PHST001 / Pheast Therap - LARVOL DELTA

Targeting CD24 activates macrophages to reduce tumor burden in preclinical models of solid tumors. (PubMed, Clin Cancer Res) - P1 | "These findings establish CD24 as a critical regulator of tumor immune evasion and support the clinical development of PHST001 as a CD24-targeted immunotherapy. A Phase I clinical study (NCT06840886) evaluating the safety and tolerability of PHST001 in adult patients with relapsed or refractory solid tumors is ongoing."

Journal • Preclinical • Oncology • Solid Tumor • CD24

PHST001 is being evaluated in the ongoing Phase 1 PHST001-101 trial (NCT06840886) in patients with relapsed or refractory solid tumors (Businesswire) - "The monotherapy dose-escalation is nearly complete, and the chemotherapy combination cohorts are underway. Pheast expects to present initial clinical data at an upcoming medical meeting."

P1 data • Trial status • Cholangiocarcinoma • Endometrial Cancer • Ovarian Cancer

Pheast Therapeutics…announced a peer-reviewed publication in Clinical Cancer Research, a journal of the American Association for Cancer Research (AACR), detailing the preclinical foundation for its lead program, PHST001 (Businesswire) - "The published findings demonstrate that PHST001 binds CD24 with high affinity, blocks CD24-Siglec-10 signaling, and drives macrophage phagocytosis of tumor cells. PHST001 showed robust anti-tumor activity across six solid tumor models - ovarian, breast, endometrial, pancreatic, lung, and cholangiocarcinoma - and enhanced the effects of chemotherapy, radiotherapy, and antibody-drug conjugates, including in treatment-resistant tumor models. The findings also reveal crucial crosstalk between the adaptive immune system and macrophages activated by PHST001."

Preclinical • Breast Cancer • Cholangiocarcinoma • Endometrial Cancer • Non Small Cell Lung Cancer • Ovarian Cancer • Pancreatic Cancer

A phase 1 study of PHST001, an anti-CD24 monoclonal antibody, in adult patients with advanced relapsed and/or refractory solid tumors. (ASCO 2026) - P1 | "The study enrolled the first patient treated in April 2025 and is currently enrolling patients in Phase 1a at Dose Level 8 (18 mg/kg) with no DLTs to date. Enrollment in Phase 1b is anticipated to begin in early 2026."

Clinical • First-in-human • Metastases • P1 data • Biliary Cancer • Cholangiocarcinoma • CNS Disorders • Endometrial Cancer • Immunology • Oncology • Ovarian Cancer • Solid Tumor • CD24

PHST001, a humanized anti-CD24 hIgG4 antibody, is effective against metastatic tumors and retains its anti-tumor activity in the presence of competing IgG (AACR 2026) - "In vivo, PHST001 shows significantly greater efficacy against solid tumors than the anti-CD47 antibody Magrolimab...When combined with a companion agent, such as the anti-Her2 ADC trastuzumab deruxtecan, the Fc-inert version of PHST001 dramatically increased phagocytosis, demonstrating the contribution of CD24 blockade to PHST001 efficacy in absence of direct Fc receptor engagement... PHST001 prevents metastatic spread and demonstrates anti-tumor activity against established metastases. In vitro, peripheral blood cells expressing CD24 are protected from PHST001-mediated phagocytosis due to competition for Fc receptors by high levels of endogenous IgG, predicting protection in treated patients. PHST001 retains anti-tumor effects in vivo despite polyclonal IgG presence, indicating that competition for Fc receptors by endogenous IgG is not a barrier for efficacy in the tumor microenvironment."

Metastases • Breast Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Solid Tumor • CD24

Initial results from a phase 1 study of PHST001, a macrophage activating anti-CD24 antibody, in patients with advanced/metastatic solid tumors (AACR 2026) - P1 | "PHST001 is well tolerated at doses evaluated to date with TRAEs being predominantly low grade and reversible. The PK profile of PHST001 confirms favorable exposure with sustained target engagement. Signals of clinical activity are emerging at higher dose levels."

Clinical • First-in-human • Metastases • P1 data • Oncology • Solid Tumor • CD24

PHST001 combination with standard-of-care chemotherapy enhances macrophage-mediated elimination of tumor cells (AACR 2026) - "We subsequently validated select chemotherapy and PHST001 combinations (e.g. cisplatin) in vivo with mouse xenograft studies. Mechanistically, we discovered that certain chemotherapy agents increased the surface expression of the 'Eat me' signal phosphatidylserine (PS) on cancer cells, while others directly enhanced the phagocytosis capacity of macrophages. Taken together, these data support therapeutic combination of PHST001 with multiple standard-of-care chemotherapies to deepen tumor-killing response in patients."

Tumor cell • Oncology • CD24

PHST001-101: A Study of PHST001 in Advanced Solid Tumors (clinicaltrials.gov) - P1 | N=272 | Recruiting | Sponsor: Pheast Therapeutics | N=155 ➔ 272

Enrollment change • First-in-human • Biliary Cancer • Brain Cancer • Cholangiocarcinoma • CNS Tumor • Endometrial Cancer • Oncology • Ovarian Cancer • Refractory Ovarian Cancer • Solid Tumor

Pheast Therapeutics Reports Initial Phase 1a Data Showing Early Clinical Activity and Target Engagement for PHST001 at AACR 2026 (GlobeNewswire) - "In the ongoing Phase 1a first-in-human study, PHST001 was generally well-tolerated across dose-escalation cohorts....The dataset demonstrated linear pharmacokinetics, increasing CD24 receptor occupancy at higher dose levels, and pharmacodynamic changes consistent with innate immune activation. Early signs of clinical activity were observed, including disease stabilization and tumor shrinkage....Pheast plans to present updated clinical data from the ongoing PHST001-101 study at a future medical meeting."

