Pheast Unveils First Preclinical Data for PHST001, an Anti-CD24 Macrophage Checkpoint Inhibitor

May 13, 2024

PALO ALTO, Calif., May 13, 2024 — Pheast Therapeutics (“Pheast”), a biotech developing novel macrophage checkpoint therapies to defy cancer, today announced the first presentation of preclinical data for PHST001, an anti-CD24 antibody drug candidate that is designed to block a key macrophage “don’t eat me” signal on cancer cells. The data to be presented at the 20th Annual PEGS Boston Summit demonstrate that PHST001 can powerfully induce an anti-cancer immune response and drive therapeutic efficacy in in vivo models.

“Pheast’s lead drug candidate, PHST001, is an exceptionally well-engineered, well-expressed antibody against an exciting new target, CD24,” said Roy Maute, Ph.D., Cofounder and CEO, Pheast Therapeutics. “Our preclinical studies show potent efficacy in challenging mouse model systems, which supports the possibility of clinical efficacy in cancers where other immunotherapies have failed and the unmet need remains high. The Pheast team is making rapid progress to support filing an investigational new drug application with the goal to enter the clinic in patients in the first half of next year.”

CD24 is a newly discovered immune checkpoint that is highly expressed by many human cancers, including ovarian and triple negative breast cancer (TNBC). High expression of CD24 is a negative prognostic factor in multiple cancer indications. CD24 interacts with the macrophage receptor Siglec-10, and shields cancer cells from attack by macrophages. Pheast has engineered PHST001 to bind recombinant CD24 and cell surface CD24 with high affinity and specificity and to block Siglec-10 binding.

Pheast scientists have demonstrated that blocking CD24 with PHST001 induces macrophage phagocytosis of multiple cancer subtypes in vitro, and have shown potent efficacy for PHST001 in vivo. In some preclinical models, PHST001 monotherapy is sufficient to shrink and fully eradicate tumors in all treated mice.

“These data demonstrate Pheast’s robust in-house antibody discovery and protein engineering capabilities, allowing rapid discovery and development of therapeutic monoclonal antibodies,” said John Burg, Ph.D., Senior Director, Protein Sciences. “Our innovative platform for discovery of tumor-specific immune checkpoints for precision immuno-oncology treatments will support exploring additional targets and developing new pipeline programs.”

Dr. Burg will present these data on Monday, May 13, 2024, at 1:15 pm ET in a talk titled, “Engineering a Therapeutic Monoclonal Antibody Targeting CD24, a Macrophage Checkpoint.”

About Pheast Therapeutics

Pheast is a preclinical stage immuno-oncology company focused on targeting immune evasion pathways to activate the innate immune system to defy cancer and help patients thrive. Founded and led by scientific experts in innate immunity and cancer immunotherapy, Pheast is developing novel immunotherapies for some of the most difficult-to-treat and aggressive cancers, including ovarian cancer and triple negative breast cancer. For more info, visit


Company: Roy Maute, Ph.D., [email protected]

Media: Jessica Yingling, Ph.D., [email protected]