Antengene to Present Latest Preclinical Results of ATG-207 (αCD3-TGF-β Bifunctional Fusion Protein) at ACR 2026

SHANGHAI and HONG KONG, Oct. 9, 2026 /PRNewswire/ -- Antengene Corporation Limited ("Antengene", SEHK: 6996.HK) , a leading innovative, commercial-stage global biotech company dedicated to discovering, developing and commercializing first-in-class and/or best-in-class medicines for autoimmune diseases, solid tumors and hematological malignancies indications, today announced that it will release the latest preclinical results of ATG-207 (αCD3-TGF-β Bifunctional Fusion Protein) in a Poster Presentation at the 2026 American College of Rheumatology (ACR) Annual Meeting, taking place from November 6th to November 11th in Orlando, Florida, the United States. ATG-207 is our proprietary, globally first-in-class αCD3-TGF-β bifunctional fusion protein being developed for the treatment of T cell–mediated autoimmune diseases.

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Details of the Poster Presentation

Title: Preclinical Characterization of ATG-207, a Masked and TGFβRIII-Biased αCD3-TGF-β Bi-specific Fusion Protein, for the Treatment of T cell-related Autoimmune Diseases

Abstract Number: 0974

Session: Poster Session B, (0965-0976) T Cell Biology & Targets in Autoimmune & Inflammatory Disease Poster B

Date: Monday, November 9, 2026

Time: 10:30 AM - 12:30 PM (Eastern Time)

11:30 PM, November 9 - 01:30 AM, November 10 (Beijing Time)

Study Overview:

  • T cell–mediated autoimmune diseases are characterized by persistent pathogenic effector T-cell activity and inadequate regulatory T-cell (Treg) function, resulting in loss of durable immune tolerance. Therapies that restore immune balance through Treg induction are therefore of significant interest. Transforming growth factor-beta (TGF-β) is a pivotal cytokine for Treg differentiation and maintenance, yet its systemic delivery is clinically restricted by broad receptor engagement that raises significant safety concerns.
  • ATG-207 was developed by introducing a peptide-masked and TGFβRIII-biased TGF-β domain to an anti-CD3 antibody. In vitro assays were performed to assess TGFβ receptor binding affinity, TGFβ signaling, T cell activation/exhaustion, T cell receptor (TCR) expression, cytokine release and regulatory T cell induction. In vivo efficacy and pharmacodynamic effects were evaluated in murine models of T cell-mediated autoimmune disease. Preclinical safety was evaluated in humanized mice. Developability was assessed over a four-week stability study.

Results:

  • ATG-207 demonstrated a binding preference for TGFβRIII with a KD of 2.42E-06M with no detectable binding to TGFβRII in SPR assay. It showed approximately 100-fold reduced binding affinity compared to unmasked TGF-β due to the conformationally dynamic peptide masking. ATG-207 displayed comparable binding affinity with attenuated NFAT-luciferase signaling and reduced proinflammatory cytokine production in whole blood compared to the parental anti-CD3 antibody. In addition, ATG-207 effectively downregulated surface T cell receptor (TCR) expression on T cells. ATG-207 induced stronger TGF-β pathway activation, as measured by p-SMAD signaling, in T cells compared with CD3-negative cells. Importantly, ATG-207 potently induced regulatory T cells in ex vivo studies using T cells isolated from healthy donors or SLE patients.
  • In vivo, mouse surrogate ATG-207 exhibited robust therapeutic efficacy in an experimental autoimmune encephalomyelitis (EAE) mouse model, collagen-induced arthritis (CIA) model and adoptive T cell transfer colitis model. ATG-207 potently induced Treg in CD3 humanized mice in vivo. In a repeat-dose mouse toxicology study, both ATG-207 and its mouse surrogate were well tolerated. ATG-207 demonstrated favorable stability under multiple stress conditions.

Conclusion: ATG-207 combines CD3-mediated T cell modulation with TGFβRIII-biased TGF-β signaling to suppress pathogenic T cells while promoting regulatory T cell differentiation. These preclinical findings support receptor-biased, context-restricted TGF-β delivery as a potential strategy for durable immune tolerance restoration in T cell–mediated autoimmune diseases.

About Antengene

Antengene Corporation Limited ("Antengene", SEHK: 6996.HK) is a global, R&D-driven, commercial-stage biotech company focused on developing first-in-class/best-in-class therapeutics for diseases with significant unmet medical needs. Its pipeline spans from preclinical to commercial stages, with key investigational candidates including ATG-022 (CLDN18.2 ADC), ATG-037 (oral CD73 inhibitor), ATG-101 (PD-L1 x 4-1BB bispecific antibody), ATG-125 (B7-H3 × PD-L1 bispecific ADC), ATG-207 (αCD3-TGF-β bifunctional fusion protein), as well as T cell engager (TCE) programs developed using Antengene's proprietary AnTenGager® platform.

AnTenGager®, is Antengene's proprietary TCE 2.0 platform, featuring "2+1" bivalent binding for low expressing targets, steric hindrance masking, and proprietary CD3 sequences with fast on/off kinetics to minimize cytokine release syndrome (CRS) and enhance efficacy. These characteristics support the platform's broad applicability across autoimmune diseases, solid tumors and hematological malignancies, with programs targeting CD19 x CD3 (ATG-201 for B cell-related autoimmune diseases; partnered with UCB), CDH6 x CD3 (ATG-106 for ovarian cancer and kidney cancer; partnered with K2 Therapeutics established by MPM BioImpact), ALPPL2 x CD3 (ATG-112 for gynecological tumors, digestive system malignancies, bladder cancer and NSCLC), LY6G6D x CD3 (ATG-110 for microsatellite-stable colorectal cancer), GPRC5D x CD3 (ATG-021 for multiple myeloma), LILRB4 x CD3 (ATG-102 for acute myeloid leukemia and chronic myelomonocytic leukemia) and FLT3 x CD3 (ATG-107 for acute myeloid leukemia).

To date, Antengene has obtained 35 investigational new drug (IND) approvals in the U.S. and Asia, and obtained new drug application (NDA) approvals in 10 Asia Pacific markets. Its lead commercial asset, XPOVIO® (selinexor), is approved in the Mainland of China, Taiwan China, Hong Kong China, Macau China, South Korea, Singapore, Malaysia, Thailand, Indonesia and Australia, and has been included in the national insurance schemes in five of these markets (Mainland of China, Taiwan China, Australia, South Korea and Singapore).

Forward-looking statements

The forward-looking statements made in this article relate only to the events or information as of the date on which the statements are made in this article. Except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this article completely and with the understanding that our actual future results or performance may be materially different from what we expect. In this article, statements of, or references to, our intentions or those of any of our Directors or our Company are made as of the date of this article. Any of these intentions may alter in light of future development. For a further discussion of these and other factors that could cause future results to differ materially from any forward-looking statement, please see the other risks and uncertainties described in the Company's Annual Report for the year ended December 31, 2025, and the documents subsequently submitted to the Hong Kong Stock Exchange.

For more information, please contact:

PR / IR Contacts:

Peter Qian

E-mail: peter.qian@antengene.com

BD Contacts:

Ariel Guo

E-mail: ariel.guo@antengene.com

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