NEW YORK – Startup Domus Diagnostics is developing an instrument-free, isothermal, rapid molecular infectious disease diagnostics system that enables multiplexing and easy accommodation of new targets.
The Park City, Utah-based startup, which emerged from stealth mode last month, has created a scalable manufacturing process for its proprietary laminate card technology that supports a very low test price.
The firm is now starting clinical validation of its system for COVID-19, with an initial eye toward World Health Organization Emergency Use Listing and, ultimately, US authorization and CLIA waiver.
Paul Chapman, president and CEO of Domus, has been at the forefront of molecular diagnostics from the beginning, selling Roche Diagnostics PCR tests in Canada in 1993. He also previously served as senior VP of hospital point of care for Roche, as well as CEO of Quanterix, among other roles.
"There has always been a call for an infectious disease test deployed in developing countries that doesn't need an instrument or electricity, for under $5," Chapman said in a recent interview, referring to the beginnings of molecular diagnostics.
High quality, low-cost, easy-to-use testing is the only way to impact global health inequities, he noted. "That's not just for COVID, it is for future pandemics, and it is for all infectious diseases."
Up until now, this hasn't been possible for a number of reasons, but Domus' technology can potentially enable this "Holy Grail" for the first time, he said.
Domus' core technology incorporates multiplex reverse transcriptase loop mediated isothermal amplification (RT-LAMP) and a proprietary lyophilization method to create stable assays that can also be easily modified.
The technology was initially developed at Duke University by the scientific founders of the company, John Reif and Xin Song.
The team found a way to put all the primers, probes, and enzymes required for the 30-minute test into one lyophilized bead that has long-term stability, Chapman said.
This "one-pot" lyophilization is the foundational intellectual property, as it "allows a one-step, one-temperature reaction," he said.
The RT-LAMP approach was a method of choice for rapid COVID screening from the early days of the pandemic.
There are now also commercial COVID-19 tests for home use — such as systems from Cue Health and Detect — that perform RT-LAMP using lyophilized beads, Chapman said. However, Domus' price point is significantly lower than that of others in the space, in part because its test does not require any instrument or electricity to run.
It is also very inexpensive to manufacture. Domus' technology uses a laminate card with a few injection-molded pieces, Chapman said. As such, it can be made at large scale using a process known as roll-to-roll manufacturing. "This enables very high throughput and very low cost," he said.
The simplicity of the manufacturing template, in turn, could enable the firm to quickly scale up production of millions of tests in developing countries, with the potential for adding manufacturing lines for endemic diseases like schistosomiasis, dengue, or yellow fever.
"The swapping out of primers and probes is a relatively easy process to validate for new targets" with the technology, he said.
In a proof-of-concept study published this year in Scientific Reports, the firm's scientific founders demonstrated that the system could detect SARS-CoV-2 RNA with 95 percent sensitivity and 99 percent specificity, with a limit of detection of 500 copies of virus per milliliter.
The study noted that the addition of a chemical called trehalose also reduced false positive results, with the addition of guanidine hydrochloride offsetting a reduction in reaction speed.
Importantly, the study noted that the test can be manufactured for a total cost of approximately $2.
The prototype testing used a thermos water bath, but the firm is now pursuing a chemical heat method for the test, Chapman said. Chemical heat for isothermal testing has also been developed by researchers at PATH, a nonprofit organization focused on global health, while isothermal diagnostics run with body heat have been validated by researchers at Rice University.
The rapid point-of-care diagnostics space ballooned during the pandemic, with both rapid antigen tests and molecular tests now sold directly to consumers.
For consumers, as well as for traditional clinical users, price point is critical, and many manufacturers have already had to drop their prices in order to stay competitive. Against a backdrop of higher shipping costs and supply chain pressures, having the lowest possible manufacturing cost is particularly important.
But while low-cost testing is a priority for at-home diagnostics, it is de rigueur for global use in low- and middle-income countries.
Domus has been working with FIND, an international infectious disease diagnostics organization, on test validation and has also been in conversations with the Bill and Melinda Gates Foundation, as well as the US Department of Health and Human Services' Office of the Assistant Secretary for Preparedness and Response Biomedical Advanced Research and Development Authority (BARDA), Chapman said.
Going forward, the firm intends to maintain a focus on infectious disease testing, with a possible menu for infectious diseases including pathogens like strep A and strep B, influenza A and B, tuberculosis, and chlamydia and gonorrhea.
And, as "domus" is Latin for home, the firm expects to be a player in the continued expansion of at-home infectious disease testing in the future.
For the US market, in particular, the goal would be a multiplex test for COVID, influenza, and respiratory syncytial virus, Chapman said, and Domus plans to pursue Emergency Use Authorization from the Food and Drug Administration as well as CLIA waivers for its tests.
The firm will also likely continue to be based in a number of locations. Its headquarters are in Park City, as is cofounder Harald Stock. Its lab is in North Carolina, while Chapman and the firm's manufacturing partners are located in the Boston area.
"We were born in a pandemic, so we were a virtual company out of the gate," Chapman said.