Atea Pharmaceuticals and Roche entered a strategic global collaboration to develop, manufacture and distribute AT-527, an oral direct-acting antiviral RdRp inhibitor, for COVID-19. Atea received $350M upfront cash plus eligibility for up to $1B in additional payments ($330M tied to regulatory milestones). Atea retained US rights; Roche took ex-US rights. Deal terminated late 2021 after Phase 2 miss.