REALiTEC: a multi-country observational retrospective study of teclistamab in patients with relapsed/refractory multiple myeloma outside of clinical trials.

Teclistamab is the first approved anti-B-cell maturation antigen (BCMA) bispecific antibody for patients with triple-class exposed relapsed/refractory multiple myeloma (RRMM), based on the results of the MajesTEC-1 clinical trial. Here, we first report the findings from REALiTEC, a retrospective observational study of patients who received teclistamab outside of clinical trials in Europe and Israel. The study included 113 patients from 23 sites in eight countries, with most (88.5%) accessing the medication through pre-approval access programs. The median age was 66 years, and patients had a median of 6 prior lines of therapy. Notably, 78.8% were triple-class refractory, 44.2% penta-class refractory, and 35.4% had previous anti-BCMA treatment. Overall response rate (ORR) was 60.2%, with 52.2% of patients achieving a very good partial response or better (≥VGPR). After a median follow-up of 20.7 months, median duration of response (DOR) was 20.3 months, median progression-free survival (PFS) was 9.7 months, and median overall survival (OS) was 26.3 months. Patients attaining ≥VGPR experienced longer DOR (median 26.1 months), with 12-month PFS and OS rates of 71.2% and 83.1%, respectively. Subgroup analyses demonstrated consistent outcomes across different patient groups, even in those with historically poorer outcomes. Most common adverse events were infections (all grades 70.8%), cytokine release syndrome (55.8%), neutropenia (35.4%), and anemia (25.7%), with no new safety signals identified. Infection rates decreased over time, and immunoglobulin replacement therapy was used in up to 60% of patients. REALiTEC corroborates the efficacy observed in the MajesTEC-1 study, supporting teclistamab as an effective treatment option in heavily pre-treated RRMM patients.