Successes and Challenges of Bispecific T-cell Engager Antibodies in the Treatment of Multiple Myeloma.

Recent advances in drug development have revolutionized the field of oncology, leading to the development of novel therapeutic strategies. Among them, bispecific antibodies (BsAbs) targeting CD3 and tumor antigens have shown significant efficacy in relapsed or refractory multiple myeloma (RRMM). In triple-class exposed RRMM, where the median survival is less than 2 years, BsAbs redirect T cells toward targets such as BCMA and GPRC5D, achieving response rates of approximately 60%-70% with durable efficacy, resulting in regulatory approvals. Adverse events, such as cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, and infections, are generally manageable. However, reduced efficacy in patients with high tumor burden, antigen loss, and T-cell exhaustion remains a challenge. Ongoing research is focused on optimizing dosing, combination strategies, and earlier use. BsAbs offer a promising therapeutic option with the potential to reshape treatment paradigms and improve long-term outcomes in multiple myeloma patients.