Vir Biotechnology has officially closed an exclusive worldwide license agreement with Sanofi, gaining rights to three clinical-stage masked T-cell engagers (TCEs) and the PRO-XTEN masking platform. This strategic move significantly expands Vir's oncology pipeline and enhances its capabilities in developing targeted cancer therapies.
The licensed assets include SAR446309, a dual-masked HER2-targeted TCE currently in Phase 1 trials for metastatic HER2+ tumors like breast and colorectal cancers; SAR446329, a dual-masked PSMA-targeted TCE also in Phase 1 for metastatic castration-resistant prostate cancer; and SAR446368, a dual-masked EGFR-targeted TCE with an active IND, slated for a Phase 1 study in Q1 2025 for EGFR-expressing tumors.
PRO-XTEN Masking Platform
The PRO-XTEN platform is designed to improve the therapeutic index of TCEs by exploiting the high protease activity in the tumor microenvironment (TME). This allows for selective activation of the drug candidates within tumor tissues, minimizing off-target activity and systemic immune activation typically associated with traditional TCEs.
Marianne De Backer, M.Sc., Ph.D., MBA, Vir’s Chief Executive Officer, stated, "The closing of this strategic agreement with Sanofi is a pivotal moment for Vir and a significant opportunity to help address patient unmet needs. We are excited to further advance the masked T-cell engagers in clinical development, bolstering our clinical pipeline and adding near-term value creation opportunities."
Clinical Programs
SAR446309 is currently in a Phase 1 clinical study for patients with metastatic treatment-resistant HER2+ tumors, including breast and colorectal cancers. SAR446329 is also in Phase 1, targeting metastatic castration-resistant prostate cancer. The third asset, SAR446368, is expected to enter Phase 1 in early 2025, focusing on EGFR-expressing tumors of various types.
The acquisition of these assets and the PRO-XTEN platform positions Vir Biotechnology to make significant strides in developing more effective and targeted therapies for cancer and infectious diseases. Further details on the TCEs and development plans will be shared at Vir’s upcoming R&D Day in November.
