Teclistamab Monotherapy in Relapsed or Refractory Multiple Myeloma: A Real-World Focused Systematic Review and Meta-Analysis of Efficacy and Safety

Background/Objectives: Teclistamab is a B-cell maturation antigen (BCMA)-directed bispecific antibody approved for relapsed or refractory multiple myeloma (RRMM). Although prior analyses have summarized teclistamab outcomes, some have included combination regimens or broader comparative studies. Given the expanding real-world experience with teclistamab, we conducted a systematic review and meta-analysis focused on teclistamab monotherapy in RRMM. Methods: We performed a systematic review and meta-analysis of clinical trials and retrospective real-world studies evaluating teclistamab monotherapy in RRMM. The primary endpoint was overall response rate (ORR). Secondary endpoints included complete response (CR), overall mortality rate (OMR), mortality due to multiple myeloma progression, teclistamab-attributed mortality, adverse event-related mortality, grade ≥3 cytokine release syndrome (CRS), grade ≥3 immune effector cell-associated neurotoxicity syndrome (ICANS), and other grade ≥3 adverse events. Pooled proportions were estimated using random-effects models. Results: Twelve studies including 761 patients were analyzed, comprising two clinical trials and ten real-world retrospective cohorts. The pooled ORR was 60.9%, and the pooled CR rate was 25.2%. The pooled OMR was 26.9%, with mortality due to myeloma progression of 23.9%, adverse event-related mortality of 8.1%, and teclistamab-attributed mortality of 3.3%. Severe (grade ≥3) CRS and ICANS were uncommon, with grade ≥3 events occurring in 1.7% and 3.1%, respectively. Grade ≥3 infections occurred in 28.3%. Common grade ≥3 hematologic adverse events included lymphopenia, neutropenia, anemia, and thrombocytopenia. Conclusions: Teclistamab monotherapy demonstrates meaningful clinical activity and a manageable immune toxicity profile in heavily pretreated RRMM. However, severe infections and hematologic toxicities remain important clinical considerations, supporting the need for close monitoring, infection prevention, and supportive care during therapy.