On July 22, 2026 Healx, an AI-powered, clinical-stage biotech company dedicated to rare diseases, reported that the first patient has been dosed in its Phase 1/2 dose-escalation and dose-confirmation clinical trial to evaluate the safety and efficacy of HLX-4310, an investigational oral combination of a class I selective HDAC inhibitor and an mTOR inhibitor, in adolescents and adults with relapsed, refractory sarcoma, with a focus on osteosarcoma.

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Osteosarcoma is a rare, aggressive bone cancer that most often affects children, adolescents, and young adults. Patients who develop metastatic disease face particularly poor outcomes, with a five-year survival rate of less than 30% ¹. The past 40 years have brought little improvement in survival outcomes for patients with osteosarcoma, underscoring a critical need for new approaches designed to reduce relapse risk and improve long-term outcomes.

HLX-4310 represents the first clinical proof point for Healx’s broader rare oncology strategy focused on preventing metastatic recurrence, which is responsible for the vast majority of cancer-related deaths. Healx is leveraging its AI-driven discovery capabilities together with rapid iterative laboratory testing and translational validation to advance this initial therapeutic combination and generate new drug combinations designed to explore a new approach to preventing metastatic recurrence in rare oncology settings.

The trial is being advanced in collaboration with the National Pediatric Cancer Foundation’s (NPCF) flagship research program, the Sunshine Project.

Addressing an Unmet Need in Rare Oncology

"Metastatic osteosarcoma is so difficult to treat because patients can undergo intensive therapy, reach remission, and still relapse within months or within several years," said David Warshawsky, Ph.D., Global Head of Metastatic Prevention at Healx. "We believe that HLX-4310 provides a novel and differentiated approach focused on the unique biology hypothesized to drive cancer recurrence, and we are delighted to see it advance into trials."

"I’m excited to see this study begin dosing patients and to evaluate a strategy that is explicitly focused on preventing metastatic recurrence," said Amy Armstrong, M.D., Principal Investigator for the Phase 1/2 HLX-4310 trial. "This trial will evaluate the safety and tolerability of HLX-4310 and assess efficacy, including its potential to reduce cancer recurrence risk."

Partnership with NPCF’s Sunshine Project

"We are proud to support the advancement of HLX-4310 through the Sunshine Project," said David Frazer, President of the National Pediatric Cancer Foundation. "Our consortium brings together leading pediatric cancer centers to accelerate promising science into clinical studies. This trial reflects the shared commitment of the Sunshine Project and Healx to drive progress for children and young adults facing high-risk cancers like osteosarcoma."

About HLX-4310
HLX-4310 is a combination approach built around the concept of preventing metastatic recurrence rather than focusing only on overt tumors. The scientific hypothesis behind this novel strategy is based on targeting biological programs that enable micro-metastatic tumors to survive and persist at distant sites and later re-emerge as deadly metastatic disease.

HLX-4310 combines two agents with complementary activity profiles:

An investigational class I selective histone deacetylase (HDAC) inhibitor being evaluated for its epigenetic modulation of gene expression programs involved in tumor cell survival and in tumor-immune interactions; and
An mTOR inhibitor, which targets a central pathway involved in cell growth, metabolism, and stress responses.

(Press release, Healx, JUL 22, 2026, View Source [SID1234669383])