Vir Biotechnology finalizes Sanofi license for T-cell engagers

Vir Biotechnology has secured an exclusive global licence agreement with Sanofi to access several advanced T-cell engagers (TCEs) and the innovative PRO-XTEN masking technology. The agreement, initially announced on 1 August 2024, was finalized after the expiration of the Hart-Scott-Rodino Antitrust Improvements Act of 1976 waiting period.

Under this agreement, Vir gains exclusive worldwide rights to three key clinical-stage TCEs, which have demonstrated potential in treating various types of cancer. In addition, Vir will have exclusive use of the PRO-XTEN masking technology in both oncology and infectious disease fields. The agreement also involves the transfer of key Sanofi employees, who bring extensive scientific and development expertise in TCEs and experience with the PRO-XTEN platform, to Vir's team.

The TCEs covered in this licence include SAR446309, SAR446329, and SAR446368, each targeting different cancer markers and in various stages of clinical development. SAR446309 is a dual-masked HER2-targeted TCE currently being evaluated for metastatic treatment-resistant HER2+ tumors, such as breast and colorectal cancers. SAR446329 is designed to target PSMA and is being researched for metastatic castration-resistant prostate cancer. SAR446368, an EGFR-targeted TCE, has active investigational new drug (IND) status and is set to begin Phase I trials for EGFR-expressing tumors in the first quarter of 2025.

The PRO-XTEN technology, now exclusively licensed to Vir, is intended to improve the therapeutic index of drug candidates by capitalizing on the high protease activity present in the tumor microenvironment (TME). This selective activation mechanism aims to minimize off-target effects and reduce toxicity, which are common challenges with traditional TCEs, by specifically releasing the active molecule within the TME.

Marianne De Backer, CEO of Vir Biotechnology, described the deal with Sanofi as a critical milestone for the company. She emphasized the significant opportunity it presents to meet patient needs and advance the development of masked T-cell engagers, thereby strengthening Vir's clinical pipeline and creating immediate value. De Backer noted that Vir's expertise in antibody engineering and clinical development, combined with the innovative PRO-XTEN masking platform, offers a unique opportunity to develop new therapies in oncology and infectious disease.

Coinciding with the Sanofi agreement, Vir Biotechnology initiated a strategic restructuring in August 2024. This restructuring includes a 25% reduction in workforce and the discontinuation of its influenza and Covid-19 programs. Vir will also phase out its T cell-based viral vector platform as part of this strategy.