Case No. 05-1313 (November 29, 2006). Kenyon & Kenyon LLP client Impax Laboratories, Inc. announced that the United States Court of Appeals for the Federal Circuit ruled that the district court had erred in deciding, after trial, that the patent relating to the use of riluzole in treating ALS (Pat. No. 5,527,814) was valid. Thus, the Federal Circuit vacated that decision and remanded it back to the district court for further proceedings related to the validity issue of anticipation. Rilutek, marketed by Aventis for the treatment of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, had U.S. sales of approximately $37 million for the 12 months ended August 31, 2006, according to Wolters Kluwer Health.