The patent infringement suit filed against Transkaryotic Therapies Inc. last week by Genzyme General is likely be argued on more narrow grounds than TKTX's ongoing litigation with Amgen Inc., as TKTX will be defending against a single process patent in the GENZ suit compared to five composition and process patents in the AMGN litigation over erythropoietin. Nevertheless, there may be parallels between the cases, focused on arguments over production.

In the GENZ matter, TKTX will have to defend against U.S. Patent No. 5,356,804, issued in 1990, covering the production of alpha-galactodisase in mammalian cells. The patent, exclusively licensed to GENZ from Mount Sinai School of Medicine in New York, relates to GENZ's Fabrazyme agalsidase beta enzyme replacement therapy to treat Fabry disease.