Kali Therapeutics Receives FDA Clearance for KT501 Clinical Trials

Kali Therapeutics Receives FDA Clearance for KT501, Advancing Clinical Development in the U.S.

Kali Therapeutics, a clinical-stage biotechnology company headquartered in San Mateo, California, has received clearance from the U.S. Food and Drug Administration (FDA) for its Investigational New Drug (IND) application for KT501. The approval marks a significant step in the company's plans to conduct clinical trials of KT501 in the United States, a first-in-class CD19xBCMAxCD3 tri-specific T-cell engager aimed at treating a range of B cell, mediated autoimmune diseases.

KT501 is designed to address the limitations of previous therapies by targeting both CD19, which is expressed on most B-cells, and BCMA, which is found on plasma cells. The novel, IgG-like tri-specific antibody employs a proprietary masking design to engage CD3, a component of T-cells, while minimizing cytokine release. This innovative approach is intended to maximize potency and safety, enabling deep, multi-targeted B-cell depletion with a reduced risk of toxicity.

The clearance is based on safety data from KT501’s ongoing first-in-human Phase 1a study in Australia, where it has demonstrated favorable safety, tolerability, pharmacokinetic, and pharmacodynamic profiles. The study is being conducted in adults with rheumatoid arthritis (RA) and is an open-label, dose-escalation trial involving single subcutaneous injections.

"We are delighted to receive FDA clearance to move KT501 into clinical evaluation in the United States," said Weihao Xu, Ph.D., Chief Executive Officer and Founder of Kali Therapeutics. "This milestone underscores the safety and efficacy of our CD3 masking platform and brings us closer to realizing our vision of safely achieving deep, multi-targeted B-cell depletion for patients with autoimmune diseases."

The clearance follows a worldwide exclusive agreement announced in March 2026 between Kali Therapeutics and Sanofi, a global healthcare company. The partnership has been productive, and Kali Therapeutics anticipates that this collaboration will continue to drive the development and eventual clinical availability of KT501.

"The IND clearance is a testament to the robust safety data and innovative technology behind KT501," added Xu. "We are committed to bringing this transformative therapy to more patients living with B cell, mediated autoimmune diseases."

KT501’s subcutaneous delivery and "off-the-shelf" availability offer a scalable and convenient alternative to complex cell-based therapies, potentially making it a valuable addition to the treatment landscape for autoimmune diseases. The company’s proprietary immune cell engager platform, which enables precise optimization of functionality, manufacturability, and developability, is expected to continue driving advancements in biologics.

Kali Therapeutics remains focused on developing transformative therapies for autoimmune and inflammatory diseases, leveraging advanced protein engineering and high-throughput experimental techniques to streamline the drug discovery and research process. The company’s commitment to precision and innovation positions KT501 as a promising candidate for addressing the complex needs of patients with B cell, mediated autoimmune diseases.