NEW YORK – The US Food and Drug Administration issued a letter on Monday alerting clinical labs and healthcare providers about two concerns related to a COVID-19 test from Thermo Fisher Scientific.
In the letter, the agency said that issues with sample processing for the Thermo Fisher Scientific TaqPath COVID-19 Combo Kit as well as with the Applied Biosystems COVID-19 Interpretive Software for the test could potentially produce inaccurate results.
Specifically, investigations of customer complaints have indicated that inadequate vortexing and centrifugation of RT-PCR reaction plates can lead to false-positive results. The firm has now updated the instructions for use to reduce the risk of inaccurate results.
In addition, interpretive software used with the test also needs to be upgraded for the most accurate reporting. The FDA said the issue is related to the assay's internal positive control and "requires laboratory staff to upgrade their software to reduce the risk of invalid, potential false negatives, or inconclusive tests and to decrease the potential need to retest."
In the letter, the FDA recommended that clinical laboratory staff and healthcare providers using the Thermo Fisher Scientific TaqPath COVID-19 Combo Kit promptly implement software updates, stop using Applied Biosystems COVID-19 Interpretive Software versions 1.2, 2.0 and 2.2, and upgrade to versions 1.3 or 2.3.
Customers will need to pass an exam and acknowledge that they reviewed information to upgrade the Applied Biosystems COVID-19 Interpretive Software, and re-registration is needed for the upgrade.
Labs and healthcare providers are also encouraged to read the new IFU, and for all positive results to review the amplification curves within the instrument software for controls and patient specimens to determine whether the plate should be retested due to inadequate vortexing and centrifugation. Users should also implement routine plate level checks of the amplification curves and healthcare providers should consider positive results in combination with clinical observations, patient history, and epidemiological information, FDA said.
The agency also guided that labs and providers notify all users in their facility of the letter and report any issues to Thermo Fisher and the FDA.
Thermo Fisher's test was the second commercial diagnostic assay to be granted Emergency Use Authorization. It received US EUA in March and is also authorized in 50 other countries as of April. The EUA was expanded in May to include additional test instruments, and the firm said recently that it expects strong demand for the test and that it has capacity to manufacture 10 million assays each week.
In a statement, Thermo Fischer said it is working with the FDA to make sure that laboratory personnel understand the need for strict adherence to the instructions for use. "Our goal is that every sample is collected and tested with the high level of accuracy associated with qPCR-based tests, which are the gold standard for molecular diagnostic testing," the firm said.
The company also noted that it strongly encourages labs to participate in the training that it offers, "to make sure all workflow processes are followed," and emphasized that it provides 24-hour support for labs that are processing COVID-19 test kits.