Barts patient data demonstrates potential of Parsortix for prostate cancer detection clinical application
ANGLE plc, the specialist medtech company, is delighted to announce that the results of Barts Cancer Institute’s ongoing work with ANGLE’s Parsortix system have provided evidence in support of the use of Parsortix in the detection and assessment of prostate cancer.
Barts patient data suggests that the Parsortix system may be used both to detect prostate cancer and to assess its aggressiveness, all through a simple blood test. This is crucial because it means that men with low level disease could avoid unnecessary and potentially harmful solid biopsy and surgical intervention instead having “active surveillance”, whereas men with an aggressive form of disease could be fast-tracked for further investigation and treatment. The current gold standard for detection is the prostate-specific antigen (PSA) blood test, which is known to have low sensitivity and low specificity (i.e. high levels of false positives) and the digital rectal exam (DRE – which is less effective than the PSA test). Where the PSA level is high or the DRE indicates an enlarged prostate, a solid prostate biopsy will be undertaken to detect cancer and assess the aggressiveness of the disease. This process results in many men having invasive biopsies unnecessarily.
Prostate cancer is the second most common cancer in men and the fourth most common overall. More than 1.1 million new cases of prostate cancer were recorded in 2012, accounting for around 8 per cent of all new cancer cases and 15 per cent in men with an estimated 3.9 million men living with the disease (Source: World Cancer Research Fund International) and as the risk increases with age and men are living longer these numbers are increasing. There is a far larger population of men with a variety of symptoms that require investigation for the possibility of prostate cancer but do not have the disease. Currently these men are frequently subjected to solid prostate biopsy, which, even if it is negative for cancer (which is the case in 75% or more of solid biopsies), is painful, may miss the cancer and can cause infection. A simple blood test to assess whether this procedure is necessary would improve patient care as well as reduce healthcare costs.
Barts Cancer Institute (BCI), Queen Mary University of London presented a poster on 19 March 2016 at the 10th ISMRC International Symposium on Minimal Residual Cancer: Liquid Biopsy in Cancer Diagnostics and Treatment in Hamburg.
Key conclusions from the BCI work include the following:
- The Parsortix system detected circulating tumour cells (CTCs) in 100% of the metastatic prostate cancer patients.
- The patients with localised disease included patients with early stage disease (determined by clinical investigation including the Gleason score of solid tissues taken through invasive procedures), where the decision had been taken that “active surveillance” was appropriate rather than medical intervention. Even for these earliest stage, indolent cancer patients, the Parsortix system harvested CTCs that could be detected in 75% of these patients.
- The Gleason score is currently the best parameter for assessing aggressiveness of prostate cancer involving pathologist assessment of the morphology of the cells obtained from the solid biopsy. The number of mesenchymal CTCs harvested by the Parsortix system was compared to the Gleason score for each of the patients and there was found to be a good correlation suggesting that Parsortix liquid biopsy may be able to provide the same or similar information as the invasive solid biopsy in assessing the aggressiveness of the cancer.
- The status of the patient – metastatic or localised – was analysed against the number of mesenchymal CTCs harvested by the Parsortix system. Separately the status of the patient – metastatic or localised – was analysed against the patient’s Gleason score. Comparison of the results suggests that the Parsortix system may be able to indicate the metastatic or localised status of the patient with a higher level of accuracy than the Gleason score.
ANGLE now intends to work with BCI and other leading cancer centres to develop and implement clinical studies to validate the use of the Parsortix system as a clinical application in the routine detection, assessment and treatment of prostate cancer patients. The multi-centre clinical studies need to be specified but would be expected to take at least 18 months to complete.
Around 75% to 80% of men that have a solid prostate biopsy do not have prostate cancer and of those that do have prostate cancer more than half will be indolent (latent disease not causing harm to the patient). Less than 10% of patients having a solid prostate biopsy have aggressive prostate cancer requiring treatment. Assuming the clinical studies confirm the recent patient study results then ANGLE will be able to make clinical sales of the Parsortix system as a non-invasive liquid biopsy alternative to the solid prostate biopsy. Use of the Parsortix system would avoid the medical complications of the solid prostate biopsy, provide more reliable results in relation to detection of prostate cancer, disease status and risk stratification, at the same time, reduce healthcare costs and offer a faster, repeatable solution enabling active surveillance where appropriate.
Dr Yong-Jie Lu, Reader in Medical Oncology at Barts Cancer Institute, commented: “The Parsortix system enables investigation of the mesenchymal CTCs in the patient blood and the results of our work to date suggests this has the potential to become a non-invasive liquid biopsy for prostate cancer. The exciting part of this research is the potential for the Parsortix system to be used to assess the severity of the disease as well as to detect it. This meets a key medical need to avoid over-treatment as well as to ensure treatment is available for patients who need it.”
ANGLE Founder and Chief Executive, Andrew Newland, commented: “These are highly encouraging results for the use of the Parsortix system for a clinical application in prostate cancer. This opens the potential of another highly differentiated liquid biopsy application for Parsortix in a key area of medical need, which cannot be addressed by ctDNA or antibody-based CTC systems, where there is the potential to improve patient care and at the same time reduce healthcare costs.”