First-in-human • P1 data • Solid Tumor

Pheast Therapeutics to Present Initial Phase 1a Clinical Data and Two New Preclinical Studies of PHST001, a Novel Anti-CD24 Antibody, at AACR 2026 (Businesswire) - "The presentations include initial data from the ongoing Phase 1 study of PHST001, an IgG4 anti-CD24 macrophage checkpoint inhibitor, in patients with advanced or metastatic solid tumors. Two additional preclinical abstracts evaluate PHST001 in combination with multiple classes of standard-of-care chemotherapy to enhance macrophage-mediated tumor cell clearance, and in metastatic tumor models assessing activity, Fc receptor contribution, and the impact of endogenous IgG competition."

P1 data • Preclinical • Solid Tumor

Phase 1 study of PHST001, a humanized anti-CD24 monoclonal antibody, in adult patients with advanced relapsed and/or refractory solid tumors (AACR-NCI-EORTC 2025) - P1 | "Other endpoints include exploring antitumor activity, pharmacokinetics/pharmacodynamics correlation (target occupancy, cytokine profiling, ctDNA and immune cell frequency) and immunogenicity of PHST001. The study is currently enrolling, and the first patient was treated in April 2025."

Clinical • Late-breaking abstract • Metastases • P1 data • Biliary Cancer • Cholangiocarcinoma • Colorectal Cancer • Endometrial Cancer • Oncology • Pancreatic Cancer • Solid Tumor • CD24

Pheast Therapeutics Receives FDA Fast Track Designation for PHST001 for the Treatment of Ovarian Cancer (Businesswire) - "Pheast Therapeutics...announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to PHST001 for the treatment of patients with advanced platinum-resistant ovarian cancer or in combination with chemotherapy in platinum-sensitive ovarian cancer. PHST001 is an investigational anti-CD24 monoclonal antibody designed to enhance innate immune recognition and anti-tumor activity in solid tumors....The multicenter, open-label Phase 1 clinical study of PHST001 is actively recruiting patients and will enroll up to 80 patients with advanced relapsed and/or refractory solid tumors (ClinicalTrials.gov Identifier: NCT06840886)."

Fast track • Platinum resistant • Platinum sensitive • Trial status • Ovarian Cancer

A Study of PHST001 in Advanced Solid Tumors (clinicaltrials.gov) - P1 | N=155 | Recruiting | Sponsor: Pheast Therapeutics | Not yet recruiting ➔ Recruiting

Enrollment open • Oncology • Solid Tumor

Pheast Therapeutics Announces First Patient Treated in Phase 1 Clinical Trial of PHST001 for Patients with Advanced Solid Tumors (Businesswire) - "Pheast Therapeutics...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 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."

Trial status • Solid Tumor

A Study of PHST001 in Advanced Solid Tumors (clinicaltrials.gov) - P1 | N=155 | Not yet recruiting | Sponsor: Pheast Therapeutics

New P1 trial • Oncology • Solid Tumor

PHST001, a humanized anti-CD24 antibody, induces phagocytosis of human tumor cells in vitro and tumor clearance in vivo (SITC 2024) - "PHST001 does not induce cytokine release in vitro and detects CD24 in human tissues. A clinical study to investigate the safety and efficacy of PHST001 in cancer patients is being developed.Download figure Open in new tab Download powerpoint Abstract 513 Figure 1 Download figure Open in new tab Download powerpoint Abstract 513 Figure 2 Download figure Open in new tab Download powerpoint Abstract 513 Figure 3 Download figure Open in new tab Download powerpoint Abstract 513 Figure 4 Download figure Open in new tab Download powerpoint Abstract 513 Figure 5 Download figure Open in new tab Download powerpoint Abstract 513 Figure 6"

Preclinical • Tumor cell • Breast Cancer • Colorectal Cancer • HER2 Breast Cancer • HER2 Positive Breast Cancer • Oncology • Pancreatic Cancer • Solid Tumor • Triple Negative Breast Cancer • CD24 • HER-2 • IFNG • IL2 • IL6 • ITGAM • SIGLEC10 • TNFA

Pheast Presents New Preclinical Data for PHST001, an Anti-CD24 Macrophage Checkpoint Inhibitor, at SITC 2024 (Businesswire) - "The presented data show that PHST001, through potent CD24 binding, promotes macrophage-induced phagocytosis in a number of cancer cells and significantly shrinks tumors in vivo. In addition, PHST001 has a favorable PK profile in non-human primates and does not induce immune-mediated toxicity in vitro....Pheast is on track to initiate clinical trials with PHST001 in the first half of 2025."

New trial • Preclinical • Solid Tumor

Pheast partners with Lonza to produce cancer-gobbling CD24 drug (BioProcess International) - "The company has partnered with contract development and manufacturing organization (CDMO) Lonza to manufacture its drug substance (DS) and drug product (DP), with the cell-line development and DS work done in Visp and the DP work done in Basel, both in Switzerland. That partnership has enabled Pheast to attain the supply needed of its lead drug candidate, PHST001, for first-in-human clinical trials. The drug was developed as a therapeutic against cluster of cell differentiation (CD) 24, a known 'don’t eat me' signal that is highly expressed in ovarian and breast cancers."

Commercial • Breast Cancer • Ovarian Cancer

Pheast Unveils First Preclinical Data for PHST001, an Anti-CD24 Macrophage Checkpoint Inhibitor (Businesswire) - "Pheast Therapeutics...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...'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.'...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....Dr. Burg will present these data on Monday, May 13, 2024, at 1:15 pm ET in a talk..."

New trial • Preclinical • Oncology • Solid Tumor