CINCINNATI, May 13, 2026 — Onconetix, Inc. (Nasdaq: ONCO) (“Onconetix” or the “Company”), together with its subsidiary Proteomedix, focused on the research, development and commercialization of innovative solutions for men’s health and oncology, today announced the publication of two peer-reviewed studies evaluating the clinical performance of Proclarix®, its CE-certified blood-based prostate cancer test.
The publications provide new clinical evidence supporting the use of Proclarix in two important areas of prostate cancer diagnosis: improving risk stratification before biopsy in men with suspected prostate cancer and identifying patients under active surveillance who are at increased risk of disease progression.
The first publication, titled “Proclarix’ performance in ruling out patients with no or indolent prostate cancer: evaluation in a Danish population,” evaluated Proclarix in a Danish cohort using retrospective serum samples collected consecutively from patients with suspected prostate cancer. In the targeted population of 373 men with PSA levels between 2–10 ng/mL and a prostate volume of at least 35 mL, a negative Proclarix test reduced the probability of clinically significant prostate cancer from 27% before testing to 5% after testing, outperforming percentage of free PSA (%fPSA, 14%) and the European Randomized Study of Screening for Prostate Cancer Risk Calculator (ERSPC-RC, 20%). Proclarix demonstrated 97% sensitivity, 95% negative predictive value and significantly greater specificity than %fPSA and ERSPC-RC.
In the extended population of 656 men with PSA levels between 2–20 ng/mL regardless of both prostate volume and DRE, Proclarix density also demonstrated in this broader and less selected population significantly (p<0.01) greater specificity of 39% than PSA density (32%) at equal sensitivity (90%).
The study concluded for both studied populations that Proclarix reduces prostate biopsies and the detection of clinically insignificant prostate cancer while maintaining a low risk of missing clinically significant disease.
The second publication, titled “The Prognostic Value of Proclarix in Prostate Cancer Patients Under Active Surveillance: Predicting Transition to Active Treatment and Disease Progression in a Danish Cohort,” investigated the prognostic value of the Proclarix Risk Score in men undergoing active surveillance for low- to intermediate-risk prostate cancer. The study retrospectively evaluated baseline serum samples from 132 men recruited from the Danish PerPros prostate biobank.
At five-year follow-up, 82% of men with a baseline Proclarix Risk Score of at least 50% had transitioned from active surveillance to active management, compared with 28% of men with a risk score below 50%. In addition, 67% of men with a risk score of at least 50% showed progression to clinically significant prostate cancer at confirmatory biopsy. The publication concluded that the Proclarix Risk Score may support clinical decision-making in active surveillance by identifying patients at higher risk of progression and informing follow-up intensity. The authors noted that the findings should be confirmed in a larger prospective study.
“These two peer-reviewed publications provide important additional evidence for the broad clinical utility of Proclarix to identify wrongly positive healthy men and to early identify clinically significant prostate cancer,” stated Beat Rheiner, PhD, CEO of Proteomedix. “The use of Proclarix reduced unnecessary follow-on treatments including biopsies and showed a low risk of missing clinically significant prostate cancers. The Proclarix Risk Score, that already previously has shown to correlate with tumor aggressiveness, showed its potential as a tool to guide clinical decision making and support more personalized monitoring strategies for patients after diagnosis.”
“The findings from these Danish cohorts suggest that Proclarix may provide clinically meaningful information for both biopsy decision-making and active surveillance management,” stated A.H. Zedan, MD, PhD, principal investigator. “In the pre-biopsy setting, Proclarix helped identify men at lower risk of clinically significant prostate cancer, while in active surveillance, the Proclarix Risk Score was associated with a higher likelihood of progression to active management. These results support the potential role of Proclarix in more personalized prostate cancer care.”
About the Publications
Publication 1
Title: Proclarix’ performance in ruling out patients with no or indolent prostate cancer: evaluation in a Danish population
Journal: BMC Cancer
Authors: Schiess R, Athanasiou A, Kasten MME, Hansen TF, Kissow GE, Obro LF, Madsen JS, Poulsen MH, Osther PJ, Zedan AH
Publication Date: May 9, 2026
DOI: 10.1186/s12885-026-16118-8
Study Population: 656 men in the extended population, including 373 men in the targeted population
Key Finding: Proclarix testing reduced the probability of clinically significant prostate cancer from 27% to 5% after a negative test in the targeted population, with 97% sensitivity and 95% negative predictive value.
Publication 2
Title: The Prognostic Value of Proclarix in Prostate Cancer Patients Under Active Surveillance: Predicting Transition to Active Treatment and Disease Progression in a Danish Cohort
Journal: Cancers
Authors: Athanasiou A, Hansen TF, Madsen JS, Poulsen MH, Mortensen MA, Kissow GE, Øbro LF, Osther PJ, Schiess R, Zedan AH
Publication Date: April 23, 2026
DOI: 10.3390/cancers18091348
Study Population: 132 men undergoing active surveillance from the Danish PerPros prostate biobank
Key Finding: At five-year follow-up, 82% of men with a baseline Proclarix Risk Score of at least 50% transitioned from active surveillance to active management, supporting the potential prognostic value of the Proclarix Risk Score.
About Proclarix®
Proclarix® is marketed by the Switzerland-based Proteomedix AG. It is CE-certified under the In Vitro Diagnostic Regulation (“IVDR”) and indicated for early prostate cancer diagnosis in patients with normal digital rectal exam (DRE), enlarged prostate volume and elevated levels of PSA at 2-10 ng/ml. The result of Proclarix® is a risk score combining in-vitro assays for the quantitative detection of relevant tumor biomarkers with a proprietary algorithm to assess a patient’s risk of having clinically significant prostate cancer. Detection of prostate cancer-related biomarkers in blood serum using the Proclarix® risk score has been demonstrated in multiple clinical studies to be a reliable indicator of the presence of clinically significant prostate cancer. Proclarix® is recommended by both the European (EAU) and American (AUA) guidelines.
About Onconetix, Inc.
Onconetix, Inc. (Nasdaq: ONCO) is a commercial-stage biotechnology company focused on the research, development, and commercialization of innovative oncology solutions. Onconetix owns Proclarix®, an in vitro diagnostic test for prostate cancer originally developed by Proteomedix and approved for sale in the European Union under the IVDR, which it anticipates will be marketed in the U.S. as a lab developed test through its license agreement with Labcorp. For more information, visit www.onconetix.com.
About Proteomedix AG
Proteomedix AG (PMX) is a fully owned Swiss subsidiary of Onconetix, Inc. focused on the development and commercialization of innovative diagnostic solutions for prostate cancer. PMX developed Proclarix®, a CE-IVD certified diagnostic blood test that, when used in combination with PSA, supports the early identification of clinically significant prostate cancer. PMX is headquartered in Switzerland. For more information, visit www.proteomedix.com.
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