Phase II Trial Focuses on Isatuximab for Resistant Myeloma
Posted: Wednesday, August 26, 2020
For patients with relapsed or refractory multiple myeloma, treatment with the anti-CD38 monoclonal antibody isatuximab may prove to be an effective therapeutic alternative, according to a phase II dose-finding study published in Leukemia. In addition, isatuximab had the “greatest efficacy” at doses higher than 10 mg/kg, reported Thomas Martin, MD, of the Helen Diller Family Comprehensive Cancer Center, San Francisco, and colleagues.
A total of 97 patients with resistant multiple myeloma were enrolled in the study. All patients had previously received more than three lines of treatment or were refractory to proteasome inhibitors and immunomodulatory drugs. Patients were assigned to one of the following treatment groups: group 1 received 3 mg/kg of isatuximab biweekly; group 2 received 10 mg/kg of isatuximab biweekly; group 3 received 10 mg/kg of isatuximab biweekly for two cycles and then once a month; and group 4 received 20 mg/kg of isatuximab weekly for one cycle and then biweekly.
The investigators reported an overall response rate of 4.3%, 29.2%, 20.0%, and 24.0% for the aforementioned treatment groups 1 through 4, respectively. For patients with high-risk cytogenetics, the overall response rate was 40.9%. In fact, responses were reported across all high-risk groups, including those with more than three prior therapies, those with double- and quadruple-refractory disease, and those 70 years of age and older. When the dose exceeded 10 mg/kg, the progression-free survival was 4.6 months, and the overall survival was 18.7 months. In addition, the density of CD38 receptors appeared to be similar between patients who did and did not respond to treatment.
Furthermore, patients treated with isatuximab experienced nonhematologic adverse events, including nausea (34%), fatigue (32%), and upper respiratory infections (29%). The study findings also revealed that approximately half of patients experienced infusion reactions.
Disclosure: For full disclosures of the study authors, visit nature.com.