The Food and Drug Administration has granted accelerated approval of selinexor, a nuclear transport inhibitor, for the treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL).
Selinexor (marketed as XPOVIO by Karyopharm Therapeutics) is intended for adult patients with relapsed/refractory DLBCL, not otherwise specified, including DLBCL arising from follicular lymphoma, after at least two lines of systemic therapy, according to the FDA’s announcement.
The FDA granted selinexor accelerated approval for this indication based on the response rate seen in the SADAL trial. Continued approval for this indication “may be contingent upon verification and description of clinical benefit in confirmatory trials,” according to the FDA.
The SADAL trial (NCT02227251) was a phase 2, single-arm, open-label study of patients with DLBCL who had previously received two to five systemic regimens. The patients received selinexor at 60 mg orally on days 1 and 3 of each week.
Results in 134 patients showed an overall response rate of 29% (95% confidence interval: 22-38), with complete responses in 13% of patients. Of 39 patients who achieved a partial or complete response, 38% had a response duration of at least 6 months, and 15% had a response duration of at least 12 months, according to the FDA announcement.
The most common adverse reactions in this trial were fatigue, nausea, diarrhea, appetite decrease, weight decrease, constipation, vomiting, and pyrexia. Grade 3-4 laboratory abnormalities occurred in 15% or more of the patients, and comprised thrombocytopenia, lymphopenia, neutropenia, anemia, and hyponatremia.
Serious adverse reactions occurred in 46% of patients, most often from infection. Gastrointestinal toxicity occurred in 80% of patients, and any-grade hyponatremia occurred in 61%. Central neurological adverse reactions occurred in 25% of patients, including dizziness and mental status changes, according to the announcement.
Warnings and precautions for adverse events – including thrombocytopenia, neutropenia, gastrointestinal toxicity, hyponatremia, serious infection, neurological toxicity, and embryo-fetal toxicity – are provided in the prescribing information.
Selinexor acts through the inhibition of exportin-1 and leads to an accumulation of tumor suppressor proteins, a reduction in oncoproteins, and apoptosis of cancer cells. The drug was previously approved in 2019 for the treatment of relapsed/refractory multiple myeloma.
The SADAL trial was sponsored by Karyopharm Therapeutics.
SOURCE: U.S. Food and Drug Administration. 2020. Approval announcement.