Sanofi licenses Kali’s trispecific KT501 – $180M up front for autoimmune trispecific

Sanofi struck a licensing agreement with Kali Therapeutics for KT501, a CD3‑masked trispecific T‑cell engager targeting CD19, BCMA and CD3, paying $180 million in up‑front and near‑term funds plus more than $1 billion in potential milestones and tiered royalties. Kali reported potent B‑cell depletion with reduced cytokine release in nonhuman primates and has begun a Phase Ia dose‑escalation study in rheumatoid arthritis. Sanofi framed the deal as a return to T‑cell engager modalities for autoimmune disease, while investors parsed the risk‑reward tradeoff of large early payments for preclinical/Phase I assets.