Abstract: Provided herein, inter alia, are isolated antibodies that bind an extracellular domain of a human SIRP-? v1 polypeptide (e.g., the D1 domain), an extracellular domain of a human SIRP-? v2 polypeptide, or both. In some embodiments, the antibodies also bind an extracellular domain of a monkey SIRP-? polypeptide, an extracellular domain of a mouse SIRP-? polypeptide, an extracellular domain of a human SIRP-? polypeptide, and/or an extracellular domain of a human SIRP-? polypeptide. In some embodiments, the antibodies block or do not binding between an extracellular domain of a human SIRP-? polypeptide and an IgSF domain of a human CD47 polypeptide, while in some embodiments, the antibodies reduce the affinity of a human SIRP-? polypeptide for binding an IgSF domain of a human CD47 polypeptide. Further provided herein are methods, polynucleotides, vectors, and host cells related thereto.

Abstract: The present disclosure features signal-regulatory protein ? (SIRP-?) polypeptides and constructs that are useful, e.g., to target a cell (e.g., a cancer cell or a cell of the immune system), to increase phagocytosis of the target cell, to eliminate immune cells such as regulatory T-cells, to kill cancer cells, to treat a disease (e.g., cancer) in a subject, or any combinations thereof. The SIRP-? constructs include a high affinity SIRP-? D1 domain or variant thereof that binds CD47 with higher affinity than a wild-type SIRP-?. The SIRP-? polypeptides or constructs include a SIRP-? D1 variant fused to an Fc domain monomer, a human serum albumin (HSA), an albumin-binding peptide, or a polyethylene glycol (PEG) polymer. Compositions provided herein include (i) a polypeptide including a signal-regulatory protein ? (SIRP-?) D1 variant and (ii) an antibody.

Abstract: The present invention relates to antibodies, e.g., full length antibodies or antigen binding fragments thereof, that specifically bind to BCMA (B-Cell Maturation Antigen) and/or CD3 (Cluster of Differentiation 3). The invention also relates to antibody conjugates (e.g., antibody-drug-conjugates) comprising the BCMA antibodies, compositions comprising the BCMA antibodies, and methods of using the BCMA antibodies and their conjugates for treating conditions associated with cells expressing BCMA (e.g., cancer or autoimmune disease). The invention further relates to heteromultimeric antibodies that specifically bind to CD3 and a tumor cell antigen, (e.g., bispecific antibodies that specifically bind to CD3 and BCMA). Compositions comprising such heteromultimeric antibodies, methods for producing and purifying such heterodimeric antibodies, and their use in diagnostics and therapeutics are also provided.

Abstract: The invention provides CARs (CARs) that specifically bind to BCMA (B-Cell Maturation Antigen). The invention further relates to engineered immune cells comprising such CARs, CAR-encoding nucleic acids, and methods of making such CARs, engineered immune cells, and nucleic acids. The invention further relates to therapeutic methods for use of these CARs and engineered immune cells for the treatment of a condition associated with malignant cells expressing BCMA (e.g., cancer).