Foster City, California, USA – May 21, 2026
Gilead Sciences, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted accelerated approval to Hepcludex® (bulevirtide-gmod), making it the first and only FDA-approved treatment for chronic hepatitis delta virus (HDV) infection in adults. The approval marks a historic milestone in liver disease treatment and introduces the first dedicated therapy for one of the world’s most severe forms of viral hepatitis. The FDA approval addresses a major unmet medical need for patients living with chronic HDV, a disease associated with rapid progression to liver failure, cirrhosis, liver cancer, and death.
The accelerated approval was based primarily on positive findings from the pivotal Phase III MYR301 clinical trial, where Hepcludex demonstrated statistically significant reductions in HDV RNA levels alongside normalization of alanine aminotransferase (ALT), a key biomarker of liver inflammation. Researchers stated that continued approval may depend on confirmation of long-term clinical benefit through ongoing post-approval studies already initiated by Gilead.
Hepcludex Introduces First FDA-Approved Therapy for HDV
Chronic HDV is considered the most aggressive form of viral hepatitis because it occurs as a co-infection in individuals already infected with hepatitis B virus (HBV), dramatically accelerating liver disease progression. According to Gilead, HDV affects an estimated 12 million people globally, including approximately 40,000 to 80,000 patients in the United States. Experts note that patients with HDV face significantly higher risks of cirrhosis, hepatic decompensation, liver cancer, and liver-related mortality compared with individuals infected with HBV alone.
Prior to Hepcludex approval, treatment options for HDV in the United States were extremely limited, leaving many patients dependent on off-label therapies with inconsistent efficacy and significant safety concerns. Hepcludex now becomes the first therapy specifically approved to target HDV infection, offering physicians a new treatment approach aimed at slowing viral progression and reducing liver damage.
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The therapy works as a first-in-class entry inhibitor, blocking both HDV and HBV from entering liver cells and interrupting a critical stage in the viral lifecycle. By targeting viral entry mechanisms, Hepcludex provides a differentiated treatment strategy compared with conventional antiviral approaches used for other forms of hepatitis. The medicine is administered as a once-daily subcutaneous injection and is approved for adults with chronic HDV infection with compensated cirrhosis or without cirrhosis.
Phase III MYR301 Study Demonstrates Durable Efficacy
The global Phase III MYR301 study evaluated the efficacy and safety of Hepcludex in adults living with chronic HDV infection over treatment periods extending up to 144 weeks. At Week 48, the study achieved its primary endpoint, showing statistically significant improvements in combined virologic and biochemical responses compared with delayed-treatment control groups. Researchers additionally reported sustained efficacy and generally favorable tolerability during long-term treatment exposure.
According to clinical investigators, the approval represents a transformative advancement in liver disease management because HDV patients previously lacked any FDA-approved therapies despite the disease’s severe clinical burden. Medical experts emphasized that HDV patients frequently face complex disease management challenges involving both hepatitis B and hepatitis D viral infections, increasing monitoring requirements and treatment complications.
The most commonly reported adverse reactions during clinical studies included injection-site reactions, headache, abdominal pain, fatigue, and itching. Gilead also highlighted an FDA boxed warning regarding potential severe acute exacerbation of hepatitis D and B following treatment discontinuation, particularly in cirrhotic patients, requiring careful post-treatment monitoring.
Gilead Strengthens Leadership in Liver Disease Innovation
The Hepcludex approval further expands Gilead’s long-standing leadership in liver disease therapeutics. Over the past several decades, the company has played a major role in transforming hepatitis C treatment and continues investing heavily in viral hepatitis, primary biliary cholangitis, and advanced liver disease research programs. Company executives stated that Hepcludex represents an important scientific breakthrough and demonstrates Gilead’s ongoing commitment to addressing historically underserved infectious diseases.
Industry analysts believe the FDA approval may accelerate global awareness and diagnosis of chronic HDV while increasing demand for specialized liver disease testing and antiviral treatment programs. Hepcludex is already approved in several European and international markets, and the U.S. approval is expected to significantly expand commercial adoption and physician access to HDV-specific treatment.
As viral hepatitis continues to represent a major global healthcare burden, experts believe targeted antiviral innovations such as Hepcludex could help reshape future liver disease treatment strategies and improve survival outcomes for patients living with severe chronic hepatitis infections.
Source: Gilead Sciences press release
