NEW YORK – Swiss diagnostics firm ProteoMedix is looking to establish itself in the prostate cancer screening space with the launch of its first test, a protein biomarker-based assay for predicting risk of cancer in men with elevated levels of prostate specific antigen.
Called Proclarix, the test measures the levels of the proteins thrombospondin-1 and cathepsin D along with free and total PSA and combines those measures with patient age to assess whether a person is at risk of clinically significant prostate cancer.
The company launched the test last week as a CE-IVD marked assay and is selling it as a self-pay test while it works through the process of securing reimbursement in the various countries where it is offered, said ProteoMedix CEO Helge Lubenow.
ProteoMedix is also raising new funding to support commercialization of the test and is targeting between CHF 10 million and CHF 15 million ($10.4 million to $15.7 million).
Lubenow said that while the company considers general practitioners and urologists to be its primary market ultimately, it plans to focus its initial commercialization efforts toward large specialist groups and centers, which, as a small firm, it can target most efficiently.
She added that ProteoMedix is rolling out Proclarix with an emphasis on Switzerland, Austria, Germany, and Denmark, where it ran clinical validation studies for the test, as well as countries like Spain and Italy that she said have a history of early adoption of self-pay tests. The test is available throughout the entire area where CE-IVD regulations apply.
Lubenow said that the market for PSA reflex tests is fairly open at the moment. In the US, Opko Health's 4kscore is perhaps the most prominent assay addressing the space Proclarix is targeting, but she noted that while the 4Kscore is available in Europe it has limited penetration.
She said that this was due to a combination of aggressive pricing and the fact that the Opko test is available only as a laboratory-developed test.
"The assay is available in Europe, but the samples must be sent to the US and then the test is performed at the Opko [CLIA] lab," she said. "It is a service offering out of a single CLIA lab with all the associated logistical issues."
Lubenow said that in Europe currently, percent free PSA is the only marker that is commonly used as a reflex marker following an elevated PSA score.
"Penetration of [free PSA] is very high," she said. "You could safely assume that a patient with a history of elevated PSA gets retested for percentage of free PSA. That is the standard in Europe. All the other tests have only minimal penetration."
In addition to counting on the CE-IVD mark helping drive test penetration by allowing ProteoMedix to sell Proclarix as a kit-based assay, the company expects to compete on price. Lubenow said that EU regulations prevented the company from disclosing the price but said that in comparison to tests like 4kscore the price of Proclarix "is going to be very attractive."
The company has had a paper detailing a retrospective clinical validation of the test accepted for publication in the British Journal of Urology and expects it to appear in the relatively near future. In that study, ProteoMedix researchers along with collaborators at several medical centers throughout Europe looked at the test's performance in biobanked blood samples from 955 men with a PSA score of between 2 and 10 ng/ml, prostate volume of greater than or equal to 35 ml, and a normal digital rectal exam. All men went on to receive a biopsy which was used to make a definitive diagnosis as to whether or not they had clinically significant prostate cancer.
At 90 percent sensitivity, the test was 43 percent specific for clinically significant prostate cancer compared to 17 percent specificity for free PSA alone. In the study population, that provided for a negative predictive value of 95 percent and a positive predictive value of 25 percent, compared to an NPV and PPV of 89 percent and 19 percent, respectively, for free PSA. At that level of performance, the test would allow doctors to reduce unnecessary biopsies by 37 percent, compared to 16 percent for free PSA.
By way of comparison, a 2015 study in European Urology found that the 4kscore could reduce unnecessary prostate biopsies by around 32 percent.
In addition to working to drive sales of Proclarix, ProteoMedix has started the process of securing reimbursement for the test in various European countries. The exact requirements vary by country but generally speaking it is necessary to publish clinical validation data in a peer-reviewed journal as well as secure inclusion in professional guidelines and then submit the test to the relevant country-specific authorities.
"It is extremely hard to achieve this in less than a couple of years," Lubenow said, noting that the company projects it will first see reimbursement from some countries in 2022.
ProteoMedix is also laying the groundwork for a US launch, she said. "We have started to liaise with a number of clinical contacts. Likely our first step will be to engage in a local clinical study. Specifically, we would like to expand our datasets in terms of the ethnic diversity we will have looked at in our validations."
Lubenow said the company planned to take the test through the US Food and Drug Administration but that it might initially offer it as an LDT.
Additionally, ProteoMedix is working to build on the Proclarix test, exploring its use in combination with other clinical data and technologies like multi-parametric magnetic resonance imaging (mpMRI). At the ASCO Genitourinary Cancers Symposium last month, the company and its collaborators presented a poster demonstrating that the test could reduce the number of men with elevated PSA undergoing unnecessary mpMRIs and reduce the number of men with indeterminate mpMRI findings who are then biopsied.
"We're not talking about just the individual value of Proclarix here, but about Proclarix in conjunction with elevated PSA and MRI and defining a new gold standard for the diagnostic patient journey," Lubenow said. "This is really about integrating the information that eventually leads to a diagnosis, and there may be elements that ProteoMedix develops, but there may also be elements from different sources."