Karyopharm announces updated results from Phase 1 study of Selinexor

Karyopharm Therapeutics announced updated results from the Phase 1 study evaluating the safety and efficacy of once-weekly selinexor in combination with ruxolitinib in patients with treatment-naive myelofibrosis. The data, featured in a poster presentation at the American Association for Cancer Research, or AACR, Annual Meeting 2023, "show that rapid, deep and sustained spleen responses and robust symptom improvement were achieved at both weeks 12 and 24, in patients treated with selinexor 60mg in combination with ruxolitinib," the company said. As of the February 24, 2023 data cut-off date, 24 patients had been assigned to either a 40mg or 60mg once weekly dose of selinexor, combined with ruxolitinib. All patients initiated treatment greater than 24 weeks prior to the data cut-off date. Both the efficacy and safety data support the 60 mg dose of selinexor as the recommended dose in combination with ruxolitinib. A double-blind, randomized, Phase 3 trial of selinexor 60 mg in combination with ruxolitinib versus placebo in combination with ruxolitinib in JAKi treatment-naive patients with myelofibrosis is expected to initiate in the first half of 2023. "We are enthusiastic about the impressive spleen volume reductions and robust symptom improvement observed with the 60mg dose of selinexor and ruxolitinib combination at week 24, which represent very meaningful improvements relative to the current standard of care of ruxolitinib alone. These data suggest that the combination of selinexor and ruxolitinib has the potential to be a transformative therapy for first line myelofibrosis patients. We are also very encouraged by the preliminary data showing rapid normalization in platelets and stability of hemoglobin levels, as potential evidence of disease modification for these patients. We look forward to building upon these findings as we plan the initiation of a pivotal Phase 3 study in front-line myelofibrosis later this quarter," said Reshma Rangwala, MD, PhD, Chief Medical Officer of Karyopharm.