Firms vie to treat genetic disease

From Philadelphia, at the annual meeting of the American Society of Human Genetics

Genzyme stands at the center of another enzyme-replacement story. The rare, fatal genetic condition in this instance is Fabry’s disease. In people with the illness, lack of the enzyme alpha-galactosidase A results in an abnormal buildup of certain lipids in blood vessel cells.

This causes episodes of severe pain and progressively damages the kidneys and heart. Genzyme scientists and collaborators from Mt. Sinai Medical Center in New York City infused the missing enzyme into 29 adults with Fabry’s disease. The treatment completely cleared the dangerous lipid in the hearts, kidneys, and skin of 20 patients. In all but one of the others, the treatment significantly slashed the lipid accumulation. Seeking approval for this therapy, Genzyme has submitted its data to the Food and Drug Administration.

Investigators from Transkaryotic Therapies (TKT) of Cambridge, Mass., and the National Institutes of Health have had similar success at treating Fabry’s disease with alpha-galactosidase A. Like Genzyme, TKT has asked the FDA for an exclusive license for the therapy.

Adding to the corporate intrigue, Genzyme is suing TKT, claiming the company has infringed on its patents covering production of alpha-galactosidase A. TKT hasn’t disclosed how it makes the enzyme, but the firm may be using its controversial technology known as gene activation. Most biotech firms produce a human protein by adding the gene that encodes it to animals or to cells growing in the laboratory. In contrast, TKT has developed methods to activate particular genes within human cells. With this strategy, TKT has sought to evade other companies’ patents on several blockbuster drugs.