The concern most likely did not come to light during clinical trials because, according to the FDA, patients who were infected with hepatitis B were excluded from participating in HCV treatment studies.
The US Food and Drug Administration (FDA) issued a strong warning this week that patients previously infected with hepatitis B could have a reactivation of that virus while undergoing treatment with certain direct-acting antiviral drugs for treatment of hepatitis C (HCV), noting that a few known cases have resulted in serious liver problems or death.
A full list of approved DAA medicines for HCV are provided on the FDA website. They include Merck’s Zepatier, Abbvie’s Viekira Pak, and Gilead Sciences’ Sovaldi, Harvoni, and Epclusa.
The agency also ordered that a warning box be placed on labels of nine DAA drugs to tell of the risk of hepatitis B becoming an active infection “in any patient who has a current or previous infection with HBV” when treated for HCV with the drugs, states an FDA safety announcement. Serious liver problems or death have been reported to the FDA in a few cases.
“As a result, FDA is requiring a Boxed Warning, our most prominent warning, about the risk of HBV reactivation to be added to the drug labels of these DAAs directing health care professionals to screen and monitor for HBV in all patients receiving DAA treatment,” states the FDA announcement. “This warning will also be included in the patient information leaflet or Medication Guides for these medicines.”
The concern most likely did not come to light during clinical trials because, according to the FDA, patients who were infected with hepatitis B were excluded from participating in those studies. During the last 31 months, the FDA has been notified of 24 cases of patients who experienced a reactivation of the hepatitis B virus after they were treated for HCV with DAA drugs, according to the FDA.
“This number includes only cases submitted to FDA, so there are likely additional cases about which FDA is unaware,” states the announcement. “Of the cases reported, two patients died and one required a liver transplant.”
Hepatitis B and C are caused by different viruses that can become chronic infections and, if left untreated, can lead to serious liver damage. Direct acting antiviral drugs to treat hepatitis C approved in recent years reduce the hepatitis C virus in the body and prevent it from multiplying.
The FDA recommends that any patient starting treatment with DAAs should first be screened for evidence of current or previous infection of hepatitis B. It also advised medical professionals to monitor patients for HBV flare-ups or reactivation during and after their hepatitis C treatment.
The warning tells patients being treated for hepatitis C to tell their doctor of any history of infection with hepatitis B or other liver problems and if they are taking DAA medicine to not stop taking it without first talking to their health care professional. Patients are advised to seek medical advice immediately if they show signs of serious liver problems such as fatigue, weakness, loss of appetite nausea and vomiting, yellow eyes or skin, or light-colored stools.
In a related matter, industry guidelines for the treatment of hepatitis C posted on HCVguidelines.org were updated recently to address concerns about reactivation of hepatitis B in patients being treated for hepatitis C using DAA drugs. The recommendation was based on an increase in the hepatitis B virus seen in some patients, according to a news release posted on the website, which is sponsored by medical and other industry experts in the field of liver and infectious diseases.