NEW YORK – Sherlock Biosciences and Binx Health said on Wednesday that they have entered into a strategic partnership to develop what will likely be the first CRISPR-based rapid, point-of-care diagnostic test for COVID-19.
The companies plan to combine the Binx io diagnostic platform with SHERLOCK (Specific High-sensitivity Enzymatic Reporter unLOCKing) CRISPR technology to create a test that's designed to provide rapid and accurate results in a single patient visit across many diverse CLIA-waived settings, such as clinics, doctors' offices, assisted living centers, pharmacies, and other easily accessible consumer venues.
Financial terms of the deal were not disclosed.
"We began with a more high-throughput test that could help alleviate some of the burden around COVID-19 testing in high patient-[volume] centers, hospitals, and reference labs," said Sherlock Bio Cofounder, President, and CEO Rahul Dhanda. "We had declared a path to get to the point of care, and what we needed was an instrument that could do that. We're really excited to work with Binx because they have a very, very rapid platform. They have proven regulatory capabilities, and they have a technology platform that can enable the SHERLOCK CRISPR technology."
Sherlock Bio first said at the end of February that it had been developing and testing a series of assays for SARS-CoV-2, the pathogen that causes COVID-19, and that it was almost ready to release a CRISPR-based diagnostic test for the virus. At the time, the company was in talks with a variety of possible partners in the US and China to deploy it on a large scale.
The assay uses one of Sherlock Bio's foundational platforms — the SHERLOCK platform, which was first developed by Feng Zhang's team at the Broad Institute in April 2017. SHERLOCK combines various CRISPR-Cas enzymes such as Cas13, Cas12a, and Csm6 to allow for the simultaneous detection of multiple nucleic acids.
In May, Sherlock Bio said it had received Emergency Use Authorization from the US Food and Drug Administration for its Sherlock CRISPR SARS-CoV-2 kit, which works by programming a CRISPR molecule to detect the presence of a genetic signature specific to SARS-CoV-2 in a nasal swab, nasopharyngeal swab, oropharyngeal swab, or broncho-alveolar lavage (BAL) specimen. When the signature is found, the CRISPR enzyme releases a detectable signal. The test is designed for use in high-volume CLIA laboratories and hospitals.
The Binx io is a molecular point-of-care platform for the detection of chlamydia and gonorrhea using PCR amplification and electrochemical detection. The company received 510(k) clearance from the US Food and Drug Administration in August 2019 for use of the platform with clinician and self-collected vaginal swab specimens, and received a second FDA clearance this April for the detection of chlamydia and gonorrhea in male urine specimens.
The platform itself consists of an easy-to-use, desktop-sized instrument and single-use cartridge with multiplex capacity of up to 24 targets, the companies said. Once a patient sample is added to the cartridge and loaded into the instrument, the process is fully automated, requiring no additional data interpretation. A simple "detected" or "not detected" result appears on a screen to indicate whether a patient has tested positive for a given illness — in this case, COVID-19.
"The workflow was one of the most attractive things. It's very low complexity and something that would be directed toward a point-of-care setting where there wouldn't be a lot that any user would have to do," Dhanda said. "Simplicity is necessary in highly decentralized patient settings like pharmacies, grocery stores, and long-term care facilities, and so the platform itself hits all the marks for point-of-care, but it also has high sensitivity, specificity, and lab quality results, and in a very rapid turnaround time."
Although the Binx platform hasn't yet been fully integrated with the SHERLOCK technology, he added, the companies expect that the COVID test will take 20 minutes or less to run. Further, their goal is to develop the platform to produce optimum results with the least invasive sample type possible. Sherlock Bio and Binx are currently testing to see whether nasal swabs, nasopharyngeal swabs, oropharyngeal swabs, BAL specimens, or saliva samples provide the best results.
Once the test is fully integrated into the platform, the companies plan to pursue FDA Emergency Use Authorization. They're hoping to have the test on the market for point-of-care use in time to address any possible resurgence of the pandemic in the fall.
The companies are also having an ongoing conversation about where to place their product first once it does receive EUA, whether that's in airports, doctors' offices, long-term care facilities, or elsewhere. "The goal is [to put it] wherever the need is the greatest, and we're closely monitoring where that will be" when the test goes on the market, Dhanda said. "Our goal is to place it where the impact will be greater, and that seems to be a shifting landscape on a day-to-day basis."
This timeline might put a crimp in the plans of rival CRISPR company Mammoth Biosciences, which teamed up with the consumer healthcare arm of pharmaceutical company GlaxoSmithKline in May to develop a CRISPR-based SARS-CoV-2 diagnostic test for use by consumers at home and healthcare providers at the point of care.
Mammoth and GSK didn't have a timeline for when the test would be available to consumers when they made their announcement in May, but said they planned to have an EUA submission ready by the end of 2020 for review by the FDA for a version of the test that would be used in healthcare facilities.
In the long term, Sherlock Bio and Binx could eventually develop a diagnostic test that contains SARS-CoV-2, influenza, and other targets on one assay, Dhanda said.
"One of the exciting things about working with Binx is that we have broader strategic plans to investigate other menus and options that would have an impact in the same places where we are placing this [COVID] test," he added. "Our expectation is that we can take their platform and our platform and truly decentralize testing around a lot of applications, inclusive and exclusive of COVID-19."
Other applications would have to go through the standard regulatory process, he noted, which is why the companies are only focusing on COVID-19 testing now.
Dhanda also said that Sherlock Bio is continuing to develop its own at-home SARS-CoV-2 test, which is based on its second foundational technology, INSPECTR (INternal Splint-Pairing Expression Cassette Translation Reaction). INSPECTR is an instrument-free synthetic biology-based molecular diagnostics system programmed to distinguish targets based on a single nucleotide. An at-home test for SARS-CoV-2 using this technology would likely work like an at-home pregnancy test, the company said.
In February, Dhanda said the INSPECTR-based test was further behind in development than the SHERLOCK-based assay because the original estimates for SARS-CoV-2 was that it would be over sometime in the late spring. The revised expectation that the pandemic will now likely stretch into this year's flu season shifted the company's thinking about the applicability of INSPECTR to SARS-CoV-2 testing.
Now, Dhanda said, the company is on track to deliver an INSPECTR-based test for the virus in the first half of 2021, though there are still several technical challenges to work out.
Sherlock Bio is also considering the best place to deploy the INSPECTR-based test. "We first thought at-home was best and we certainly focused on that," Dhanda said. "But a lot of interest in the technology is also suggesting other areas. We can have a big impact, from low-resource settings to employee testing. So, a lot of those questions are being worked out now."
The company is even considering whether there's possible value in integrating the two technologies — SHERLOCK and INSPECTR — into one platform for viral detection, and is conducting an investigatory project as to whether there's a process by which this could be achieved. However, such an integration would be a much longer-term project, and would likely not have much of an impact on the current pandemic, Dhanda said.