Kali Therapeutics has entered into a licence agreement with Sanofi for its first-in-class CD3×CD19×BCMA trispecific T-cell engager (TCE), KT501. Under the terms of the deal, Sanofi obtains exclusive global rights to the asset. Kali will receive an upfront and near-term payment of USD 180 million and is eligible for up to USD 1.05 billion in development and commercial milestone payments, plus royalties on product sales. KT501 is designed to target a broad range of B-cells and utilises a CD3 masking platform intended to maximise efficacy while minimising cytokine release.

The candidate, which has demonstrated potent B-cell depletion in preclinical studies, is currently in a Phase Ia trial for rheumatoid arthritis (RA), having dosed its first patient in March 2026. Sanofi's acquisition of the asset supports its strategy to expand its immunology pipeline with next-generation therapies for autoimmune diseases.

According to PharmCube's NextBiopharm® database, this is the largest licensing deal for a trispecific TCE in immunology. Click here to request a free trial for NextBiopharm®.