The FDA granted accelerated approval to umbralisib to treat adults with relapsed or refractory marginal zone lymphoma (MZL) who have received at least one prior anti-CD20-based regimen and adults with relapsed or refractory follicular lymphoma (FL) who have received at least three prior lines of systemic therapy. 

According to a release from the FDA, the approval was based on results from a clinical trial studying 69 MZL patients and 117 FL patients. The patients in both groups received 800 mg umbralisib orally once daily until either disease progression or unacceptable toxicity. 

Among patients with MZL, the overall response rate was 49% (95% CI: 37-61.6), with 16% achieving complete responses. The median duration of response was not reached (95% CI: 9.3-NE). For patients with FL, the overall response rate was 43% (95% CI: 33.6-52.2), with 3% achieving complete responses. The median duration of response was 11.1 months (8.3-16.4). 

The most common adverse reactions included creatinine, diarrhea, fatigue, and nausea. Eighteen percent of patients experienced serious adverse reactions, including diarrhea-colitis and infection. The release added that diarrhea-colitis and transaminase elevation were the most common reasons to adjust the doses patients were given. 

The FDA had previously granted umbralisib priority review and orphan drug designation.