Cleo’s ovarian cancer test clears first screening hurdle with strong Stage I results

Stage I screening results clear Cleo’s first hurdle

Cleo Diagnostics Limited (ASX:COV) has cleared the first formal hurdle in its attempt to build an ovarian cancer screening test, with its prototype meeting or exceeding all predefined performance targets in a retrospective study of 247 women. The result is most significant in the 62 Stage I cancer cases, where early detection could offer the greatest clinical benefit.

For a high-risk screening population, the test produced 92.2% sensitivity and 98.7% specificity for Stage I cancer, against minimum targets of 90% for both measures. In the broader general-population screening scenario, it recorded 75.0% sensitivity and 100.0% specificity, matching the sensitivity threshold and exceeding the 99.6% specificity requirement.

Prototype outperforms CA125 in study comparisons

The prototype also compared favourably with CA125, the current clinical biomarker used as a reference in the analysis. Cleo reported an area under the curve of 0.99 for Stage I cancers and 0.98 across all stages, compared with CA125 scores of 0.87 and 0.83 respectively.

Those figures are encouraging, but the study design limits how far they can be taken. The cohort was retrospective and included 87 healthy individuals, 67 women with benign gynaecological disease and 93 women with ovarian cancer. Cleo says the performance estimates require confirmation in larger, independent and intended-use populations, particularly where ovarian cancer prevalence is low.

Screening program moves into larger validation studies

The next stage will involve bridging and expanded cohort studies designed to test reproducibility, improve statistical power and examine whether sample collection, processing and storage conditions affect performance. Cleo then plans to evaluate the test using prospectively collected samples from intended-use populations, including samples from the UK Collaborative Trial of Ovarian Cancer Screening and the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

The screening work began only recently, after Cleo launched its

Triage remains the nearer-term regulatory pathway

Cleo is pursuing the screening program in parallel with its pre-surgical ovarian cancer triage test, which remains the company’s near-term path towards an FDA submission. That program has entered

Chief executive Dr Richard Allman said the results gave Cleo confidence that its underlying biology and panel design were sound, while describing screening as the larger long-term opportunity. The practical test of that confidence will come when the prototype leaves its enriched retrospective cohort and faces the statistical and operational demands of real-world population screening.