FDA Grants Priority Review to Selinexor Oral Tablets for DLBCL

The FDA granted a priority review to the supplemental new drug application for selinexor (Xpovio) oral tablets for the treatment of adult patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), not otherwise specified, who have received at least 2 prior therapies, according to Karyopharm Therapeutics, the drug’s developer. 

Under the Prescription Drug User-Fee Act (PDUFA), a user fee goal date of June 23, 2020 was assigned.

“We look forward to supporting the FDA through the review process for our second NDA for Xpovio as there remains significant unmet medical need for patients whose DLBCL has relapsed or is refractory to multiple drug therapies,” Sharon Shacham, PhD, MBA, founder, president, and chief scientific officer at Karyopharm, said in a press release. “This regulatory milestone for Xpovio represents another step towards bringing a novel, oral treatment option with a unique mechanism of action to patients and families in need.” 

According to the agent’s patient safety information, the most common adverse events (AEs) associated with selinexor include thrombocytopenia, fatigue, nausea, anemia, decreased appetite, decreased weight, diarrhea, vomiting, hyponatremia, neutropenia, leukopenia, constipation, dyspnea, and upper respiratory infection. The treatment discontinuation rate due to AEs is 27%, and 53% of patients have reduced their dose, while 65.3% have had a dose interruption. The most frequent AEs requiring permanent discontinuation in 4% or greater of patients who received selinexor include fatigue, nausea, and thrombocytopenia. The rate of fatal adverse reactions is 8.9%.

Provided marketing approval is granted, the company intends to commercialize selinexor in the US for this second indication by mid-2020. Karyopharm also anticipates submitting a marketing authorization application to the European Medicines Agency in 2020, requesting conditional approval for selinexor for the same indication. 

Selinexor has already received both orphan drug and fast track designations from the FDA for the treatment of patients with relapsed or refractory DLBCL. The oral tablets are also being evaluated in several other mid- and later-phase clinical trials across multiple cancer indications, including in multiple myeloma in the pivotal, randomized phase III BOSTON study, evaluating the agent in combination with bortezomib (Velcade) and low-dose dexamethasone (Ozurdex); as a potential backbone therapy in combination with approved therapies in the STOMP trial; in liposarcoma in the SEAL study; and in endometrial cancer in the SIENDO trial.

Additional phase I, II, and III studies are ongoing or currently planned, including multiple studies in combination with approved therapies in a variety of tumor types to further inform the clinical development priorities for the drug. 

Reference:

U.S. Food and Drug Administration Accepts Karyopharm’s Supplemental New Drug Application for XPOVIO (Selinexor) as a Treatment for Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma [news release]. Newton, Massachusetts. Published February 19, 2020. investors.karyopharm.com/news-releases/news-release-details/us-food-and-drug-administration-accepts-karyopharms-supplemental. Accessed February 19, 2020.