The US Food and Drug Administration (FDA) has granted accelerated approval to a new corticosteroid dexamethasone, Xpovio (selinexor) combo.

Karyopharm’s Xpovio is for the treatment of adult patients with relapsed refractory multiple myeloma (RRMM), 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.

The combination was evaluated in 83 patients with RRMM, and the overall response rate was measured at 25.3%. The median time to first response was four weeks, with a range of one to ten weeks and the median duration of response was 3.8 months.

Accelerated approval enables the FDA to approve drugs for serious conditions to fill an unmet medical need based on an endpoint that is reasonably likely to predict a clinical benefit to patients, but further clinical trials are required to verify and describe Xpovio’s clinical benefit.

“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, director of the FDA’s Oncology Centre of Excellence.

He continued, “Today we approved a treatment under our accelerated approval program that provides a treatment option for patients with multiple myeloma with no available therapy.”

The application was also granted Fast Track designation, and Xpovio received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.

Multiple myeloma is cancer that begins in plasma cells and may also be referred to as plasma cell myeloma. Abnormal plasma cells build up in the bone marrow, forming tumours in many bones of the body. As more antibodies are made, it can cause blood to thicken and keep the bone marrow from making enough healthy blood cells.