Kali Therapeutics Receives U.S. FDA Clearance for KT501 Investigational New Drug Application

IND clearance enables U.S. clinical development of KT501, a first-in-class CD19xBCMAxCD3 tri-specific T-cell engager for B cell–mediated autoimmune diseases, building on safety data generated in the ongoing Australian first-in-human study in rheumatoid arthritis.

SAN MATEO, Calif., Sept. 3, 2026 /PRNewswire/ -- Kali Therapeutics, a clinical-stage biotechnology company pioneering next-generation immune-resetting and multi-specific therapies, today announced that the U.S. Food and Drug Administration (FDA) has cleared the company's Investigational New Drug (IND) application for KT501. The clearance allows KT501 to advance into clinical evaluation in the United States.

KT501 is a first-in-class CD19xBCMAxCD3 tri-specific T-cell engager (TCE) being developed for a broad range of B cell–mediated autoimmune diseases. The novel, IgG-like tri-specific antibody binds CD19 and BCMA to reach a wide spectrum of B-cell populations, including plasma cells, while engaging CD3 through a proprietary masking design. This masking platform is intended to maximize potency and limit cytokine release, positioning KT501 to deliver deep, multi-targeted B-cell depletion with an improved safety margin.

The IND clearance is supported by the safety, tolerability, pharmacokinetic, and pharmacodynamic data emerging from KT501's ongoing first-in-human Phase 1a study in adults with rheumatoid arthritis (RA), which is being conducted in Australia. KT501 is licensed to Sanofi under a worldwide exclusive agreement announced in March 2026.

"Receiving FDA clearance to proceed with KT501 in the United States is an important milestone for Kali Therapeutics," said Weihao Xu, Ph.D., Chief Executive Officer and Founder of Kali Therapeutics. "This clearance validates the safety data we have generated in our first-in-human study in Australia and reflects the strength of our CD3 masking platform in decoupling potency from toxicity. It brings us a meaningful step closer to demonstrating that deep, multi-targeted B-cell depletion can be safely achieved for patients living with autoimmune disease. Working with Sanofi has been highly productive, and we look forward to continuing our efforts to bring KT501 to more patients living with B cell–mediated autoimmune diseases."

The first-in-human Phase 1a study (NCT07234773) is an open-label, dose-escalation trial designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of KT501 administered as a single subcutaneous injection in adult participants with RA.

About KT501

KT501 is a novel IgG-like tri-specific T-cell engager that binds CD19 and BCMA to reach a wide spectrum of B-cell populations, while engaging CD3 through a proprietary masking design. By targeting both CD19 (expressed on most B-cells) and BCMA (expressed on plasma cells), KT501 is designed to address the limitations of previous-generation therapies that often spare the very cells responsible for autoantibody production. Utilizing a unique CD3 masking platform, KT501 has demonstrated potent B-cell depletion in peripheral blood and tissues and significantly reduced cytokine production in non-human primate (NHP) studies. Its subcutaneous delivery and "off-the-shelf" availability provide a scalable and convenient alternative to complex cell-based therapies. These attributes position KT501 as a promising therapy with the potential to treat a broad range of B cell–mediated autoimmune diseases.

About Kali Therapeutics

Kali Therapeutics is a clinical-stage biotechnology company headquartered in San Mateo, California, dedicated to developing transformative therapies for autoimmune and inflammatory diseases. By combining advanced protein engineering and high-throughput experimental techniques, Kali Therapeutics streamlines the drug discovery and research process. The company's proprietary immune cell engager platform enables precise optimization of functionality, manufacturability, and developability of biologics with first-in-class or best-in-class potential, leveraging T-cell engagers with precise targeting and controlled cytotoxicity to enable a transformative immune system reset and regeneration.

SOURCE Kali Therapeutics