Recruiting
Phase 1

PHST001

Sponsor:

Pheast Therapeutics

Code:

NCT06840886

Conditions

Advanced Solid Tumors

Ovarian Cancer

Endometrial Cancer

Cholangiocarcinoma

CNS Tumor

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

PHST001

Chemotherapy per Standard of Care

Study Details

Brief summary:

This is a multi-center, first-in-human (FIH), open-label, Phase 1a/1b dose escalation and dose expansion study to assess the safety, PK, pharmacodynamics, and antitumor activity of PHST001 monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) in adult participants with advanced relapsed and/or refractory solid tumors (including but not limited to CNS tumors in Phase 1a only). In Phase 1b cohort expansions, the study will focus on participants with advanced relapsed and/or refractory ovarian cancer, endometrial cancer, and cholangiocarcinoma. The study's primary objective is to evaluate the safety and tolerability of PHST001 and determine the RP2D (Recommended Phase 2 dose) of PHST001 monotherapy and in combination with chemotherapy as well as assess the anti-tumor activity of PHST001 and chemotherapy in Phase 1b.

Conditions

Advanced Solid Tumors

Ovarian Cancer

Endometrial Cancer

Cholangiocarcinoma

CNS Tumor

Study ID

NCT06840886

Start date

Mar 31, 2025

Status verified date

Jun, 2026

Completion date

Apr, 2031

Anticipated

Primary completion date

Apr, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Key Inclusion Criteria:

  • Histologically or cytologically confirmed advanced solid tumor which has relapsed from or been refractory to all locally available standard therapies.
  • Adequate organ function per laboratory testing
  • Pregnancy prevention requirements
  • Measurable disease per RECIST v1.1 (or RANO) as assessed by the local site Investigator/radiology
  • Performance status of 0 or 1 on Eastern Cooperative Oncology Group (ECOG) scale

Key Exclusion Criteria:

  • Diagnosis of immunodeficiency
  • History of a previous additional malignancy, unless potentially curative treatment has been completed, with no evidence of malignancy for 5 years. Participants with basal cell carcinoma of the skin, Stage I melanoma, melanoma in situ, squamous cell carcinoma of the skin, early-stage prostate cancer, or carcinoma in situ, excluding carcinoma in situ of the bladder, who have undergone potentially curative therapy are not excluded and can be enrolled regardless of disease-free period following completion of potentially curative therapy. Participants with early-stage breast cancer who have undergone curative intent treatment and with no disease recurrence for 2 years after treatment are not excluded.
  • Active known CNS metastases and/or carcinomatous meningitis. Participants with previously treated CNS metastases may participate provided they are radiologically stable (i.e., without evidence of progression for at least 2 weeks by repeat imaging \[note that the repeat imaging should be performed during study screening\]), clinically stable, and without requirement of steroid treatment for at least 14 days prior to the first dose of study treatment.
  • Received prior systemic anticancer therapy including investigational agents within 21 days or, if shorter, within 5 half-lives prior to the first dose of study treatment. Participants must have recovered from all AEs due to previous therapies to Grade ≤1 or baseline. Participants with Grade ≤2 neuropathy may be eligible. Participants with endocrine-related AEs Grade ≤2 requiring treatment or hormone replacement may be eligible.
  • Prior autologous or allogeneic hematopoietic stem cell transplant or solid organ transplant.
  • Received previous treatment with another agent targeting CD24.

Study Design

Enrollment

272 participants

Anticipated

Allocation

Non randomized

Intervention Model

Sequential

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Dose Escalation (Phase 1a)

Nine dose levels will be sequentially tested in PHST001 monotherapy dose escalation: 0.1 mg/kg, 0.3 mg/kg, 1.0 mg/kg, 2.0 mg/kg, 4.0 mg/kg, 6.0 mg/kg, 9.0 mg/kg, 18.0 mg/kg, and 36.0 mg/kg.

experimental: Dose Expansion (Phase 1b)

PHST001 will be administered in combination with chemotherapy for three indicated tumor types: ovarian cancer, endometrial cancer, and cholangiocarcinoma.

The first portion of Phase 1b will consist of safety run-in groups based on the chemotherapy combination. There will be six groups: 1) combination with paclitaxel, 2) combination with topotecan, 3) combination with doxorubicin, 4) combination with 5-fluorouracil, folinic acid, and irinotecan \[FOLFIRI\], 5) combination with 5-fluorouracil, folinic acid, and oxaliplatin \[FOLFOX\], and 6) combination with gemcitabine.

The second portion of Phase 1b will begin following clearance of a safety run-in group, and subsequent participants will enroll into tumor-specific expansion cohorts at a fixed dose of PHST001 in combination with chemotherapy.

Interventions

PHST001

PHST001 is an anti-CD24 macrophage checkpoint inhibitor, administered as IV infusions every 3-weeks (Q3W) dosing intervals.

