VIR Stock Up on Early Safety & Efficacy Data on Two Cancer Candidates

Core Insights - Vir Biotechnology, Inc. announced promising initial data from a phase I study for its investigational candidates VIR-5818 and VIR-5500 targeting solid tumors [1][2] - The company's shares surged by 58.2% following the announcement, with a 21.1% increase over the past year compared to a 14.3% decline in the industry [2] Group 1: VIR-5818 for HER2-Expressing Cancers - VIR-5818 targets HER2-expressing solid tumors and is being evaluated both as a monotherapy and in combination with Merck's Keytruda [4] - Early efficacy data indicated that 50% of patients receiving doses ≥400 µg/kg experienced tumor shrinkage across multiple HER2-positive tumor types [5] - A confirmed partial response of 33% was observed in a subset of participants with HER2-positive colorectal cancer who had exhausted standard care [5] - Treatment with VIR-5818 was reported to be generally safe and well tolerated [6] Group 2: VIR-5500 for PSMA-Targeting Cancers - VIR-5500 is designed to target PSMA in metastatic castration-resistant prostate cancer (mCRPC) and is currently undergoing a phase I study [9] - All 12 patients treated with an initial dose of VIR-5500 ≥120 µg/kg experienced reductions in prostate-specific antigen (PSA), with a 58% PSA 50 response rate confirmed [9] - The treatment was also generally safe and well tolerated, with no dose-limiting cytokine release syndrome observed [9] Group 3: Technology and Mechanism - Both VIR-5818 and VIR-5500 utilize PRO-XTEN masking technology, allowing selective activation of T-cell engagers in the tumor microenvironment, which minimizes damage to healthy cells [3]