– Phase 1b/2 Study Evaluating Selinexor and Dexamethasone in Combination With Backbone Multiple Myeloma Therapies –

NEWTON, MA, USA I October 19, 2015 I Karyopharm Therapeutics Inc. (KPTI), a clinical-stage pharmaceutical company, announced today the initiation of the Selinexor and Backbone Treatments of Multiple Myeloma Patients, (STOMP) study. STOMP is a multi-center, Phase 1b/2 study of selinexor and other standard therapies in patients with multiple myeloma (MM). Selinexor, the company’s lead, novel, oral Selective Inhibitor of Nuclear Export/SINE(TM) compound, will be evaluated in combination with low-dose dexamethasone in independent cohorts with bortezomib (Velcade(R)), lenalidomide (Revlimid(R)) and pomalidomide (Pomalyst(R)). Selinexor and low dose dexamethasone is already being combined with carfilzomib (Kyprolis(R)) in an Investigator Sponsored MM Trial, where promising preliminary data were presented at the American Society of Hematology (ASH) 2014 Annual Meeting. Selinexor has received orphan drug designation from both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for MM.

 

“The activity demonstrated to-date in multiple myeloma with selinexor and low-dose dexamethasone, as well as the combination of selinexor and low-dose dexamethasone with carfilzomib, is encouraging and we look forward to further evaluating the activity of selinexor-based combinations in patients with multiple myeloma whose disease has relapsed following, or is refractory to, various agents,” said Sharon Shacham, PhD, MBA, President and Chief Scientific Officer of Karyopharm. “Despite the availability of new therapies for multiple myeloma, nearly all patients eventually relapse and eventually succumb to this disease. We hope the selinexor/low-dose dexamethasone regimen in combination with existing therapies will improve the outcomes for these patients.”

This multi-arm Phase 1b/2 study will evaluate the safety and efficacy of selinexor and low-dose dexamethasone at 60mg and 20mg, respectively, twice weekly or 80mg and 40mg, respectively, once weekly in separate combinations with either bortezomib, lenalidomide or pomalidomide. 220 patients with MM whose disease has relapsed after one or more prior therapies are expected to enroll in STOMP and overall response rate (ORR) is the primary endpoint of the study.

STOMP was designed based on both preclinical combination data as well as from Karyopharm’s ongoing Phase 1/2 study of selinexor with low-dose dexamethasone in combination with the proteasome inhibitor carfilzomib in relapsed/refractory multiple myeloma. Phase 1/2 data demonstrating the activity of selinexor with low-dose dexamethasone in combination with carfilzomib were presented at ASH 2014. In this ongoing study conducted by investigators at the University of Chicago, the first three patients, all of whom had MM refractory to carfilzomib and dexamethasone, were treated with selinexor, dexamethasone and carfilzomib achieved at least partial responses. Further clinical updates from this ongoing study are expected at the ASH 2015 annual meeting.

About Selinexor

Selinexor (KPT-330) is a first-in-class, oral Selective Inhibitor of Nuclear Export / SINE(TM) compound. Selinexor functions by binding with and inhibiting the nuclear export protein XPO1 (also called CRM1), leading to the accumulation of tumor suppressor proteins in the cell nucleus. This reinitiates and amplifies their tumor suppressor function and is believed to lead to the selective induction of apoptosis in cancer cells, while largely sparing normal cells. Over 1,200 patients have been treated with selinexor in company and investigator-sponsored Phase 1 and Phase 2 clinical trials in advanced hematologic malignancies and solid tumors. Karyopharm has initiated four later-phase clinical trials of selinexor, including one in older patients with acute myeloid leukemia (SOPRA), one in patients with Richter’s transformation (SIRRT), one in patients with diffuse large B-cell lymphoma (SADAL) and a single-arm trial of selinexor and lose-dose dexamethasone in patients with multiple myeloma (STORM). In solid tumors, Karyopharm plans to initiate a randomized, placebo-controlled Phase 2/3 trial of selinexor to treat liposarcoma during the fourth quarter of 2015. Additional Phase 1 and Phase 2 studies are ongoing or currently planned, including multiple studies in combination with one or more approved therapies in a variety of tumor types to further inform the company’s clinical development priorities for selinexor. The latest clinical trial information for selinexor is available at www.clinicaltrials.gov.

About Karyopharm Therapeutics

Karyopharm Therapeutics Inc. (KPTI) is a clinical-stage pharmaceutical company focused on the discovery and development of novel first-in-class drugs directed against nuclear transport targets for the treatment of cancer and other major diseases. Karyopharm’s SINE(TM) compounds function by binding with and inhibiting the nuclear export protein XPO1 (or CRM1). In addition to single-agent activity against a variety of different human cancers, SINE(TM) compounds have also shown biological activity in models of cancer, inflammation, autoimmune disease, certain viruses, and wound-healing. Karyopharm was founded by Dr. Sharon Shacham and is located in Newton, Massachusetts. For more information, please visit www.karyopharm.com.

SOURCE: Karyopharm