The Food and Drug Administration (FDA) has granted accelerated approval to Xpovio (selinexor; Karyopharm Therapeutics Inc) in combination with dexamethasone for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least 4 prior therapies and whose disease is resistant to at least 2 proteasome inhibitors, at least 2 immunomodulatory agents, and an anti-CD38 monoclonal antibody.

Xpovio is a first-in-class, oral selective inhibitor of nuclear export compound. It works by blocking the nuclear export of tumor suppressor, growth regulatory and anti-inflammatory proteins, leading to accumulation of these proteins in the nucleus and enhancing their anti-cancer activity in the cell. The approval was based on data from the phase 2b, single arm, open label, multicenter STORM trial which evaluated the efficacy of selinexor with dexamethasone in 83 patients with relapsed or refractory multiple myeloma. The major efficacy outcome measure was overall response rate (ORR).

Results demonstrated an overall response rate of 25.3%; the median time to first response was 4 weeks (range: 1 to 10 weeks). The median duration of response was 3.8 months. Continued approval for this indication may be contingent upon efficacy outcomes from the ongoing, phase 3 BOSTON trial which is evaluating selinexor in combination with bortezomib (Velcade) and low-dose dexamethasone. 

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“While there is no cure for multiple myeloma, there are FDA-approved treatments to target the cancer and slow down the spread of the disease. Sadly, often over time, patients can exhaust all available treatments and still see their disease progress,” said Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Today we approved a treatment under our accelerated approval program that provides a treatment option for patients with multiple myeloma with no available therapy.”

Regarding safety, the most common treatment-emergent adverse events were thrombocytopenia, fatigue, nausea, anemia, decreased appetite, decreased weight, diarrhea, vomiting, hyponatremia, neutropenia, leukopenia, constipation, dyspnea, and upper respiratory tract infection.

The Company expects Xpovio to be commercially available in the US on or before July 10, 2019.

For more information visit xpovio.com.

This article originally appeared on MPR