Chemotherapy per Standard of Care

Participants will receive PHST001 at a dose level and schedule based on monotherapy data in Phase 1a. PHST001 will be combined with chemotherapeutic agents used as standard of care.

Primary outcome measure

  • Frequency of Dose-Limiting Toxicities (DLTs) to assess the safety and tolerability of PHST001 as monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) [ Time Frame: From first dose of PHST001 through 21 days after the first dose of PHST001 ]
  • Frequency of Serious Adverse Events (SAEs) to assess the safety and tolerability of PHST001 as monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) [ Time Frame: From signed consent up to 90 days after the last dose of PHST001 ]
  • Frequency of Treatment Emergent Adverse Events (TEAEs) to assess the safety and tolerability of PHST001 as monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) [ Time Frame: From first dose up to 90 days after the last dose of PHST001 ]
  • Frequency of Treatment Related Adverse Events (TRAEs) to assess the safety and tolerability of PHST001 as monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) [ Time Frame: From first dose up to 90 days after the last dose of PHST001 ]
  • Frequency of Adverse Events of Special Interest (AESIs) to assess the safety and tolerability of PHST001 as monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) [ Time Frame: From first dose up to 90 days after the last dose of PHST001 ]
  • Frequency of AEs Leading to Dose Interruption or Treatment Discontinuation and AEs Leading to Death to assess the safety and tolerability of PHST001 as monotherapy (Phase 1a) or in combination with chemotherapy (Phase 1b) [ Time Frame: From first dose up to 90 days after the last dose of PHST001 ]
  • Overall Response Rate (ORR) based on RECIST v1.1 to assess the preliminary antitumor activity of PHST001 in combination with chemotherapy (Phase 1b) [ Time Frame: From screening and during treatment up to 2 years ]
  • Duration of Response (DOR) based on RECIST v1.1 to assess the preliminary antitumor activity of PHST001 in combination with chemotherapy (Phase 1b) [ Time Frame: From screening and during treatment up to 2 years ]
  • Best Overall Response (BOR) based on RECIST v1.1 to assess the preliminary antitumor activity of PHST001 in combination with chemotherapy (Phase 1b) [ Time Frame: From screening and during treatment up to 2 years ]
  • Progression-Free Survival (PFS) based on RECIST v1.1 to assess the preliminary antitumor activity of PHST001 in combination with chemotherapy (Phase 1b) [ Time Frame: From screening and during treatment up to 2 years ]
  • Overall Survival (OS) based on RECIST v1.1 to assess the preliminary antitumor activity of PHST001 in combination with chemotherapy (Phase 1b) [ Time Frame: From screening and during treatment up to 2 years ]

Central Contacts and Locations

Central contacts

Andrew Ferguson/VP Clinical Development, PhD

434-249-2349medical@pheast.com

Locations

Precision NextGen Oncology & Research Center

Recruiting

Beverly Hills, California, United States, 90212

USC Norris Comprehensive Cancer Center

Recruiting

Los Angeles, California, United States, 90033

Stanford University School of Medicine

Recruiting

Palo Alto, California, United States, 94304

Sarah Cannon Research Institute (SCRI) Oncology Partners - Denver Health One

Recruiting

Denver, Colorado, United States, 80218

Yale Cancer Center

Recruiting

New Haven, Connecticut, United States, 06520

University of Chicago Medical Center

Recruiting

Chicago, Illinois, United States, 60637

Dana Farber Cancer Institute

Recruiting

Boston, Massachusetts, United States, 02215

University of Michigan Rogel Cancer Center

Recruiting

Ann Arbor, Michigan, United States, 48109

START Center for Cancer Research - Midwest

Recruiting

Grand Rapids, Michigan, United States, 49546

START Center for Cancer Research - Long Island New York

Recruiting

Lake Success, New York, United States, 11042

Mount Sinai

Recruiting

New York, New York, United States, 10029

Duke Cancer Institute

Recruiting

Durham, North Carolina, United States, 27710

Sarah Cannon Research Institute (SCRI) Oncology Partners

Recruiting

Nashville, Tennessee, United States, 37203

Vanderbilt-Ingram Cancer Center

Recruiting

Nashville, Tennessee, United States, 37203

START Center for Cancer Research - Texas

Recruiting

Fort Worth, Texas, United States, 76104

MD Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030

NEXT Oncology - Dallas

Recruiting

Irving, Texas, United States, 75039

START Center for Cancer Research - San Antonio

Recruiting

San Antonio, Texas, United States, 78229

Contacts

HOPE Team

210-593-5250hopeteam@startresearch.com

Principal Investigator:

Kyriakos Papadopoulos, MD

University of Texas (UT) Health

Recruiting

San Antonio, Texas, United States, 78229

NEXT Oncology - Virginia

Recruiting

Fairfax, Virginia, United States, 22031

More Information

Sponsor

Pheast Therapeutics

Last update posted

Aug 12, 2026

Last verified

Jun, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Pheast Therapeutics on 2026-08-12.