FDA reviewers said Friday the OraQuick In-Home HIV test could play a significant role in slowing the spread of HIV, according to briefing documents posted online. They also raised concerns about the accuracy of the test, a mouth swab that returns results in about 20 minutes.
The review comes one day after an FDA advisory panel endorsed the HIV pill Truvada for preventive use. If FDA follows the group's advice, the daily medication would become the first drug approved to prevent healthy people from becoming infected with the virus that causes AIDS.
Public health experts estimate one-fifth, or about 240,000 people, of the 1.2 million HIV carriers in the U.S. are not aware they are infected. Testing is one of the chief means of slowing new infections, which have held steady at about 50,000 per year for two decades.
In a trial conducted by the company OraSure Technologies Inc., the test correctly detected HIV in those carrying the virus 93 per cent of the time. That rate is below the FDA-recommended 95 per cent threshold for accuracy.
The FDA estimates the test would miss about 3,800 HIV-positive people per year, if approved for U.S. consumers.
The test was more accurate at correctly clearing patients who do not have the disease. In company studies, OraQuick correctly identified HIV-negative users 99 per cent of the time.
In their briefing documents, FDA scientists noted both the benefits and risks of expanding HIV testing with the take-home diagnostic kit.
"There is considerable personal and public health value in informing infected, but otherwise untested, persons of their true positive HIV status," the reviewers state. "However, this benefit is offset in some measure by HIV-positive individuals who receive an incorrect message that they are not infected."
The lukewarm endorsement apparently spooked investors. OraSure's stock tumbled $1.47, or 13 per cent, to $9.70 in the hours after the review was posted.
On Tuesday, the FDA will ask a panel of outside experts whether the test should be approved for over-the-counter sales in the United States. The agency is not required to follow the group's advice, although it usually does.
Based in Bethlehem, Pennsylvania, OraSure has marketed a version of OraQuick to doctors, nurses and other health care practitioners since 2004. The test sells for $17.50, though OraSure declined to discuss how it would price the consumer version. When used by professionals, the test is shown to identify both carriers and non-carriers accurately 99 per cent of the time.