OPKO Health, Inc. (NYSE:OPK) announced the successful completion of the calibration confirmation phase of the 4Kscore™ test clinical validation study currently underway at 21 urology clinics in the United States. The OPKO 4Kscore™ test clinical validation protocol involves two parts: a calibration confirmation phase and a validation phase. The calibration confirmation phase evaluated the applicability of the 4Kscore™ algorithm, developed using banked samples from European studies, to the OPKO study samples collected in the United States and shipped directly to OPKO Lab in Nashville, TN for testing. The results confirmed the validity of the algorithm. The study is now more than 50% complete toward the final goal of 1,200 subjects. These results support the U.S. launch of the 4Kscore™ test in March 2014. “We are extremely pleased that results of the calibration phase confirmed the 4Kscore™ algorithm is an accurate predictor of prostate cancer, and especially aggressive disease,” said David Okrongly, President of OPKO Diagnostics. “The reproducibility of the algorithm speaks to the robustness of the biomarkers used in the 4Kscore™ algorithm, as well as the quality of the multiple clinical studies published in peer-reviewed journals.” “These results reinforce our belief that the 4Kscore™ test will be an important addition to the urologists’ means of assessing a patient’s risk for aggressive prostate cancer as well as an important new diagnostic product for OPKO,” said Phillip Frost, M.D., OPKO's Chairman and Chief Executive Officer. About the 4Kscore™ Test The 4Kscore™ is a convenient blood test that measures the serum levels of four different prostate-derived kallikrein proteins: total PSA, free PSA, intact PSA and hK2. Levels of these biomarkers are combined with a patient's age and digital rectal exam (DRE) status using a proprietary algorithm to calculate the probability of a finding of aggressive prostate cancer. The 4Kscore™ test is based on over a decade of research of the four kallikrein panel of biomarkers conducted by scientists at Memorial Sloan Kettering Cancer Center and leading research centers in Europe on over 10,000 patients. The information provided by the 4Kscore™ test can help facilitate the shared decision-making process between urologist and patient in determining the advisability of a prostate biopsy.