• PDUFA Action Date Extended by Three Months to July 6, 2019
• FDA Has Requested Additional Existing Information for Review

{{image}}Newton, MA (Press Release) – Karyopharm Therapeutics Inc. (Nasdaq: KPTI), a clin­i­cal-stage pharma­ceu­tical com­pany, today announced that the U.S. Food and Drug Admin­istra­tion (FDA) has extended the Prescription Drug User Fee Act (PDUFA) action date for the New Drug Application (NDA) for selinexor. The NDA, which is cur­rently under Priority Review by the FDA, is seeking accelerated approval for selinexor in com­bi­na­tion with dexa­meth­a­sone for the treat­ment of patients with re­lapsed refractory multiple myeloma who have received at least three prior ther­a­pies and whose disease is refractory to at least one pro­te­a­some inhibitor (PI), one immuno­modu­la­tory agent (IMiD), and one anti-CD38 mono­clonal anti­body. The pre­vi­ously disclosed April 6, 2019 PDUFA date has been extended by three months to July 6, 2019.

On February 26, 2019, the FDA's Oncologic Drugs Advisory Committee (ODAC) met to discuss the selinexor NDA and voted 8 to 5 rec­om­mending that the FDA wait for the results from Karyopharm's ran­dom­ized, open-label, Phase 3 BOSTON study eval­u­ating selinexor in patients with re­lapsed or refractory multiple myeloma, before making a final de­ci­sion re­gard­ing approval. Although the FDA con­siders the recom­men­da­tion of this panel, the final de­ci­sion re­gard­ing the approval of the prod­uct is made by the FDA solely, and the recom­men­da­tions by the panel are non-binding.

Following the ODAC meeting, at the FDA's request, Karyopharm submitted addi­tional, existing clin­i­cal in­for­ma­tion as an amendment to the NDA, which allowed the FDA to extend the PDUFA action date by three months. "We look for­ward to the con­tinued col­lab­o­ration with FDA in trying to meet the needs of patients with re­lapsed refractory multiple myeloma," said Sharon Shacham, PhD, MBA, Founder, Pres­i­dent and Chief Scientific Officer of Karyopharm.

About Selinexor

Selinexor is a first-in-class, oral Selective Inhibitor of Nuclear Export (SINE) 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. In 2018, Karyopharm reported pos­i­tive data from the Phase 2b STORM study eval­u­ating selinexor in com­bi­na­tion with low-dose dexa­meth­a­sone in patients with triple class refractory multiple myeloma who have been pre­vi­ously exposed to all five of the most commonly prescribed anti-myeloma ther­a­pies cur­rently avail­able. Selinexor has been granted Orphan Drug Desig­na­tion in multiple myeloma and Fast Track desig­na­tion for the patient pop­u­la­tion eval­u­ated in the STORM study. Karyopharm's New Drug Application (NDA) has been accepted for filing and granted Priority Review by the FDA, and oral selinexor is cur­rently under review by the FDA as a possible new treat­ment for patients with triple class refractory multiple myeloma. The Company has also submitted a Marketing Authorization Application (MAA) to the European Medicines Agency (EMA) with a request for con­di­tional approval and was granted accelerated assess­ment. Selinexor is also being studied in patients with re­lapsed or refractory diffuse large B-cell lym­phoma (DLBCL). In 2018, Karyopharm reported pos­i­tive top-line results from the Phase 2b SADAL study eval­u­ating selinexor in patients with re­lapsed or refractory DLBCL after at least two prior multi-agent ther­a­pies and who are in­eli­gible for trans­plan­ta­tion, in­­clud­ing high dose chemo­ther­apy with stem cell rescue. Selinexor has received Fast Track desig­na­tion from the FDA for the patient pop­u­la­tion eval­u­ated in the SADAL study. Selinexor is also being eval­u­ated in several other mid-and later-phase clin­i­cal trials across multiple cancer indi­ca­tions, in­­clud­ing in multiple myeloma in a pivotal, ran­dom­ized Phase 3 study in com­bi­na­tion with Velcade® (bor­tez­o­mib) and low-dose dexa­meth­a­sone (BOSTON), as a poten­tial back­bone ther­apy in com­bi­na­tion with approved ther­a­pies (STOMP), in liposarcoma (SEAL), and an investigator-sponsored study in endometrial cancer (SIENDO), among others. Additional Phase 1, Phase 2 and Phase 3 studies are ongoing or cur­rently planned, in­­clud­ing multiple studies in com­bi­na­tion with approved ther­a­pies in a variety of tumor types to further inform Karyopharm's clin­i­cal devel­op­ment priorities for selinexor. Additional clin­i­cal trial in­for­ma­tion for selinexor is avail­able at www.clinicaltrials.gov.

