Karyopharm’s bid to expand Xpovio (selinexor) into endometrial cancer stumbled again as top-line Phase 3 results failed to meet the primary progression-free survival endpoint. The company disclosed that XPORT-EC-042 did not achieve statistical significance in adults with TP53 wild-type advanced or recurrent endometrial cancer. Shares sank sharply as the outcome marked the second Phase 3 flop for Xpovio in this setting, further tightening the company’s runway. Karyopharm said it had $91.2 million in cash as of Q1 2026, which it estimated funds operations through the latter part of Q3, while it explores financings and strategic alternatives. Despite the trial miss, Karyopharm signaled it still intends to submit an sNDA in August, seeking priority review and accelerated approval for Xpovio plus Jakafi (ruxolitinib) in myelofibrosis based on overall survival data from the Phase 3 Sentry trial—an effort to offset the endometrial setback with a different regulatory pathway.