The FDA now requires a boxed warning — its most prominent warning — on certain direct-acting antiviral agents, saying patients with hepatitis C taking them might be at risk for hepatitis B recurring, potentially causing serious liver problems and death, according to a safety announcement. Two dozen such instances in patients treated from Nov. 22, 2013 through July 18, 2016 have been identified.
“This number includes only cases submitted to FDA, so there are likely additional cases about which FDA is unaware,” according to the safety announcement.
Of the reported cases, two patients with HCV died and one required a liver transplant. Most HBV reactivations transpired within 4 to 8 weeks of starting DAA therapy, according to the FDA.
Clinicians should test all patients for existing or previous HBV infections before giving patients DAAs; they should also conduct blood tests to check for flare-ups and recurrences. Patients are encouraged to meet with their health care professional before ceasing DAA treatment; they should tell their clinician if they have a history of HBV or other liver problems, or if they develop light-colored stools, yellowing of the eyes or skin, vomiting, nausea, loss of appetite, weakness, or fatigue, as these may indicate serious liver problems, the safety announcement said.
Both patients and health care professionals are also encouraged to notify the FDA’s MedWatch Safety Information and Adverse Event Reporting Program if adverse events occur.
The reactivation — whose cause is unknown — was not reported in clinical trials because patients with HBV co-infection were excluded from such trials, according to the FDA.
The HCV Guidance Panel — which recently recommended HBV testing as part of a HCV guidelines update — told Healio.com/Hepatology in a statement this warning by the FDA now shows the threat and absolute importance of testing for HBV.
“In an update posted online Sept. 16, , we raised concerns regarding the accumulating evidence for reactivation of hepatitis B in HCV co-infected persons undergoing therapy with direct acting antiviral agents for HCV. Now, the FDA warning represents a clear acknowledgment of this threat…. These reports highlight the importance of screening HCV-infected persons for the presence of current or prior infection with [HBV] prior to embarking on a course of DAA therapy, and of taking appropriate steps to treat or closely monitor HBV when co-infection is identified.” – by Janel Miller
Reference: FDA’s List of Direct-Acting Antivirals (DAAs). Published Oct. 4, 2016. Accessed Oct. 4, 2016
Editor’s Note: This story has been updated to include a quote from the HCV Guidance Panel.