By Randall Osborne

West Coast Editor

Edging nearer to filing for marketing approval in Europe and U.S., the joint venture between Genzyme General Corp. and Pharming Group NV began a Phase II/III trial of recombinant alpha glucosidase in infants afflicted with Pompe's disease, caused by a shortage of the enzyme.

"The trial is designed as a Phase II trial, but there's always the possibility that, if the results are dramatic, we would seek approval [based on them]," said Bo Piela, manager of media relations for Genzyme.

"There have been positive results in the first trial, at Duke University [Medical Center]," he told BioWorld Today. "We hope to be able to build on those results. That was a small trial, and this will be larger." He declined to specify the number of patients in the new trial, conducted at centers in Europe and the U.S.

The Duke Phase I/II study involved three infants, and results were published March 20 in the journal Genetics and Medicine.

"All patients treated so far are still alive after one year," Piela said. "You try to diagnose as quickly as possible and get them on it as early as possible. We've seen clearing of the glycogen buildup, but we've only followed them for a short time."

Alpha glucosidase is required for breaking down glycogen for conversion to glucose. Otherwise, the glycogen builds up in the body, leading to damage to the skeletal system, as well as the heart and lungs. In the infantile form, Pompe's disease usually means heart failure before age 1. In patients who develop it as juveniles, motor disabilities result, with severe respiratory complications and death within 20 or 30 years.

Between 5,000 and 10,000 people in the U.S. and Europe are believed to have Pompe's disease. Genzyme, of Cambridge, Mass., and Pharming, of Leiden, the Netherlands, have been working on the enzyme treatment since 1998, when they finalized their joint venture, called Genzyme-Pharming Alliance LLC. (See BioWorld Today, Oct. 15, 1998.)

Pharming developed transgenic rabbits that secrete human alpha glucosidase in their milk, and Genzyme has rights to a cell-derived form, Piela said. The drug received orphan designation in 1996, and Genzyme expects to use its marketing experience with two other enzyme replacement products - Ceredase and Cerezyme, for Gaucher disease - in selling alpha glucosidase.

Genzyme's stock (NASDAQ:GENZ) closed Friday at $90.33, down $2.17. n