ProteinQure Announces First Patient Dosed in Phase I Clinical Trial of PQ203 in Advanced Metastatic Cancer

September 17, 2025 at 10:33 AM EDT

ProteinQure, a Toronto-based biotech company pioneering computational peptide drug discovery, today announced the successful dosing of the first patient in its Phase I clinical trial evaluating PQ203 – a novel, rationally designed peptide therapeutic for advanced metastatic solid tumors.

"Dosing our first patient with PQ203 represents a defining moment not just for ProteinQure, but for the vision from the founding of the company — that computational tools can unlock new medicines," said Lucas Siow, CEO and Co-Founder of ProteinQure. "Having created PQ203 in Toronto and starting the trial with the exceptional clinical team at Princess Margaret underscores the ability to advance world-class science in Canada."

The trial is being started at Princess Margaret Cancer Centre in Toronto, one of the world’s top five cancer research centers. There, the trial is led by investigator Dr. Philippe Bedard,

“It’s exciting to be part of a groundbreaking program that was discovered using the latest in computational science,” said Dr. Bedard. “Peptides open up a new and promising path for targeted cancer treatments, and we’re looking forward to seeing how PQ203 might help patients who currently have limited treatment options.”

About the Trial

The Phase 1 trial is a first-in-human trial with three parts: dose escalation, dose expansion (in multiple tumor types), and dose optimization. The study will evaluate the safety, tolerability, pharmacokinetics, preliminary activity, and pharmacodynamics of PQ203. It will take place across Canada and the US at clinical sites including Princess Margaret Cancer Centre, McGill, Yale, MD Anderson, and Next Oncology.

For more information about the PQ203 trial, visit www.clinicaltrials.gov (NCT# pending) or contact info@proteinqure.com.

About PQ203

PQ203 is the company’s first internally owned AI designed peptide therapeutic entering the clinic 3 years after the program was started. PQ203 is composed of a peptide targeting the Sortilin receptor conjugated to the cytotoxic agent MMAE. The Sortilin receptor is expressed in a high percentage of diseased tissue from Triple Negative Breast Cancer (TNBC) patients. ProteinQure has generated data that PQ203 exhibits potent efficacy in a patient-derived xenograft (PDX) model resistant to Sacituzumab Govitecan (Trodelvy™), an antibody drug conjugate that is the standard of care for metastatic TNBC.