Patient Enrollment is Complete in the DOD-Funded Study of Extracorporeal Hemopurification of Critically Ill COVID-19 Patients
Jan 18, 2022

MARTINEZ, Calif. – PURIFY OBS, an observational study of critically-ill COVID patients treated with the Seraph® 100 Microbind® Affinity Blood Filter (Seraph 100), has recently completed enrollment.

A multicenter effort led by the US Department of Defense (DOD) published interim results in April 2021. Observations included dramatic improvement in survival and reduction in median ICU length of stay for patients treated with the Seraph 100 vs controls.

Another interim analysis from the ‘COSA Registry,’ a multicenter European study of COVID-19 patients treated with the Seraph 100 Microbind Affinity filter, also yielded positive results: Patients treated with the Seraph 100 early in their ICU stay had higher survival rates than patients treated later in their ICU stay.

“We expect the first peer-reviewed PURIFY-OBS clinical trial publication soon, now that the study has concluded. We are pleased to see these consistent and very positive results and we’re pleased to know we have helped save the lives of many critically-ill COVID-19 patients,” said ExThera Medical CEO Robert Ward. “Having treated more than 800 patients with Seraph 100 in the US alone, we have increased confidence in its safety and ability to improve outcomes for critically ill patients with COVID 19 and other serious bloodstream infections.”

The PURIFY RCT (a multicenter randomized controlled trial studying blood purification for the treatment of pathogen associated shock) has been initiated and is expected to begin enrollment in early 2022. Multicenter RCT trials are rare in the field of extracorporeal therapy and require robust signals of efficacy. It is expected that the positive clinical results observed in PURIFY OBS will continue during PURIFY RCT.

Physicians across the country are using ExThera Medical’s Seraph 100 under Emergency Use Authorization from the U.S. Food and Drug Administration to treat COVID-19 patients admitted to the ICU with confirmed or imminent respiratory failure. In 2019, the Seraph 100 was granted CE mark in the European Union for the reduction of bloodstream pathogens.

The complete PURIFY observational study is expected to be published during Q1 2022.


About ExThera Medical Corporation
ExThera Medical Corporation develops and commercializes extracorporeal blood filtration devices, including the Seraph® 100 Microbind® Affinity Blood Filter for removing a broad range of pathogens from the bloodstream of patients. Seraph can be used in hospitals, clinics, or field hospitals to address nosocomial and community-acquired infections as well as those caused by battlefield wounds and pandemics. ExThera Medical’s extracorporeal products have demonstrated life-saving capabilities in a wide range of critically ill patients suffering from sepsis and other severe infections. With a growing body of outcome and health economic evidence from independent clinical studies, success in the DARPA Dialysis-Like Therapeutics program, and from successful clinical use in the US, the EU, and the Middle East, the company is well positioned to serve healthcare professionals and patients alike. The Seraph 100® is CE marked and commercially available in the EU and has FDA Emergency Use Authorization (EUA) for treatment of COVID-19 in the USA.

For more information visit the company’s website at

About Seraph 100
As a patient’s blood flows through the Seraph 100 filter, it passes over beads with receptors that mimic the receptors on human cells that pathogens target when they invade the body. Harmful substances are quickly captured and adsorbed onto the surface of the beads and are thereby subtracted from the bloodstream. Seraph adds nothing to the bloodstream. It targets the pathogens that cause the infection, while it also binds and removes harmful substances generated by the pathogen and by the body’s response to the infection. Seraph’s adsorption media (the beads) constitute a flexible platform that uses immobilized (chemically bonded) heparin for its well-established blood compatibility and its unique ability to bind bacteria, viruses, fungi, and important sepsis mediators reported to contribute to organ failure during sepsis.

For more news stories on the Seraph 100 click here.

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