Isatuximab Monotherapy Demonstrates Efficacy in Relapsed/Refractory Multiple Myeloma

A study published in Cancer Science observed that isatuximab monotherapy was an effective and well-tolerated treatment for relapsed/refractory multiple myeloma (MM).

The open‐label, single‐arm, multicenter, phase I/II trial assessed the tolerability, safety, and efficacy of isatuximab monotherapy in a cohort of Japanese patients with heavily pretreated relapsed/refractory MM.

In phase I of the trial, patients were sequentially assigned to receive isatuximab once weekly in cycle one and every two weeks in subsequent cycles. Cohort one (n=3) received isatuximab 10 mg/kg, and cohort two (n=5) received isatuximab 20 mg/kg. No dose‐limiting toxicities occurred, so the recommended phase II dose was isatuximab 20 mg/kg (n=28).

The safety profile of isatuximab was consistent with previously safety data associated with this therapy. The most common adverse events were infusion reactions (42.9%; n=12/28), all of which were grade 1/2 and generally occurred during the first infusion.

The overall response rate with isatuximab 20 mg/kg was 36.4% (n=12/33). Patients with high‐risk cytogenetic abnormalities had comparable response rates. In phase II, the median progression‐free survival was 4.7 months (95% confidence interval, 3.75 to not reached), while the median overall survival was not reached.

“Isatuximab monotherapy was well tolerated and effective in patients with heavily pretreated relapsed/refractory MM, including high‐risk cytogenetic patients,” the authors concluded.