Recruiting
Phase 1

PQ203

Sponsor:

ProteinQure Inc.

Code:

NCT07190469

Conditions

Triple Negative Breast Cancer (TNBC)

Advanced Solid Tumors Cancer

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

PQ203

Study Details

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

Study ID

NCT07190469

Start date

Sep 16, 2025

Status verified date

Feb, 2026

Completion date

Feb, 2029

Anticipated

Primary completion date

Dec, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 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
  • Urine protein < 2+

Cardiac Function

• Left ventricular ejection fraction (LVEF) ≥ 50%

Other

  • Understand and voluntarily sign an Institutional Review Board (IRB)/Independent Ethics Committee (IEC)/Research Ethics Board (REB)-approved informed consent form prior to any study-specific evaluation.
  • PT/PTT or INR <1.2x upper limit of normal
  • Non-surgically sterile men and women of child bearing potential must agree to use highly effective methods of contraception for at least 4 months beyond the final dose received.
  • Toxicity of previous antitumor therapy has returned to Grade ≤1

Exclusion Criteria:

  • 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
  • Major surgery ≤28 days from first dose of study drug
  • Patients with a history of cerebrovascular accident within 6 months of planned first dose.
  • Patients with clinically symptomatic ocular toxicities
  • Patients with history of (noninfectious) interstitial lung disease (ILD)/pneumonitis that require steroids, with current ILD/pneumonitis, or where suspected ILD/pneumonitis cannot be ruled out by imaging at screening
  • Patients with active Grade >1 peripheral neuropathy

Study Design

Enrollment

80 participants

Anticipated

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: PQ203

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.

Interventions

PQ203

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.

Primary outcome measure

  • Incidence of treatment-emergent Adverse Events [ Time Frame: From the time of informed consent until ~28 days after the last dose of PQ203 ]
  • Objective Response Rate (ORR) [ Time Frame: From informed consent until ~28 days after the last dose of PQ203 ]

Central Contacts and Locations

Locations

MD Anderson Cancer Center

Recruiting

Houston, Texas, United States, 77030

Contacts

Desirae Dufner

713-745-7813DDufner@mdanderson.org

Principal Investigator:

Timothy A Yap, MBBS, PhD, FRCP

NEXT Oncology

Recruiting

San Antonio, Texas, United States, 78229

Contacts

nxt_txreferrals@nextoncology.com

210-580-9500nxt_txreferrals@nextoncology.com

Principal Investigator:

David Sommerhalder, MD

START Mountain Region

Recruiting

West Valley City, Utah, United States, 84119

Contacts

Olivia Darais

801-917-4750olivia.darais@startresearch.com

Princess Margaret Cancer Centre

Recruiting

Toronto, Ontario, Canada, M5G 0C6

Contacts

Clinical Cancer Research Unit

416-946-4559patientrelations@uhn.ca

Principal Investigator:

Philippe Bedard, MD

More Information

Sponsor

ProteinQure Inc.

Last update posted

Feb 23, 2026

Last verified

Feb, 2026

Keywords

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

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by ProteinQure Inc. on 2026-02-23.