HAYWARD, Calif. Generic drug maker Impax Labs is challenging the patent on a drug used to treat patients on kidney dialysis, Impax said Friday.
Impax said it filed a regulatory approval application with the Food and Drug Administration for sevelamer carbonate for suspension in the 2.4 g and 0.8 g strength. The drug is a generic version of Genzyme’s Renvela, used to control serum phosphorus in kidney dialysis patients.
Impax’s application contains a Paragraph IV certification, a legal assertion that the patent covering Renvela is invalid, unenforceable or won’t be infringed by a generic version. Genzyme filed a patent infringement suit against Impax in the U.S. District Court for the District of Maryland on Thursday to halt the FDA’s approval of the generic drug.
Renvela had sales of $6.8 million during the seven-month period ending in April, according to Wolters Kluwer Health.