Updated phase 1 results of teclistamab, a B-cell maturation antigen (BCMA) × CD3 bispecific antibody, in relapsed/refractory multiple myeloma (MM)
- As of Feb 4, 2021, 156 pts received teclistamab (IV n = 84; SC n = 72). The RP2D, identified as weekly SC 1500 µg/kg teclistamab with 60.0 and 300 µg/kg step-up doses, was given to 40 pts (median follow-up 4.3 mo [range 1.1–10.4+]).
- Patients dosed at the RP2D (median age, 62.5 y [range, 39–84]; 65% male) had received a median of 5 prior lines of therapy (range 2–11; 100% triple-class exposed; 65% penta-drug exposed; 83% triple-class refractory; 35% penta-drug refractory; 85% refractory to their last line of therapy).
- There were no dose-limiting toxicities at the RP2D in part 1. The most common AEs at the RP2D were CRS (70%; grade 3/4 0) and neutropenia (60%; grade 3/4 40%); grade 1 neurotoxicity was reported in 1 (3%) patient.
- Median time to CRS onset was later with SC vs IV dosing (day after SC injection vs day of IV infusion).
- The overall response rate in response-evaluable patients treated at the RP2D (n = 40) was 65%;
- 58% achieved a very good partial response or better and 30% achieved a complete response (CR) or better;
- median time to first confirmed response was 1.0 mo (range 0.2–3.1).
- At the RP2D, median duration of response was not reached; 23 of 26 responders (88%), after median follow-up of 5.3 mo (range 1.2–10.4+), were alive and continuing on treatment with responses deepening over time.
- Of 14 evaluable pts across all cohorts, 9 with CR were minimal residual disease–negative at 10-6. At the RP2D, teclistamab exposure was sustained across the dosing interval and exceeded target levels, and consistent T cell activation was observed.