NEW YORK – One of a handful of startups to obtain US Food and Drug Administration Emergency Use Authorization for an over-the-counter molecular diagnostic, Aptitude Medical Systems now strives to bring its low-cost testing to more homes and clinics.
Over the past two years, the firm has been awarded more than $14.2 million from the Bill and Melinda Gates Foundation, including a recent bolus of approximately $10 million disclosed earlier this week. Aptitude aims to use the funds to bring molecular diagnostic testing for sexually transmitted infections to underserved populations globally, as well as to clinics and home-use customers in the US.
Aptitude's core technology involves modified real-time isothermal amplification chemistries, with a twist. Rather than the more typical optical detection — with colorimetric or fluorescent dyes signaling test results — the device uses an electrochemical sensor modeled on a blood glucose reader.
Called Metrix, the device can be manufactured cheaply such that "the cost of the reader is about the same as the cartridges," Aptitude CEO Scott Ferguson said in an interview this week.
Goleta, California-based Aptitude obtained Emergency Use Authorization for a COVID test in late 2022 following the Omicron wave, just as testing was declining and proof of vaccination requirements were being lifted.
However, Ferguson said the firm has still recorded Metrix sales, particularly in the point-of-care clinical space and among home users who require frequent, sensitive testing.
The test was authorized for both over-the-counter and CLIA-waived use and could be run on either saliva or nasal swabs, making it the first authorized saliva-based OTC molecular test.
The development of the Metrix device has also been supported by a contract issued in 2023 by the US Department of Health and Human Services' Biomedical Advanced Research and Development Authority (BARDA). The contract was worth up to $53.7 million and included options for the further development of COVID-19 and combined COVID/flu assays as well as other infectious disease multiplex tests.
Aptitude's first awards from the Gates Foundation came in 2023. In June, it won approximately $1 million to support initial STI test development, followed by $1.5 million in July for a human papillomavirus screening test, and $1.7 million in October for a genital ulcer disease assay.
In 2024, the firm was granted $755,000 to support studies of STI test usability in Africa, approximately $2.4 million to reduce the cost of goods of its Metrix platform and $2 million for low-cost STI test development generally, and approximately $5 million to support its multiplex STI assay.
The latter grant spans 15 month and is meant to advance research and development as well as support FDA regulatory submission of a point-of-care test for gonorrhea, chlamydia, and trichomonas that will improve management and outcomes for these infections, according to the foundation's website.
Now, "our goal is to get through clinical studies as quickly as possible and get to the market," Ferguson said. In addition to serving the global public health space, Ferguson said Aptitude expects Metrix to be adopted in professional settings like urgent care and community health centers, as well as by at-home test consumers.
Kevin Nichols, VP at Aptitude, said that the cost and ease of use of the molecular device is such that Aptitude hopes to be "one of the first to be able to address the whole market in the US" while also making "a good dent globally, as well." Nichols is a former principal investigator at Global Health Labs, a nonprofit corporation fully funded by Gates Ventures. He was most recently CSO for new products at Amazon spearheading development and launch of medical diagnostics and devices.
Besides Aptitude's Metrix, five other at-home molecular COVID-19 assays were granted EUA by the FDA during the SARS-CoV-2 pandemic.
Among these manufacturers, Talis Biomedical ceased making EUA tests and Cue Health is no longer in business. Meanwhile, LumiraDx was acquired by Roche last year for $350 million, while Lucira Health was acquired by Pfizer in 2023 for $36.4 million after a bankruptcy action. 3EO Health was granted a $6 million RADx award last year and has previously disclosed that it is considering developing STI assays.
Michael Mina, an epidemiologist who publicly advocates for expanded decentralized testing, noted in an interview that cost is a key pivot point as consumers decide between molecular and antigen-based tests.
Now executive chairman at C2Sense, a developer of optical sensing systems, Mina said he has no investment or financial stake in Aptitude.
"I am excited about their tech because they have come up with a solution … that is actually very small and very, very cheap," he said.
Mina resigned from his position at Harvard's School of Public Health in November 2021 to serve as CSO at eMed for three years, during which time he was also codirector of the National Institutes of Health's Test-to-Treat program. He currently also serves as a strategic adviser to Sanofi and Walgreens, among other roles.
POC STI MDx
To Mina, decentralized testing is the future for STI diagnostics, and other companies besides Aptitude are already driving toward this goal.
Startups that have publicly disclosed ongoing work on point-of-care molecular tests for STIs, for example, include Detect, Visby Medical, Scout, Midge Medical, Prompt, and Credo Diagnostics.
Established firms are entering the space, as well. For example, Becton Dickinson recently disclosed its plans to enter the clinical point-of-care space with a rapid molecular instrument and STI test. OraSure, meanwhile, is positioning itself in the molecular OTC market with its investment in assay developer Sapphiros and recent acquisition of Sherlock Biosciences. The latter incorporated $20 million in milestone payments contingent on FDA approval of Sherlock's chlamydia and gonorrhea assay and would potentially add nucleic acid CT/NG detection to the firm's STI portfolio of antigen-based HIV and syphilis offerings.
Molecular testing is recommended for infectious diseases like chlamydia and gonorrhea, and the unmet needs in the STI space include people whose sexual activity puts them at risk but who may be reluctant to visit a clinician.
