FDA Approves First Hepatitis Delta Treatment in United States

Gilead Sciences announced that the U.S. Food and Drug Administration (FDA) has granted accelerated approval to Hepcludex® (bulevirtide-gmod) 8.5 mg for the treatment of adults living with chronic hepatitis delta virus (HDV) infection, marking the first approved therapy for the disease in the United States and offering a long-awaited treatment option for patients with one of the most severe forms of viral hepatitis.

The approval establishes Hepcludex as the first and only FDA-approved treatment for chronic HDV, a serious liver disease associated with rapid progression, liver failure, and significantly higher mortality risk compared with hepatitis B infection alone.

The FDA granted accelerated approval based primarily on findings from the pivotal Phase 3 MYR301 clinical trial, which evaluated Hepcludex in adults with chronic HDV infection. The decision was supported by reductions in hepatitis delta virus RNA levels and normalization of alanine aminotransferase (ALT), a key liver enzyme used to assess liver inflammation and damage.

According to Gilead, the MYR301 study demonstrated statistically significant improvements at Week 48 compared with a delayed-treatment control group, achieving a combined virologic and biochemical response. The study assessed the efficacy and safety of Hepcludex in patients treated for up to 144 weeks, followed by a 96-week off-treatment observation period.

Researchers reported that Hepcludex met its primary endpoint at Week 48 and maintained sustained efficacy during long-term treatment exposure. The therapy was also generally well tolerated across the study period, reinforcing its potential role as a treatment for a disease with historically limited options.

Because the approval was granted under the FDA’s accelerated approval pathway, continued approval may depend on confirmatory studies demonstrating a clear clinical benefit. While reductions in viral markers and liver enzyme normalization were observed, improvement in long-term disease-related outcomes such as survival or reduced liver failure risk has not yet been formally established.

Hepatitis delta virus is considered the most aggressive form of viral hepatitis and only occurs in people infected with hepatitis B virus (HBV), as HDV depends on HBV to replicate. Patients living with both viruses often experience accelerated liver damage, increased monitoring needs, and complex treatment burdens.

Studies estimate that between 2% and 4% of people living with chronic hepatitis B in the United States also have hepatitis delta, representing roughly 40,000 to 80,000 individuals. Despite the severity of the disease, treatment options have remained extremely limited, leaving physicians with few effective therapeutic interventions.

Dr. Ira Jacobson of the Department of Medicine at NYU Grossman School of Medicine said chronic HDV is associated with rapid disease progression and serious liver-related complications. He noted that patients diagnosed with both hepatitis B and hepatitis D face the challenge of managing two interconnected viral liver diseases, each contributing to worsening disease and increasing care complexity.

Jacobson described the approval of Hepcludex as a critical advancement that addresses a major unmet medical need and may meaningfully alter the disease course for affected patients in the United States.

Dietmar Berger, chief medical officer at Gilead Sciences, called the FDA decision a historic milestone and said the approval reflects years of scientific work and collaboration with regulators aimed at addressing a disease area long overlooked in viral hepatitis treatment.

The approval also represents an important step forward in liver disease management as healthcare systems continue to emphasize earlier diagnosis and intervention for viral hepatitis. With Hepcludex now available, clinicians may gain a new tool to manage chronic HDV and potentially slow the progression of a disease long associated with poor outcomes and limited therapeutic options.