October 18, 2019 Emily Hill Chief Financial Officer PTC Therapeutics, Inc. 100 Corporate Court South Plainfield, NJ 07080 Re: PTC Therapeutics, Inc. Form 10-K for the Fiscal Year Ended December 31, 2018 Filed March 1, 2019 File No. 001-35969 Dear Ms. Hill: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Life Sciences