Expert: Ralph Schiess (Proteomedix)
What if a smart blood test could transform the lives of millions of men worldwide? Swiss company Proteomedix is turning precisely this vision into a reality – with the aim of detecting cancer earlier, reducing patient suffering and delivering clearer diagnoses.
Prostate cancer affects approximately one in ten men across Western industrialised nations. Accounting for over 30 percent of all cancer diagnoses, it ranks not only as the most common cancer in men, but also as the most prevalent type of cancer overall. An individual’s disease risk depends on their genetic predisposition and age, among other things. The insidious nature of prostate cancer lies in its early silent progression. Symptoms rarely manifest until advanced stages, often resulting in delayed diagnosis.
Prostate-specific antigen (PSA) is a crucial early warning system. This tissue marker is already detectable in the blood during the early stages of the disease. Consequently, PSA screening has become routine for men over 50. Elevated levels trigger suspicion of cancer, yet this presents a diagnostic dilemma: elevated PSA indicates actual prostate cancer in very few cases. Multiple factors influence PSA levels in addition to malignancy. Age-related prostate enlargement, inflammatory conditions, medications, physical activity and even sexual activity can artificially elevate PSA readings. Additionally, PSA fluctuates daily, making single measurements challenging to interpret. Despite these limitations, elevated PSA typically prompts additional magnetic resonance imaging (MRI) or a invasive prostate biopsy to establish diagnostic certainty.
Prostate biopsy procedures are a source of significant stress for patients, and also carry inherent risks, including infections, bleeding and discomfort. Reducing unnecessary biopsies both benefits patient wellbeing and cuts healthcare costs.
Proteomedix, a Swiss company established in 2010 as a spin-off from ETH Zurich, tackled this challenge head-on and developed Proclarix® – a non-invasive diagnostic test offering risk assessment through simple blood sampling. CEO Ralph Schiess explains the purpose of the innovation: “Our test empower both medical professionals and patients to make informed decisions about whether biopsy procedures are genuinely necessary.”
How does this diagnostic breakthrough work? The answer lies in comprehensive data integration. Like traditional approaches, the Proclarix test takes into account PSA readings. But it also analyses the concentration of specific blood-based biomarkers that specifically indicate the presence of a tumour. A sophisticated bioinformatics algorithm synthesises all the relevant clinical and diagnostic information and uses it to generate a personalised risk score reflecting each individual’s risk of developing cancer. The detailed explanation is more complex, as the underlying science draws on insights from proteomics (the study of protein populations within biological samples or living organisms. Central to this approach is the phosphoinositide 3-kinase signalling pathway, which enables cellular communication from cell surface receptors to the cell interior and into the nucleus through numerous intermediate steps. This pathway also plays an important role in regulating cell growth, division and survival. If chronically hyperactive, it duels excessive cancer cell proliferation – including in prostate malignancies. The two key enzymes – thrombospondin 1 and cathepsin D – influence this phosphoinositide 3-kinase signalling pathway.
The Proclarix blood test measures concentrations of the biomarkers thrombospondin 1 and cathepsin D in addition to PSA, combining the findings with patient age data. Afterwards, a patented algorithm converts these inputs into the risk score. The results speak volumes. The test detects prostate cancer with exceptional accuracy, while also reducing the number of (unnecessary) biopsies by 43 per cent. Negative tests also offer a high level of assurance that prostate cancer is absent despite elevated PSA readings. This diagnostic certainty relieves both the physical and mental burden on patients. Ralph Schiess is enthusiastic when thinking about the new possibilities: “Knowing that a simple blood test can reduce the need for invasive biopsies for large numbers of healthy men – sparing them unnecessary stress and medical risks – serves as both motivation and inspiration for our ongoing work.”
As of today, Proclarix is approved in the European Union, Switzerland and the United Kingdom. Since 2020, the test has been available in various European countries such as Germany, the UK, Italy and Switzerland, and is being used in pilot applications. However, it is not yet reimbursed by health insurance companies, making widespread use difficult. Proclarix has been incorporated into the guidelines of the European Association of Urology and the American Urological Association since 2023. This is a significant step towards reimbursement by health insurers and market approval in the USA.
Proteomedix has set itself the goal of further developing both the Proclarix test and the risk score. Imaging procedures such as MRI are to be integrated with it to make the approach even more multimodal. All of this is being done with the vision of making the test even more powerful and meaningful and revolutionising prostate cancer diagnostics.
The development of Proclarix thrives on collaboration between researchers from the fields of biotechnology, biostatistics, medicine, and product and quality management. Ralph Schiess firmly believes that “bridges must be built and collaborative partnerships pursued”. Partnerships are expected to be a superb support in the search for additional biomarkers and subsequently integrating them into diagnostic tests. Combined with AI-supported analysis, this results in new and effective tools for creating individual risk profiles – not only for prostate cancer, but for other types of cancer too. Proclarix could be at the very start of a paradigm shift in cancer diagnostics, and thus also in cancer treatment.
