Kali Therapeutics Announces Poster Presentation of KT209, a Novel CD19 x CD20 x CD3 Trispecific Antibody, at the EHA 2026 Annual Congress

SAN MATEO, Calif., June 8, 2026 /PRNewswire/ -- Kali Therapeutics, a clinical-stage biotechnology company pioneering next-generation immune-resetting and multi-specific therapies, today announced that preclinical data for KT209, its novel trispecific antibody candidate, will be presented in a poster session at the European Hematology Association (EHA 2026) Annual Congress.

KT209 is a novel trispecific antibody engineered to co-engage CD19, CD20, and CD3, redirecting endogenous T cells to achieve deep B-cell depletion. While traditional bispecific T-cell engagers (TCEs) targeting a single antigen face challenges with treatment failure due to antigen escape (low or lost CD19/CD20 expression), KT209's dual-antigen targeting mechanism is designed to prevent escape and improve clinical outcomes. Enhanced by a proprietary CD3 masking design, KT209 delivers exceptional anti-tumor potency alongside a highly optimized safety profile.

Presentation Details

• Poster Title: A NOVEL TRISPECIFIC ANTIBODY KT209 TARGETING CD19, CD20, AND CD3 (CD19XCD20XCD3) DEMONSTRATED POTENT ACTIVITY IN B-CELL DISEASES WITH LOWER CYTOKINE RELEASES
• Poster Number: PF369
• Session: Poster Session 1
• Dates: Thursday, June 11 – Friday, June 12, 2026

Highly Differentiated Preclinical Profile

The upcoming poster presentation highlights comprehensive preclinical data evaluating KT209 across in vitro, in vivo, and non-human primate (NHP) models:

• Resistance-Proof Cytotoxicity: KT209 demonstrated robust clearance against both Raji and Nalm19 leukemia cells. Crucially, in Nalm19 models—which express low levels of CD20—the approved TCE glofitamab suffered a significant drop-off in efficacy, whereas KT209 maintained potent tumor-killing activity.
• Decoupling Potency from Toxicity: In head-to-head human PBMC assays, KT209 demonstrated a clear trend of lower inflammatory cytokine release compared to glofitamab, successfully mitigating the primary driver of Cytokine Release Syndrome (CRS).
• In Vivo Tumor Clearance: In humanized NOG mouse models, KT209 achieved potent, dose-dependent anti-leukemia activity.
• Favorable NHP Safety and Tolerability: In non-human primates, a single subcutaneous dose of KT209 triggered rapid and deep peripheral B-cell depletion at the lowest tested dose. The molecule was completely well-tolerated with zero clinical adverse events and only minimal, transient cytokine release restricted to the first dose.

Leadership Commentary

John Wang, Chief Scientific Officer of Kali Therapeutics, commented:

"The data to be showcased at EHA underscores the highly differentiated profile of KT209. By integrating dual-antigen B-cell targeting with our proprietary CD3 masking technology, we have engineered a molecule that is fundamentally more potent than currently approved TCEs in low-antigen environments, yet operates with a much wider safety window. This allows us to achieve maximum tumor attrition while strictly limiting systemic cytokine release."

Weihao Xu, Chief Executive Officer of Kali Therapeutics, stated:

"Our presentation at EHA 2026 marks a pivotal milestone in the strategic expansion of Kali. By bringing our platform into the oncology space, we are demonstrating that our ability to safely engage T-cells is truly drug-class agnostic. The unique safety profile of our TCEs, which has already validated our autoimmune pipeline, allows us to aggressively target hematologic malignancies where tumor escape and severe CRS have historically limited patient outcomes. With KT209, we look forward to advancing into first-in-human clinical trials in Q1 2027."

About KT209

KT209 is a novel CD19 x CD20 x CD3 trispecific antibody engineered using Kali's proprietary multi-specific antibody platform. It is designed to maximize therapeutic efficacy by simultaneously binding to two distinct B-cell antigens (CD19 and CD20) and co-engaging CD3 on T cells. This dual-targeting approach minimizes the risk of tumor escape while its unique CD3 masking design controls T-cell activation kinetics, reducing cytokine release syndrome (CRS) risks while enabling complete removal of pathogenic B-cell populations.

About Kali Therapeutics

Kali Therapeutics is a clinical-stage biotechnology company based in San Mateo, California, dedicated to developing next-generation multi-specific therapies. By leveraging proprietary antibody engineering, Kali aims to redefine the treatment landscape for patients suffering from severe autoimmune diseases and advanced hematologic malignancies.

SOURCE Kali Therapeutics