The FDA granted its first emergency authorization for a CRISPR-based test for COVID-19, developed by Sherlock Biosciences, designed to turn results around in about an hour compared to the four to six hours needed for other molecular diagnostics.
The test is based on the company’s namesake technology, SHERLOCK, short for Specific High-sensitivity Enzymatic Reporter unLOCKing, a Cas13a-based CRISPR system that targets RNA rather than DNA. It looks for an RNA sequence specific to SARS-CoV-2, the virus that causes COVID-19, in patient samples taken from the upper airways with a swab or from airways in the lungs known as bronchoalveolar washing.
“If it’s there, it attaches to the Cas13 enzyme and activates it, which leads to the chewing up and cleaving of RNA probes,” Sherlock CEO Rahul Dhanda told FierceMedTech. When cleaved, those RNA molecules release a fluorescent signal to show the virus is present.
Sherlock did more than 2,000 tests in preparation for its FDA submission, finding it had 100% specificity and sensitivity in its clinical data, Dhanda said, meaning that it turned up no false positives or false negatives.
The Sherlock CRISPR SARS-CoV-2 kit is designed to test many samples in a high-volume hospital lab, but the company is working with potential partners to make it adaptable to a point-of-care system, Dhanda said. It’s also working on its own point-of-care efforts using its synthetic biology platform, INSPECTR, or Internal Splint-Pairing Expression Cassette Translation Reaction.
That said, the company hopes the newly OK’d test will ease the bottleneck faced by testing labs around the country.
“We launched to alleviate that issue. We felt by giving everybody a different kind of test that had a different kind of process would supplement the testing they are doing now,” Dhanda said.
Sherlock is working to ramp up production of the test kit and will unveil distribution plans in the coming weeks.
“We are incredibly fortunate in that we’re working out details with a very large-scale manufacturer in terms of what their capacity will be. We have a well-vetted and trusted group that has scaled molecular diagnostics to very large volumes,” Dhanda said. “We’re confident that we’ll have tens of thousands of tests available as soon as we launch.”
And if the healthcare system needs more?
“They are the team that can scale it.”