Antengene Presents Latest Clinical Results for ATG-022 and ATG-037 at ESMO 2026

SHANGHAI and HONG KONG, Oct. 25, 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, today announced that it has presented the latest clinical results from the Phase II study of Claudin 18.2 antibody-drug conjugate (ADC) ATG-022 and the Ib/II study of oral CD73 small-molecule inhibitor ATG-037 in poster presentations at the 2026 European Society for Medical Oncology Annual Congress (ESMO 2026).

Details of the Poster Presentations

ATG-022 (Claudin 18.2 Antibody-Drug Conjugate)
Title: ATG-022, a Claudin 18.2 ADC, in Advanced Gastric and Gastroesophageal Junction Cancer (CLINCH): Phase 2 Results
Poster Number: 2886P
Date: October 25, 2026
Time: 12:00PM-12:45PM (Central European Time)         
           7:00PM-7:45PM (Beijing Time)

Study Overview:

ATG-022 is a CLDN18.2-targeting ADC comprising a humanized antibody (sub-nM affinity) linked to vc-MMAE. The CLINCH study is a Phase Ⅰ/Ⅱ clinical trial conducted in patients with advanced gastric or gastroesophageal junction adenocarcinoma (GC/GEJC), designed to evaluate the safety, tolerability and preliminary efficacy of ATG-022 monotherapy. The study included a dose escalation phase and a dose expansion/optimization phase. In the dose escalation phase, patients with advanced solid tumors were enrolled regardless of CLDN18.2 expression and received ATG-022 once every three weeks at doses of 0.3–3.0 mg/kg (Q3W). In the Phase Ⅱ dose expansion, CLDN18.2-positive (IHC 1+, ≥1%) patients were enrolled to receive ATG-022 monotherapy at 1.8 mg/kg or 2.4 mg/kg. The efficacy endpoints included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), evaluated per RECIST 1.1 criteria, and overall survival (OS).

Results:

• As of October 12, 2026, a total of 82 patients with GC/GEJC from Australia and China received treatment in the Phase Ⅱ dose expansion phase. This poster highlights data from the 1.8 mg/kg cohort: among the 31 patients, 30 were efficacy evaluable, with an ORR of 46.7%, a DCR of 86.7%, and a mPFS of 5.6 months. Notably, the mOS for the 1.8 mg/kg cohort had not yet been reached after a median follow‑up of 17.4 months, and the 18-month OS rate of intention to treat （ITT）population was 54.8%.
• In terms of safety, the incidence of Grade ≥3 TRAEs in the 1.8 mg/kg cohort was 25.8%, the incidence of serious TRAEs was 12.9%, and 12.9% of patients experienced dose interruption due to TRAEs. No individual Grade ≥3 TRAE exceeded 10% incidence in the 1.8 mg/kg cohort.

Conclusion:

• These findings demonstrate that ATG-022 monotherapy delivers differentiated efficacy and a favorable safety profile in patients with GC/GEJC. Together with its prior Breakthrough Therapy Designation, these results lay an important foundation for the rapid advancement of CLINCH-3, the pivotal Phase III study of ATG-022. The study has received IND approval from the National Medical Products Administration (NMPA) of China, and the 1.8 mg/kg dose has been recommended for the trial.
• In addition, the Company is concurrently conducting the CLINCH-2 study, which evaluates ATG-022 in combination with standard-of-care chemotherapy and an anti-PD-1 antibody for 1L treatment, targeting the broadest CLDN18.2-positive population starting from IHC 1+ ≥1%. Additional data will be presented at future international scientific congresses.

ATG-037 (Oral CD73 Small Molecule Inhibitor)
Title: Efficacy and safety of ATG-037, an oral CD73 inhibitor, plus pembrolizumab in patients with checkpoint inhibitor (CPI) resistant melanoma: Updated results from the STAMINA-01 trial
Poster Number: 2087P
Date: October 24, 2026
Time: 12:00PM-12:45PM (Central European Time)       
           6:00PM-6:45PM (Beijing Time)

Study Overview:

• The immunosuppressive adenosine pathway plays a key role in mediating resistance to PD-(L)1 therapies across tumor types. Preclinical studies have demonstrated synergy when combining CD73 or A2AR blockade with PD-1 or CTLA-4 inhibition. ATG-037 is an oral small-molecule CD73 inhibitor developed by Antengene, designed to achieve complete enzyme inhibition without the "hook effect".
• This poster reports updated efficacy and safety data from CPI-resistant melanoma patients receiving ATG-037 in combination with pembrolizumab. As of 28 April 2026, 25 patients with CPI-resistant melanoma received ATG-037 (60–600mg BID) in combination with pembrolizumab (200mg Q3W). Efficacy was assessed via RECIST v1.1. CD73 expression was evaluated by immunohistochemistry (IHC) on tumor or immune cells.

Results:

• Among 23 evaluable patients, ATG-037 in combination with pembrolizumab demonstrated an ORR of 21.7% (1 CR, 4 PR) and a DCR of 95.6%. Clinical activity was enriched in patients with high CD73 expression (IHC ≥50% on tumor or immune cells), achieving an ORR of 33.3% (4/12).
• The median PFS was 4.4 months (95% CI: 3.7–11.9), and median DOR was not reached. Notably, one patient with cutaneous melanoma achieved an ongoing CR exceeding 167 weeks.
• TEAEs and TRAEs occurred in 88% and 52% of patients, respectively. Grade ≥3 TRAEs were limited to a single patient (4%) who experienced Grade 3 diarrhea. The most common TRAEs of any grade included diarrhea (24%), rash (20%), and pruritus (16%).

Conclusion:

ATG-037 in combination with pembrolizumab demonstrates robust, durable efficacy and a favorable safety profile in heavily pretreated, CPI-resistant melanoma. CD73-enriched responses validate the mechanism, supporting further evaluation in CPI-resistant populations.

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: [email protected]  

BD Contacts:
Ariel Guo
E-mail: [email protected] 

SOURCE Antengene Corporation Limited