Posted: Friday, March 31, 2023
The addition of the monoclonal antibody isatuximab to the combination of bortezomib, cyclophosphamide, and dexamethasone (VCd) has demonstrated favorable clinical activity in patients with newly diagnosed multiple myeloma who are ineligible for transplantation, according to a letter published in the journal HemaSphere (powered by the European Hematology Association). In a multicenter phase Ib study, there were no new safety signals associated with the novel anti-CD38 antibody quadruplet regimen, explained María-Victoria Mateos, MD, PhD, of the University Hospital of Salamanca and Cancer Research Center, Spain, and colleagues.
A total of 17 transplantation-ineligible patients with newly diagnosed multiple myeloma were enrolled in the study. In the 12-cycle induction phase, 13 patients received the isatuximab dose limit of 10 mg/kg, and 4 received the agent’s dose limit of 20 mg/kg. The dose-escalation cohort consisted of four patients who received isatuximab at 10 or 20 mg/kg plus VCd. Patients continued maintenance treatment with their initial assigned dose of isatuximab plus 20 mg of daily dexamethasone for 28 days.
No dose-limiting toxicity was observed, and the maximum tolerated dose was not reached; therefore, a dose of isatuximab at 10 mg/kg was chosen for the dose-expansion part of the study. For 4 weeks, nine additional patients received weekly doses of isatuximab at 10 mg/kg plus VCd. Dosing then switched to every 2 weeks.
Treatment-emergent adverse events were experienced by 100% of patients; however, the events were mostly grade 1 or 2. Median progression-free survival was estimated to be 63.3 months (95% confidence interval = 28.6 months to not calculable) in the group receiving isatuximab at 10 mg/kg plus VCd and the overall efficacy population, whereas median overall survival was not reached in either group. Moreover, the overall response rate was 91.7% in evaluable patients treated with isatuximab at 10 mg/kg plus VCd and 93.3%, in the overall efficacy population.
Disclosure: For full disclosures of the study authors, visit journals.lww.com.