Siemens Healthineers’ real-time PCR molecular assay has one of the lowest limits of detection in a comparison of COVID-19 tests updated this week by FDA.
The test was missing from the list FDA published earlier this year as the agency said data generated using its SARS-CoV-2 reference panel were uninterpretable. Having resolved that issue, FDA put Siemens’ FTD SARS-COV-2 fifth on its list of the most sensitive COVID-19 tests, which are less likely to return false negatives.
The Siemens Healthineers product was joined in the top five by two other new entries from Viracor Eurofins Clinical Diagnostics and Zymo Research Corporation. Viracor is tied for first place with a test from PerkinElmer.
FDA sent a SARS-CoV-2 reference panel to the developers of 176 authorized assays over the summer to generate data on the relative performance of different tests. Prior to that point, most data on tests came from validation studies that used contrived specimens, making it impossible to reliably compare test performance. By September, FDA had enough reference panel data to publish an initial list.
However, the original list was missing results on many tests, for reasons including the failure of the company to send results or the uninterpretable nature of the information they did send. As of late October, the list for tests that analyze swabs in transport media featured 76 entries. The current list has 118 completed entries.
The new additions have reshaped the top of the leaderboard. PerkinElmer remains in the top spot with a LoD of 180 detectable units per mL but is now tied with the Viracor SARS-CoV-2 assay. Siemens Healthineers has joined the list at number five with a LoD of 540.
Zymo, the other new entry to the top five, achieved a LoD of 450. The test is the only entry on the list tagged as using sputum samples. The instructions for use for the test state it is suitable for use with a range of sample types, including sputum, and Zymo puts the turnaround for the test at less than 1.5 hours.
The new entries achieved lower LoDs than tests from some leading names in diagnostics. Tests from BD, Quest Diagnostics and Roche had LoDs of 1,800. The LoD for the Abbott RealTime SARS-CoV-2 assay was 2,700.
Some big names appear toward the bottom of the list. Thermo Fisher Scientific’s TaqPath COVID-19 Combo Kit achieved a LoD of 180,000.
FDA publishes separate lists for tests that analyze dry swabs or saliva. The most notable change to those lists is the arrival of Quadrant Biosciences’ Clarifi COVID-19 Test Kit at the top of the saliva list. With a LoD of 600, Quadrant’s test is more sensitive than all but five of the assays that analyze swabs in transport media.
The composition of the lists could still change. FDA, working with manufacturers, has filled in some of the gaps on the original list but there are still tens of entries missing. The agency is still reviewing data on Abbott’s Alinity m SARS-CoV-2 assay and LabCorp’s COVID-19 RT-PCR Test. Verily Life Sciences appears yet to provide FDA with data.