At a median follow-up of 8.6 months (range, 0.3-19.6), 76.5 percent (39/51) of response-evaluable patients enrolled in the study achieved a response, including 36 patients (70.6 percent) who achieved a very good partial response (VGPR) or better. In patients with prior anti-CD38 exposure, an ORR of 73.7 percent was achieved. The median time to first confirmed response was one month, and responses remained durable and deepened over time. At the analysis cutoff, 66.7 percent of patients who achieved a response (26/39) were alive and continuing on therapy.

As of April 6, 2022, 65 patients received daratumumab 1800mg at the approved schedule plus teclistamab 1.5mg/kg weekly (QW) or 3mg/kg every other week (Q2W) subcutaneously. Pre-medications, including steroids, were limited to the two step-up doses and the first full dose of teclistamab. Treatment with the combination regimen were tolerable and no unexpected or overlapping toxicities were observed. The most common adverse events were cytokine release syndrome (CRS) (67.7 percent, all Grade 1 or 2); neutropenia (49.2 percent, 41.5 percent Grade 3 or 4); and anemia (41.5 percent, 27.7 percent Grade 3 or 4). One patient (2 percent) had Grade 1 immune effector cell–associated neurotoxicity syndrome (ICANS) which fully resolved. Infections were experienced by 67.7 percent of patients (27.7 percent Grade 3 or 4). Four patients died from adverse events, all unrelated to teclistamab or daratumumab treatment.