NEW YORK – After receiving CE marking for its molecular diagnostic Dragonfly platform, Imperial College London spinout ProtonDx is further developing its pipeline and planning for broader commercialization.
The company, which began in 2020, has licensed key intellectual property from Imperial College to form the basis of its platform, which includes its SmartLid sample preparation system and isothermal colorimetric detection to return results in about 30 minutes. The CE mark, received last month, was for the platform and its first test, a multiplex assay detecting SARS-CoV-2, influenza A/B, respiratory syncytial virus, and human rhinovirus. The firm also offers a COVID-19-only test.
According to ProtonDx President and Chairman Bob Enck, one benefit of the platform lies in the proprietary SmartLid sample prep technology. It uses a custom magnetic lid to transfer magnetic nanoparticles, as well as attached RNA or DNA, through three sample preparation steps: lysis-binding, wash, and elution, CSO Jesus Rodriguez-Manzano said. A patient's sample is transferred into Tube A, which contains silica-coated magnetic beads and a binding buffer. Once the mixture is combined with the sample, the sample's nucleic acids bind to the magnetic beads, and the beads are then captured by a magnet and transferred into Tube B.
Tube B contains a wash buffer to remove contaminants from the previous buffers, and the nanoparticles with the attached nucleic acids undergo a "brief evaporation step," Rodriguez-Manzano said. Finally, they are transferred to Tube C, which has an elution buffer to release the purified material.
Once the sample is purified, the extracted RNA or DNA is loaded into a panel of eight different tubes that contain lyophilized colorimetric loop-mediated isothermal amplification reagents with primers specific to each pathogen target, along with three tubes that act as controls. Those tubes are then placed into the Dragonfly instrument and heated, and if a pathogen is present, there is a color change from pink to yellow, making it effectively "colorblind-proof," Rodriguez-Manzano, who is colorblind, emphasized. Depending on which tube changes color, the user will be able to determine which pathogen is present.
A companion app is also available that provides instructions on how to run the test, automatic result capture, and data management once results are available.
Up to four samples can be incubated at a time, Rodriguez-Manzano added. Right now, the platform has been validated with nasal, throat, and nasopharyngeal swab samples, but he noted the firm is working on validating it with other sample types.
Enck added that for all targets, the time to positive is 25 minutes if a pathogen is present. Compared to PCR, the sensitivity is between nearly 98 percent and 99 percent with a specificity of 100 percent, according to studies conducted by an independent laboratory.
The platform itself is "truly portable" and only needs to be plugged into an outlet to run, he added. ProtonDx sees the Dragonfly being used in settings where there's a need for portability and speed, as well as accuracy, and Enck identified care homes, sporting events, movie sets, and businesses as potential opportunities, as well as primary care clinics.
In addition to the CE mark, Enck said the company has filed for regulatory approval in the UK, which it expects to come soon, and is "exploring the US market."
Thus far, ProtonDx has inked one distribution partnership with an undisclosed partner and has two more in process, Enck said. It plans to have the "primary source" of its sales conducted through distribution partners, although it has been introduced to "a number of key opinion leaders in elite sports" and may distribute its platform directly in that market, he said.
Another potential market would be in low- and middle-income countries, since the system doesn't require anything more than an electrical outlet, Enck said. Imperial College has a project to develop digital diagnostic tests for infectious diseases that could provide opportunities for the Dragonfly, he said.
The firm is still finalizing pricing for the platform and declined to disclose exact numbers, but Enck said the Dragonfly would be "competitive in the marketplace." The heater itself is inexpensive, so the company would be charging per test for the sample collection chemistry and reagents.
While sample preparation is performed independent of the current instrument, requiring a user to ready the sample before placing it inside, a next-generation system that is in development will perform all sample preparation within the instrument itself and have an automated readout, Enck added.
As for future tests, Enck said the "science behind new tests is fairly readily available," but that the timing for validation and regulatory approval is what takes longer. The company has plans for antimicrobial resistance panels, such as for gastrointestinal pathogens, Rodriguez-Manzano added.
"It's an open approach platform, so it's easy to adapt to other pathogens," he said.