Dismissed as undruggable in the early 2000s, Src homology 2 domains are now viable and at the heart of Recludix Pharma Inc.’s new deal with Sanofi SA’s U.S. unit. The two will collaborate on developing and commercializing treatments for immunological and inflammatory diseases. In the near term, Recludix will get $125 million, but long term it could add up to $1.2 billion in milestones. Recludix could also bring in up to double-digit royalties on possible future product sales.