At The Liver Meeting, Immunocore reported positive phase 1 data for its T-cell receptor (TCR) bispecific candidate, IMC-I109V. The results highlight encouraging early signs of antiviral activity and consistent pharmacodynamic effects in people with chronic hepatitis B virus (HBV) infection.
IMC-I109V is engineered to eliminate HBV-infected hepatocytes expressing hepatitis B surface antigen (HBsAg) by redirecting non-exhausted T cells toward infected cells. The Phase 1 study evaluated ascending single doses of the agent (0.8, 2.4, 7, and 20 mcg) in 20 participants. All individuals received a single IV infusion and were monitored through week 4 for safety, pharmacokinetics, and pharmacodynamic activity.
Across dose levels, IMC-I109V was generally well tolerated, with treatment-related adverse events largely limited to transient Grade 1–2 systemic symptoms following infusion. ALT elevations occurred as expected with the mechanism of action and resolved within two weeks. A single Grade 2 cytokine release syndrome event was observed in the 20 mcg cohort, resolving within hours and prompting the use of corticosteroid premedication in subsequent participants, which successfully prevented recurrence.
Pharmacodynamic effects became consistent at doses ≥ 7 mcg, with dose-dependent reductions in HBsAg and associated immune activation signals, including IL-6 elevations and transient ALT increases. Four participants—two each in the 7 mcg and 20 mcg cohorts—achieved ≥ 0.2 log10 declines in HBsAg, with reductions typically reaching their lowest point by day 8. Importantly, three of these individuals maintained levels below baseline throughout follow-up.
What You Need to Know
IMC-I109V produced consistent reductions in HBsAg at doses ≥ 7 mcg, with four participants meeting predefined response thresholds after a single dose.
Most adverse events were mild to moderate and transient, with only one case of Grade 2 cytokine release syndrome that resolved quickly and did not recur with premedication.
The early results validate the TCR bispecific approach and provide a foundation for multi-dose studies aimed at achieving functional cure for chronic HBV.
David Berman, Immunocore’s head of Research and Development, noted that the dose-dependent reductions in serum HBsAg support continued exploration of TCR-based therapies for chronic HBV. “These data—alongside the encouraging safety profile and antiviral activity seen in our ImmTAV candidate for HIV – reinforce the potential of our platform to achieve functional cures for chronic infectious diseases,” Berman said in a statement.
About the Agent and the Company
Immunocore is a commercial-stage biotechnology company pioneering the development of a novel class of TCR bispecific immunotherapies called ImmTAX —Immune mobilizing monoclonal TCRs Against X disease—designed to treat a broad range of diseases, including cancer, autoimmune diseases and infectious diseases.
ImmTAV (Immune-mobilizing monoclonal TCRs Against Virus) molecules are next-generation bispecific therapeutics designed to help the immune system identify and destroy cells infected by viruses. Immunocore is developing ImmTAV candidates aimed at curing HIV and hepatitis B virus (HBV).
For HIV, the goal is to achieve a functional cure—sustained viral control after patients discontinue antiretroviral therapy (ART), without relapse or risk of transmission. In HBV, Immunocore aims to enable long-lasting clearance of viral antigens and replication markers after treatment cessation for people living with chronic infection.
The company believes the findings offer the strongest early indication yet that TCR bispecific therapies may overcome HBV-specific T cell exhaustion and drive meaningful clearance of HBsAg—a key step toward achieving functional cure. The company plans further evaluation of IMC-I109V in multi-dose regimens.
Reference
1.Immunocore presents Phase 1 data for hepatitis B candidate at AASLD’s The Liver Meeting. Immunocore press statement. November 7, 2025. Accessed November 11, 2025.
https://www.immunocore.com/investors/news/press-releases/detail/120/immunocore-presents-phase-1-data-for-hepatitis-b-candidate-at-aaslds-the-liver-meeting
