Highlights

• Filed two provisional patent applications covering candidate biomarker combinations for early ovarian cancer detection, ahead of initial proof-of-concept screening data.

• Started prototype development of a multi-marker screening blood test, beginning with a 250-patient cohort enriched for Stage I disease.

• Completed pivotal trial sample collection, enrolling 624 women across 19 US sites against a 500-woman minimum target.

• Engaged Bio-Techne's CLIA-certified Asuragen laboratory to run clinical validation using more than 1,300 samples, supporting a targeted FDA submission.

Two new provisional patent applications now protect the biomarker combinations behind the ovarian cancer screening test being developed by CLEO Diagnostics (ASX:COV), while its lead blood test moves through final validation steps before an FDA filing. Shares were trading at A$0.320 on 23 October 2026, up 4.92%.

One Biomarker, Three Planned Steps

CLEO's technology centres on CXCL10, a biomarker the company says is produced early and at high levels in ovarian cancer but is largely absent in benign disease. The company cites more than 15 years of research and says ovarian cancer carries the highest five-year mortality rate among cancers affecting women, with 51% of patients dying within five years.

Management has staged its strategy in three steps: a pre-surgical triage test, then recurrence monitoring, then global screening. On 24 September 2026, the company said prototype development of its multi-marker screening test had begun. It cited a global addressable market of $150B for screening asymptomatic women, against a nearer-term pre-surgical triage market of $1.6B.

The first screening study will use a 250-patient cohort enriched for Stage I ovarian cancers. Bridging and confirmation studies in a larger cohort are planned next, followed by evaluation in prospectively collected high-risk and general screening populations. CLEO said it can draw on the UKCTOCS biobank through University College London and on the US PLCO biobank.

Patents Land Before the First Screening Data

On 30 September, CLEO disclosed the two provisional filings, lodged before initial proof-of-concept screening data expected in early Q4 CY2026. The company intends to file a Patent Cooperation Treaty application within the 12-month priority period.

Pivotal Test Works Through Validation

The lead product, the Pre-Surgical Ovarian Cancer Test, is on a separate track. On 31 March 2026, CLEO reported completing sample collection for its pivotal US trial: 514 blood samples from eligible patients met the recruitment target, with 624 women enrolled across 19 sites against a design minimum of 500.

Kit manufacturing with Bio-Techne followed. On 13 July the company said it had finished preparations for analytical validation, with three additional Ella instruments installed at its Melbourne facilities. The validation will test three independently manufactured production batches for reproducibility, consistency and robustness, and is expected to take about four months, subject to Bio-Techne's manufacturing timeline. By 10 September, the first production batch of kits had arrived and was in internal verification before formal validation began.

That same day, CLEO signed a Statement of Work with Asuragen, Bio-Techne's CLIA-certified US laboratory, for clinical validation. The program will generate data from more than 1,300 samples to establish sensitivity, specificity, positive predictive value and negative predictive value. It covers about 600 pivotal-trial samples, about 570 from patients with non-ovarian conditions and about 300 from healthy individuals.

Milestones Management Has Flagged

CLEO is targeting an FDA 510(k) submission in the first half of calendar 2027. Remaining steps include analytical validation, finalising the commercial assay algorithm, clinical validation and trial data analysis. The company expects commercial launch next year.

On the screening side, CLEO is targeting finalisation of its test panel architecture by the end of calendar 2026, with proof-of-concept data due early in the fourth quarter.