Gen-Probe (San Diego) reported that the FDA has granted an emergency use authorization (EUA) for its test, the Prodesse ProFlu-ST, to be used in CLIA high complexity laboratories for the diagnosis of the 2009 H1N1 influenza virus infection.

According to the company, it is the first commercially available polymerase chain reaction test that can detect the virus, aided by an algorithm that relies on seasonal influenza A/H1 virus and seasonal influenza A/H3 virus results, from a single sample in individuals diagnosed with influenza A by FDA-cleared or authorized devices. Because the three influenza A subtypes currently have different susceptibilities to influenza antiviral drugs, this capability is important for clinicians and patients during this flu season, Gen-Probe says.

"The idea here is, a lot of experts have said that they expect the seasonal H1 – the regular flu if you will – to overlap with the H1N1," Michael Watts, VP of investor relations and corporate communications at Gen-Probe, told Medical Device Daily. If that happens, it will be important for clinicians to be able to differentiate between the two types of flu, he added.

For example, Watts said, the regular seasonal H1 flu tends to be resistant to Tamiflu, whereas at least at this point, novel H1N1 is not resistant to Tamiflu.

The FDA has only authorized use of the Pro-Flu-ST during the H1N1 emergency.

"We do intend to pursue FDA clearance, the EUA provision where HHS in times of emergency can make important medical devices available to deal with a discrete need," Watts said. This particular emergency is currently set to expire in April, he added.

The real-time PCR technology used in ProFlu-ST is simple to use and easily integrates into a lab's existing workflow, according to the company. The product has been optimized for use with automated extraction technology that minimizes technician hands-on time. This ease-of-use enables labs to quickly validate the product for use, Gen-Probe said. Test results can be obtained in as little as three hours using the assay - a significant improvement over culture-based methods that can take up to weeks to produce a result. During a public health emergency, this speed to result and the exceptional sensitivity of molecular testing are extremely important from an infection control perspective.

Gen-Probe recently completed its acquisition of Prodesse (Waukesha, Wisconsin) in a deal worth up to $85 million that was first reported last month (Medical Device Daily, Oct. 8, 2009). Gen-Probe says it completed the deal on Oct. 21. Now a subsidiary of the company, Gen-Probe Prodesse develops molecular diagnostic reagents for a variety of infectious disease applications.

"This is a logical extension for us, Prodesse has done a great job of developing these tests," Watts said.

The FDA cleared Prodesse's ProFlu+ test in January 2008 for the detection and discrimination of Influenza A Virus, Influenza B Virus and Respiratory Syncytial Virus. According to the company, it is the only commercially available, FDA-cleared molecular test for these respiratory viruses that uses real-time PCR technology (MDD, Jan. 2, 2008).

"Many experts are expecting continued high levels of 2009 H1N1 infections through this next flu season, along with a return of either or both of the seasonal flu strains, so we believe that with this EUA, ProFlu-ST can help provide top-notch care," said Andy Shrago, head of marketing for Prodesse products. "This test complements nicely our FDA cleared ProFlu+ assay, which from a single sample, detects and discriminates influenza A virus, influenza B virus and RSV."

While the ProFlu+ test differentiates between flu A, flu B, and RSV, that test does not differentiate among Flu A subtypes, Watts said. For example, it won't tell you that you have regular seasonal H1 versus novel 2009 H1N1, often called swine flu, he said. The ProFlu-ST is designed to differentiate among the three dominant subtypes of influenza A, Watts said, noting that the ST stands for subtype.

Prodesse also sells FDA-cleared, real-time PCR assays for the clinical diagnosis of Clostridium difficile, a bacterium that is the most serious cause of antibiotic-associated diarrhea, and human metapneumovirus, a common cause of lower respiratory infection in children.

Amanda Pedersen; 229-471-4212
amanda.pedersen@ahcmedia.com