NEW YORK (GenomeWeb) – Renishaw Diagnostics wants its newly CE-marked Fungiplex assay to become the go-to test for invasive fungal infection management in immunocompromised patients.
Renishaw announced last week that the fungal test and PCR-based platform it runs on, the RenDx, received CE-IVD certification. As it prepares to roll out the system to customers in Western Europe, it's making the case that hospitals should fundamentally alter their approach to managing fungal infections in their most immunocompromised patients.
The Fungiplex assay detects two of the most prevalent invasive fungal pathogens, those of the families Candidia and Aspergillus. "To our knowledge, we're the only commercial assay that does detect both species," Ally McInroy, Renishaw's product marketing manager for the RenDx platform, told GenomeWeb. The test can also specify species that require a different treatment plan. In addition to a broad-spectrum Candida probe, it has additional probes that pick up C. glabrata, C. krusei, A. flavus, and A. terreus.
At its maximum, the system can run 46 assays in seven hours.
The RenDx platform uses PCR but the detection technology is based on surface enhanced resonant Raman spectroscopy. Instead of fluorescence, the dye-labeled probes produce very specific spectra. "We can pull an awful lot of info from one sample and it allows us to do a high level of multiplexing," McInroy said. "Because we're so specific, there are lots of specific bands associated with each target, [and] it allows us to multiplex quite comfortably to double figures."
The Fungiplex assay could help hospitals transition in the way they care for their immunocompromised patients. Transplant patients and hematology/oncology patients are at risk for invasive fungal infections that carry a high mortality rate.
"What often happens is any at-risk patient is put on a series of prophylactic antifungal drugs," McInroy said. "There are two problems with that: antifungal drugs are themselves quite toxic and not particularly good for the patient, and they're extremely expensive."
But the prevalence of those invasive infections is actually very low, he said, making the drugs mostly unnecessary. Though still a contentious issue, some hospitals are thinking about adopting an approach driven by diagnostics rather than prophylactic treatment.
"In that case they would test every at-risk patient two to three times a week," McInroy said. The tests would have to be molecular, since culture testing — which still dominates the field — could take days. "The Fungiplex assay provides one of those tests, and the idea is that by testing a patient regularly, any patient that does develop invasive fungal disease, which won't be many, will be caught early and then put on suitable drugs," McInroy said.
McInroy cited several papers that have suggested a diagnostics-driven approach to preventing fungal infections could save hospitals money without negatively affecting the care of immunocompromised patients.
That makes Renishaw's ideal customer a large hospital that has both transplant and hem/onc wards, which could run as many as 2,500 tests per year. "There are 1,500 suitable hospitals that fit the profile in Western Europe," Jim Greaves, Renishaw's head of marketing and business development, said. "Currently, very few are using a diagnostic test like [the Fungiplex assay] because there isn't one on the market. They're not all going to swap over to our system, but on average the equivalent tests they'll be doing — culture, galactomannan — are not particularly reliable techniques."
Several other firms are developing molecular diagnostic tests for fungal infections. Abbott has landed CE-marking for its Iridica platform for bacterial and fungal pathogen detection. Clinical studies are showing the utility of T2 Biosystems' Candida panel. And startup firm Immunetics has received a Phase II Small Business Innovation Research grant to develop a PCR- and array-based platform to detect 30 fungal species.
To help convince hospitals to buy the RenDx system and Fungiplex assay, Renishaw is setting up evaluation stations throughout Europe. Greaves said the firm is placing a system at a hospital in Milan, Italy this week.
If Renishaw can convince customers of the system's clinical utility, it will continue to concentrate on Western Europe.
"Our plans at the moment are to establish the system and fungal assay in Europe and then follow that with a couple of additional assays before we even think about the US," Greaves said.
The firm has only three sales people but will sell directly to start with. "It's a fairly complex product and it's a long sell. It's not going to be a lightning takeoff," Greaves said. "Certainly, whilst we're new and the product isn't established, then we expect multiple evaluations similar to the one in Italy," which can take three months or more.
Greaves said that the firm doesn't have immediate plans for submitting its platform to the US Food and Drug Administration. "The FDA is particularly time consuming and our board would like to see proven success in [the] first product before we cross the Atlantic," he said.
Renishaw is already working on two bacterial follow-up assays that it believes will help improve the value of the RenDx platform for potential customers — one to identify the cause of bacterial gastroenteritis and another to detect genes for carbapenem resistance in bacteria.
"The rationale for picking those two is that we expect hospitals to want to use the system for more than one assay and get utility out of it," Greaves said. Renishaw has built the experience to develop assays for a number of targets, but chose the gastroenteritis and antibiotic resistance assays due to the floor plans of their potential customers.
"In Europe the mycology department, the people who are going to be buying the fungal assay, are usually neighbors to the bacteriology lab," Greaves said. "We're looking for a pipeline that will bring additional utility to existing customers."