achieve one or more of the benefits listed in Table 3. [Table 3-1] [Table 3-2]

[0191] In some embodiments, the methods described herein result in a sustained Hgb response in the patient (e.g., Hgb ≥ 10 g / dL and / or an increase of ≥ 2 g / dL from baseline). In embodiments, the sustained response is obtained without the use of blood transfusions or GC rescue therapy before achieving the sustained response.

[0192] In some embodiments, the methods described herein result in a change in the FACIT-F score from baseline to 24 weeks of treatment according to the methods described herein.

[0193] In some embodiments, the methods described herein result in a beneficial change in the proportion of patients who have not received blood transfusions or GC rescue therapy up to 24 weeks of treatment according to the methods described herein.

[0194] In some embodiments, the methods described herein result in beneficial changes in the cumulative dose of GC rescue therapy up to week 24 of treatment according to the methods described herein.

[0195] In some embodiments, the methods described herein result in a beneficial change in the percentage of patients who have not received a blood transfusion up to 24 weeks of treatment according to the methods described herein.

[0196] In some embodiments, the methods described herein result in changes from baseline to week 24 in the FACIT-F score, EQ-5D-5L index score, physician's overall assessment of changes in disease activity, overall impression of changes in the patient's daily activities, and / or overall impression of changes in the patient's fatigue severity.

[0197] In some embodiments, the methods described herein result in changes over time from baseline to week 24 in one or more of the following: - Reduction of circulating absolute T cell count, B cell count, and NK cell count, - Reduction of Ig levels and ratios (e.g., IgG, IgM, IgA, IgE), - Increased CD19 target receptor occupancy, - Decreased reticulocyte count, - Decrease in LDH, - Increase in haptoglobin, and - Reduction of indirect bilirubin (unconjugated bilirubin).

[0198] In some embodiments, the methods described herein result in a significant improvement in HgB levels in the patient (e.g., compared to baseline HgB levels). In embodiments, the improvement in Hgb concentration is observed by 8 weeks of treatment according to the method herein. In embodiments, the improvement in Hgb concentration is observed by 24 weeks of treatment according to the method herein. In some embodiments, the methods described herein result in a sustained Hgb response in the patient (e.g., Hgb ≥ 10 g / dL and / or an increase of ≥ 2 g / dL from baseline). In embodiments, the sustained response is obtained without the use of blood transfusions or GC rescue therapy before the sustained response is achieved.

[0199] In some embodiments, the methods described herein result in the patient achieving normal levels of lactate dehydrogenase (LDH), haptoglobin, and / or indirect bilirubin. In some embodiments, normal levels of LDH, haptoglobin, and / or indirect bilirubin are achieved from the 12th week onward of treatment by the methods described herein. In some embodiments, normal levels of LDH, haptoglobin, and / or indirect bilirubin are achieved without the use of blood transfusions or GC rescue therapy.

[0200] In some embodiments, the method described herein results in the patient achieving an increase of ≥3 points in the FACIT-F score. In embodiments, the patient achieves an increase of ≥3 points in the FACIT-F score after 24 weeks of treatment according to the method described herein. In multiple embodiments, the increase in the FACIT-F score is obtained without prior use of blood transfusion or GC rescue therapy.

[0201] Sustained Hgb response: A sustained Hgb response may be an Hgb ≥ 10 g / dL or an increase of ≥ 2 g / dL from baseline. In some embodiments, a sustained Hgb response is achieved after at least 3 weeks out of 4 consecutive weeks. In some embodiments, Hgb levels increase within a minimum of 1 week. In some embodiments, Hgb levels increase after a minimum of 1 week. In some embodiments, Hgb levels increase after a minimum of 2 weeks. In some embodiments, Hgb levels increase after a minimum of 3 weeks. In some embodiments, Hgb levels increase after a minimum of 4 weeks. In some embodiments, Hgb levels increase after a minimum of 5 weeks. In some embodiments, Hgb levels increase after a minimum of 6 weeks. In some embodiments, Hgb levels increase after a minimum of 7 weeks. In some embodiments, Hgb levels increase after a minimum of 8 weeks. In some embodiments, Hgb levels increase after a minimum of 9 weeks. In some embodiments, Hgb levels increase after a minimum of 10 weeks. In some embodiments, Hgb levels increase after a minimum of 11 weeks. In some embodiments, Hgb levels increased after a minimum of 12 weeks. In some embodiments, patients who achieved an increase in Hgb did not use blood transfusions or GC rescue therapy before achieving the increase in Hgb.

