Ascentage Pharma Group International (NASDAQ:AAPG, HKEX: 6855))), a global, commercial-stage, integrated biopharmaceutical company engaged in the discovery, development and commercialization of novel therapies to address unmet medical needs in cancer, today announced that the Company presented its first dataset of alrizomadlin (APG-115), an MDM2-p53 inhibitor from the Company's apoptosis-targeted pipeline, as monotherapy or in combination with lisaftoclax (APG-2575) in pediatric patients with relapsed/metastatic rhabdomyosarcoma (RMS) or other soft-tissue sarcomas (STSs), in a rapid oral presentation at the 62nd American Society of Clinical Oncology (ASCO) Annual Meeting.

The ASCO Annual Meeting showcases cutting-edge research in clinical oncology and advanced cancer therapies and is the world's largest gathering of the clinical oncology community. This year marks Ascentage Pharma's ninth consecutive appearance at ASCO. A total of six studies involving three of the Company's key assets were selected for presentation, including three rapid oral presentations.

The data presented demonstrated preliminary antitumor activity and a manageable tolerability profile of alrizomadlin in pediatric solid tumors. Results showed that alrizomadlin monotherapy demonstrated initial clinical benefit in pediatric rhabdomyosarcoma (RMS), with one pediatric patient achieving a complete response (CR). In combination with investigational selective Bcl-2 inhibitor lisaftoclax, encouraging antitumor activity was observed, with an objective response rate (ORR) of 23.5% among 17 response-evaluable patients, including one complete response in a patient with Ewing sarcoma and three partial responses (PRs). In terms of safety, alrizomadlin, either as monotherapy or in combination with lisaftoclax, demonstrated a manageable safety profile in pediatric patients with solid tumors.

Alrizomadlin is an orally administered, highly selective MDM2-p53 inhibitor independently developed by Ascentage Pharma. It is the first investigational agent of its class to enter clinical development in China and has global first-in-class potential. By blocking the MDM2-p53 protein-protein interaction, alrizomadlin restores the tumor suppressor activity of p53 and induces apoptosis in tumor cells. Recently, alrizomadlin was officially included by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA) in the Pilot Program for the Support of Anti-tumor Drugs R&D for Kids, also known as the "SPARK Plan," for development in pediatric solid tumors including neuroblastoma, rhabdomyosarcoma, and Ewing sarcoma.