-- 40% of Patients with Myelofibrosis Who Received at Least 24 Weeks of Selinexor Treatment Achieved a Response, Defined as ≥35% Spleen Volume Reduction --
-- Responses were Durable with Median Treatment Duration of 11 months, with Some Patients Remaining on Long Term Therapy for Over Two Years --
NEWTON, Mass., Dec. 11, 2021 /PRNewswire/ -- Karyopharm Therapeutics Inc. (Nasdaq:KPTI), a commercial-stage pharmaceutical company pioneering novel cancer therapies, today announced an oral presentation highlighting updated data from the Phase 2 ESSENTIAL study, an investigator-sponsored study evaluating single-agent selinexor, a first-in-class, oral Selective Inhibitor of Nuclear Export (SINE) compound, in patients with myelofibrosis (MF) previously treated with JAK inhibition. These updated results were presented at the American Society of Hematology (ASH) 2021 Annual Meeting and Exposition taking place in Atlanta, GA on December 11-14, 2021.
"The results presented at ASH this year demonstrate that once weekly single-agent oral selinexor resulted in an impressive spleen volume reduction rates in myelofibrosis patients who received at least 24 weeks of treatment, with 40% and 60% of those patients achieving a response, defined as spleen volume reduction (SVR) of at least 35% and 25%, respectively. The durable responses and well-tolerated safety profile highlight selinexor's potential in patients with JAK-refractory myelofibrosis," said Srinivas Tantravahi, MBBS, MRCP, University of Utah Hospital and principal investigator of the Phase 2 ESSENTIAL study. "With JAK inhibitors being the only class of drugs approved for this disease and with less than half of patients responding, there remains a high unmet need for patients who either progress following treatment with a JAK inhibitor or are intolerant."
"Following the encouraging data from the Phase 2 ESSENTIAL trial, we recently dosed the first patient in Karyopharm's new Phase 2 study evaluating single-agent selinexor versus physician's choice in patients with previously treated myelofibrosis," said Sharon Shacham, PhD, MBA, Co-Founder and Chief Scientific Officer of Karyopharm. "As part of our strategic imperatives and pipeline priorities, we remain focused on diseases with the highest unmet needs and greatest potential to make an impact in patient outcomes."
Results from the Phase 2 ESSENTIAL Study Evaluating Single-Agent Selinexor in Patients with MF Refractory or Intolerant to JAK Inhibitors
The results were based on the open label, prospective, investigator-initiated single center ESSENTIAL study in adult patients with primary or secondary MF with resistance or intolerance to JAK inhibitor therapy (NCT03627403). Selinexor was administered orally at a dose of 80mg or 60mg once weekly to 12 patients. The primary endpoint of the study is to assess the efficacy of selinexor on SVR. Median duration of prior JAK inhibitor therapy was 22 months (range 0.5 to 96 months) and 92% (11 of 12) patients had MF refractory to ruxolitinib.
As of the data cutoff, the median duration of treatment was 11 months (range 2.8 to 28.8 months). Of the ten patients who were on treatment for at least 24 weeks, four (40%) patients achieved SVR of ≥35% and six (60%) patients achieved SVR of ≥25%. Of the five patients who were transfusion dependent at screening, two (40%) achieved transfusion independence. Of the three patients with hemoglobin