FDA approves OPKO's point-of-care PSA test
OPKO Diagnostics has received premarket approval for a prostate-specific antigen (PSA) test that delivers results at the point of care.
The microfluidic-based finger prick immunoassay provides quantitative PSA results within 15 minutes, eliminating the need to send samples to laboratories for analysis.
OPKO won the approval on the strength of data from a 434-patient clinical trial that found performing the test in combination with a digital rectal examination (DRE) improved cancer detection.
The importance of early detection of prostate tumors has spurred interest in PSA, despite the fact that high levels of the protein are associated with multiple other non-cancerous conditions. That interest has established PSA tests as part of the toolkit physicians use to identify patients who may have prostate cancer. The test is performed in combination with a DRE.
Testing PSA levels typically entails taking a venous blood sample and sending it to a laboratory. OPKO developed the Sangia Total PSA Test to accelerate the process by cutting out the laboratory, enabling physicians to learn a patient’s PSA level at the point of care.
To get the test to market, OPKO enrolled 434 men aged 50 or older who were scheduled to undergo a prostate biopsy. OPKO administered the test to the participants and compared their PSA levels to the results of DREs and the biopsy.
The clinical trial found the test has a high false positive rate, reflecting the fact that high PSA levels are associated with many non-cancerous conditions such as inflammation of the prostate. Despite that, the 85% sensitivity of the test means it may still have value. OPKO calculated using the test with DRE resulted in the detection of three times as many cancers as the rectal examination alone.
Other data reviewed by FDA include the results of preclinical studies showing the test records PSA levels from 0.08 ng/mL to 15 ng/mL. As finger stick tests are performed routinely, FDA deemed the test to be safe, resulting in OPKO having an overall dataset strong enough to win approval.
The approval positions OPKO to find out whether there is a market for its test. Over the past decade organizations have questioned the value of PSA screening when lab services are available. To gain share, OPKO will need to persuade people of the need for rapid PSA results at the point of care.