PQ203 in Advanced Malignant Tumors Including Triple Negative Breast Cancer

NCT07190469 | Recruiting Phase 1 DMC FDA Drug

• 1 other identifier: PQ203-001
• Study Type: interventional
• Target: 80
• Locations: 2 countries
• Sites: 4

Brief Summary

The primary purposes of this study are to determine the safety and tolerability of PQ203 in patients with advanced solid tumors including triple negative breast cancer (TNBC), and to determine a recommended Phase 2 dose level for future studies in TNBC.

Conditions

Triple Negative Breast Cancer (TNBC); Advanced Solid Tumors Cancer

Keywords

Triple Negative Breast Cancer; TNBC; PQ203; advanced solid tumors; Phase 1

Outcome Measures

Primary Outcomes (2)

• Incidence of treatment-emergent Adverse Events

  The incidence and severity of Adverse Events (AEs) will be graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) to assess safety and tolerability.

  From the time of informed consent until ~28 days after the last dose of PQ203

• Objective Response Rate (ORR)

  Tumor growth will be assessed using standard imaging techniques and scored by Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1). An Objective response rate (ORR), defined as the proportion of patients with a best overall response (BOR) of complete response (CR) or partial response (PR) will be calculated to assess preliminary signals of anti-tumor activity.

  From informed consent until ~28 days after the last dose of PQ203

Secondary Outcomes (5)

• Progression free survival

  From informed consent to ~28 days after the last dose of PQ203

• Pharmacokinetics: Determine the Cmax of PQ203

  From first day of dosing to ~28 days after the last day of dosing

• Pharmacokinetics: half-life of PQ203 in plasma

  From first day of dosing until ~28 days after the last dose

• Pharmacokinetics: PQ203 exposure

  from first dose through ~28 days after the last dose

• Duration of Objective Response

  From Informed consent to ~28 days after the final dose

Study Arms (1)

PQ203

EXPERIMENTAL

A Phase 1, first-in-human (FIH), multiple ascending dose study of the peptide drug-conjugate PQ203 to evaluate the safety, pharmacokinetics, tolerability and preliminary anti-cancer activity in patients with advanced cancers with solid tumors. Comprises up to 7 planned ascending dose cohorts with expansion of doses to identify recommended dose levels for testing in the Phase 1B Dose Optimization study. This is an open label study and all participants will receive PQ203.

Drug: PQ203

Interventions

PQ203 DRUG

PQ203 is a peptide drug-conjugate given once weekly by intravenous infusion intended for the treatment of advanced solid tumor cancers including triple negative breast cancer.

PQ203

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• At least 18 years old
• Histologically or cytologically documented metastatic or locally advanced solid tumor malignancies having progressed through or being otherwise ineligible to receive approved standard-of-care therapies
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1
• Documented presence of RECIST v1.1 measurable disease
• Adequate organ function confirmed by the following laboratory values obtained within 14 days of the first dose of PQ203:
• Bone Marrow Function
• Absolute neutrophil count (ANC) ≥ 1.5 × 10e9/L
• Platelets \> 100 × 10e9/L
• Hemoglobin ≥ 9 g/dL
• Hepatic Function
• AST, alanine transaminase ALT or ALP ≤ 2.5 × upper limit of normal (ULN); if liver metastases, then ≤ 5 × ULN
• Bilirubin ≤ 1.5 × ULN (\< 2 × ULN if hyperbilirubinemia is due to Gilbert's syndrome)
• Serum albumin ≥ 35 g/L (3.5 g/dL)
• Renal Function
• Calculated creatinine clearance of ≥ 60 mL/min by the Cockcroft-Gault equation

You may not qualify if:

• Patients with primary central nervous system (CNS) malignancies (Patients with stable brain metastases (≥ 4 weeks after a treatment) not requiring steroids or other treatment will be allowed on study).
• Blood transfusion within 14 days of study treatment
• Serious comorbid medical conditions such as heart, lung, kidney, liver, and brain disease that, in the opinion of the enrolling investigator, could interfere with study treatment
• Subjects with history of severe heart disease
• QTc interval using Fridericia's formula (QTcF) \> 470 ms
• Estimated or known weight \> 115 kg (253 lbs)
• Known/suspected pregnancy and/or lactation
• Diastolic blood pressure \< 60 mmHg or \>110 mmHg
• Uncontrolled intercurrent illness
• Long term care facility resident or prisoner
• Any prior receipt of a MMAE-containing drug
• Any prior receipt of a SORT1-targeting medication
• Participation in another clinical study investigating a drug or medical device or a neuro-interventional or surgical procedure that is not considered as standard care in the 30 days preceding study enrolment
• Treatment with any of the following:
• Chemotherapy or other systemic anti-cancer therapy ≤14 days or 5 half-lives (whichever is shorter) prior to first dose of study drug except for Nitrosoureas or mitomycins ≤42 days

Sponsors & Collaborators

• ProteinQure Inc.: lead

Study Sites (4)

MD Anderson Cancer Center

Houston, Texas, 77030, United States

RECRUITING

NEXT Oncology

San Antonio, Texas, 78229, United States

RECRUITING

START Mountain Region

West Valley City, Utah, 84119, United States

RECRUITING

Princess Margaret Cancer Centre

Toronto, Ontario, M5G 0C6, Canada

RECRUITING

Related Links

• Sponsor website

MeSH Terms

Conditions

Triple Negative Breast Neoplasms

Condition Hierarchy (Ancestors)

Breast Neoplasms; Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 19, 2025
• First Posted: September 24, 2025
• Study Start: September 16, 2025
• Primary Completion (Estimated): December 1, 2028
• Study Completion (Estimated): February 1, 2029
• Last Updated: February 23, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1); US (3)