Healx, an AI-powered clinical-stage biotechnology company focused on rare diseases, has announced that the first patient has been dosed in its Phase 1/2 clinical trial evaluating HLX-4310, an investigational oral combination therapy for adolescents and adults with relapsed, refractory sarcoma, with a primary focus on osteosarcoma.

The open-label, dose-escalation and dose-confirmation study will assess the safety, tolerability, and preliminary efficacy of HLX-4310, which combines a class I selective histone deacetylase inhibitor with an mTOR inhibitor. The trial is being conducted in collaboration with the National Pediatric Cancer Foundation’s (NPCF) Sunshine Project, a research consortium dedicated to accelerating innovative therapies for childhood cancers.

Osteosarcoma is the most common bone cancer in children and adolescents and remains one of the most challenging cancers to treat once it spreads beyond the primary site. Patients with metastatic disease have a five-year survival rate of less than 30 percent, with limited progress in treatment outcomes over the past four decades.

HLX-4310 is designed to target the biological mechanisms believed to drive metastatic recurrence, an area responsible for the majority of cancer-related deaths. Rather than focusing solely on existing tumours, the therapy aims to prevent dormant micro-metastatic cancer cells from surviving and re-emerging as advanced metastatic disease.

Healx is leveraging its proprietary artificial intelligence-driven drug discovery platform alongside laboratory validation and translational research to identify novel therapeutic combinations for rare cancers. The company views HLX-4310 as the first clinical validation of its broader strategy to develop AI-enabled treatments that address metastatic recurrence across multiple rare oncology indications.

David Warshawsky, Ph.D., Global Head of Metastatic Prevention at Healx, said the therapy represents a differentiated approach aimed at the underlying biology of cancer recurrence, offering new hope for patients at high risk of relapse.

Amy Armstrong, M.D., Principal Investigator for the Phase 1/2 trial, noted that the study will evaluate not only the safety and tolerability of HLX-4310 but also its potential to reduce the risk of cancer recurrence in patients with relapsed disease.

David Frazer, President of the National Pediatric Cancer Foundation, said the collaboration reflects a shared commitment to accelerating promising research into clinical development for children, adolescents, and young adults facing high-risk cancers such as osteosarcoma.

Beyond osteosarcoma, Healx believes that the biological mechanisms targeted by HLX-4310 may have relevance across other cancers, including breast, kidney, and melanoma, potentially opening the door to broader applications in metastatic disease prevention.