Enzon Inc. has reported preclinical data showing that its bloodsubstitute product, a bovine hemoglobin modified withpolyethylene glycol, runs a reduced risk of rejection by theimmune system.

"PEG-hemoglobin prevents toxicities normally associated withnative unmodified bovine hemoglobin," said Robert Shorr, vicepresident of research. Native hemoglobin can't presently beused due to kidney and other organ toxicities, he said.

Hemoglobin in the urine is associated with damage to kidneyand other organs. In data presented last week at the Federationof American Societies for Experimental Biology in Anaheim,Calif., the company reported that PEG-hemoglobin completelyeliminated hemoglobin in the urine when up to 20 percent oftotal blood volume was replaced, compared with hemoglobinwithout PEG.

Enzon's hemoglobin also has a longer circulating life thanbovine hemoglobin. "In rats, we see a circulating life of about13 hours," Shorr said. "In humans, that would translate to asmuch as a 64-hour half-life. The half-life of native bovinehemoglobin in rats is two hours or less."

The South Plainfield, N.J., company (NASDAQ:ENZN) plans to filean investigational new drug application to begin clinical trialsin 1993. Its stock closed down 13 cents on Monday at $9.88. --Karen Bernstein

(c) 1997 American Health Consultants. All rights reserved.