X0609 4 2026-10-14 0001070081 PTC THERAPEUTICS, INC. PTCT 0001288952 SCHMERTZLER MICHAEL false C/O PTC THERAPEUTICS, INC. 500 WARREN CORPORATE CENTER DRIVE WARREN NJ 07059 true false false false 1 Common Stock 163266 D Common Stock 2026-10-14 4 S 0 2118 59.52 D 1291976 I See footnote Common Stock 2026-10-14 4 S 0 382 60.14 D 1291594 I See footnote This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by Section Six Partners, L.P., of which the Reporting Person is a general partner and limited partner, on May 14, 2026. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $58.85 to $59.82 per share. The Reporting Person hereby undertakes, upon request by the SEC staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Represents shares of common stock held by Section Six Partners, L.P. The Reporting Person is a general and limited partner of Section Six Partners, L.P. The Reporting Person disclaims beneficial ownership of the shares of common stock held by Section Six Partners, L.P. except to the extent of his pecuniary interest therein. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $59.87 to $60.54 per share. The Reporting Person hereby undertakes, upon request by the SEC staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. /s/ Avraham S. Adler, Attorney-in-Fact 2026-10-16