Pheast Therapeutics, a private biotechnology company developing novel therapies to unleash the power of macrophages on aggressive, difficult-to-treat cancers, today announced that the first patient has been treated in its Phase 1 clinical trial evaluating PHST001, an anti-CD24 macrophage checkpoint inhibitor, in patients with advanced solid tumors.
“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, Pheast Therapeutics. “We believe PHST001 has the potential to provide new treatment options for patients, particularly in cancers where other immunotherapies have not been effective.”
The multicenter, open-label Phase 1 study will enroll up to 80 patients with advanced relapsed and/or refractory solid tumors (ClinicalTrials.gov Identifier: NCT06840886). The study’s primary objectives include evaluating safety and tolerability of PHST001 and establishing the recommended Phase 2 dose, with secondary endpoints assessing pharmacokinetics and early signs of anti-tumor activity.
Raphaël Rousseau, M.D., Ph.D., Chief Medical Officer, Pheast Therapeutics, said, “PHST001 has demonstrated robust activity across tumor types and a favorable safety profile in preclinical studies. Furthermore, these data suggest that PHST001 may overcome tumor immune evasion through a differentiated approach to macrophage activation. We are pleased to have initiated this study as a first step in understanding the clinical potential of PHST001 to improve patient outcomes across multiple cancer types.”
Irving Weissman, M.D., scientific co-founder of Pheast Therapeutics added, “CD24 is a key mechanism that tumors use to evade macrophage-mediated immune responses. PHST001 was developed based on foundational research into this pathway, and I’m encouraged to see this science progressing into the clinic. It’s a meaningful step toward harnessing the full potential of the innate immune system in cancer.”
Preclinical data presented at SITC 2024 highlight PHST001’s potential across multiple cancer types, and its differentiation as a novel macrophage checkpoint inhibitor uniquely designed to target all glyco-variants of CD24. By binding CD24 with high affinity and specificity, PHST001 promotes macrophage-induced phagocytosis in a variety of cancer cell types and significantly shrinks tumors in in vivo models. Additionally, PHST001 has a favorable pharmacokinetic profile in non-human primates and does not induce immune-mediated toxicity in in vitro studies.
About CD24
CD24 is a cell surface protein that plays a key role in tumor immune evasion by engaging Siglec-10, an inhibitory receptor on macrophages. This interaction suppresses macrophage-mediated clearance of cancer cells, allowing tumors to escape destruction by the innate immune system. CD24 was identified as a novel macrophage checkpoint through foundational work by Dr. Amira Barkal, principal founder of Pheast. Along with other co-founders, Drs. Irving Weissman, Ravi Majeti, and Roy Maute, Pheast's research opened the door to therapeutic strategies targeting CD24 to drive innate immune responses against cancer.
About PHST001
PHST001 is an anti-CD24 macrophage checkpoint inhibitor designed to overcome immune suppression in the tumor microenvironment. CD24 is highly expressed by many human cancers, including ovarian and triple negative breast cancer (TNBC), and high expression of CD24 is a negative prognostic factor in multiple cancer indications. Pheast has engineered PHST001 to be a best in class antibody designed to induce macrophages to phagocytose cancer cells and initiate a powerful immune response.
About Pheast Therapeutics
Pheast is a clinical-stage immuno-oncology company focused on activating the innate immune system in the fight against cancer. Founded as a spinout from Stanford University and led by scientific experts in innate immunity and cancer immunotherapy, Pheast is developing novel therapies for some of the most difficult-to-treat and aggressive cancers. Pheast is backed by leading life sciences investors, Catalio Capital Management and ARCH Venture Partners. For more info, visit Pheast.com and connect on LinkedIn.
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“The start of this Phase 1 trial is an important milestone for Pheast and for the advancement of next generation macrophage checkpoint therapies,” Roy Maute, Ph.D., Cofounder and CEO, Pheast Therapeutics.
Contacts
Company: info@pheast.com
Media: Jessica Yingling, Ph.D., Little Dog Communications Inc., jessica@litldog.com
