(May 13, 2024, 2:11 PM EDT) -- ALEXANDRIA, Va. — An effort by Regeneron Pharmaceuticals Inc. to undo a final rejection of an application to patent a method of characterizing proteins failed May 13 when the Patent Trial and Appeal Board said it found no error in a determination by an examiner that substituting prior art neonatal fragment crystallizable receptor (FcRn) resins with Regeneron’s claimed protein A resins would have been obvious....