Mercy BioAnalytics Publishes Validation Study in Gynecologic Oncology Demonstrating Unprecedented Performance of Blood Test for Early Detection of Ovarian Cancer

Test demonstrates 89% sensitivity for detection of preclinical stage I/II high grade serous ovarian cancer at 98% specificity in average risk postmenopausal women

WALTHAM, Mass., Oct. 28, 2025 /PRNewswire/ -- Mercy BioAnalytics, Inc., a pioneer in blood-based detection of early-stage cancer, today announced the publication of a validation study in the journal of Gynecologic Oncology highlighting the performance of a novel blood test for detection of preclinical early-stage ovarian cancer.

Led by Mercy researchers in partnership with the Medical Research Council Clinical Trials Unit (MRC CTU) at University College London (UCL), this landmark study represents the first demonstration of a blood test capable of detecting ovarian cancer up to three years prior to diagnosis in prospectively collected preclinical samples from the landmark UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS).

Study Highlights

• The blood test achieved 89% sensitivity and 98% specificity for detecting stage I/II high-grade serous carcinoma (HGSC) in average-risk, postmenopausal women, with significantly improved specificity and discrimination compared to CA125.
• The blinded evaluation of samples that were prospectively collected prior to cancer diagnosis from the intended use population minimizes bias while demonstrating generalizability of performance.
• These findings build upon Mercy's previous published work validating their blood-based detection technology and establishes the Mercy Halo™ assay as a promising next-generation screening platform.

The results demonstrate that the test, which detects tumor-derived extracellular vesicles and particles, can identify ovarian cancer with high accuracy—even in preclinical, early-stage disease where intervention is most impactful. These findings suggest the technology has the potential to enable a practical, blood-based screening approach for average-risk women, addressing a critical unmet need in ovarian cancer care. The test's high specificity minimizes the potential for false positives, while its high early-stage sensitivity enables the detection of ovarian malignancy even before symptoms arise.

"This study marks a watershed moment for noninvasive ovarian cancer screening," said Dawn Mattoon, Ph.D., Chief Executive Officer of Mercy. "Achieving nearly 90% sensitivity with 98% specificity in early-stage disease is unprecedented in this space. We are more confident than ever that our technology can transform how ovarian cancer is detected, offering women a real chance at earlier intervention and improved outcomes."

Ovarian cancer is one of the leading causes of cancer death among women and will kill nearly 13,000 women in the U.S. this year. More than 70% of ovarian cancer is diagnosed in women over 50 years of age, and nearly 80% of ovarian cancer is diagnosed at an advanced stage of disease, when survival is poor. When ovarian cancer is detected early, when disease is still localized, nearly 90% of women survive for ten years or more. Unfortunately, legacy diagnostic test methods have not shown adequate clinical performance to enable broad adoption for ovarian cancer screening.

"This study demonstrates that blood-based biomarkers can provide a highly specific and sensitive signal for early ovarian cancer," said Dr. Usha Menon, Professor of Women's Cancer at UCL and senior author of the paper. "The blinded evaluation of preclinical samples from the no screening and ultrasound arms of UKCTOCS represents an important step forward in population screening. The next stage is to assess the robustness and reliability of these findings by assessing performance in the third arm of the UKCTOCS trial (the multi-modal screening arm)."

The article is available online at Gynecologic Oncology (here) and will be featured in an upcoming print issue.

About Mercy BioAnalytics
Mercy BioAnalytics, Inc. is on a mission to relieve suffering and save lives through the early detection of cancer. Early-stage cancer is difficult to detect, but when found, is more often amenable to curative therapy. The patented Mercy Halo™ liquid biopsy platform utilizes biomarker co-localization to interrogate highly abundant, blood-based extracellular vesicles that carry unique cancer signatures from their parent cells. The Mercy Halo platform is designed to detect early-stage cancer, when it is most treatable, and enhance the quality of life for cancer patients and their families. Mercy's initial focus is the early detection of ovarian and lung cancers. Ovarian cancer, the most lethal gynecological cancer, typically goes undetected until it is too late to cure. Lung cancer, the number one cancer killer, takes more lives than breast and prostate cancers combined.

About Medical Research Council Clinical Trials Unit at University College London
The Medical Research Council Clinical Trials Unit (MRC CTU) at UCL is at the forefront of resolving internationally important questions in infectious diseases, cancer and neurodegenerative disease, and delivering swifter and more effective translation of scientific research into patient benefits. It does this by carrying out challenging and innovative studies, and developing and implementing methodological advances in study design, conduct and analysis.

UKCTOCS
UKCTOCS is the largest ovarian cancer screening trial to date. Over 200,000 eligible postmenopausal women from the general population, aged 50–74 years, with intact ovaries were recruited between 2001 and 2005 and randomly allocated (2:1:1) to no screening or annual screening (multimodal screening or ultrasound screening) until Dec 31, 2011. Follow-up was through national registries until 2020. There was no reduction in deaths due to ovarian cancer in either screening arms compared to no screening. However, in the multimodal screening arm, fewer women with high grade serous ovarian cancer were diagnosed with advanced stage disease and had improved short-term outcomes. While the trial findings do not support ovarian cancer screening using CA125 and ultrasound, they suggest that novel approaches that can detect more women earlier in the course of the disease are likely to positively impact mortality.

SOURCE Mercy BioAnalytics