FDA Fast Tracks RRMM Drug for Potential Combination Therapy

This week, the United States Food and Drug Administration gave Kayropharm Therapeutics accelerated approval for its oral therapy drug selinexor (Xpovio), to be used with the corticosteroid dexamethasone as a combination therapy for adults with relapsed/refractory multiple myeloma (RRMM) and have run out of treatment options. 

Relapsed/refractory multiple myeloma is a type of blood cancer that is commonly known to be quite treatment resistant.  In some cases it will respond to an initial course of treatment but then will stop responding in future treatment rounds. As a matter of fact, this quite a common trend among RRMM patients.  

Dana-Farber Cancer Institute clinical program leader and director of clinical research at the Jerome Lipper Multiple Myeloma Center, Paul Richardson, MD, explains, “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 drug is more specifically aimed at patients who have tried at least four other therapies but have not been able to treat their treatment-resistant disease.  At least two of these four therapies, also, would have been proteasome inhibitors and/or immunomodulatory agents, and/or an anti-CD38 monoclonal antibody. 

Richard Pazdur, MD, is the director of the Oncology Center of Excellence at the FDA.  He explains, “Today we approve a treatment under our accelerated approval program that provides a treatment option for patients with multiple myeloma with no available therapy.”

Also an acting director for the FDA Center for Drug Evaluation and Research Office of Hematology and Oncology Products, Pazdur goes on to say that we currently have no cure for multiple myeloma.  While there are some treatments that can target the cancer and slow its disease progression, many patients exhaust their available treatment options and still see disease progression. 

Originally, Selinexor was approved on basic safety and efficacy data, but the cohort was only 83 patients.  These patients had been diagnosed with RRMM, of course, and had also been treated with Selinexor in combination with dexamethasone.  In these patients, the small study found an overall response rate of 25 percent.  Also, median time between administration and first response was 4 weeks (in a full range of 1 to 10 weeks); median duration for this response was nearly 4 months.