[0202] In some embodiments, the patient achieves an increase of ≥0.5 g / dL from baseline in at least three of four consecutive available visits. In some embodiments, the patient achieves an increase of ≥1 g / dL from baseline in at least three of four consecutive available visits. In some embodiments, the patient achieves an increase of ≥1.5 g / dL from baseline in at least three of four consecutive available visits. In some embodiments, the patient achieves an increase of ≥2 g / dL from baseline in at least three of four consecutive available visits.

[0203] In some embodiments, the increase in Hgb levels persists until week 13. In some embodiments, the increase in Hgb levels persists until week 14. In some embodiments, the increase in Hgb levels persists until week 15. In some embodiments, the increase in Hgb levels persists until week 16. In some embodiments, the increase in Hgb levels persists until week 17. In some embodiments, the increase in Hgb levels persists until week 18. In some embodiments, the increase in Hgb levels persists until week 19. In some embodiments, the increase in Hgb levels persists until week 20. In some embodiments, the increase in Hgb levels persists until week 21. In some embodiments, the increase in Hgb levels persists until week 22. In some embodiments, the increase in Hgb levels persists until week 23. In some embodiments, the increase in Hgb levels persists until week 24.

[0204] In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥9 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥10 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥11 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥12 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥13 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥14 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥15 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥16 g / dL. In some embodiments, the Hgb response is defined as a patient achieving an Hgb of ≥17 g / dL.

[0205] In some embodiments, a sustained Hgb response is defined as a patient achieving an increase of ≥2 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥0.5 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥1 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥3 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥4 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥5 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥6 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥7 g / dL from baseline. In some embodiments, a patient may achieve an increase of ≥8 g / dL from baseline.

[0206] In some embodiments, a sustained Hgb response maintains Hgb levels for 1 week, at least 2 weeks, at least 3 weeks, at least 4 weeks, at least 5 weeks, at least 6 weeks, at least 7 weeks, at least 8 weeks, at least 9 weeks, at least 10 weeks, at least 11 weeks, at least 12 weeks, at least 14 weeks, at least 15 weeks, at least 16 weeks, at least 17 weeks, at least 18 weeks, at least 19 weeks, at least 20 weeks, at least 21 weeks, at least 22 weeks, at least 23 weeks, at least 24 weeks, or at least 25 weeks.

[0207] In some embodiments, the patient achieves an increase in Hgb levels within one week. In some embodiments, the patient achieves an increase in Hgb levels within two weeks. In some embodiments, the patient achieves an increase in Hgb levels within three weeks. In some embodiments, the patient achieves an increase in Hgb levels within four weeks. In some embodiments, the patient achieves an increase in Hgb levels within five weeks. In some embodiments, the patient achieves an increase in Hgb levels within six weeks. In some embodiments, the patient achieves an increase in Hgb levels within seven weeks. In some embodiments, the patient achieves an increase in Hgb levels within eight weeks. In some embodiments, the patient achieves an increase in Hgb levels within nine weeks. In some embodiments, the patient achieves an increase in Hgb levels within ten weeks. In some embodiments, the patient achieves an increase in Hgb levels within eleven weeks. In some embodiments, the patient achieves an increase in Hgb levels within twelve weeks.

[0208] In some embodiments, the patient maintains Hgb levels for at least three weeks without the use of blood transfusions or GC rescue therapy before achieving a sustained response.

[0209] Quality of life assessment Quality of life assessment may be carried out as part of the treatment methods described herein. In some embodiments, improvement in quality of life is improvement of one or more characteristics of fatigue or malaise, and improvement of its impact on daily activities and functions. Assessment means may include items such as fatigue, weakness, lethargy, lack of energy, and the impact of these feelings on daily functions (e.g., sleep, social activities). In some embodiments, this disclosure provides a method for treating autoimmune hemolytic anemia (AIHA), a method for measuring the FACIT-F score or EQ-5D-5L index score, and a method for subcutaneously administering obexerimab to a human patient at a dose of 250 mg once weekly.

[0210] In some embodiments, quality of life is measured by the FACIT-F scale. In some embodiments, quality of life is measured by the EQ-5D-5L questionnaire. In some embodiments, quality of life is measured by the SF-36 survey.

