ASCO20: Selinexor-Based Combination Therapy for Resistant Multiple Myeloma
Posted: Thursday, June 4, 2020
A weekly regimen of the combination of selinexor, daratumumab, and dexamethasone demonstrated activity in patients whose multiple myeloma was refractory to protease inhibitors and immunomodulatory drugs, according to a presentation during the ASCO20 Virtual Scientific Program (Abstract 8510). In fact, in this patient population, the triple regimen yielded an overall response rate of 73% in those previously untreated with daratumumab.
“This supports further development of a novel non-protease inhibitor, non–immunomodulatory drug backbone in earlier lines of therapy,” stated Cristina Gasparetto, MD, of Duke University Cancer Center, Durham, North Carolina, and colleagues.
Patients who had received more than three lines of therapy, including a protease inhibitor and an immunomodulatory drug, or whose multiple myeloma was refractory to a protease inhibitor and immunomodulatory drug, were enrolled in the phase Ib/II dose-escalation and dose-expansion study. All patients were required to be previously untreated with an anti-CD38 monoclonal antibody during the dose-expansion stage. Patients were administered 40 mg of dexamethasone and 16 mg/kg of daratumumab, with either 100 mg of selinexor once weekly (n = 31), or 60 mg of selinexor twice weekly (n = 3) at each testing schedule.
The investigators found that grade 3 thrombocytopenia and grade 2 fatigue were two dose-limiting toxicities with the 60-mg twice weekly dosage and required dose reduction. In contrast, no dose-limiting toxicities were found for the 100-mg once-weekly cohort. In daratumumab-naive patients, the overall response rate was 73%, and the median progression-free survival was 12.5 months. Moving forward, based on these early findings, the dosages will be selinexor at 100 mg, daratumumab at 16 mg/kg, and dexamethasone at 40 mg, administered once weekly.
Disclosure: For full disclosures of the authors, visit coi.asco.org.
