Studies show Biopure's oxygen therapeutic improves oxygenation and prevents tissue damage.

Biopure Corporation (Cambridge, MA; 617-234-6826) announced that its investigational hemoglobin-based oxygen therapeutic, Hemopure (hemoglobin glutamer - 250 (bovine)), has been shown to improve tissue oxygenation and prevent tissue damage in ischemic conditions relating to hemorrhagic shock, brain hypoxia and heart attack, according to results from pharmacology studies recently reported at the 27th Annual Meeting of the International Society on Oxygen Transport to Tissue (ISOTT) at Dartmouth College (Hanover, NH).

"This research adds to a growing body of literature showing that Hemopure delivers oxygen efficiently and may have potential use in treating ischemia-related conditions," said Carl W. Rausch, chairman and chief executive officer of Biopure. Hemopure is being evaluated in humans in a pivotal United States Phase III clinical trial for its ability to eliminate or reduce red blood cell transfusions in orthopedic surgery.

At the ISOTT meeting, study results were presented showing the effects of low doses of Hemopure in three different animal models of hypoxia (oxygen deprivation). Results from one study showed that Hemopure restored brain oxygenation and stabilized hemodynamic parameters (such as blood pressure and cardiac output) following hemorrhagic shock (physical collapse caused by sudden, massive blood loss). Results from a second study demonstrated the product's ability to maintain oxygenation of hemoglobin in the brain following respiratory hypoxia. A third study showed that an infusion of Hemopure significantly reduced injury to the heart muscle following heart attack and reperfusion.

Cerebral Resuscitation and Oxygenation in Trauma Hemorrhagic shock, hypoxia and hypotension (low blood pressure) are significant causes of brain ischemia and death following major trauma. A pharmacology study presented by Geoffrey T. Manley, MD, PhD, a neurosurgeon at the San Francisco Injury Center, University of California (San Francisco, CA), evaluated the effect of Hemopure on brain oxygen tension and mean arterial pressure in hemorrhaged swine. Results showed that small volume administration of Hemopure significantly increased (P0.001) brain tissue oxygen tension (a measure of brain oxygenation) from 7.6 mm Hg (plus or minus 5.3) to 44.6 mm Hg (plus or minus 8.1) and increased mean arterial pressure to 84 percent of baseline, demonstrating that the product restored brain oxygen and hemodynamic parameters and stabilized the hemorrhaged animals.

Dr. Manley concluded that these results suggest that small volume resuscitation with Hemopure may provide an ideal fluid for rapid and early cerebral resuscitation, particularly in the pre-hospital setting, and may provide temporary oxygen-carrying support, or an "oxygen bridge," during transport and initial hospital management of trauma patients.

Another pharmacology study, presented by Jeffrey F. Dunn, PhD, director of the Biomedical Nuclear Magnetic Resonance Research Center at Dartmouth Hitchcock Medical Center (Hanover, NH), evaluated the effect of Hemopure on brain oxygenation in acute hypoxia in rats. The effects of hypoxia on the levels of oxygenated hemoglobin in the brain were measured by a magnetic resonance technique called blood oxygen level dependent imaging. Results showed significantly higher levels of oxygenated hemoglobin in animals treated with Hemopure than in control animals receiving saline or no treatment.

Coronary artery occlusion (blockage) can lead to severe myocardial injury (heart damage) by limiting oxygen delivery to the heart. David J. Lefer, PhD, assistant professor of physiology at Louisiana State University Medical Center (Shreveport, LA), presented the results of a pharmacology study evaluating the effects of Hemopure on cardiovascular function and injury to the heart in a dog model of myocardial ischemia caused by coronary artery occlusion. Hemodynamic and cardiac parameters, blood borne markers of tissue injury and myocardial tissue samples showed that pretreatment with Hemopure (10 percent of total blood volume) significantly protected against the loss of cardiac function and reduced the extent of injury to the heart muscle following myocardial ischemia and reperfusion compared to control animals receiving an equal amount of saline.

Biopure is a leading developer, manufacturer and marketer of oxygen therapeutics. These pharmaceuticals are intravenously administered into the circulatory system to deliver oxygen to the body's tissues. Hemopure is an investigational product being evaluated for human use in a pivotal United States Phase III clinical trial. Oxyglobin (hemoglobin glutamer - 200 (bovine)), the only hemoglobin-based oxygen therapeutic approved by the United States Food and Drug Administration, is commercially available in the United States for the treatment of anemia in dogs, regardless of the cause.

Both products consist of bovine hemoglobin that has been purified, chemically cross-linked for stability and formulated in a balanced salt solution similar to Ringer's lactate. These polymerized hemoglobin molecules have no cell membrane, are much smaller than red blood cells, circulate in plasma (the fluid part of blood) when administered, and have a lower viscosity (resistance to flow) and more readily release oxygen to tissues (P50 of 38 mm Hg) than blood. Both products are stable at room temperature for at least two years, are compatible with all blood types, and are purified to remove potential infectious agents and other contaminants.