By Lisa Seachrist

Washington Editor

WASHINGTON — Genzyme General Corp. has finalized its joint venture with Pharming Group NV to develop an enzyme replacement therapy for the lysosomal storage disorder Pompe's disease.

The move marks the second joint venture that the Cambridge, Mass.-based biotech has undertaken in an effort to become the leader in developing treatments for patients suffering from a variety of lysosomal storage disorders. The venture will develop alpha glucosidase to treat Pompe's.

"This is something we know how to do," said Bo Piela, manager of media relations for Genzyme. "We are looking to leverage the infrastructure we have built around Ceredase and Cerezyme for the treatment of Gaucher disease, another lysosomal storage disorder."

Genzyme has already made an equity investment of $14 million in Pharming, of Leiden, the Netherlands. (See BioWorld Today, July 16, 1998, p. 1.) Genzyme will provide another $14 million in development costs for the joint venture, after which the two companies will share development costs equally. Pharming will receive a $7 million milestone payment from Genzyme should alpha glucosidase receive FDA approval.

Like all lysosomal storage disorders, Pompe's disease is a rare genetic disease. It is caused by the partial or total lack of the enzyme human alpha glucosidase. Affecting just 5,000 to 10,000 people in the Western world, the disease takes three forms (infant, juvenile and adult), all of which are fatal.

These diseases arise when a patient lacks the enzymes needed to break molecules down into cellular building blocks. As a result, the molecules accumulate in lysosomes until the cell no longer functions normally. In Pompe's disease, glycogen accumulates in muscles.

"The build-up of glycogen ultimately leads to death," Piela said. "The disease causes progressive muscle weakness, but the ultimate cause of death is respiratory or heart failure."

Patients stricken as infants typically show symptoms in the first few months after birth. They often die before age 2. Those afflicted as juveniles develop progressive muscle weakness, usually succumbing to the disease by age 20. The adult form appears between the ages of 20 and 50.

Pharming has developed transgenic rabbits that secrete human alpha glucosidase in their milk. They received orphan drug designation for the enzyme in September 1996. Pharming has completed Phase I trials to determine safety in healthy volunteers. The joint venture will enter Phase II/III trials by the end of 1998 and aims to file a BLA in the first half of 2000.

Genzyme's Gaucher's disease enzymes, Ceredase and Cerezyme, recorded 1997 sales of $333 million. They are given as an infusion every two weeks, with a year's treatment costing approximately $150,000.

BioMarin Deal Also Centers On Lysosomal Storage

Genzyme also has a joint venture with BioMarin Pharmaceutical Inc., of Novato, Calif., to develop an enzyme replacement treatment for the lysosomal storage disorder mucopolysaccharidosis I (MPS I), a fatal childhood genetic disorder of which the best known form is Hurler syndrome. (See BioWorld Today, June 4, 1998, p. 1.)

BioMarin has completed a pivotal trial for alpha-L-iduronidase as an enzyme replacement in MPS I and will present the results Oct. 31 at the American Society for Human Genetics Meeting in Denver.

"We intend to launch this product sometime next year," Piela said.

Genzyme's stock (NASDAQ:GENZ) closed at $37.25 a share, up $0.8125. *