ExThera Medical Develops Device-Based Therapy for Bacterial Infections

A recently-published study has concluded that a blood filter developed by ExThera Medical Corporation can virtually eliminate two kinds of blood-resistant bacteria.

The study, appearing in the online journal PLOS ONE, found the company’s Seraph Microbind Affinity Blood Filter (Seraph) removed 99.9 percent of two Carbapenem-Resistant Enterobacteriaceae (‘CRE Superbugs’) — E. coli and Klebsiella pneumonia — from blood samples spiked with the bacteria in just brief contact with the Seraph adsorption media.

Carbapenems are a group of antibiotics that had broad-spectrum activity when first introduced. They were developed to replace antibiotics that lost the ability to kill bacteria due to the emergence of microbes that produce ‘lactamases’ — enzymes that protect the germs against a large class of β-lactam antibiotics (including penicillin and cephalosporin). Although carbapenems currently are considered “last resort” antibiotics, it now is clear that bacteria are evolving to become resistant to even this newer class of anti-infective drugs.

Roughly 1.8 million new cases of bloodstream infections occur annually in the United States and Europe, causing patients serious complications and imposing a high cost burden on health care systems. Not all are bacteria drug-resistant.

“CRE bloodstream infections have an average mortality rate of 50 percent due to the total lack of effective antibiotics. With fewer anti-infective drugs being developed, and the continuing emergence of drug-resistant pathogens, clinicians need new tools to fight bloodstream infections,” said Robert S. Ward, Ph.D., CEO of ExThera Medical.

Since 2008, privately funded ExThera (short for Extracorporeal Therapy) has been developing these tools. ExThera’s Seraph Microbind Affinity Blood Filter (Seraph), now fully developed and about to enter clinical trials, is a broad-spectrum “hemoperfusion” device with a demonstrated ability to bind and remove a long list of disease-causing agents. These include viruses, bacteria, fungi and inflammatory cytokines, according to the company.

“Since its inception ExThera’s mission has been to offer simple, device-based therapies for rapid treatment of a broad spectrum of bloodstream infections—including those caused by agents for which there are no effective therapeutic drugs,” noted Keith McCrea, Ph.D., chief technology officer of ExThera. “We are very pleased to report our results against two often deadly bacteria, so-called ‘CRE Superbugs.’ After only brief contact with our adsorption media 99.9 percent of both (CRE) E. coli and (CRE) Klebsiella pneumonia were removed from blood samples spiked with the bacteria. In addition, we measured the total binding capacity of our Seraph device for these pathogens and found it to be very high, exceeding the entire bloodstream load in bacteremic patients.”

Seraph uses a biomimetic “adsorption media” that includes chemically bound heparin and supplemental adsorbent materials in a simple flow-through cartridge. The blood-thinning or anti-thrombogenic property of heparin contributes to the safety of the device, especially in situations when it must be used without systemic blood thinners.

Seraph is the only device reported to remove both bacteria and viruses directly from whole blood without adding anything to the blood being treated, ExThera executives said. In addition to the potential to treat viral and bacterial bloodstream infections for the prevention of sepsis, Seraph is a flexible platform that may be configured with optional supplemental adsorbents to deal with future ‘weaponized’, or naturally-evolved, pathogens.

ExThera Medical’s Seraph® device is not cleared by the FDA for distribution in the United States.

Privately held ExThera Medical, based in Berkeley, Calif., developa broad-spectrum, dialysis-like therapeutic devices to treat life-threatening bloodstream infections.