Perimeter Medical Imaging AI (TSXV:PINK; OTCQX:PYNKF) announced that detailed, positive results from the pivotal trial evaluating the use of its next-generation B-Series OCT with ImgAssist AI 2.0 for intraoperative margin assessment during breast-conserving surgeries (BCS), were presented at the 26th Annual Meeting of the American Society of Breast Surgeons (ASBrS).
This, the first-ever successful trial of a new intraoperative margin assessment technology in breast cancer, met its primary endpoint with statistically significant reduction in patients with residual cancer during surgery (p-value = 0.0050) and demonstrated super-superiority compared to standard-of-care alone.
The presentation, delivered by Dr. Alastair Thompson, the trial’s Primary Principal Investigator, Surgeon and Professor, Section Chief of Breast Surgery, Olga Keith Wiess Chair of Surgery at Baylor College of Medicine, Breast Cancer Program Leader at the Dan L Duncan Comprehensive Cancer Center, highlighted:
Primary Endpoint
- Of the 206 patients evaluated, 56 residual diseased margins in 35/206 patients remained after intraoperative Standard of Care (SOC) alone (17.0% patients with residual diseased margins).
- Use of Perimeter B-Series after SOC evaluation resulted in correct detection of residual disease in 14/35 (40.0%) additional patients, fully clearing 7/35 (20.0%) additional patients of all residual disease, and meeting the prespecified super-superiority performance goal for the primary endpoint (P=0.0050).
- Mean total lumpectomy tissue volume excised in the device arm of the trial was 74.0 cm3: 76.4% (56.5 cm3) of the volume was from the primary lumpectomies, 19.9% (14.7 cm3) from 499 SOC shaves, and only 3.8% (2.8 cm3) from 115 Perimeter B-Series shaves.
- The overall Perimeter B-Series margin accuracy was 88.1%.
Clinical Benefit
In total, 26 patients benefited clinically from the identification of residual disease by OCT-AI after SOC was completed. Importantly, this includes six patients with Perimeter B-Series-aided shaves, which contained pathology-confirmed disease missed by both SOC and histopathology at the previous margin.
Dr. Thompson commented, “Today, intraoperative margin assessment remains one of the most pressing problems for both surgeons and their patients. The final results of this pivotal trial clearly demonstrate that the use of Perimeter B-Series has the potential to change the current paradigm by empowering surgeons to identify regions of interest, enhance real-time intraoperative decision-making, and reduce the incidence of re-excision due to unaddressed residual disease following lumpectomy.”
In a statement, Adrian Mendes, CEO of Perimeter, remarked, “We believe Perimeter B-Series will empower surgeons to more effectively identify and address residual cancer at the margin—removing less healthy tissue, reducing re-operations, and sparing breast cancer patients the anxiety of waiting days for post-op pathology results. The goal of interoperative margin assessment with OCT-AI is a single, successful surgery so these patients can return to their lives and loved ones sooner.”
Mr. Mendes added, “We are deeply grateful to the clinicians, researchers, and especially the breast cancer patients that participated in the pivotal trial.”
In March 2025, Perimeter announced the submission of a Premarket Approval (“PMA”) application to the U.S. Food and Drug Administration (“FDA”) for use of Perimeter B-Series during BCS in the United States. The FDA PMA submission represents the achievement of a major milestone – Perimeter’s first pre-market regulatory submission for its AI-enabled wide-field OCT technology, as well as for a specific indication label. The PMA including the pivotal study results are currently under review with the FDA.
