PARSIPPANY, N.J. — Watson Pharmaceuticals is challenging three of Swiss drug maker Novartis' patents on a drug used to treat dementia, Watson said.
The company said subsidiary Watson Labs had filed for approval generic rivastigmine transdermal system patches in the 4.6-mg and 9.5-mg strengths, both designed to last for 24 hours, with the Food and Drug Administration. The patches are used to treat mild to moderate dementia associated with Alzheimer's or Parkinson's disease.
The drug is a generic version of Novartis' Exelon, which had sales of about $424 million during the 12-month period ended in September, according to IMS Health. Novartis responded by filing a patent-infringement suit against Watson on Wednesday in the U.S. District Court for the District of Delaware in order to prevent Watson from commercializing the patches before the expirations of three patents, which are set to occur in 2014 and 2019, according to FDA records.