Sanofi secures global rights to Kali Therapeutics’ tri-specific T-cell engager KT501 for autoimmune diseases in a licensing deal worth up to $1.23 billion.
Written By: Pharmacally Medical News Desk
Clinical-stage biotech company Kali Therapeutics has entered into a global licensing agreement with Sanofi for KT501, a tri-specific T-cell engager designed to treat a broad range of B-cell–mediated autoimmune diseases.
Under the agreement, Sanofi will obtain exclusive worldwide rights to KT501, a novel tri-specific antibody discovered using Kali Therapeutics’ proprietary biologics discovery platform. The candidate is currently being evaluated in a first-in-human clinical study assessing safety, tolerability, pharmacokinetics, and pharmacodynamics in patients with Rheumatoid Arthritis.
The deal includes upfront and near-term payments totalling $180 million to Kali Therapeutics. The company is also eligible to receive up to $1.05 billion in development and commercial milestone payments, along with tiered royalties on future product sales ranging from high-single-digit to double-digit percentages.
KT501 leverages Kali Therapeutics’ proprietary CD3 masking technology, which is designed to enhance the potency of T-cell engagers while minimizing toxicity. By selectively targeting and depleting pathogenic B-cell populations while reducing cytokine release, the therapy aims to deliver a safer immune-modulating approach for autoimmune disorders.
“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, chief executive officer of Kali Therapeutics. “Our platform leverages advanced protein engineering to address complex therapeutic challenges and aims to decouple potency from toxicity through our CD3 masking technology.”
Xu added that KT501 could offer a significant advancement for autoimmune disease treatment by effectively eliminating broad B-cell populations while maintaining a favorable safety profile. He noted that Sanofi’s expertise in immunology and global development capabilities could accelerate the clinical progress of the therapy.
KT501 is an investigational tri-specific antibody engineered to engage T cells and selectively eliminate pathogenic B-cell populations implicated in autoimmune diseases. The therapy is designed to achieve potent immune cell targeting while mitigating excessive cytokine release, a common challenge with T-cell–engaging therapies.
References
Kali Therapeutics Announces Worldwide Exclusive License Agreement with Sanofi for Next-Generation Tri-Specific T-Cell Engager for Autoimmune Diseases, 23 March 2026, https://www.kalitherapeutics.com/post/kali-therapeutics-announces-worldwide-exclusive-license-agreement-withsanofi-for-next-generation-tri