About Karyopharm Therapeutics

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

Forward-Looking Statements

This press release con­tains for­ward-looking state­ments within the meaning of The Private Se­cu­ri­ties Lit­i­ga­tion Reform Act of 1995. Such for­ward-looking state­ments in­clude those re­gard­ing our ex­pec­ta­tions relating to sub­missions to, and the review and poten­tial approval of selinexor by, regu­la­tory author­i­ties, in­­clud­ing the antic­i­pated timing of such sub­missions and actions, and the poten­tial avail­a­bil­ity of accelerated approval path­ways, the thera­peutic poten­tial of and poten­tial clin­i­cal devel­op­ment plans for Karyopharm's drug can­di­dates, especially selinexor, and the plans for com­mer­cial­iza­tion. Such state­ments are subject to numerous im­por­tant factors, risks and un­cer­tain­ties, many of which are beyond Karyopharm's control, that may cause actual events or results to differ ma­teri­ally from Karyopharm's current ex­pec­ta­tions. For example, there can be no guar­an­tee that regulators will agree that selinexor qualifies for accelerated approval in the U.S. or con­di­tional approval in the E.U. as a result of our clin­i­cal data, in­­clud­ing the data from the STORM study in patients with triple class refractory myeloma or the SADAL study in patients with re­lapsed or refractory DLBCL, or that any of Karyopharm's drug can­di­dates, in­­clud­ing selinexor, will suc­cess­fully com­plete nec­es­sary clin­i­cal devel­op­ment phases or that devel­op­ment of any of Karyopharm's drug can­di­dates will con­tinue. Further, there can be no guar­an­tee that any pos­i­tive devel­op­ments in Karyopharm's drug can­di­date portfolio will result in stock price ap­pre­ci­a­tion. Management's ex­pec­ta­tions and, there­fore, any for­ward-looking state­ments in this press release could also be affected by risks and un­cer­tain­ties relating to a number of other factors, in­­clud­ing the fol­low­ing: Karyopharm's results of clin­i­cal trials and pre­clin­i­cal studies, in­­clud­ing sub­se­quent analysis of existing data and new data received from ongoing and future studies; the content and timing of de­ci­sions made by the U.S. Food and Drug Admin­istra­tion and other regu­la­tory author­i­ties, inves­ti­ga­tional review boards at clin­i­cal trial sites and publication review bodies, in­­clud­ing with respect to the need for addi­tional clin­i­cal studies; Karyopharm's ability to obtain and main­tain requisite regu­la­tory approvals and to enroll patients in its clin­i­cal trials; unplanned cash requirements and ex­pen­di­tures; devel­op­ment of drug can­di­dates by Karyopharm's com­pet­i­tors for diseases in which Karyopharm is cur­rently devel­op­ing its drug can­di­dates; and Karyopharm's ability to obtain, main­tain and enforce patent and other intellectual property protection for any drug can­di­dates it is devel­op­ing. These and other risks are described under the caption "Risk Factors" in Karyopharm's Annual Report on Form 10-K for the year ended December 31, 2018, which was filed with the Se­cu­ri­ties and Exchange Com­mis­sion (SEC) on February 28, 2019, and in other filings that Karyopharm may make with the SEC in the future. Any for­ward-looking state­ments con­tained in this press release speak only as of the date hereof, and, except as required by law, Karyopharm expressly disclaims any obli­ga­tion to update any for­ward-looking state­ments, whether as a result of new in­for­ma­tion, future events or other­wise.

Velcade® is a registered trademark of Takeda Pharma­ceu­tical Company Limited.

Source: Karyopharm.