FDA Watch: Agency Grants Emergency Clearance for CDC Novel Coronavirus Detection Test

Because the 2019 novel coronavirus outbreak was so unanticipated, there were no FDA-approved commercial products for it available in the US during its early days. On Jan. 28, the FDA unveiled its strategy for promoting the rapid development and availability of safe and effective investigational medical products “to address this urgent public health situation.” As with previous infectious disease outbreaks like Zika, the centerpiece of the FDA strategy is expedited clearance of new coronavirus tests and treatment products via the Emergency Use Authorization (EUA) pathway. The FDA called on diagnostic test sponsors interested in potential EUA for detection tests to contact the Center for Devices and Radiological Health (CDRH) (CDRH-EUA-Templates@fda.hhs.gov) for information and templates.

The CDC Test

On Feb. 4, the agency took the first step by issuing an EUA for a reverse transcriptase real-time PCR (rRT-PCR) assay (aka, the 2019 Real Time RT-PCR Diagnostic Test Panel) developed by the US Centers for Disease Control and Prevention (CDC) for use in detecting coronavirus from respiratory and blood serum samples, including nasal or oral swabs. The test can be used in the US only by CDC-designated laboratories that are certified to perform high-complexity testing in accordance with agency protocol. The CDC published the test formula and created kits using the assay for distribution to state health departments and public health laboratories around the country.

Nancy Messonnier, director of the CDC National Center for Immunization and Respiratory Diseases, says that the agency deems the rapid development and distribution of the test a success. But while the agency has shipped the kits to all 50 US states (and 30 international sites), the kits may not be used unless and until they undergo quality assessment and validation by the public health laboratories of the particular state. “When a state gets the test kit, they have to verify that it works the same in their laboratory as it worked at CDC,” Messonnier explained during a press conference. And, of course, some states will complete that process faster than others.

Already, the limitations of the CDC assay have become evident. Thus, while a positive result is a fairly reliable indicator of coronavirus infection, the early feedback suggests that a negative result cannot be counted on to rule it out. Accordingly, the FDA has warned against relying on negative tests as the lone basis for treatment and patient management decisions. Negative results must also be evaluated along with clinical observations, patient history and epidemiological information, the agency stresses. Meanwhile, the CDC acknowledged that it will probably need to remanufacture one of the kit reagents to address the test quality results issues.

Takeaway

While it has obvious flaws that need to be worked out, the CDC (rRT-PCR) assay is the only approved test for coronavirus currently available in the US, one designed as a stopgap measure to hold down the fort until the private sector develops better alternatives.

Key new product approvals announced from late-January through mid-February 2020:

NEW FDA APPROVALS