PITTSBURGH, April 23 -- Preliminary results of a new bio-artificial liver assist device were presented by University of Pittsburgh Medical Center (UPMC) researchers today at the 44th annual American Society for Artificial Internal Organs (ASAIO) conference in New York City. The device, designed by Excorp Medical Inc., significantly improved liver failure in animal studies, and researchers anticipate their results will help secure approval to begin studies in humans soon.
The researchers are awaiting U.S. Food and Drug Administration (FDA) approval to allow further testing in humans as a phase I clinical trial which will evaluate whether the device is safe.
The Excorp bio-artificial liver assist device is intended to provide temporary support to patients with acute liver failure until their liver recovers spontaneously or until transplantation is possible. When human trials begin, researchers will place patients with acute liver failure on the device, which is connected to a vein and remains outside their bodies. Researchers believe it should help remove toxins from the patient's own liver cells, as the patient's blood circulates in a chamber with pig liver cells inside polymer membranes. The membranes allow toxins to pass through, but prevents proteins, and other cell byproducts from the pig cells to get into the patient's blood.
"Initially, the agreement between UPMC and Excorp allowed researchers to gather engineering and pre-clinical information about the device," said Jack Patzer, Ph.D., assistant professor of surgery and chemical engineering at the University of Pittsburgh, who presented the findings at the ASAIO meeting.
"But with the bio-artificial liver assist device demonstrating such a significant impact on the course of liver failure in our animal trials, we hope within the month to secure FDA approval to begin phase I human trials in our patients," added George V. Mazariegos, M.D., assistant professor of surgery at the University of Pittsburgh Thomas E. Starzl Transplantation Institute.
The UPMC study presented results on an animal model of acute liver failure, comparing the performance of the Excorp device against standard treatment. The animals were divided into three treatment groups, one receiving standard intensive care attention, and the remaining two groups being placed on the bio-artificial liver assist device at either 16-18 hours or 24-26 hours after liver failure was initiated.
The report indicated survival times in the groups treated with the Excorp device could be extended. These results suggest that the bio-artificial liver assist device does in fact have a marked effect on the course of acute liver failure. The intercranial pressure also improved in the treated animals.
The anticipated phase I human trials of the device would have the primary aim of ensuring the safety of the device for human use. The researchers would monitor the clinical stability of patients, their neurological status, and development of infection. Researchers also hope to gain insight about the device's impact on treating liver failure, although a second trial would need to be conducted to thoroughly study its treatment efficacy.
"We are very encouraged by these preliminary findings," commented Dr. Mazariegos. "The need for some type of bridging device between liver recovery or transplantation is intense. This bio-artificial liver assist device may someday help the thousands of liver failure patients whose options are limited."
Acute liver failure can be caused by poisonous mushrooms, reactions to Tylenol toxicity, or as a result of a virus. There are currently more than 10,000 patients awaiting liver transplants in the United States. Less than five percent of the approximately 4,000 patients who underwent liver transplants in 1996 had acute liver failure, according to the United Network for Organ Sharing.
The UPMC houses the world's largest liver transplant program, where surgeons perform more types of transplants than any other center. Excorp Medical, Inc., is an emerging company focused on the therapeutic application of cell-culture and bioengineering technology.