Dr Bose on Early Data With Selinexor in Myelofibrosis that Led to SENTRY

“There was an unexpected but statistically significant survival benefit that emerged at an early time point. The median follow-up to date is about 11 months. There was still a survival benefit in favor of [selinexor plus ruxolitinib], and the hazard ratio was 0.43, which is…impressive.”

Prithviraj Bose, MD, a professor and co-leader of the section of myeloproliferative neoplasms (MPNs) in the Department of Leukemia at The University of Texas MD Anderson Cancer Center, in Houston, Texas, discussed efficacy data from the phase 3 SENTRY trial (NCT04562389) evaluating selinexor (Xpovio) plus ruxolitinib (Jakafi) vs placebo plus ruxolitinib in patients with JAK inhibitor–naive myelofibrosis, tracing how earlier phase 1 findings (NCT04562389) supported moving the combination into randomized testing.

At the 2026 SOHO Annual Meeting, Bose noted how an investigator-initiated trial conducted at the University of Utah showed monotherapy activity for selinexor in JAK inhibitor–pretreated, relapsed/refractory, or intolerant patients. A subsequent phase 1 study enrolled 24 patients, 14 of whom received the selinexor 60-mg weekly dose; in that cohort, the spleen response rate was 79%, and the symptom response rate was 58%, results Bose described as the basis for advancing to SENTRY.

As it relates to SENTRY, Bose reported a week-24 spleen volume reduction of at least 35% (SVR35) rate of 49.8% with the combination (n = 235) vs 28.0% (n = 118) with placebo plus ruxolitinib (odds ratio, 2.58; 95% CI, 1.60-4.17; 1-sided P < .0001). He noted that the roughly 28% rate with ruxolitinib alone was consistent with prior JAK inhibitor monotherapy data. Symptom score improved similarly in both arms, with mean reductions of 9.9 (95% CI, –11.2 to –8.6) and 10.9 points (95% CI, –12.6 to –9.1), respectively, without statistical significance, he said.

Bose highlighted an unexpected early survival signal: at a median follow-up of approximately 11 months, risk of death favored the selinexor arm (HR, 0.43; 95% CI, 0.19-1.00; nominal 1-sided P = .022). The causes of death still need characterization, and longer follow-up is required to confirm the benefit, Bose said, noting that this is an early finding that could potentially extend the combination's value.