Karyopharm’s Phase 3 Endometrial Cancer Trial Misses Primary Endpoint

The clinical trial evaluated selinexor as a maintenance therapy for patients with TP53 wild-type endometrial cancer. In the modified intent-to-treat population of 236 patients, those receiving selinexor achieved a median progression-free survival of 12.75 months, compared to 7.43 months for those in the placebo group. Despite a observed trend favoring the drug, the results did not reach statistical significance, with a hazard ratio of 0.76 and a p-value of 0.0791.

Karyopharm confirmed that the safety profile of selinexor remained consistent with prior clinical data, showing no new safety signals. Following the trial's outcome, the company plans to reduce investment in its endometrial cancer research. CEO Richard Paulson stated that the organization will prioritize its profitable multiple myeloma business and upcoming milestones in its myelofibrosis program, including an expected sNDA submission in the second half of 2026. Researchers intend to present the full study data at an upcoming medical meeting.