San Francisco, California-based Vir Biotechnology (Nasdaq: VIR) has agreed to discover and engineer three dual-masked T-cell engager (TCE) candidates against selected solid tumor-associated antigens for Gilead Sciences (Nasdaq: GILD). Gilead will provide USD 90 million in upfront consideration for exclusive rights to develop, manufacture, and commercialize the candidates, with Vir eligible for up to USD 1.785 billion in additional milestone payments.
Vir's upfront fee is divided into USD 65 million in cash and a USD 25 million equity investment priced at a 30% premium. The deal also includes up to USD 45 million in near-term preclinical milestones, up to USD 1.74 billion in development, regulatory, and commercial milestones, and tiered high-single-digit to low-double-digit royalties on net sales.
The candidates will be built on Vir's PRO-XTEN masking platform, designed to keep each TCE inactive until tumor-specific proteases in the tumor microenvironment cleave the mask — an approach the company says is intended to concentrate activity in tumors, could limit TCE-associated toxicity in solid tumors, and could extend molecular half-life. Vir will apply its dAIsY (data AI structure and antibodY) discovery platform and protein engineering capabilities to optimize the three candidates; Gilead takes over at the development stage.