Tests using at-home sample collection are a step closer, but Mina noted that they still must be shipped back and forth, which might not be discrete enough for some potential customers.
Widely available molecular STI tests could also be a boon to college campuses, he said. Although student health services may initially balk at the idea for fear of missing cases, Mina believes that infected people would ultimately seek treatment and be counted.
Another unmet need for decentralized STI testing, and a primary focus of the Gates Foundation, is among people in low- and middle-income countries.
A gonorrhea diagnostics landscape review released by Unitaid in September, for example, highlighted the lack of low-cost point-of-care gonorrhea tests amid 82 million infections globally per year, a substantial proportion of which occur in low-resource settings.
Kelsey Barrett, a technical officer at Unitaid, said in an email that she and her team identified more than 75 technologies, most of which were molecular, with relatively few non-molecular options. Furthermore, they found that rapid diagnostic tests and disposable molecular tests were less common than "true POC" options or near-POC molecular, she said.
Overall, "the available and in-development technologies are remarkable — an acceleration driven by pandemic funding for product development," Barrett said. "This creates an unprecedented opportunity to transform STI management, including etiological diagnosis," but she warned that low-resource settings are at risk of missing out if there isn't increased attention.
Bird flu looming
Aptitude's Ferguson said the firm is awaiting a decision from the FDA on its combination test for COVID and influenza A and B submitted in the spring, and the firm can quickly develop new Metrix assays, should the need arise.
At the current moment, many in the diagnostics space are closely tracking the highly pathogenic avian influenza H5N1 outbreak plaguing dairy and poultry farms.
This strain of influenza A has yet to acquire mutations that would enable it to spread more easily between people, but at least one study suggests that a single base change might do the trick.
To Mina's mind, the path to FDA-regulated H5N1-specific home testing is frighteningly long — he estimates at least one year before the agency could authorize a test — but authorized and cleared combination COVID/flu home tests currently on the shelves could serve a vital role. For example, Healgen's test, which Mina said has the potential to be sold under private label by firms like CVS and Walgreens, could be used as a way to monitor for H5N1.
For these antigen tests, "the flu A target picks up H5," Mina noted. In his opinion, the Centers for Disease Control and Prevention "should be promoting the fact that the COVID/flu tests that are on shelves already, which the government helped to get cleared through the Independent Test Assessment Program, can detect H5," he added.
With buy-in from the CDC and public health departments, Mina suggested that these tests could potentially be adapted to serve H5N1 surveillance functions. For example, with the appropriate guidance, people with positive flu A results on lateral flow tests could allow their test to dry, cut out the flu A line, and mail it to their local public health department.
Alternatively, people using a flu A home test that doesn't have a colorimetric readout, such as Aptitude's as-yet-uncleared combo test, could be instructed to collect and send something analogous to a dried blood spot, but using the test buffer. These samples could then be sequenced by public health departments to provide valuable information on the virus while also enabling moderately ill people to self-quarantine.
These tests could also be further adapted to perform pooled testing, Mina said. Unlike lab-based pooling protocols, where patient samples are added together and can potentially dilute the targets, adding more than one swab to a test would theoretically only increase the concentration of analyte. In his social media posts, Mina has advocated this approach for COVID screening prior to family gatherings, for example, and it could theoretically be adapted for other targets if needed.
Mina suggested that "a really good surveillance system" could be based entirely around these types of home tests.
So far it seems, however, that "people don't even know that a flu A combo test with COVID even exists and can be bought over the counter, much less that it covers H5," he said.
Ultimately, Mina said consumers may be making cost/benefit decisions about diagnostics that are perhaps counterintuitive from a laboratory perspective, namely they tend to eschew bulk purchasing or acquiring tests with readers because, for the most part, they'd rather not prep for future sicknesses they may not catch.
Readerless devices have the benefit of being cheap and completely disposable, he said, noting that RT MicroDx's disposable molecular strep throat test is a great example. And, amplification-free molecular testing also lends itself to these target profiles.
In the meantime, however, molecular home tests likely need to come down in cost to be more widely adopted, but the ideal target price point for the at-home consumer is a bit unknown.
"In some ways the molecular companies have, over the last couple of years, been competing with 'free,' [and] it has really skewed everyone's view," Mina said, referring to a federal government program that made rapid antigen tests freely available through the US Postal Service.
Still, on balance it seems like the target price that could lead home test consumers to adopt molecular is in the $20 to $30 range, Mina said, basing this number on conversations with stores like CVS and Walgreens as well as assessments of consumer willingness to pay for testing.
However, in cases like Aptitude's, "it's a little bit of the chicken and the egg; if they're selling more, then they can bring costs down," he added.
Furthermore, point-of-care users may be more amenable to using a molecular test that requires a reader, Mina suggested, while average consumers may still be averse to shelling out for readers when they vainly hope never to become sick again after their current illness passes. In the meantime, they may prefer to use an algorithm whereby they first test with an inexpensive antigen test to quickly catch a strong positive and reserve at-home molecular tests for suspicious, symptomatic antigen test-negative cases.
Going forward, Mina noted that point-of-care and over-the-counter diagnostic testing is "really important to help curb transmission and keep people empowered over their health care."
Aptitude's Ferguson concurred. "We're still seeing a push toward more distributed testing driven by patient needs for mode convenient, better medicine that is not extremely expensive," he said.