Myeloma: Daratumumab Monotherapy Induces Rapid, Deep, Durable Responses

Daratumumab 16 mg/kg monotherapy induced rapid, deep, and durable responses in heavily pretreated patients with multiple myeloma, an updated pooled analysis of 2 studies published in Blood has shown.¹

Previous research has demonstrated the efficacy and favorable safety profile of single-agent daratumumab in patients with multiple myeloma. Now, researchers have conducted a pooled analysis of 148 patients treated with daratumumab 16 mg/kg.

Data were collected from a phase 1/2 study of patients who relapsed after or were refractory to 2 or more prior therapies and a phase 2 study of patients previously treated with 3 or more prior lines of therapy, including a proteasome inhibitor and immunomodulatory drug, or were double refractory to both.

Patients from the pooled population had received a median of 5 prior lines of therapy, and 86.5% were double refractory to a proteasome inhibitor and an immunomodulatory agent.

Results showed that the overall response rate was 31.1%, which included 4 complete responses, 3 stringent complete responses, and 13 very good partial responses. The median duration of response was 7.6 months (95% CI, 5.6-not evaluable).

Researchers found that the median progression-free survival was 4.0 months (95% CI, 2.8-5.6) and median overall survival was 20.1 months (95% CI, 16.6-not evaluable).

Further, the study demonstrated that clinical benefit extended to patients with stable disease or better. Median progression-free survival was 15.0 months (95% CI, 7.4-not evaluable), 3.0 months (95% CI, 2.8-3.7), and 0.9 months (95% CI, 0.9-1.0) among responders, patients who had stable disease/minimal response, and those who had progressive disease/were not evaluable, respectively. Median overall survival was not evaluable, 18.5 months (95% CI, 15.1-22.4), and 3.7 months (95% CI, 1.7-7.6), respectively.

In terms of safety, no new daratumumab-related toxicities were identified.

Reference

1. Usmani SZ, Weiss BM, Plesner T, et al. Clinical efficacy of daratumumab monotherapy in patients with heavily pretreated relapsed or refractory multiple myeloma [published online ahead of print May 23, 2016]. Blood. doi: 10.1182/blood-2016-03-705210.