[0211] Rescue therapy The present invention also provides a method for treating AIHA (e.g., wAIHA), which includes administering rescue therapy. In some embodiments, rescue therapy includes GC therapy or administration of blood transfusion. In some embodiments, rescue therapy is any therapy given for the treatment of wAIHA accompanied by new or worsened anemia due to a decrease in Hgb and / or an increase in LDH compared to previous Hgb levels.

[0212] In some embodiments, GC therapy is administered at a dose of 1 to 1.5 mg / kg. In some embodiments, GC therapy is administered at a dose of 0.5 to 2 mg / kg. In some embodiments, GC therapy is administered at a dose of 0.6 mg / kg. In some embodiments, GC therapy is administered at a dose of 0.7 mg / kg. In some embodiments, GC therapy is administered at a dose of 0.8 mg / kg. In some embodiments, GC therapy is administered at a dose of 0.9 mg / kg. In some embodiments, GC therapy is administered at a dose of 1 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.1 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.2 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.3 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.4 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.5 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.6 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.7 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.8 mg / kg. In some embodiments, GC therapy is administered at a dose of 1.9 mg / kg. In some embodiments, GC therapy is administered at a dose of 2.0 mg / kg.

[0213] In some embodiments, GC therapy is administered at a dose of 20-60 mg / day of prednisone or an equivalent dose. In some embodiments, GC therapy is administered at a dose of 10-100 mg / day of prednisone or an equivalent dose. In some embodiments, GC therapy is administered at doses of approximately 1-70 mg / day, approximately 5-70 mg / day, approximately 10-70 mg / day, approximately 15-70 mg / day, approximately 20-70 mg / day, approximately 25-70 mg / day, approximately 30-70 mg / day, approximately 35-70 mg / day, approximately 40-70 mg / day of prednisone or an equivalent dose. In some embodiments, GC therapy is administered at doses of approximately 1-60 mg / day, 5-60 mg / day, 10-60 mg / day, 15-60 mg / day, 20-60 mg / day, 25-60 mg / day, 30-60 mg / day, 35-60 mg / day, or 40-60 mg / day of prednisone or an equivalent dose.

[0214] In some embodiments, GC therapy is administered at doses of prednisone or equivalent, approximately 1-150 mg / day, 5-150 mg / day, 10-150 mg / day, 15-150 mg / day, 20-150 mg / day, 25-150 mg / day, 30-150 mg / day, 35-150 mg / day, 40-150 mg / day, 45-150 mg / day, 50-150 mg / day, 55-150 mg / day, 60-150 mg / day, 65-150 mg / day, 70-150 mg / day, 75-150 mg / day, 80-150 mg / day, 90-150 mg / day, or approximately 100-150 mg / day. In some embodiments, GC therapy is administered at doses of approximately 5-120 mg / day, approximately 5-110 mg / day, approximately 10-90 mg / day, approximately 15-100 mg / day, approximately 20-100 mg / day, approximately 25-100 mg / day, approximately 30-100 mg / day, approximately 35-100 mg / day, approximately 40-100 mg / day, approximately 45-100 mg / day, approximately 50-100 mg / day, approximately 55-100 mg / day, approximately 60-100 mg / day, approximately 65-100 mg / day, approximately 70-100 mg / day, approximately 75-100 mg / day, approximately 80-100 mg / day, or approximately 90-100 mg / day of prednisone or an equivalent dose.

[0215] In some embodiments, GC therapy is administered at a maximum dose of approximately 150 mg / day, 120 mg / day, 110 mg / day, 100 mg / day, 90 mg / day, 80 mg / day, 70 mg / day, 60 mg / day, 50 mg / day, 40 mg / day, 30 mg / day, 20 mg / day, 15 mg / day, 10 mg / day, 5 mg / day, or approximately 1 mg / day of prednisone or an equivalent dose.

[0216] In some embodiments, GC therapy is administered in doses of 0.1–1 mg / kg / day, 0.1–0.8 mg / kg / day, 0.1–0.7 mg / kg / day, 0.1–0.6 mg / kg / day, 0.1–0.5 mg / kg / day, 0.1–0.4 mg / kg / day, 0.1–0.3 mg / kg / day, 0.1–0.2 mg / kg / day, or 0.05–0.1 mg / kg / day of prednisone or an equivalent dose.

