Antengene Corporation Limited is presenting encouraging clinical data of the Company's four key drugs in clinical development: ATG-101 (PD-L1/4-1BB bispecific antibody), ATG-022 (Claudin 18.2 antibody-drug conjugate), ATG-037 (oral CD73 inhibitor), and ATG-008 (dual mTORC1/2 inhibitor), at its 2023 R&D Day taking place today. The event will also include presentations and discussion with three well-known clinical experts from leading medical centers in the U.S. and Australia. ATG-101 (PD-L1/4-1BB bispecific antibody): Early data from the Phase I PROBE trial have shown a partial response (PR) in a patient with metastatic colon adenocarcinoma (microsatellite stability biomarker [MSS], liver metastasis, and three prior lines of therapy) which is ongoing. Additionally, two patients have been on ATG-101 for 18 cycles and 17 cycles (Q3W), respectively, demonstrating durable stable disease (SD) with a good safety profile with no liver toxicities. This distinguishes ATG-101 as a safer drug compared to many molecules currently under development targeting 4-1BB. At present, Antengene is conducting the Phase I clinical trials with ATG-101 for the treatment of patients with solid tumors or B-cell non-Hodgkin's lymphoma (B-NHL) in Mainland of China, Australia, and the U.S. ATG-022 (Claudin 18.2 antibody-drug conjugate): Initial clinical data include a complete response (CR) and a PR in two late-stage metastatic gastric cancer patients in the Phase 1 CLINCH trial.

The PR was observed in Cohort 3 (1.8 mg/kg), a dose lower than the anticipated efficacious range; while the CR was observed in Cohort 4 (2.4 mg/kg). At present, Antengene is conducting a Phase I clinical study of ATG-022 for the treatment of patients with advanced or metastatic solid tumors in Australia and Mainland of China. ATG-037 (oral CD73 inhibitor): In the dose escalation portion of the Phase I STAMINA trial, 12 patients, all previously treated with a checkpoint inhibitor (CPI, pembrolizumab or nivolumab), have received ATG-037 in combination with pembrolizumab after at least 2 cycles of ATG-037 monotherapy, with 7 patients still under treatment. PRs were observed in two melanoma patients (with prior anti-PD-1 treatment), and in one patient with non-small cell lung cancer (NSCLC) who had also undergone treatment with chemotherapy in addition to a CPI (anti-PD-1). In Australia and Mainland of China, Antengene is currently conducting a Phase I study of ATG-037 single agent and in combination with pembrolizumab for the treatment of patients with locally advanced or metastatic solid tumors. ATG-008 (dual mTORC1/2 inhibitor): Clinical  efficacy data have shown promising results from the Phase II TORCH-2 study evaluating ATG-008 in combination with toripalimab (anti-PD-1 antibody) for relapsed/metastatic cervical cancer patients.

The trial enrolled 54 late-stage metastatic cervical cancer patients (30 CPI-naïve and 17 CPI-pre-treated patients with at least one tumor assessment). For the CPI-naïve patients, the objective response rate (ORR) is 53.3%, accompanied by a disease control rate(DCR) of 86.7% and a median progression-free survival (mPFS) of 8.41 months. For the CPI-pre-treated patients, the ORR, DCR, and mPFS stands at 29.4%, 82.4%, and 4.17 months respectively. These results support the efficacy of the treatment and compare favorably with previously published benchmark data. Antengene expects that updated and detailed study results of the studies that will be presented at international scientific conferences in 2024 or later.

The English session will be held virtually November 17, 2023. The Chinese session will be held in-person at the Antengene Shanghai Office and virtually November 17, 2023.