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 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.本發明係關於特異性地結合至BCMA(B細胞成熟抗原)及CD3(白血球分化簇3(Cluster of Differentiation 3))之抗體,例如全長抗體或其抗原結合片段。本發明亦關於包含BCMA抗體之抗體共軛物(例如抗體藥物共軛物)、包含BCMA抗體之組成物、及使用該BCMA抗體及其共軛物以治療與表現BCMA之細胞有關之病症(例如癌症或自體免疫疾病)的方法。本發明進一步關於特異性地結合至CD3及腫瘤細胞抗原之異源多聚體抗體(例如特異性地結合至CD3及BCMA之雙特異性抗體)。亦提供包含此異源多聚體抗體之組成物、製造及純化此異源二聚體抗體之方法、及其於診斷及治療之用途。