PTC Therapeutics announced it will not pursue FDA approval for Translarna (ataluren) in Duchenne muscular dystrophy after regulators signaled the submitted data were unlikely to meet the agency’s standard for substantial evidence of effectiveness. The company said it cannot reconcile key interpretive differences with the FDA and has ended its U.S. filing effort. Industry outlets and subsequent reports framed the withdrawal as the latest regulatory rebuke for a long-running, controversial program that has faced setbacks in Europe and the U.S. The decision underscores the limits of historical or mixed evidence packages in the current regulatory climate and highlights the challenge sponsors face in meeting evolving evidentiary expectations for rare-disease therapies.