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.