Selinexor (XPORT-MF-034) - (SENTRY)

July 30, 2026: Karyopharm Therapeutics (NASDAQ: KPTI) said it plans to submit an sNDA in August 2026 to the FDA seeking accelerated approval of selinexor plus ruxolitinib for myelofibrosis. The company said FDA written feedback indicated spleen volume reduction of at least 35% (SVR35) appears to qualify as a reasonably likely surrogate endpoint for overall survival and could support an accelerated approval filing.

The sNDA is planned to rely on the randomized, double-blind Phase 3 SENTRY trial (NCT04562389) in JAK inhibitor-naïve myelofibrosis patients with platelet counts above 100 x 10^9/L (N=353), which compared once-weekly 60 mg selinexor plus ruxolitinib versus placebo plus ruxolitinib. Karyopharm said SENTRY showed a statistically significant improvement in week-24 SVR35, along with rapid, deep, and sustained spleen responses, a promising overall survival signal, reductions in variant allele frequency, and supportive safety data. Overall survival, a prespecified secondary endpoint, will be used from long-term follow-up of the ongoing SENTRY study to verify clinical benefit.

Karyopharm intends to request Priority Review; if granted, the PDUFA target action date would be about six months after FDA receipt. SENTRY results were presented at the 2026 ASCO Annual Meeting and 2026 EHA Congress and published in the Journal of Clinical Oncology.