The U.S. Food and Drug Administration has warned in an Aug. 28 letter that AbbVie Inc.'s Mavyret, Merck & Co. Inc.'s Zepatier and Gilead Sciences Inc.'s Vosevi — all hepatitis C treatments — led to rare cases of worsening liver function and liver failure in patients with the disease.
Symptoms occurred in patients who already had moderate to severe liver impairment, and their condition improved after stopping treatment. In patients with no or mild liver impairment, the drugs were still safe and effective, the FDA said.
The U.S. regulator has approved the drugs to treat chronic hepatitis C in patients with only mild liver impairment at worst. The agency did not recommend a recall of the drugs.
The agency advised that physicians discontinue the medicines in patients with liver decompensation, a severe type of cirrhosis, which typically occurred within the first four weeks of treatment.
All three drugs contain antiviral elements called protease inhibitors, which reduce the amount of hepatitis C virus in the body.
