Efficacy and Safety of Teclistamab in Relapsed/Refractory Multiple Myeloma: 2‐Year Follow‐Up From MajesTEC‐1 China Cohort

Introduction With an additional year of follow‐up compared with the previous report, this study presents the 27.2‐month efficacy and safety outcomes of the MajesTEC‐1 China cohort. Methods A total of 26 participants with triple‑class exposed relapsed/refractory multiple myeloma (TCE‐RRMM) received subcutaneous teclistamab 1.5 mg/kg weekly, with potential transition to every 2 weeks in sustained responders. Results Overall response rate (ORR) was 76.9%, with all responders achieving a very good partial response or better (≥ VGPR), and 75% achieving a complete response or better (≥ CR). Median progression‑free survival (PFS) was 25.1 months, while median duration of response (DOR) and overall survival (OS) were not reached. Among patients achieving ≥ CR, estimated 30‑month DOR, PFS, and OS rates were favorable at 80.0%, 80.0%, and 93.3%, respectively. Patients with poor prognostic features achieved ORRs comparable to overall population, and their DOR was generally consistent. Quality‐of‐life assessments showed improvements from baseline in global health status, physical functioning, fatigue, and pain. Safety profile was consistent with previous publication. Incidence of new‐onset Grade ≥ 3 infections decreased over time, which was consistent with the timing of transition to biweekly dosing and may be related to immunoglobulin use. Conclusion These findings support teclistamab as a standard‐of‐care for patients with TCE‐RRMM in China. Clinical Trial Registration ClinicalTrials.gov identifier: NCT03145181/NCT04557098