FDA postpones decision on selinexor to treat relapsed refractory multiple myeloma

Karyopharm Therapeutics Inc. announced that the FDA Oncologic Drugs Advisory Committee (ODAC) met to discuss the New Drug Application (NDA) for selinexor, a first-in-class, oral Selective Inhibitor of Nuclear Export (SINE) compound. The NDA, which is currently under Priority Review by the FDA, is seeking accelerated approval for selinexor in combination with dexamethasone for the treatment of patients with relapsed refractory multiple myeloma who have received at least three prior therapies and whose disease is refractory to at least one proteasome inhibitor (PI), one immunomodulatory agent (IMiD), and one anti-CD38 monoclonal antibody.

The ODAC voted 8 to 5 recommending that the FDA wait for the results from Karyopharm’s randomized, open-label, Phase III BOSTON study evaluating selinexor in patients with relapsed or refractory multiple myeloma, before making a final decision regarding approval. The BOSTON study is evaluating selinexor in combination with Velcade (bortezomib) and low-dose dexamethasone compared to bortezomib and low-dose dexamethasone in patients with multiple myeloma who have had one to three prior lines of therapy. Importantly, in the selinexor arm of the study, both selinexor and bortezomib are administered once per week while in the control arm, bortezomib is administered at its currently indicated, twice per week schedule. Patient enrollment in the BOSTON study is now complete and top-line data are expected by the end of 2019 at the earliest, or into 2020, pending progression-free survival (PFS) events, a primary endpoint in this trial.