Sanofi inks up-to-$1.2bn autoimmune T-cell engager deal with Kali Therapeutics

Under the agreement, Sanofi gains global rights to KT501, an IgG like CD3/CD19/BCMA antibody which is already in a first in human trial in rheumatoid arthritis. In exchange, Sanofi will pay Kali US$180m in upfront and near term payments. The California-based biotech is also eligible for up to US$1.05bn in development and commercial milestones plus tiered royalties.

KT501’s design aims to maximise B cell depletion across peripheral blood and tissues while minimising cytokine release, using a proprietary CD3 masking platform to decouple potency from toxicity. According to Kali, has the potential to treat a broad range of B cell-mediated autoimmune diseases. “Autoimmune diseases require treatments that are not only highly potent but also exhibit a superior safety profile,” commented Weihao Xu, CEO of Kali Therapeutics. “By depleting a broad range of B cell populations effectively while minimising cytokine release, we believe KT501 can address significant unmet needs of autoimmune patients.”

Valuable addition to immunology pipeline

For Sanofi, the deal adds an early clinical T-cell engager to its immunology pipeline at a time when TCEs are moving beyond oncology into chronic inflammatory indications. The French pharma will take over development of KT501 across a range of autoimmune indications, positioning the asset as a potential best in class entrant in an increasingly competitive T cell engager space. Earlier this month, Belgian biopharma UCB struck a global licensing deal worth up to US$1.1bn with Hong Kong–based Antengene for ATG-201, a CD19/CD3 bispecific T-cell engager designed to deplete B cells.