On Tuesday, September 12, 2017, as expected, Regeneron Pharmaceuticals Inc. petitioned the Court of Appeals for the Federal Circuit (CAFC) for a rehearing en banc of its panel decision rendered in Regeneron Pharmaceuticals Inc. v. Merus N.V., 864 F3d 343 (Fed. Cir. 2017). On September 26, 2017, Washington Legal Foundation (WLF) filed an amicus brief with the CAFC requesting the court grant Regeneron’s petition for rehearing en banc. WLF’s brief asserts that the panel decision conflicts with the court’s earlier precedent in Therasense, Inc. v. Becton, Dickinson and Co., 649 F.3d 1276 (Fed. Cir. 2011)(en banc) and Star Scientific, Inc. v. R.J. Reynolds Tobacco Co., 537 F.3d 1357 (Fed. Cir. 2008), and that inequitable conduct claims are likely to proliferate as a result of the panel decision.