P177 Clinical experience with bulevirtide for hepatitis D virus infection at leeds teaching hospitals NHS trust

<h3>Background</h3> Hepatitis D virus (HDV) infection affects approximately 5% of individuals with chronic hepatitis B virus (HBV) worldwide and is associated with rapid progression to cirrhosis, liver failure and increased risk of hepatocellular carcinoma. Promising results have been demonstrated in patients with HDV treated with Bulevirtide, a novel HDV entry inhibitor, with improvements in combined virologic and biochemical responses as well as liver stiffness readings. Here we report the Leeds Teaching Hospitals NHS Trust (LTHT) experience of patients receiving treatment with Bulevirtide. <h3>Methods</h3> Data were collected from the electronic patient records and drug monitoring database, including baseline demographics, virological and biochemical markers, fibroscan readings, treatment duration and adverse events. Analysis was performed using Microsoft Excel. <h3>Results</h3> Of 1,500 HBV patients under follow-up at LTHT, 41 (3%) tested positive for HDV antibodies. Active infection, with detectable HDV RNA, was confirmed in 18/41 (44%), of whom 11 initiated Bulevirtide. The remaining 7 were ineligible as per NICE criteria, declined treatment or were lost to follow-up. Of those treated, 10/11 (91%) were male, with a median age of 41 years. Ethnic origins were predominantly Romanian (8/11, 73%), followed by African (2/11, 18%). The country of origin was unrecorded in one case. HBV/HDV co-infection was diagnosed prior to UK entry in 2/11, at LTHT in 5/11, and at other UK NHS trusts in 4/11. HDV RNA reduction was observed in 10/11 patients by week 4 of therapy, with an average 0.48 log reduction. The remaining patient (1/11) had a pre-treatment viral load (VL) measured over a year before starting Bulevirtide, likely underestimating baseline levels; however, subsequent monitoring confirmed a decline in VL. To date, 4/11 patients (36%) have achieved viral suppression with HDV RNA &lt;250 IU/mL. All treated patients showed reductions in alanine aminotransferase (ALT) levels, with 5/11 (45%) achieving normalisation with ALT &lt;40 U/L. Of these 5 patients, 2 (40%) have achieved ≥2-log reduction in VL at their current stage of treatment. Fibroscans are planned at 12 months of treatment. <h3>Summary</h3> These preliminary results show that Bulevirtide is well tolerated, with no significant adverse events or treatment discontinuations. Asymptomatic bile acid elevation occurred in 8/11 patients. These findings support Bulevirtide as a treatment option for patients with HDV and compensated liver disease who are treated within the current NICE approved criteria.