Selinexor Offers Hope Against a Tough-to-Treat Blood Cancer

In continuation of my update on Selinexor

Patients with a form of blood cancer known as multiple myeloma who haven't responded to other therapies might have a new weapon against the disease, researchers say.

A drug called selinexor appeared to help patients with the blood and bone marrow cancer, according to a clinical trial involving 122 people.

"This study proved that a novel, first-in-class drug with a new mechanism of action can kill a patient's cancer cells," said study senior author Dr. Sundar Jagannath. He directs the multiple myeloma program at the Tisch Cancer Institute at Mount Sinai in New York City.

Selinexor also "worked in patients who had exhausted every other treatment and who would have been placed on hospice care otherwise," Jagannath said in a hospital news release.

In the trial, which was funded by the drug's maker, Karyopharm, patients at centers in the United States and Europe received a combination therapy of two pills, selinexor and the standard anti-cancer medicine dexamethasone.

As reported in the Aug. 22 issue of the New England Journal of Medicine, nearly 40% of the patients showed at least a minimal response to the therapy within one or two months. There were "significant" responses in more than a quarter of the patients, the researchers said, and two patients had their cancers go into complete remission.

As the team explained, selinexor works in a new way to fight myeloma, blocking a key mechanism in cancer cell growth and causing the cell to die.

Although the drug caused no toxicity to organs, there were side effects for some patients. These included low blood counts without bleeding, nausea, vomiting, lack of appetite or fatigue.

The U.S. Food and Drug Administration had already approved selinexor in early July to treat patients with multiple myeloma resistant to multiple therapies.

"This study is meaningful for patients with multiple myeloma who haven't had success on multiple other therapies," said study first author Dr. Ajai Chari, director of clinical research in the multiple myeloma program at the Tisch Cancer Institute.

"An increasing number of patients have resistance to the standard drugs used in the treatment of multiple myeloma, and the overall survival in these patients is short, sometimes less than three months," Chari said in the news release.

One myeloma expert unconnected to the research was heartened by the findings.

The trial results are "cautiously positive and very encouraging," said hematologist Dr. Kanti Rai. He works in the CLL Research and Treatment Program at Northwell Health Cancer Institute in New Hyde Park, N.Y.

Rai noted that while newer drugs are helping many multiple myeloma patients, others are still left without viable treatment options.

"The need for better treatments is especially urgent for those patients who are elderly, have compromised functions of other vital organs, have had multiple chemotherapy regimens in the past and still have evidence of progressive disease," he explained. "For such patients, unfortunately, death seems imminent."

Rai called the advent of selinexor "a positive step forward for patients with myeloma who otherwise have no hope for the future."

For their part, the Tisch researchers said they are also assessing selinexor for treatment of multiple myeloma in combination with other approved multiple myeloma drugs, as well for treatment of other cancers such lymphoma and ovarian cancer.

https://en.wikipedia.org/wiki/Selinexor

FDA Approves Xpovio (selinexor) for the Treatment of Patients with Relapsed or Refractory Multiple Myeloma

In continuation of my update on Selinexor

Karyopharm Therapeutics Inc. an oncology-focused pharmaceutical company, announced that the U.S. Food and Drug Administration (FDA) has approved oral Xpovio (selinexor), a nuclear export inhibitor, in combination with dexamethasone for the treatment of adult patients with relapsed or refractory multiple myeloma (RRMM) who have received at least four prior therapies and whose disease is refractory to at least two proteasome inhibitors, at least two immunomodulatory agents, and an anti-CD38 monoclonal antibody. This indication is approved under accelerated approval based on response rate. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial. The ongoing, randomized Phase 3 BOSTON study evaluating selinexor in combination with Velcade® (bortezomib) and low-dose dexamethasone will serve as the confirmatory trial. The FDA’s Accelerated Approval Program was developed to allow for expedited approval of drugs that treat serious conditions and that fill an unmet medical need.  

Karyopharm expects Xpovio to become commercially available in the U.S. on or before July 10, 2019.  A Marketing Authorization Application for selinexor is also currently under review by the European Medicines Agency.

“With today’s accelerated approval of Xpovio by the FDA, patients with heavily pretreated multiple myeloma will now have a new therapeutic option to treat their disease,” said Sharon Shacham, PhD, MBA, Founder, President and Chief Scientific Officer of Karyopharm. “Discovering, developing and securing FDA approval for XPOVIO with its novel mechanism of action over the past decade required the dedication of many people, including the patients, caregivers and physicians involved in our clinical trials, along with the many employees at Karyopharm.  We are tremendously grateful for everyone’s contributions to this important milestone, and we look forward to the next stage in our pursuit of improving the lives of patients with cancer.”

“The 25.3% response rate seen in the subgroup of 83 patients in the pivotal Phase 2b STORM study that served as the basis for Xpovio's accelerated approval is clinically meaningful and a validated surrogate marker for clinical benefit in our patients with advanced refractory disease,” said Sundar Jagannath, MD, Director of the Multiple Myeloma Program, Professor of Medicine (Hematology and Medical Oncology) at Tisch Cancer Institute at Mount Sinai School of Medicine, and principal investigator of the STORM study.

“Despite recent advances in the treatment of multiple myeloma, almost all our patients will develop disease that is resistant to the five most commonly used anti-myeloma drugs we currently have available, and the prognosis for this patient population is particularly poor.  The accelerated approval of oral Xpovio marks an important advance in the treatment paradigm for patients with relapsed refractory multiple myeloma, and in my view, is an important addition to our therapeutic armamentarium,” said Dr. Paul Richardson, MD, Clinical Program Leader and Director of Clinical Research, Jerome Lipper Multiple Myeloma Center at the Dana-Farber Cancer Institute.

Michael G. Kauffman, MD, PhD, Chief Executive Officer of Karyopharm, commented, “Having worked on novel drugs in myeloma beginning with Velcade in the year 2000, I have been thrilled to see such exciting progress overall in the field where there are substantial increases in patients’ duration and quality of life.  The accelerated approval of oral Xpovio targeting XPO1 represents the first approval against a new target in myeloma since 2015, and we look forward to advancing the further clinical development of Xpovio.”

https://pubchem.ncbi.nlm.nih.gov/compound/Selinexor

Karyopharm Announces FDA Extension of Review Period for Selinexor New Drug Application

  

Karyopharm Therapeutics Inc. (Nasdaq: KPTI), a clinical-stage pharmaceutical company,  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'sOncologic 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.

https://pubchem.ncbi.nlm.nih.gov/compound/Selinexor#section=2D-Structure

Karyopharm Announces FDA Extension of Review Period for Selinexor New Drug Application