Cleo Diagnostics (ASX:COV) gains PLCO biobank access to strengthen FDA submission for ovarian cancer test

Cleo Diagnostics Limited (ASX:COV), the oncology diagnostics developer focused on improving early detection of ovarian cancer, announced on June 25, 2025, that it has secured access to the U.S. National Cancer Institute’s Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial biobank. The approval is expected to significantly strengthen the company’s FDA 510(k) application for its Pre-Surgical Test and accelerate development of a future Screening Test targeting asymptomatic populations.

The PLCO cohort is considered one of the most authoritative biobank resources in the world, having enrolled over 155,000 participants with longitudinal follow-up over more than a decade. Cleo Diagnostics’ ability to access these rigorously collected samples positions it alongside a select group of diagnostic firms using prospective, real-world U.S. data for regulatory submission support.

This milestone adds a new dimension to Cleo Diagnostics’ clinical strategy, following its previously disclosed access to the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) biobank in April 2025. Together, these biobank partnerships create a globally representative intended-use population that enhances the credibility and translatability of performance data for both regulatory and commercial stakeholders.

How does access to the PLCO biobank advance Cleo Diagnostics’ FDA strategy for its Pre-Surgical Test?

Cleo Diagnostics will use PLCO samples to initiate two key studies designed to validate the performance of its CXCL10-based diagnostic platform. The first study focuses on differentiating malignant from benign adnexal masses using prospectively collected pre-surgical samples. The second study aims to demonstrate lead-time improvement in early detection by analyzing longitudinal blood samples from asymptomatic individuals up to three years before diagnosis.

Both studies are intended to complement the company’s ongoing pivotal clinical trial in the United States, serving as critical components of the FDA 510(k) submission. While the pivotal trial will provide the core evidence for clinical safety and performance, the PLCO-derived data will offer additional support across regulatory touchpoints. These include strengthening total evidence volume, addressing potential FDA questions in advance, substantiating product labelling, and improving the efficiency of the review process.

Cleo Diagnostics’ platform is underpinned by a novel biomarker—CXCL10—which is highly expressed early in the development of ovarian cancers but remains largely absent in non-malignant conditions. The test demonstrated 95% sensitivity and 95% specificity in prior studies involving over 500 patients, significantly outperforming existing standard-of-care diagnostics. These early results suggest strong potential for clinical adoption and third-party reimbursement once regulatory approvals are secured.

Why is the PLCO biobank considered a critical asset in clinical validation and regulatory de-risking?

The PLCO study, sponsored by the U.S. National Cancer Institute, is among the most comprehensive longitudinal cancer screening trials ever conducted in the United States. Beyond its scale, the study’s biospecimen collection and clinical data annotation have set a gold standard for early detection research. Access to the PLCO biobank is tightly controlled, and inclusion typically signals high levels of scientific rigor and translational value.

Institutional investors and industry analysts view Cleo Diagnostics’ access as a meaningful validation of its technology and strategic planning. The addition of U.S.-specific data to its clinical evidence package not only aligns with FDA expectations but also enhances downstream market adoption prospects by reflecting real-world disease incidence and patient diversity.

According to analysts, companies that successfully integrate prospective U.S. datasets into their regulatory strategy tend to command greater confidence during payer negotiations and launch planning. Cleo Diagnostics’ integration of both PLCO and UKCTOCS samples gives it a dual-market validation framework that few emerging diagnostic players can match.

What is the latest update on Cleo Diagnostics’ pivotal clinical trial in the United States and when will it be completed?

Cleo Diagnostics is currently advancing its pivotal FDA-enabling trial with patient recruitment already underway across multiple U.S. general practice clinics. This initial focus on regional sites reflects an intentional strategy to satisfy patient diversity criteria consistent with FDA guidelines. The final recruitment phase, expected to begin in July 2025, will expand to high-volume surgical centers and academic institutions.

These include major cancer and research centers such as Beth Israel Deaconess Medical Center (part of the Dana-Farber Cancer Institute), Yale University Medical Center, Rush University, Duke University, Cleveland Clinic, Columbia University Medical Center, and University of Florida – Jacksonville. Activation at these sites is expected to provide a strong final enrollment push, keeping the trial on track for completion in the fourth quarter of calendar year 2025.

The pivotal trial will serve as the cornerstone of Cleo Diagnostics’ FDA 510(k) submission, with the PLCO and UKCTOCS studies acting as complementary data pillars that enhance robustness and mitigate potential regulatory risks.

How do institutional investors view Cleo Diagnostics’ strategy and near-term milestones?

Institutional sentiment around Cleo Diagnostics has remained cautiously optimistic as the company progresses along its regulatory and clinical roadmap. The recent addition of the PLCO cohort is viewed as a de-risking move, particularly as FDA reviews for diagnostic tools in oncology are known to be stringent.

Investors have noted that access to world-class biobank resources often correlates with improved chances of regulatory clearance, especially when combined with statistically significant early data. While Cleo Diagnostics remains in the pre-revenue phase, its structured trial rollout, dual-market biobank strategy, and track record of scientific partnerships (such as its license with Hudson Institute of Medical Research) position it favorably in the high-need field of women’s health diagnostics.

With ovarian cancer remaining one of the deadliest gynecologic cancers globally, investor interest is expected to build as Cleo nears its Q4 2025 clinical trial completion milestone. The next inflection point for shareholders will likely revolve around the company’s formal FDA filing and any corresponding commercial or distribution announcements in the U.S. and international markets.

What broader strategy is Cleo Diagnostics pursuing to capture value in the ovarian cancer diagnostics market?

Cleo Diagnostics is pursuing a modular commercialization approach, enabling it to sequentially enter multiple segments of the ovarian cancer diagnostics market. The initial focus is on surgical triage—helping physicians accurately distinguish between benign and malignant masses pre-operatively. The second-phase Screening Test, powered by longitudinal insights from the PLCO and UKCTOCS samples, targets broader asymptomatic and high-risk populations.

In terms of technology platform readiness, Cleo Diagnostics’ test is compatible with standard diagnostic laboratory infrastructure. This allows for easier integration into existing workflows without requiring new hardware—an important consideration for scalability and adoption.

The company’s intellectual property is protected via an exclusive global license from the Hudson Institute of Medical Research. Its scientific development has been backed by over a decade of biomarker research, two multi-site clinical studies, and peer-reviewed validation.

As analysts point out, modular platforms in oncology diagnostics that can scale across surgical and screening use cases are rare but highly valuable. Cleo Diagnostics’ twin-pronged biobank strategy—spanning both the U.S. and U.K.—positions it to validate its platform across real-world populations and meet regulatory standards across multiple geographies.

How Cleo Diagnostics is using biobank strategy to build a globally credible ovarian cancer diagnostic platform

With access to the U.S. PLCO biobank now secured, Cleo Diagnostics has crossed a critical milestone in its regulatory and clinical roadmap. The inclusion of rigorously annotated, longitudinal U.S. samples enhances the firm’s FDA submission strategy and solidifies its broader position in global ovarian cancer diagnostics.

Institutional investors and regulatory observers will now turn their attention to the completion of the company’s pivotal U.S. trial by the end of 2025. If the final data aligns with earlier results, Cleo Diagnostics may be positioned to set a new standard in pre-surgical and early detection testing for ovarian cancer—backed by real-world datasets, scientific rigor, and a market-ready modular approach.