Quanterix PSA Test Found to be a Reliable Predictor of Prostate Cancer Recurrence Following Surgery

British Journal of Urology Publishes Multicenter Study Results

CAMBRIDGE, MA – October 13, 2011 – Quanterix Corporation, a company enabling a new generation of molecular diagnostic tests based on its revolutionary Single Molecule Array (SiMoA™) technology, today announced results from a clinical evaluation of its Prostate Specific Antigen (PSA) test, a fifth–generation digital immunoassay, demonstrating that the assay is a reliable predictor of five–year biochemical recurrence (BCR)–free survival following radical prostatectomy (RP). The pilot study was published online by the British Journal of Urology International.

"These results have important implications for the way prostatectomy patients will be managed in the future," states Dr. Herbert Lepor, prostate cancer expert and Chairman of the Department of Urology at NYU School of Medicine. "Not only will physicians be able to reassure patients who are at low risk of recurrence following radical prostatectomy, but the identification of a reliable predictor of recurrence soon after surgery has important implications for the frequency of PSA testing and selection of candidates for adjuvant therapy. In addition to providing patients with peace of mind, implementation of this test could lead to a reduction in healthcare costs."

To determine the ability of this test to predict five–year BCR–free survival following RP, researchers utilized frozen serum specimens, provided by NYU Langone Medical Center and the Johns Hopkins University School of Medicine, from men who had undergone RP and who had no evidence of BCR using conventional PSA measurement methods. The Quanterix single molecule PSA assay, which has an analytical sensitivity 1000– fold lower than conventional ultrasensitive PSA assays, was capable of accurately measuring PSA levels in all men following surgery. Researchers found that the PSA nadir value (lowest level of PSA following RP) was a significant predictor of BCR. A Kaplan Meir analysis demonstrated that 100% of men with low PSA nadir values did not develop BCR, whereas 63% of men with higher PSA values eventually recurred. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the SiMoA PSA test was 100%, 75%, 69% and 100% respectively.

"We are encouraged by these results, which further supports the value of our SiMoA platform," said Martin Madaus, Ph.D., Executive Chairman of Quanterix. "We are actively validating assays important in oncology and several other applications while working towards our goal of automating the SiMoA system to offer a menu of assays to the life sciences and in vitro diagnostics markets."

Data from this pilot study was also presented at the American Association of Clinical Chemistry in July and focused on the analytical performance of the PSA test, which demonstrated improved sensitivity over current PSA assays.

About Quanterix

Quanterix Corporation is developing its proprietary Single Molecule Array (SiMoA™) technology for the in vitro diagnostics and life science research markets. The digital nature of SiMoA yields unprecedented assay performance, stemming from a 1,000–fold improvement in sensitivity compared with today’s analog only technology. SiMoA will enable researchers in life science to validate novel, low abundance biomolecules from a single droplet of blood, leading to greater insight into disease detection, diagnosis, therapy selection and disease monitoring. Automated systems based on SiMoA will provide diagnostic test information to healthcare practitioners faster, with greater reliability, unprecedented range and increased cost effectiveness. Founded in 2007, the privately held Cambridge, Massachusetts–based company is backed by leading life science investors including ARCH Venture Partners, Bain Capital Ventures, and Flagship Ventures. For additional information, please visit www.quanterix.com.