FDA approves Karyopharm’s treatment for refractory multiple myeloma

The U.S. FDA has granted accelerated approval to Karyopharm Therapeutics’s Xpovio (selinexor) tablets in combination with the corticosteroid dexamethasone for the treatment of certain adult patients with relapsed refractory multiple myeloma (RRMM).

In particular, the FDA has approved the use for patients who have received at least four prior therapies and whose disease is resistant to several other forms of treatment, including at least two proteasome inhibitors, at least two immunomodulatory agents, and an anti-CD38 monoclonal antibody.

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.

Sharon Shacham, Founder, President and Chief Scientific Officer of Karyopharm, said: “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 FDA granted this application Fast Track designation. Xpovio also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.

The FDA has noted that common side effects of patients taking Xpovio in combination with dexamethasone include a low white blood cell count (leukopenia), a low count of neutrophils, a type of white blood cell (neutropenia), low count of platelets (thrombocytopenia) and low amount of red blood cells (anemia).

Patients also reported vomiting, nausea, fatigue, diarrhea, fever, decreased appetite and weight, constipation, upper respiratory tract infections and low blood sodium levels (hyponatremia).
Health care professionals are advised to monitor patients for low blood counts, platelets and sodium levels.

Patients should avoid taking Xpovio with other medications that may cause dizziness or confusion and avoid situations where dizziness may be a problem. Health care professionals are advised to optimize the patient’s hydration status, blood counts and other medications to avoid dizziness or confusion.

The FDA advised health care professionals to tell females of reproductive age and males with a female partner of reproductive potential to use effective contraception during treatment with Xpovio.

Women who are pregnant or breastfeeding should not take Xpovio because it may cause harm to a developing fetus or newborn baby, the FDA said.