Kali Therapeutics signed a global licensing agreement with Sanofi for its trispecific T‑cell engager KT‑501 in a deal that could reach $1.2 billion. Sanofi will provide roughly $180 million in upfront and near‑term payments, with potential downstream milestones and commercial upside. The asset recently entered a Phase Ia study for rheumatoid arthritis, and Sanofi’s deal underscores renewed big‑pharma interest in T‑cell engager approaches for autoimmune diseases. Kali stands to fund early development while Sanofi brings global development and commercialization capacity; the pact signals continued appetite for multispecific biologics beyond oncology.