Immunocore presents Phase 1 data for hepatitis B candidate at AASLD

Immunocore (IMCR) announced data from its Phase 1 trial of IMC-I109V, a TCR bispecific candidate designed to specifically eliminate HBV-infected hepatocytes expressing hepatitis B surface antigen via T cell redirection. At doses greater than or equal to 7 mcg, consistent PD activity was observed, including a dose-dependent decrease in HBsAg, which typically reached a nadir by day 8. Reductions meeting the predetermined threshold of greater than or equal to 0.2 log10 IU/ml were seen in 4 individuals, 2/6 in the 7 mcg cohort and 2/8 in the 20 mcg cohort. In 3 of these 4 participants, HBsAg remained below pre-dose levels throughout follow-up. Reductions in HBsAg levels coincided with immune activation and transient elevations in ALT, which were expected based on the mechanism of action. Treatment-related adverse events were observed in 8 participants, including transient systemic symptoms in the 24h following infusion. ALT elevations, resolved to less than or equal to Grade 1 within 14 days. Bilirubin and prothrombin values remained within normal ranges throughout the study. The rapid resolution of all TRAEs was consistent with the short serum half-life of IMC-I109V.