The U.S. Food and Drug Administration (FDA) has found 24 cases of reactivation of hepatitis B (HBV) in patients who are using direct-acting antiviral (DAA) drugs for the treatment of hepatitis C virus (HCV). This discovery led to a “black-box warning” requirement for labels of at least 9 brand names of these costly medications. A black-box warning is the most serious level of warning that the FDA gives.
“We identified 24 cases of HBV reactivation reported to FDA and from the published literature in HCV/HBV co-infected patients treated with DAAs during the 31 months from November 22, 2013 to July 18. This number includes only cases submitted to FDA so there are likely additional cases about which we are unaware. Of the cases reported, two patients died and one required a liver transplant,” reported the FDA.
The direct-acting antiviral drug was tested during clinical trials on patients infected with HCV only. The testing excluded those who were co-infected with HBV because the FDA wanted to assess the risk of developing side effects on patients with HCV only. It was not taken into account that this type of treatment might lead to a reactivation of hepatitis B virus on HVC patients who also had HBV. As a result, the FDA is now requiring the addition of the boxed warning to the labels of these medications, YAHOO Finance reports.
The black-box warning affects Sovaldi and Harvoni from Gilead Sciences Inc. (GILD), Viekira Pak from AbbVie Inc. (ABBV) and Zepatier from Merck & Co. (MRK).
About 3 percent of the world’s population, approximately 150 million to 200 million people, live with chronic hepatitis C. An additional 3.5 million new diagnoses of infection from hepatitis C virus are made each year, reports YAHOO Finance.