Arbutus' Imdusiran with Short Course Interferon Achieves Sustained Undetectable HBsAg, a Necessity for HBV Functional Cure

Core Insights - The Phase 2a clinical trial IM-PROVE I demonstrated that imdusiran combined with pegylated interferon (IFN) and ongoing nucleoside analogue (NA) therapy resulted in significant reductions in HBsAg levels, with 33.3% of patients achieving undetectable HBsAg at the end of treatment, which was maintained in 100% of these patients 24 weeks post-treatment [1][2][3] Group 1: Clinical Trial Results - 33.3% of patients receiving imdusiran for 48 weeks and IFN for 24 weeks achieved undetectable HBsAg levels at the end of treatment, sustained in 100% of these patients 24 weeks after treatment [1][2] - Among patients who discontinued all therapy, six maintained undetectable levels of HBsAg and HBV DNA, with two achieving this status for 12 weeks off therapy [1][2] - All six patients with sustained HBsAg loss have seroconverted, showing high levels of anti-HBsAg antibodies, indicating potential immune control [2][3] Group 2: Safety and Tolerability - The combination of imdusiran and IFN was generally safe and well-tolerated, with no serious adverse events related to either treatment [4] - The most common treatment-emergent adverse events included transient ALT elevations and injection site bruising, consistent with known safety profiles [4][5] Group 3: Company Overview and Future Directions - Arbutus Biopharma is focused on developing a functional cure for chronic hepatitis B virus (cHBV) infection, with imdusiran being a key component of their therapeutic strategy [9][10] - The company is conducting multiple Phase 2a trials to evaluate imdusiran in combination with other immunomodulators, aiming to enhance treatment efficacy [5][10] - The global burden of chronic HBV infection is significant, with over 250 million people affected worldwide, highlighting the urgent need for effective treatments [8]