Efficacy and safety of bulevirtide in patients with chronic hepatitis D treated under early access in Switzerland: a retrospective analysis

BACKGROUND AND AIMS: Bulevirtide 2 mg/day was approved in Switzerland in February 2025 for the treatment of chronic hepatitis D virus (HDV) infection. We present real-world data on efficacy and safety in patients treated under an early access programme. METHODS: This retrospective, multicentre Swiss cohort study included patients with compensated HDV-associated cirrhosis in whom bulevirtide therapy (2 mg/day) was initiated between January 2020 and August 2024 under a compassionate use programme. Virological response was defined as a HDV RNA level that was undetectable or declined ≥2 log10 IU/ml from baseline. Biochemical response was defined as normalisation of ALT. Combined response was defined as achieving both virological and biochemical response. Liver-related events and adverse events were assessed. RESULTS: Fourteen patients with compensated HDV-related cirrhosis received bulevirtide for a median duration of 1.85 years (1.1–2.1). Median age was 51.3 years (43.9–58.5), and 71.4% were men. Baseline ALT was 81 U/l (55.8–88.8), platelet count 102.5 × 109/l (67.3–141.3) and liver stiffness 15.3 kPa (11.8–22.1). Baseline HDV RNA was 4.82 log10 IU/ml (4.52–6.23). Biochemical, virological and combined responses were observed in 50%, 64.3% and 35.7% at 6 months; 66.7%, 75% and 58.3% at 12 months; and 62.5% for all three response types at 24 months. Two patients (14.3%) developed de novo hepatocellular carcinoma, and one (7.14%) patient underwent liver transplantation. No serious adverse events were reported. Mild transient pruritus occurred in two (14.3%) patients. CONCLUSIONS: In this real-world cohort of patients with compensated HDV cirrhosis, bulevirtide demonstrated favourable efficacy and safety. These findings support the integration of bulevirtide into routine care for patients with HDV and compensated cirrhosis in Switzerland following its reimbursement status as of 2025. Longer-term follow-up is warranted to assess the impact on liver-related outcomes.