Repare Therapeutics Inc. (Nasdaq: RPTX), a clinical-stage precision oncology company, recently announced promising data from a study evaluating camonsertib, an oral small molecule ATR inhibitor, in combination with palliative radiation for treating metastatic tumors with an ataxia-telangiectasia-mutated (ATM) mutation. The data, gathered from a clinical trial in collaboration with Memorial Sloan Kettering Cancer Center, were presented at the American Society for Radiation Oncology (ASTRO) annual meeting in Washington, DC. The presentation was led by Dr. Nancy Lee, a Radiation Oncologist and Early Drug Development Specialist at Memorial Sloan Kettering Cancer Center, under the title, “Genotypically-Selected Pan Cancer Trial of Camonsertib with Palliative Radiation in the Treatment of Metastatic Tumors Harboring an Ataxia-Telangiectasia Mutated (ATM) Mutation.”
Maria Koehler, MD, PhD, Executive Vice President and Chief Medical Officer of Repare, stated, “These early Phase 1 results highlight the broad clinical potential of camonsertib. This first-in-human study, combining camonsertib with palliative radiation, shows the potential of this combination to enhance radiosensitivity in patients with tumors harboring pathogenic ATM mutations compared to those with variants of unknown significance (VUS). We are optimistic about the initial response rates and safety profile of this combination in the Phase 1 setting.”
Key Study Findings:
- A total of 17 patients with metastatic tumors harboring ATM mutations participated in the trial, including 12 with pathogenic ATM mutations and 5 with variants of unknown significance (VUS).
- Primary cancer types included gastrointestinal (n=5), pancreas (n=5), breast (n=2), lung (n=2), bladder (n=2), and thyroid (n=1).
- The recommended Phase 2 dose of camonsertib was set at 160 mg daily, administered before radiation (4Gy) on days 1-5.
- Interim results were available for 16 patients at the time of submission:
- At 2 months, there were 2 complete responses (CR), 5 partial responses (PR), and 4 cases of stable disease (SD) among patients with pathogenic ATM mutations, compared to 1 PR and 4 SD in the VUS group.
- At 6 months, among 9 evaluable patients, 2 CR, 4 PR, and 1 SD were observed in the pathogenic mutation group, while the VUS group reported 1 SD and 1 case of progressive disease (PD).
These early results provide encouraging evidence for the potential of camonsertib combined with radiation to improve outcomes for patients with ATM-mutated tumors.
About Repare Therapeutics Inc.
Repare Therapeutics is a leading clinical-stage precision oncology company enabled by its proprietary synthetic lethality approach to the discovery and development of novel therapeutics. The Company utilizes its genome-wide, CRISPR-enabled SNIPRx® platform to systematically discover and develop highly targeted cancer therapies focused on genomic instability, including DNA damage repair. The Company’s pipeline includes lunresertib (also known as RP-6306), a PKMYT1 inhibitor currently in Phase 1/2 clinical development; camonsertib (also known as RP-3500), a potential leading ATR inhibitor currently in Phase 1/2 clinical development; RP-1664, a Phase 1 PLK4 inhibitor; RP-3467, a preclinical Polθ ATPase inhibitor program; as well as additional, undisclosed preclinical programs.
