Wednesday, October 21, 2020 The Canadian Cancer Trials Group (CCTG) has started a new sub-study evaluating CFI-400945, an oral, first-in-class inhibitor of Polo-like Kinase 4 (PLK4), in patients with metastatic castrate-resistant prostate cancer (mCRPC). “We are very excited to see the initiation of this trial, that builds on preclinical work demonstrating an association between loss of the tumor suppressor PTEN, a common alteration in this disease setting, and response to CFI-400945,” says Dr. Mark Bray, Treadwell Chief Scientific Officer and Co-Founder. “This is the first trial that evaluates a precision medicine approach for patients with advanced prostate cancer using liquid biopsies for genomic testing. This innovative trial design, which incorporates liquid biopsy-based biomarker evaluation, helps meet the urgent need to identify more effective therapies for men with advanced prostate cancer,” said Dr. Lesley Seymour, CCTG’s Director, Investigational New Drug Program and a Medical Oncologist in the Department of Oncology at Queen’s University. The study is supported by the Canadian Cancer Society, Prostate Cancer Canada and the Movember Foundation through a Translation Acceleration Grant to Tak Mak (The Princess Margaret Cancer Centre), the Canadian Clinical Trials Group and a team of co-investigators from across Canada. “Our understanding of the molecular drivers of prostate cancer is increasing, and for some of these molecular variations we have few therapeutic options,” says the trial study chair Dr. Aaron R. Hansen, GU Medical Oncology Site Lead Division of Medical Oncology at Princess Margaret Cancer Center. “The innovative trial design of IND234 will match men with metastatic castration resistant prostate cancer with agents designed to target their specific molecular abnormalities, in order to improve their outcomes.” This sub-study is part of the IND.234 - Prostate Cancer Biomarker Enrichment and Treatment Selection (PC-BETS) Study. The primary endpoint is clinical benefit rate defined as proportion of patients who had PSA decline ≥ 50%, complete or partial objective response, or stable disease for ≥ 12 weeks. The CCTG IND234 trial will be open at sites across Canada, for a full list of participating centers and for additional information about the study, please visit www.clinicaltrials.gov. About CFI-400945 CFI-400945 is a first-in-class, oral selective and potent inhibitor of Polo-like Kinase 4 (PLK4), which regulates centriole duplication and thus mitotic progression. PLK4 is overexpressed in a variety of solid tumors and elevated expression is associated with poor clinical outcomes. Depletion of PLK4 expression in cancer cells by RNA interference leads to mitotic defects and cell death. PLK4 was identified as a drug target based on functional screening to identify vulnerabilities of genomically unstable breast cancers. Anti-tumor activity of CFI-400945 has been shown in mice bearing human cancer xenografts, including robust tumor growth inhibition and durable tumor regression in primary tumor xenografts from breast cancer.