Ozisiran Delivers Sustained Viral and Antigen Suppression in Chronic Hepatitis D - Preliminary Interim Phase IIa Results
October 22, 2026 - Suzhou, China and Mölndal, Sweden
Suzhou Ribo Life Science (06938.HK) and its subsidiary Ribocure Pharmaceuticals AB (collectively referred to as “Ribo”) announced, the preliminary interim results from the ongoing Phase Ⅱa study evaluating ozisiran (RBD1016) in patients with chronic hepatitis D (HDV) [NCT06649266] were presented in an oral session at the Delta Cure Meeting in Milan lately.
The trial includes a randomized, single-blind, placebo-controlled treatment period during the first 16 weeks, and evaluated ozisiran, an investigational siRNA therapeutic designed to suppress hepatitis B surface antigen (HBsAg), on top of tenofovir alafenamide (TAF). The preliminary analysis includes interim data through week 36 from 14 patients enrolled at Karolinska University Hospital and Danderyd Hospital in Stockholm, Sweden.
Results demonstrated that HDV-related ALT flares were few and successfully managed. Ozisiran treatment was generally well tolerated with most other adverse events being mild, and no serious adverse events were reported. Ozisiran suppressed HDV RNA and HBsAg at week 24 (12 weeks after last dose) and through Week 36 (24 weeks after last dose).
“These findings provide encouraging evidence that ozisiran can deliver durable suppression of both HBsAg and HDV RNA, key virological markers in chronic hepatitis D. The sustained activity observed after a relatively short dosing period supports the potential of RNAi-based approaches to address the significant unmet medical need in HDV.” says Anders Gabrielsen, CMO Suzhou Ribo Life Science.
The data further reinforces the potential of ozisiran as a novel therapeutic approach for chronic hepatitis D, a severe liver disease for which treatment options remain limited.
About ozisiran (RBD1016)
Ozisiran is an investigational small interfering RNA (siRNA) therapeutic designed to reduce the production of hepatitis B surface antigen (HBsAg). By targeting a key driver of HBV and HDV infection, ozisiran aims to enable sustained viral control and improve clinical outcomes for patients with chronic hepatitis D.