The U.S. Food and Drug Administration (FDA) issued an emergency use authorization on Friday for a blood purification treatment for coronavirus patients with confirmed or imminent respiratory failure.

“We continue to work across all sectors to expedite the development of numerous innovative potential preventive and treatment approaches by both facilitating emergency access for patients, to the extent we can, and supporting the evaluation of potential therapies,” FDA Commissioner Stephen Hahn wrote in a statement on Friday.

The blood purification system operates, according to the FDA, by:

reducing the amount of cytokines and other inflammatory mediators, i.e., small active proteins in the bloodstream that control a cell’s immune response by filtering the blood and returning the filtered blood to the patient. The proteins that are removed are typically elevated during infections and can be associated with a “cytokine storm” that occurs in some COVID-19 patients, leading to severe inflammation, rapidly progressive shock, respiratory failure, organ failure and death.

“With today’s authorization of a blood purification device, we are expediting the availability of a treatment option for patients in the ICU to help reduce the severity of the disease,” Hahn added. “Our staff will continue our around the clock review of all medical products to expedite the availability of treatments to help fight this devastating disease.”

The FDA issued this emergency use authorization to Terumo BCT Inc. and Marker Therapeutics AG for their Spectra Optia Apheresis System and Depuro D2000 Adsorption Cartridge devices.

Hahn said this week that the agency continues to work with plasma-based treatments to help Americans afflicted with the coronavirus.

He wrote, “In addition, these test results can aid in determining who may donate a part of their blood called convalescent plasma, which may serve as a possible treatment for those who are seriously ill from COVID-19.”