FDA Approves Hepatitis B Drug

The FDA has approved Vemlidy (tenofovir alafenamide) from Gilead for the treatment of chronic hepatitis B infection with compensated liver disease. Specifically, the drug has been approved in a once-daily 25-mg dose for adult patients.

Vemlidy is a targeted prodrug of tenofovir that has shown antiviral efficacy similar to that of Viread at less than one-tenth of Viread’s dose. Because Vemlidy has greater plasma stability and delivers tenofovir to hepatocytes more efficiently, it can be administered at a lower dose than Viread.

The most common adverse reactions associated with Vemlidy are headache, abdominal pain, fatigue, cough, nausea, and back pain. It also has a boxed warning for lactic acidosis/severe hepatomegaly with steatosis. Discontinuation of the drug may result in severe acute exacerbations of hepatitis B virus (HBV).

“Chronic hepatitis B is a life-threatening illness that affects up to 2.2 million people in the US,” said Calvin Pan, MD, Clinical Professor of Medicine at NYU Langone Medical Center, in a press release. “Clinical trials demonstrated Vemlidy is efficacious with improved renal and bone safety parameters compared to Viread, representing an important development for people living with this chronic disease.”

Vemlidy’s approval was based on 2 phase 3 studies that involved 1298 participants. Some of them were treatment-naive, while others were treatment-experienced. All participants had a chronic HBV infection. Both studies met their primary endpoint of noninferiority to Viread.