[0217] In some embodiments, GC therapy is administered at a maximum dose of 1 mg / kg / day of prednisone or an equivalent dose. In some embodiments, GC therapy is administered at a maximum dose of 0.9 mg / kg / day, 0.8 mg / kg / day, 0.7 mg / kg / day, 0.6 mg / kg / day, 0.5 mg / kg / day, 0.4 mg / kg / day, 0.3 mg / kg / day, 0.2 mg / kg / day, or 0.1 mg / kg / day of prednisone or an equivalent dose.

[0218] In some embodiments, GC therapy is administered at a high dose of prednisone or an equivalent dose. In some embodiments, the patient has been administered high-dose GC therapy and is unlikely to respond to any other therapeutic treatment. In some embodiments, the patient has not responded to previous therapy before administration of an anti-CD19 antibody (e.g., obexerimab).

[0219] In some embodiments, GC therapy is continued during treatment with obexerimab. In some embodiments, GC therapy is tapered off during treatment with obexerimab. In some embodiments, GC therapy is tapered off before treatment with obexerimab. In some embodiments, GC therapy is tapered off to complete discontinuation. In some embodiments, obexerimab is administered in combination with GC therapy. [Examples]

[0220] Example 1: Administration of obexerimab for the treatment of wAIHA This example describes exemplary patient selection criteria for the administration of an anti-CD19 antibody (e.g., obexerimab) to patients enrolled in a Phase 2 / 3, multicenter, randomized, double-blind, placebo-controlled trial. As shown in Figure 1, the trial included an open-label safety and dose-determining introduction period (SRP) to evaluate the safety and efficacy of obexerimab in patients with wAIHA. Patients selected for the randomized controlled period (RCP) using the selection and exclusion criteria described below will receive either placebo or obexerimab.

[0221] A placebo, which does not contain the active substance, is also supplied as a solution for SC injection. The placebo formulation is pH 5.5 and contains 2.35 mg / mL sodium acetate trihydrate, 0.17 mg / mL acetic acid (density 1.053 g / mL), 30 mg / mL L-proline, 0.1 mg / mL polysorbate 80, and 115 mg / mL dextran-40. The placebo SC formulation is a sterile liquid product supplied in single-use glass vials. Each 2-mL glass vial is filled with 1.2 mL of placebo. The single-use glass vials are masked so as not to be distinguishable from obexerimab. Table 2 shows the administration regimens and the obexerimab formulations.

[0222] During the randomized controlled period (RCP), patients will be evaluated for efficacy, safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity at trial visits as defined in the evaluation schedule (SoA). Adverse events (AEs), serious adverse events (SAEs), and treatment-induced adverse events (TEAEs), or clinically significant safety laboratory abnormalities will be assessed.

[0223] Selection Criteria Patients are selected for treatment based on the following criteria: 1. Males and females aged 18 or older. 2. You must have been diagnosed with wAIHA and have been currently receiving treatment for wAIHA for at least three months, or have received treatment for wAIHA in the past (patients with no prior treatment experience are not eligible). 3. Diagnosis of primary or secondary wAIHA documented as positive for anti-IgG or anti-IgA specific DAT. 4. At least one previous wAIHA treatment regimen was unsuccessful, including steroids, rituximab, azathioprine, cyclophosphamide, cyclosporine, mycophenolate mofetil, danazol, vincristine, erythropoiesis-promoting agents, or splenectomy (folic acid, iron, or other supplements do not meet this criterion). 5. In the case of prednisone / prednisolone administration, the dose must not exceed 20 mg / day, and must be stable for at least 4 weeks prior to randomization and remain stable throughout the SRP and RCP. 6. If receiving immunosuppressants, patients must have received a stable dose for at least 12 weeks prior to randomization and maintain that stable dose throughout the SRP and RCP. Concomitant immunosuppressants are azathioprine, mycophenolate mofetil / mycophenolate, cyclosporine, and cyclophosphamide. 7. Hgb ≥ 7 to < 10 g / dL 8. At least one sign or symptom of anemia as assessed by the principal investigator at baseline. 9. Screening: Platelet count ≥ 50,000 mm³ 10. Screening: Neutrophil count ≥ 1,000 mm³ 11. Screening for serum albumin and serum calcium concentrations within the normal range. 12. Screening for serum total IgG ≥ 600 mg / dL 13. Screening <2×ULN creatinine kinase levels 14. Patients with a history of splenectomy must be at least four months post-splenic and vaccinated according to their country-specific vaccination schedule before randomization. 15. Patients with autoimmune disorders (e.g., systemic lupus erythematosus, rheumatoid arthritis) may be eligible if they are receiving stable treatment (no changes in disease-related concomitant medications) and their disease severity has been stable for at least four months prior to randomization. 16. In the case of SRP only (Part A), LPD patients (Cohort 2) may be eligible if they are receiving stable treatment (no changes in concomitant disease-related medications), their disease severity has been stable for at least 4 months prior to randomization, and the investigator believes they are unlikely to require chemotherapy or mAb therapy during the study period.

