A New Way to Test for Sexually Transmitted Infections

By Jane Farrell

The federal Food and Drug Administration (FDA) has cleared for marketing two tests to detect the sexually transmitted infections chlamydia and gonorrhea, through diagnostic testing of extragenital specimens. The Aptima Combo 2 Assay and the Xpert CT/NG are the first devices cleared for extragenital diagnostic testing of these infections via the throat and rectum, the FDA said. These tests were previously cleared only for testing urine, vaginal and endocervical samples.

“Prior to today, there were no chlamydia or gonorrhea tests cleared for use on samples from the throat and rectum. The availability of these two tests will fill an unmet public health need, by allowing for more screening,” said Tim Stenzel, M.D., Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health. “It is best for patients if both of these sexually transmitted infections are caught and treated right away, as significant complications can occur if left untreated. Today’s clearances provide a mechanism for more easily diagnosing these infections.”

According to the Centers for Disease Control and Prevention’s Sexually Transmitted Infections Surveillance Report, the rate of sexually transmitted infections is steadily increasing, with an estimated 1.7 million cases of chlamydia and more than 500,000 cases of gonorrhea in the U.S. in 2017 alone. Both infections can be contracted through vaginal, anal or oral intercourse. Typically, both infections can be easily treated, but if left untreated, both infections can cause serious complications for patients, including infertility.

The Aptima Combo 2 Assay and Xpert CT/NG were reviewed through the premarket notification (510(k)) pathway, the FDA said. A 510(k) is a premarket submission made to the FDA to demonstrate that the device to be marketed is at least as safe and effective, that is, substantially equivalent, to a legally marketed device.

In its evaluation of the devices, the FDA reviewed clinical data collected through a cross-sectional study coordinated by the Antibacterial Resistance Leadership Group, which is funded and supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH).

This study was a collaborative, multi-site clinical study of more than 2,500 patients that evaluated the diagnostic accuracy of multiple commercially available nucleic acid amplification tests for detection of Neisseria gonorrhoeae and Chlamydia trachomatis from throat and rectal sites. The results of this study, along with other information reviewed by the FDA, demonstrated that the Aptima Combo 2 Assay and the Xpert CT/NG for extragenital specimens are safe and effective for extragenital testing for chlamydia and gonorrhea.

The FDA granted clearance of Aptima Combo 2 Assay to Hologic, Inc., and clearance of the Xpert CT/NG to Cepheid.