FDA approved Hepcludex (bulevirtide-gmod) on May 22, 2026 for chronic hepatitis delta in adults, with or without compensated cirrhosis, per the agency's 2026 novel drug approvals list — bringing to the US a therapy European clinicians have used since 2020 against the most severe form of viral hepatitis.
This article publishes information, not medical advice. Hepatitis delta requires specialist management, and screening is the practical first step: anyone with hepatitis B should ask their clinician about delta testing.
What is hepatitis delta and why is it severe?
Hepatitis D is caused by a defective virus that cannot replicate on its own — it needs the hepatitis B virus's surface antigen to infect cells. When both viruses coexist, the combination drives the fastest progression to cirrhosis and liver cancer of any common viral hepatitis; studies cited by WHO estimate hepatocellular carcinoma risk rises sharply in coinfection compared with hepatitis B alone. Global infection estimates run in the tens of millions, yet delta remains underdiagnosed in the US because testing is not automatic after a hepatitis B diagnosis.
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How does bulevirtide work?
Bulevirtide takes a different approach from antivirals that attack viral enzymes: it mimics a liver-cell surface protein and plugs the NTCP receptor the hepatitis D virus uses to enter hepatocytes, effectively locking the door. Blocking entry, rather than replication, is why it works in delta — the virus offers few enzyme targets — and why it is given alongside standard hepatitis B suppression therapy.
Why did US approval take years after Europe?
The European Medicines Agency authorized the drug in 2020 under conditional pathways; the US path required additional efficacy and manufacturing data, and the 2026 approval arrives as a finished formulation with dosing by weight-independent daily injection under the skin. Rare-disease economics and a small US patient population — concentrated in immigrant communities and among people who inject drugs — made commercial incentives thin.
What to watch next
Watch payer coverage for a specialty-tier injection with a six-figure annual list price, and whether professional societies update guidance to recommend universal delta testing at hepatitis B diagnosis — earlier detection, earlier treatment, less cirrhosis. Patients on hepatitis B care should simply ask: have I been tested for hepatitis D?
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