[0224] Exclusion criteria Patients may be selected for treatment with obexerimab based on exclusion criteria: 1. Having cold antibody AIHA, cold agglutinin syndrome, mixed type (i.e., warm and cold) AIHA, or paroxysmal cold hemoglobinuria. 2. Having other related causes of hereditary or acquired hemolytic anemia. 3. In the case of RCP only (Part B), patients with secondary wAIHA not caused by autoimmunity. Disorders including LPD 4. Received a blood transfusion within two weeks prior to randomization. 5. Use of B-cell depletion, B-cell targeting, or other biological immunomodulatory agents within 6 months prior to randomization. Patients who have received B-cell targeted therapy within 6 to 12 months prior to randomization must have a screening B-cell count within the clinical laboratory reference range as measured by the Central Laboratory. 6. Patients who received IV Ig or epoetin alfa within 6 weeks prior to randomization. You can undergo rescreening after a 6-week exclusion period. 7. At the time of screening, the patient is receiving two or more concomitant medications for the treatment of wAIHA. (Excluding vitamins or other supplements) 8. Within 12 weeks prior to screening, or within <5 half-lives of the investigational drug treatment (whichever is shorter), the patient received investigational drug treatment or direct medical intervention in another clinical trial. 9. Received a live vaccine or live therapeutic infectious agent within 6 weeks prior to randomization. 10. Active tuberculosis (TB) or evidence of high risk of TB based on at least one of the following: a. A history of active or latent TB, unless completion of treatment in accordance with local guidelines is documented. b. Unless treatment is documented, the interferon-gamma (IFNγ) release assay result at screening is positive, inconclusive, or invalid. Patients with inconclusive test results may undergo one repeat test at either a central or regional facility, but if the repeat test is also inconclusive, the patient will be excluded. c. Signs of symptoms that may indicate active TB d. Chest radiographs, computed tomography, or magnetic resonance imaging that suggest the possibility of diagnosing TB. 11. A history or evidence of any clinically unstable / uncontrolled disorder, condition, or disease (including cardiopulmonary, oncological, renal, hepatic, metabolic, hematological, psychiatric, or active infection) that, in the opinion of the principal investigator, could pose a risk to patient safety or could interfere with the evaluation, procedure, or completion of the trial. 12. Known allergies to monoclonal antibody therapy 13. Known hypersensitivity to dextran or components of dextran 14. Active infection (pneumonia, biliary tract infection, diverticulitis, Clostridium difficile infection) within 8 weeks prior to screening, requiring parenteral or oral anti-infective therapy and / or hospitalization, and / or assessed as severe / clinically serious by the principal investigator. Patients may be rescreened after an 8-week exclusion period. 15. Chronic infections (e.g., bronchiectasis, chronic osteomyelitis, chronic pyelonephritis) or Chronic treatment with anti-infective drugs (antibiotics, antiviral agents, etc.) is required. 16. If a clinical immunodeficiency syndrome unrelated to the treatment of wAIHA is confirmed or suspected, or if there is a family history of congenital or hereditary immunodeficiency unless it is confirmed that the patient does not have immunodeficiency. 17. Acute hepatitis B infection (positive for hepatitis B surface antigen), active hepatitis C virus (HCV) or HIV infection. Patients who test positive for active hepatitis B based on the detection of hepatitis B surface antigen may be excluded from treatment. In Japan, (a) Hepatitis B surface antigen, or (b) Hepatitis B surface antibody, or (c) Patients will be excluded if hepatitis B core antibodies are detected. Patients with a history of HCV may be excluded from this study unless it is documented that their serum HCV ribonucleic acid levels are negative at least 12 weeks after completion of HCV therapy.

