Kali Therapeutics Signs $1B+ Licensing Deal With Sanofi For Tri-Specific Antibody KT501 In Autoimmune Diseases

Kali Therapeutics has entered into a licensing agreement with Sanofi for a novel tri-specific T-cell engager designed to treat a wide range of B cell-mediated autoimmune diseases. The deal highlights growing interest in advanced biologics targeting complex immune pathways.

Under the agreement, Sanofi will gain exclusive worldwide rights to KT501, an investigational tri-specific antibody developed using Kali Therapeutics’ proprietary platform. The therapy is currently being evaluated in a first-in-human clinical study to assess its safety, tolerability, pharmacokinetics, and pharmacodynamics in patients with rheumatoid arthritis.

"We are thrilled to collaborate with Sanofi, a global leader in immunology, to advance the development of KT501, our lead tri-specific program," said Weihao Xu, CEO of Kali Therapeutics. "Our platform leverages state-of-the-art protein engineering to solve complex therapeutic challenges. This collaboration highlights the potential of our unique CD3 masking technology to decouple potency from toxicity, aiming to provide safer, more effective options for patients."

Kali Therapeutics will receive $180 million in upfront and near-term payments under the deal. In addition, the company is eligible for up to $1.05 billion in potential milestone payments tied to development and commercialisation, as well as tiered royalties on future product sales.

Weihao Xu, CEO of Kali Therapeutics, added: "Autoimmune diseases require treatments that are not only highly potent but also exhibit a superior safety profile. KT501 represents a significant leap forward in this regard. 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. We are confident that Sanofi's extensive expertise will accelerate the development of this promising therapy."

This collaboration positions Sanofi to expand its immunology pipeline while enabling Kali Therapeutics to advance its innovative biologics platform. The partnership underscores the continued momentum in developing next-generation therapies for autoimmune diseases.