TKTX, GENZ Markman ruling

Both Transkaryotic (TKTX) and Genzyme (GENZ) reported favorable claims construction related to GENZ's U.S. patent No. 5,356,804 following a Markman ruling by Judge Gregory Sleet in the U.S. District Court for the District of Delaware. The ruling comes in a patent infringement suit filed by GENZ claiming that Replagal agalsidase alfa enzyme replacement therapy for Fabry disease from TKTX infringes the '804 patent.

The patent, to which GENZ has an exclusive license from Mount Sinai School of Medicine (New York, N.Y.), covers methods of making alpha-galactosidase, an enzyme deficient in patients with Fabry disease, in mammalian cells and genetically engineered cells. According to TKTX, the judge adopted its proposed definition that the patent covers the production of alpha-galactosidase using a combination of "the chromosome of the host cell and an exogenous nucleotide sequence encoding human alpha-galactosidase A with a promoter and selectable marker." TKTX said its method of producing Replagal is not based on this combination, because the company relies on the endogenous alpha-galactosidase A already resident in the cell and introduces only a promoter sequence. ...