[0225] Patients treated with obexerimab showed significantly improved HgB levels compared to patients treated with placebo.

[0226] Example 2: Effectiveness Analysis and Evaluation Items This example shows the efficacy analysis of the clinical trial described in Example 1. The primary efficacy endpoint is the percentage of patients with an Hgb response.

[0227] Samples will be collected at baseline and during weekly study visits. Assessment parameters will include evaluating patients who have achieved a sustained Hgb response (defined as Hgb ≥ 10 g / dL and / or an increase of ≥ 2 g / dL from baseline) and measuring LDH levels. Blood chemistry and hematology panels will be evaluated to determine Hgb levels in response to obexerimab treatment. If a patient exhibits a recurrence of previous signs / symptoms of wAIHA or new signs / symptoms, physical examination, imaging, and / or biochemical parameters may be obtained.

[0228] Secondary outcome parameters include assessing improvements in quality of life using, for example, the change in FACIT-F score from baseline to week 24, the EQ-5D-5L index score, the physician's overall assessment of changes in disease activity, the patient's overall impression of changes in impact on daily activities, and / or the patient's overall impression of changes in fatigue severity.

[0229] Additional evaluation parameters include changes over time from baseline to week 24 in the following areas: - Reduction of circulating absolute T cell count, B cell count, and NK cell count - Reduction of Ig levels and ratios (e.g., IgG, IgM, IgA, IgE) - Increased CD19 target receptor occupancy - Decrease in reticulocyte count - Decrease in LDH - Increase in haptoglobin - Reduction of indirect bilirubin (unconjugated bilirubin)

[0230] Secondary assessments of disease activity in SRP include the change in FACIT-F score from baseline to week 24, the proportion of patients who did not require transfusion or GC rescue therapy up to week 24, the cumulative dose of GC rescue therapy up to week 24, and the proportion of patients with a sustained Hgb response.

[0231] Part A (Safety and Dose Confirmation Induction Period): Approximately 20 patients will be enrolled. Patients will be divided into two cohorts. Cohort 1 consists of patients with primary wAIHA or secondary wAIHA resulting from an autoimmune disorder (e.g., systemic lupus erythematosus). Cohort 2 consists of patients with secondary wAIHA resulting from a lymphoproliferative disorder (LPD). Results from this part will provide preliminary safety, tolerability, PK / PD, and efficacy data in a wAIHA population similar to the population intended to be enrolled during the randomized control period. The randomization control period (Part B) will begin when all 14 patients with primary wAIHA or secondary wAIHA due to underlying autoimmune disorders (Cohort 1) reach weeks 8–12 (or withdraw from the study), at least 5 patients meet the primary endpoint, there are no TEAE grade 4 or higher patients in Cohort 1, there are no major safety events as described above, and the PK and PD data are comparable to PK / PD data from other clinical trials or to the PK modeling of obexerimab. Results from patients with secondary wAIHA enrolled in Cohort 2 will provide preliminary data on the broader wAIHA population.

[0232] The primary analysis of Hgb response was performed in Cohort 1 and is based on point estimates of the Hgb response rate from week 8 onward, and the corresponding 90% exact confidence intervals. For Hgb response rates, a lower confidence limit of 15% or greater is considered clinically significant and indicates the possibility that patients who were unsuccessful with previous wAIHA treatment may achieve the endpoint without any additional treatment.

[0233] The order in which the primary efficacy endpoints and primary secondary efficacy endpoints will be tested is as follows: 1. The proportion of patients who achieved a sustained Hgb response (defined as Hgb ≥ 10 g / dL and an increase of ≥ 2 g / dL from baseline, at least 12 weeks later) without the use of blood transfusions or GC rescue therapy prior to achieving a sustained response (primary endpoint). 2. Change in FACIT-F score from baseline to week 24 (primary secondary endpoint) 3. Percentage of patients who did not require blood transfusion or GC rescue therapy by week 24 (primary secondary endpoint) 4. Cumulative dose of GC rescue therapy up to week 24 (primary secondary endpoint) 5. Percentage of patients who do not require blood transfusions by week 24 (primary secondary endpoint)

[0234] Other embodiments While several embodiments of the present invention are described herein, this disclosure and examples may be modified to provide other methods and configurations of the present invention. It will be understood that the scope of the present invention is defined by the appended claims, in addition to the specific embodiments described as examples. All references cited herein are incorporated herein by reference.

