REDWOOD CITY, Calif— Pheast Therapeutics announced that the first patient has been dosed in a Phase 1 clinical trial evaluating its lead candidate, PHST001, an anti-CD24 macrophage checkpoint inhibitor, for the treatment of advanced solid tumors.
The open-label, multicenter trial (NCT06840886) aims to enroll up to 80 patients with relapsed or refractory solid tumors. The study’s primary goals are to assess the safety and tolerability of PHST001 and determine the recommended dose for future studies. Secondary endpoints include evaluating pharmacokinetics and early signs of anti-tumor activity.
“The start of this Phase 1 trial is an important milestone for Pheast and for the advancement of next-generation macrophage checkpoint therapies,” said Roy Maute, Ph.D., cofounder and CEO of Pheast. “We believe PHST001 could offer new treatment options, especially for cancers resistant to existing immunotherapies.”
PHST001 is designed to target CD24, a key molecule tumors use to evade immune detection. The therapy promotes macrophage-mediated phagocytosis and has shown robust anti-tumor activity and a favorable safety profile in preclinical studies.
“PHST001 may overcome tumor immune evasion through a differentiated approach to macrophage activation,” said Raphaël Rousseau, M.D., Ph.D., Pheast’s chief medical officer. “This study is a crucial first step in understanding its clinical potential.”
Scientific cofounder Irving Weissman, M.D., added that PHST001 was developed from foundational research into the CD24 pathway and represents a significant move toward leveraging the innate immune system in cancer therapy.
Preclinical results presented at SITC 2024 demonstrated that PHST001 effectively shrank tumors across multiple cancer types and bound all glyco-variants of CD24 with high affinity. The therapy also showed a favorable pharmacokinetic profile and no immune-mediated toxicity in laboratory models.
