About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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
Disqualifiers
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.
Trial design
Sequential
Treatments tested in this trial
PHST001
Biological/VaccinePHST001 is an anti-CD24 macrophage checkpoint inhibitor, administered as IV infusions every 3-weeks (Q3W) dosing intervals.
Chemotherapy per Standard of Care
DrugParticipants 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.
Treatment groups
Trial outcomes
Primary outcomes
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)
Based on toxicities observed
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)
Based on toxicities observed
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)
Based on toxicities observed
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)
Based on toxicities observed
Secondary outcomes
Overall Response Rate (ORR) based on RECIST v1.1 (or RANO for primary CNS Tumors) to assess the preliminary antitumor activity of PHST001 as monotherapy (Phase 1a)
Defined as the proportion of subjects with confirmed complete response (CR) or partial response (PR); a confirmed response is a response that persists on repeat-imaging ≥ 4 weeks after initial documentation of response.
Duration of Response (DOR) based on RECIST v1.1 (or RANO for primary CNS Tumors) to assess the preliminary antitumor activity of PHST001 as monotherapy (Phase 1a)
Defined as time from date of first objective response (either CR or PR) to first documentation of radiographic disease progression.
Best Overall Response (BOR) based on RECIST v1.1 (or RANO for primary CNS Tumors) to assess the preliminary antitumor activity of PHST001 as monotherapy (Phase 1a)
Defined as the best response recorded for a participant across all time-point assessments from the start of treatment until disease progression or end of treatment.
Progression-Free Survival (PFS) based on RECIST v1.1 (or RANO for primary CNS Tumors) to assess the preliminary antitumor activity of PHST001 as monotherapy (Phase 1a).
Defined as the time from first dose of PHST001 to first documentation of radiographic disease progression or death, whichever occurs first.
Sponsors and contacts
Click on the lead sponsor to view all of their trials.