Claims

1. A method for treating autoimmune hemolytic anemia (AIHA), comprising subcutaneously administering obexerimab at a dose of 250 mg once weekly to a human patient.

2. The method according to claim 1, wherein the patient has an Hgb level of ≥7 to <10 g / dL.

3. The method according to claim 1 or 2, wherein the patient has been diagnosed with warm autoimmune hemolytic anemia (wAIHA).

4. The method according to any one of the prior claims, wherein the patient has at least one sign or symptom of anemia.

5. The method according to any one of the prior claims, wherein the patient has also been unsuccessful with at least one previous wAIHA treatment regimen.

6. The aforementioned prior wAIHA treatment regimen, GC or The method according to any one of claims 5, which is an immunosuppressive therapy.

7. The method according to claim 5, wherein the failure of the previous wAIHA treatment regimen includes a reduction in Hgb of ≥ 1 g / dL.

8. The method according to claim 5, wherein the failure of the previous wAIHA treatment regimen includes an increase in LDH of ≥ 1.5 × upper limit of normal (ULN).

9. The method according to any one of the prior claims, wherein obexerimab is administered concurrently with GC therapy.

10. The method according to claim 9, wherein the GC therapy is administered at a dose of 1 to 1.5 mg / kg / day of prednisone or an equivalent dose.

11. The method according to any one of the prior claims, wherein the patient maintains an Hgb level of ≥7 g / dL after administration of obexerimab.

12. The method according to any one of the prior claims, wherein the patient maintains an Hgb level of ≥7 g / dL, ≥8 g / dL, ≥9 g / dL, or ≥10 g / dL.

13. The method according to any one of the prior claims, wherein the patient achieves an Hgb of ≥ 10 g / dL.

14. The method according to any one of the prior claims, wherein the patient achieves an Hgb level that is ≥2 g / dL higher than the Hgb level before treatment with obexerimab.

15. The method according to any one of the prior claims, wherein obexerimab is administered for a period of time sufficient to improve, stabilize, or reduce one or more symptoms of wAIHA compared to a control.

16. The method according to any one of the prior claims, wherein the patient achieves an improvement in Hgb after administration of obexerimab for at least 4, 5, 6, 7, 8, 9, 10, 11, or 12 weeks.

17. The method according to any one of the prior claims, wherein the patient achieves an improvement in the FACIT-F score compared to the FACIT-F score before treatment.

18. The method according to any one of the prior claims, wherein the patient achieves an improvement in the EQ-5D-5L index score compared to the EQ-5D-5L index score before treatment.

19. The aforementioned patient, after receiving obexerimab, exhibited the following: a) Decrease in circulating absolute T cell count, B cell count, and NK cell count, b) Decrease in Ig levels and ratios (e.g., IgG, IgM, IgA, IgE), c) Increased CD19 target receptor occupancy, d) Decrease in reticulocyte count, e) Decrease in LDH, f) Increase in haptoglobin, g) Decrease in indirect bilirubin (unconjugated bilirubin) A method according to any one of the prior claims, which achieves one or more of the following.

20. The method according to any one of the prior claims, wherein the human patient is relapsed or refractory to rituximab.

21. The method according to any one of the prior claims, wherein the patient is 18 years of age or older.

22. The method according to any one of the prior claims, wherein the patient does not have cold autoimmune hemolytic amenorrhea (amenia) or CAD.

23. The method according to any one of the prior claims, wherein the patient does not have mixed autoimmune hemolytic amenorrhea.

24. The method according to any one of the prior claims, wherein the patient does not have paroxysmal cold hemoglobinuria (PCH).

25. The method according to any one of the prior claims, wherein obexerimab is administered in a liquid formulation containing 125 mg / mL of obexerimab, 2.35 mg / mL of sodium acetate trihydrate, 0.17 mg / mL of acetic acid, 30 mg / mL of L-proline, and 0.1 mg / mL of polysorbate 80 at pH 5.

5.

26. The method according to claim 25, wherein obexerimab is administered as a 2 x 1 mL injection or a 1 x 2 mL injection.

27. The method according to claim 25 or 26, wherein obexerimab is administered using a pre-filled syringe or an autoinjector.

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