Two phase III trials show tenofovir alafenamide superior to Viread in hepatitis B- Gilead

Gilead Sciences has announced that two Phase III clinical trials (Studies 108 and 110) evaluating investigational use of once-daily tenofovir alafenamide (TAF) 25 mg in treatment-naïve and treatment-experienced adults with HBeAg-negative and HBeAg-positive chronic hepatitis B virus (HBV) infection met their primary objectives. The studies demonstrated that TAF was non-inferior to Gilead’s Viread (tenofovir disoproxil fumarate, TDF) based on the percentage of patients with HBV DNA levels below 29 IU/mL at 48 weeks of therapy. In addition, TAF demonstrated improved renal and bone laboratory safety parameters compared to Viread.

In Study 108, evaluating HBeAg-negative patients, 94.0% of patients receiving TAF and 92.9% of patients receiving TDF achieved HBV DNA below 29 IU/mL at week 48. In Study 110, evaluating HBeAg-positive patients, 63.9% (of TAF patients and 66.8% of TDF patients achieved HBV DNA <29 IU/mL at week 48. Discontinuations due to adverse events were uncommon in both treatment arms (0.7% for both treatments in Study 108, and 1.0% for both treatments in Study 110). The most commonly reported adverse events in both studies included headache, upper respiratory tract infection, nasopharyngitis and cough.

Based on the results of Studies 108 and 110, Gilead plans to submit regulatory applications for TAF for chronic HBV in the United States and the European Union in the first quarter of 2016. Gilead also plans to submit data from both studies for presentation to a scientific conference in 2016.