MajesTEC-1 Trial: Teclistamab for Relapsed or Refractory Multiple Myeloma

An open-label, single-arm, phase I clinical trial showed that teclistamab displayed promising effectiveness, a durable response, and was well tolerated in treating patients with relapsed or refractory multiple myeloma (MM). The study, led by Saad Zafar Usmani, MD, FACP, and colleagues, was published in The Lancet. Given the results from the study, the authors suggested that further clinical development of teclistamab is warranted.

Patients with MM who were relapsed, refractory, or intolerant to established therapies were eligible to participate. Teclistamab was administered intravenously (range 0·3-19·2 μg/kg [once every 2 weeks] or 19·2-720 μg/kg [once per week]), or subcutaneously (range 80-3000 μg/kg [once per week]) in different cohorts, with step-up dosing for 38·4 μg/kg or higher doses. The study’s objectives were to identify the recommended phase II dose, and to assess the safety and tolerability of teclistamab at that dose.

Patients were screened for eligibility, and enrolled between June 8, 2017, and March 29, 2021. A total of 157 patients, with a median of six previous therapy lines, received at least one dose of teclistamab (intravenous n = 84; subcutaneous n = 73).

A subgroup of 40 patients received the identified recommended phase II dose, once per week subcutaneous teclistamab at 1500 μg/kg, after 60 μg/kg and 300 μg/kg step-up doses (median follow-up 6·1 months, IQR 3·6-8·2). Among the subgroup, cytokine release syndrome (28 patients; 70%; all grade I or II events), and neutropenia (26 patients; 65%; grade III or IV in 16 patients [40%]) were the most common treatment-emergent adverse events. The overall response rate at the recommended dose was 65% (95% CI, 48-79), and 58% achieved a very good partial response or better.

According to the authors, the results of the study provide support for teclistamab as an emergent treatment option for patients with relapsed or refractory MM, when administered at the recommended phase II dose.