Spontaneous, pharmacological observational, no-profit, retrospective, multi-center.

This study was designed to get a "real-life" snapshot across several Italian Hepatology centers. All HDV patients are followed up according to EASL 2017 guidelines. This allows uniformity on the indication for antiviral treatment and management of that antiviral therapy. No off-label medications are used. All data are retrievable from the patient's medical record. In addition, clinical and biochemical data from patients at month 0, 1, 2, 4, 6 and 12 of treatment, and otherwise within the study period, will be collected retrospectively/longitudinally.

The primary objective of the study is to describe the virological response to BLV in all patients starting BLV therapy, defined as a >2 Log decline in HDV-RNA or undetectable HDV-RNA (using the Robogene 2.0 quantitative kit, LLQ <6 IU/ml) at month 12 of therapy.

All patients with active HDV chronic hepatopathy (quantifiable HDV-RNA) who initiated treatment with BLV 2 mg/day during the study period at the S.C. Gastroenterology and Hepatology (Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico) and at participating centers, and who met the inclusion criteria and none of the exclusion criteria.

Inclusion Criteria:

• 18 years of age or older
• Chronic hepatitis delta
• Compensated cirrhosis HDV related
• Bulevertide 2 mg/day within December 15, 2020, to December 31, 2022

Exclusion Criteria:

- HDV-related decompensated cirrhosis (CPT ≥7)

All patients with active HDV chronic hepatopathy (quantifiable HDV-RNA) who initiated treatment with BLV 2 mg/day during the study period at the S.C. Gastroenterology and Hepatology (Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico) and at participating centers, and who met the inclusion criteria and none of the exclusion criteria.