NEW YORK – With its system for microchip-based electrical analysis of bacteria, UK-based iFAST Diagnostics aims to provide antimicrobial susceptibility profiles about two days earlier than the conventional culture-based tests that are used to guide the treatment of patients with bacteremia.
The University of Southampton spinout is using about £5 million ($6.5 million) in recent seed funding to support its development of multiplex panels and instruments to provide phenotypic antimicrobial susceptibility profiles, starting with panels for use in patients with bloodstream infections with Gram-negative bacteria, including patients who are at risk of sepsis.
The company intends to first bring its system to market in the UK, where it is beginning clinical trials in January, followed by launches in the US, EU, and other regions.
Toby King, iFAST CEO, said that the iFAST (impedance-based fast antimicrobial susceptibility test) system provides answers within three hours compared to a typical turnaround time of 48 hours for a culture-dependent test that results in a susceptibility profile. The total time from a blood draw to results, including overnight culture in a blood bottle, is about 18 hours for iFAST's tests compared to a typical time of 60 hours for a conventional culture-based test.
Under the current standard of care, King said, "Antimicrobial susceptibility testing takes too long and, as a result, people are on inappropriate therapy." Patients can develop more severe illnesses or die because of the ineffective therapies that are used ahead of the results of antimicrobial susceptibility tests, he said, adding that the toll of drug-resistant infections has been predicted to rise by 2050 in the absence of effective interventions.
The iFAST system is used along with separate tests for pathogen identification, typically matrix-assisted laser desorption-ionization time of flight (MALDI-TOF) mass spectrometry. After Gram staining and sample enrichment, bacteria from a patient sample are mixed into growth media, which are added to the iFAST test plate's 96 wells, and incubated for two hours.
Each well contains freeze-dried antibiotics in various concentrations, so that the results can provide data on drug resistance and minimum inhibitory concentrations for up to 15 drugs per sample. The MALDI-TOF results are entered into the instrument and used to determine which wells will be analyzed to aid treatment selection.
Wells with ineffective antibiotics will contain higher volumes of bacteria following incubation, and the test instrument uses multi-frequency impedance to measure the change. The analyzer also is used to determine the size and cell wall permeability of the bacteria because certain bug-drug combinations will result in targets swelling and bursting.
Researchers from the UK and Australia wrote in a 2020 article in Nature Communications that the iFAST technology is used to measure changes in electrical and morphological properties of thousands of individual particles at high throughput through microfluidic impedance flow cytometry. The approach has already become established for the label-free characterization of mammalian cells by measuring the electrical properties of particles as they flow between pairs of electrodes, they noted, adding they developed a new electrode arrangement that improved the signal-to-noise ratio and allowed the characterization of up to 1,000 microorganisms and other small particles per second.
"It thus provides a new way of characterizing subtle biophysical changes in bacteria, enabling the effects of antibiotic exposure to be measured after a very short time window," the authors wrote.
King said that the company has developed simple algorithms for the assays in part to avoid the more complex regulatory hurdles of securing US Food and Drug Administration marketing authorization for a system that was developed through artificial intelligence and machine learning. He added that more complex algorithms also would be unnecessary to provide the test results.
King said that iFAST's testing process would work well with the molecular assays and other culture-free tests that are used to quickly identify the causes of infection, although the use of those molecular systems is more common in the US than in the UK, where MALDI-based tests and disk diffusion assays are more common. He noted that BioMérieux's BioFire and Diasorin's Verigene analyzers are among the molecular systems that are used in the US to identify bacteria and antibiotic resistance markers, though those markers are typically used for Gram-positive bacteria.
"In terms of Gram-negative infections, there's too much variability in the genotype to be able to figure out whether they're resistant or not based on those genotypic molecular methods," he said. "And so, our view is for quite some considerable time yet, there will be a market for phenotypic AST testing, especially for Gram-negatives."
The market for rapid, phenotypic antimicrobial susceptibility tests is heating up, though, with recent or expected entries that are also aimed at shortening turnaround times for Gram-negative bacteria. BioMérieux is also seeking FDA 510(k) clearance for its CE-IVDD marked Vitek Reveal phenotypic AST system to help guide the treatment of bacterial sepsis with results for Gram-negative bacteria from a positive blood culture in about five-and-a-half hours. Selux Diagnostics, meanwhile, raised $48 million this spring to support the commercialization of its Next Generation Phenotyping System with results in about five to seven hours from a positive blood culture or isolated bacterial colonies grown in culture.
Accelerate Diagnostics also has been preparing to launch its Wave platform delivers AST results from positive blood culture and isolated bacterial colonies in about 4.5 hours. Lastly, Pattern Bioscience said last summer that it had developed a phenotypical antibiotic susceptibility testing system that delivers results in about four to six hours, and the firm was studying the use of that system for an initial test for pneumonia and planning during that study to look at the performance of its assay for assessing positive blood cultures.
King said that iFAST expects to launch sales of its system in the UK during Q2 2025 and hopes to complete US clinical trials in 2025 and seek FDA 510(k) clearance for a 2026 launch. The company plans to launch in the EU soon after bringing its tests to market in the US, although he said that different panels are needed in Northern and Southern Europe because of differences in antibiotic resistance profiles.
The panels for each market will require clinical study results to support the use of different bug-drug combinations, King said. About half of the UK panel, for example, will be the same as the US panel, he said.
The low cost of using that technology also makes it suitable for use in low- and middle-income countries, particularly countries such as India that have a high burden of antimicrobial-resistant pathogens, according to King.
The iFAST panels will sell for well below $100 each, and according to the company website they are estimated to cost about £20 per sample that is analyzed, while the iFAST System will sell for £40,000 to £50,000. However, King said that he expects most of the analyzers will be rented.
The firm estimates that each system is expected to generate £50,000 to £100,000 in consumables revenues annually. It further said on its website that the health economics consulting firm Aquarius Population Health compared the the iFAST system against current testing methods and determined that the use of iFAST could cut the use of ineffective antibiotics by nearly half as well as save the UK National Health Service about £1,000 per patient tested.
The company said that each iFAST instrument can process 25 samples in an eight-hour shift, and King said that the company's target customers are the microbiology laboratory managers at medium to large hospitals.
Founded in January 2023 at the University of Southampton, iFAST Diagnostics' 16-person team has been developing its tests and instruments with the support of £2 million in pre-seed funding and the more recent £5 million seed funding round. The company said in its presentation materials that it intends to raise another £10 million in 2026 through a Series A funding round.
In addition to the Gram-negative panels, the company is also developing AST panels for Gram-positive bacteria and fungal infections as well as a high-volume urine-based test.
"Our mission is to build…a successful British diagnostics business of real scale," King said. "There are very few, and we think we've got something really very special here in terms of the technology."