144/A 0001628280-26-058006 0001288952 XXXXXXXX LIVE 0001070081 PTC THERAPEUTICS, INC. 001-35969 500 Warren Corporate Center Drive Warren NJ 07059 9082227000 Section Six Partners, L.P. Affiliate of Director Common Merrill Lynch 225 Liberty Street Fl 39 New York NY 10281 50000 3650000 83460802 08/19/2026 NASDAQ Common 06/25/2013 Automatic Conversion of Preferred Stock into Common Stock Upon IPO Issuer N 50000 06/25/2013 Automatic Conversion of Preferred Stock into Common Stock upon IPO (Preferred Stock acquired from Issuer for cash) Y This amendment is being filed to revise the name of the seller and certain information related to certain securities to be sold. Michael Schmertzler is a member of the Board of Directors of the Issuer. He is also a general partner and limited partner of Section Six Partners, L.P. Mr. Schmertzler disclaims beneficial ownership of the shares held by Section Six Partners, L.P., except to the extent of his pecuniary interest therein. 08/25/2026 05/14/2026 Michael Schmertzler, as President of S6 GP Holding, LLC, the General Partner of, and on behalf of, Section Six Partners, LP