Hepatitis B: US approves injection course after which some can stop their pills

The US Food and Drug Administration approved Hibsago (bepirovirsen), made by British drugmaker GSK, for chronic hepatitis B on 20 October 2026. According to the FDA, it is the first approved antisense oligonucleotide for the liver infection: it targets the genetic instructions the virus uses to replicate and make proteins. The drug is injected under the skin once a week for up to 24 weeks, on top of existing antiviral therapy. That therapy continues for at least 24 weeks after the last injection; afterwards, some patients may stop it if they meet certain health and laboratory criteria, the FDA says.

Hibsago is approved for certain adults without cirrhosis who have taken antivirals for at least six months, have suppressed viral levels and a surface antigen (HBsAg) level of no more than 3,000 IU/mL. The FDA also authorised a Roche test to select patients. In the phase III trials B-Well 1 and B-Well 2 across 29 countries, 19 percent of treated patients (233 of 1,220) achieved so-called functional cure six months after all therapy ended, compared with none on placebo, according to GSK. HCPLive notes that this does not necessarily mean the virus is completely eliminated or that control lasts for life.

The drug carries a boxed warning for serious liver reactions and low platelet counts, which can raise the risk of bleeding; regular blood tests are required. Common side effects included injection site reactions, fever, fatigue and headache. According to GSK, more than 240 million people worldwide live with chronic hepatitis B, about 1.7 million of them in the US. "Hibsago provides a new treatment approach that gives some patients the possibility of maintaining control of the virus," said Wendy Carter of the FDA. Bepirovirsen is already approved in Japan, GSK says, with further decisions expected "in the coming months".