Mark A. DeSorbo
PORT WASHINGTON, NYExtracting specific contents from spent blood filters to develop a remedy for an infectious disease may seem rather unusual, but that's just what filter manufacturer Pall Corp. and drug developer Viragen Inc. plan to do now that the companies have entered into an agreement that may yield a potential treatment for Hepatitis C. Under the terms of the agreement, Pall (Port Washington, NY) will grant an exclusive worldwide license, which excludes Japan, to a proprietary technology that will enable Viragen (Plantation, FL) to recover leukocytes, white blood cells, from used blood filters.
The filters are used to separate red blood cells, platelets and plasma from blood that is donated for transfusions. The remaining component, known as “buffycoat,” is rich in leukocytes, which fight disease and make the immune system function in a donor but can cause adverse reaction in a transfusion recipient.
Fighting disease, naturally
Mel Rothberg, Viragen's executive vice president, says interferons, proteins from leukocytes that are produced by the human body daily, will be used to make OmniFeron, one of the company's multi-subtype alpha interferons. OmniFeron is presently in the second phase of clinical trials in Europe for treating Hepatitis C, a blood and liver disease that afflicts millions.
Blood filters like these from Pall Corp. are used to filter donor blood, and scientists at Viragen believe harvesting proteins from them can provide treatments for diseases.
“Having more access to white blood cells will give Viragen the ability to produce more OmniFeron products,” Rothberg says, adding that the agreement allows Viragen to use Pall's technology with other filter companies. Along with Pall, Viragen has leukocyte-sourcing agreements with various blood organizations, including the American Red Cross, America's Blood Centers and the German Red Cross.
The human body, Rothberg explains, can develop antibodies to the recombinant treatments. Because interferons are produced naturally, tthe body accepts this therapy preferably and more effectively. In fact, the body produces 22 subtypes of Alpha interferons, many of which have been targeted as the basis for broad-spectrum utilized drugs to treat multiple sclerosis and cancer.
Dr. Judy Angelbeck, senior vice president of Pall's Cell Therapy Division, says removing leukocytes from filters has a two-fold advantage.
“Taking leukocytes out makes blood purer and safer,” she says. “We are now discovering that those leukocytes are an excellent resource, a raw material that could be available to add to the supply of white blood cells for Viragen to make their drugs.”
Known as leukocyte reduction, Angelbeck says the process has been mandated in 10 countries, including Canada, England, Scotland and Portugal. Another 14 countries, like the United States, are moving toward routine blood filtration.
“In the U.S., more than 50 percent of the blood supply is already leukocyte-reduced,” she adds.
Proposed FDA guidance
At the time of this report, the U.S. Food and Drug Administration (FDA) a proposed guidance labeled, “Pre-Storage Leukocyte Reduction of Whole Blood and Blood Components Intended for Transfusion.”
The document is the FDA's present stance on pre-storage leukocyte reduction of whole blood and blood components intended for transfusion. It was formulated following discussions held at a FDA workshop, “Implementation of Universal Leukocyte Reduction” in Bethesda two years ago as well as at the 66th meeting of the Blood Products Advisory Committee last June in Silver Spring, MD.
At a recent meeting of the U.S. Department of Health and Human Service's Advisory Committee for Blood Safety and Availability, several advantages of leukocyte reduction were noted.
For instance, Nancy Chance, blood bank coordinator at Riverview Hospital (Noblesville, IN), reports an approximate $3.25-million savings, the majority of that stemming from a reduction in post-operative infections.
In a study of cardiac surgery patients, Dr. Neil Blumberg of the University of Rochester Medical Center reports a two-percent reduction in patient mortality as well as a cost saving of $1700 per patient who received leukocyte-reduced blood. He also notes that if leukocyte-reduced blood were used for cardiac surgery patients, 10,000 to 30,000 lives would be saved each year, a savings of $6 to $12 billion annually.
“Leukoreduction for cardiac surgery has the potential to prevent a greater number of deaths annually in the U.S. than deaths that have occurred in the last two decades from the entire AIDS epidemic due to transfusion,” Dr. Blumberg says. “We urge the committee to consider recommending a policy of leukoreduction of all transfusions to surgical patients.”
Comments on the FDA draft document should be submitted by Monday, April 23. Submit comments to Dockets Management Branch (HFA-305), Food and Drug Administration, 5630 Fishers Lane, room 1061, Rockville, MD 20857. All comments should be identified with the docket number listed.
Additional copies of this draft guidance document are available from: the Office of Communication, Training and Manufacturers Assistance (HFM-40), 1401 Rockville Pike, Rockville, MD 20852-1448, or by calling 1-800-835-4709 or 301-827-1800, or from the Internet at http://www.fda.gov/cber/ guidelines.htm.