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Gradientech Poised to Enter Antibiotic Susceptibility Testing Market With Gram-Negative Panel


NEW YORK ─ Gradientech is planning the launch of a test to detect the susceptibility of Gram-negative bacteria to a panel of antibiotics, marking its commercial debut in the increasingly competitive market for rapid antimicrobial susceptibility testing (AST).

On the back of a study to assess and validate the performance of its QuickMIC rapid antibiotic susceptibility test for Gram-negative bacteria in clinical settings, the Uppsala, Sweden-based firm expects to obtain CE-IVD marking within weeks, its CEO Sara Thorslund said recently in an interview at the 32nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Lisbon, Portugal.

Thorslund added that Gradientech is also in discussions with US health systems to conduct clinical trials for the AST panel to generate validation data for a 510(k) submission to the US Food and Drug Administration to market the panel to US hospitals.

As it prepares to launch the Gram-negative panel, the company has started the development of a panel to rapidly detect the susceptibility of Gram-positive bacteria to antibiotics to expand the range of bloodstream pathogens that it can test for susceptibility and resistance to antibiotic treatments.

Though numerous rapid AST systems are in development and entering the IVD market, the QuickMIC system may have an advantage over others by offering one of the fastest times to result, according to Gradientech.

Its QuickMIC system provides "an AST result in about two hours, which would enable a clinician to get results and begin treating a patient in the same day" following a positive blood culture, Thorslund said.

To decide on an optimal therapy, clinicians need to identify the pathogen causing an illness in parallel with measuring the susceptibility or resistance of the pathogen to antibiotics, and the QuickMIC system can be used alongside all current pathogen identification systems, Thorslund said.

For identification, many labs use MALDI-TOF mass spec instruments, which include the Bruker Biotyper and BioMérieux Vitek MS, or molecular diagnostic tests such as ePlex developed by Roche's GenMark Diagnostics, FilmArray developed by BioMérieux's Biofire Diagnostics, and Unyvero developed by Curetis. Laboratories are also adopting Accelerate Diagnostics' Pheno system, which combines phenotypic pathogen identification and AST.

Meanwhile, tests in development and on the market use various technologies to determine antimicrobial susceptibility. The QuickMIC system uses microfluidic technology, applying agarose gels that are embedded with the bacteria of interest and treated with different antibiotic concentrations. Automated microscopy monitors the gels for microcolony growth, allowing clinicians to generate minimum inhibitory concentration (MIC) values for the microorganism-bacteria pairings to assess susceptibility or resistance.

"We're looking at light scattering of single microcolonies to detect their growth rate," Thorslund said, adding that the user "combines our MIC values with an ID and uses a breakpoint table to determine susceptibility or resistance."

For each blood sample, the QuickMIC platform enables susceptibility testing for 12 antibiotics. The platform consists of an instrument that can fit on a desktop and accommodate disposable test cartridges.

Additionally, instruments can be stacked on top of each other to increase testing throughput.

Each instrument conducts a single test per run. The addition of 12 instruments, enabling the testing of 12 patient blood samples, would provide enough testing capacity to meet the daily AST testing needs of most midsize European hospitals, according to Thorslund.

Nonetheless, for large hospitals, which can run up to around 50 AST samples and tests per day, QuickMIC is "not the best solution," she said.

In such settings, hospitals may decide to purchase the Gradientech system and tests to complement routine AST testing done by an AST system that can handle a larger number of samples per run. In such a scenario, QuickMIC could be used to test samples from patients suspected of having sepsis that have entered an emergency department or been admitted to an intensive care unit.

With antibiotic resistance and life-threatening bloodstream infections such as sepsis on the rise, numerous firms are developing or offering rapid AST tests that enable clinicians to make better decisions about whether to treat patients with antibiotics and that can identify the antibiotics that may lead to better health outcomes.

With the launch of QuickMIC, Gradientech would compete with rapid AST firms such as Accelerate Diagnostics, Q-linea, QuantaMatrix, and Specific Diagnostics, which is being acquired by BioMérieux. As an addition to its Pheno ID/AST system, Accelerate Diagnostics recently released the Accelerate Arc system comprised of the Arc Module and BC Kit for automated microbial identification following positive blood cultures.

Thorslund said Gradientech has not yet set a price for its test or instrument. In discussions with potential customers, however, it will emphasize the potential cost savings associated with reductions in length of stay in ICUs and hospitals as a result of more optimal prescription of antibiotics enabled by its AST system, she said.

"A lot of people are talking about the future potential of rapid AST," but how quickly suppliers "can transform the market to implement rapid AST in routine workflows and to what extent" remains to be seen, she said, adding that convincing hospitals to alter their clinical workflows will be an essential element of achieving overall adoption.

Gradientech’s main focus, she said, is preparing for the launch of its QuickMIC Gram-negative panel through distributors to countries in southern Europe where antibiotic resistance rates are highly prevalent.

For its US-based clinical studies, the firm will seek to replicate some characteristics of the study it has just completed to obtain the CE mark, including the number of strains and samples tested.

Gradientech plans to soon release performance data from the study, which involved the testing of 450 bacterial strains using about 100 patient samples, Thorslund said, adding that the firm expects to obtain the CE mark prior to the launch of the In Vitro Diagnostic Regulation (IVDR), a new law governing the regulation of in vitro diagnostic tests scheduled to take effect in Europe on May 26.

Any tests without a CE-IVD mark prior to May 26 will require an assessment by a designated notified body under the IVDR.

A separate study published in March in Frontiers in Cellular and Infection Microbiology compared the speed, accuracy, and precision of the QuickMIC system with traditional antibiotic susceptibility testing methods.

The authors — researchers at Uppsala University and Gradientech — wrote that the AST system "could allow an earlier switch to appropriate targeted therapy, thereby enhancing the chances of survival in critically ill patients and reduce unnecessary use of broad-spectrum antibiotics." They added that there was high overall agreement in the results obtained using QuickMIC with those obtained using traditional AST methods.