Selinexor, in combination with dexamethasone, has been granted conditional marketing authorization by the European Commission (EC) for the treatment of adult patients with multiple myeloma (MM) who have received at least four prior lines of therapy; whose disease is refractory to at least two proteasome inhibitors, two immunomodulatory agents, and an anti-CD38 monoclonal antibody; and who have demonstrated disease progression on the last therapy.
Like selinexor’s approval in the U.S., this authorization is based on data from the phase IIb STORM study evaluating selinexor in 123 adults with heavily pretreated, triple-class refractory MM. Patients treated with oral selinexor achieved an overall response rate of 26%. The median overall survival was 8.6 months in the total population and 15.6 months among patients who had a minimal response or better.
In the STORM study, fatal adverse events (AEs) occurred in 9% of patients, 58% of patients experienced serious AEs, with 27% discontinuing treatment because of AEs. Serious adverse events present in > 20% of patients included thrombocytopenia, fatigue, nausea, anemia, decreased appetite, decreased weight, diarrhea, vomiting, hyponatremia, neutropenia, leukopenia, constipation, dyspnea and upper respiratory tract infection. Treatment discontinuation rate due to adverse reactions was 27%.
Continued authorization of selinexor by the EC is contingent upon verification of clinical benefit in confirmational trials.