Kudos for clot buster.

Kudos for clot buster

A bioengineered protein may be almost twice as effective as the drug currently used to dissolve heart-attack-causing blood clots lodged in coronary arteries, according to preliminary results of clinical trials sponsored by the National Heart, Lung, and Blood Institute.

Although streptokinase, a bacterial product, has long been the drug of choice for dissolving blood clots, the protein called tissue plasminogen activator (t-PA) has gained support because of its specificity and immunologically neutral properties (SN: 11/26/83, p. 340; 3/10/84, p. 151). This new drug, based on a naturally occurring human protein, acts only at clots, whereas streptokinase acts throughout the bloodstream and can cause excess bleeding. Streptokinase triggers formation of antibodies, which bind up some of the drug and render it ineffective. But t-PA, as a human protein, is not likely to cause antibody production or allergic reaction.

The current study, reported in the April 4 NEW ENGLAND JOURNAL OF MEDICINE, corroborates the findings of earlier, smaller clinical and animal studies. It involved 214 heart attack patients with severe blockage of the coronary arteries, and was stopped early because t-PA produced such dramatic results. In 66 percent of patients given t-PA produced by recombinant DNA technology, the blocked arteries were significantly reopened. Arteries were reopened in only 36 percent of patients given streptokinase.