ZURICH, Aug 17 (Reuters) - Novartis said a U.S. district court upheld the validity of the dosage regimen patent for its best-selling multiple sclerosis (MS) drug Gilenya.

The Swiss drugmaker in a statement said on Monday that the decision meant the generic proposed by HEC Pharm Co. would infringe the dosage regimen patent.

The U.S. Food and Drug Administration approved three generic versions of the Novartis treatment in December. (Reporting by Silke Koltrowitz Editing by Chris Reese)