Two years ago, Federal Circuit Judge Kimberly Moore found it relatively easy to side with Apple Inc. when it sought to enjoin Samsung from marketing a few smartphone features. After all, she wrote at the time, “Apple does not seek to enjoin the sale of lifesaving drugs.”

Next week, that much thornier issue arrives at the U.S. Court of Appeals for the Federal Circuit. Sanofi, Regeneron Pharmaceuticals Inc. and Kirkland & Ellis partner Paul Clement will warn the D.C.-based appellate court that it’s putting patient lives at risk if it upholds a ban on its cholesterol-fighting biologic drug Praluent.