Item 7.01. Regulation FD Disclosure. On August 19, 2025, PTC Therapeutics, Inc. issued a press release announcing that it had received a Complete Response Letter from the U. S. Food and Drug Administration related to the New Drug Application for vatiquinone for the treatment of children and adults living with Friedreich’s ataxia. The press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this “ Report”) and is incorporated by reference into this Item 7.01. The information in this Report (including Item 7.01 and Exhibit 99.1) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing. All website addresses given in this Report or incorporated herein by reference are for information only and are not intended to be an active link or to incorporate any website information into this Report.

Item 9.01. Financial Statements and Exhibits. (d) Exhibits Exhibit No. Description 99.1 Press Release, dated August 19, 2025 issued by PTC Therapeutics, Inc. ────────────────────────────────────────────────────────────────────────────────────────────────── 104 The cover page from this Current Report on Form 8-K, formatted in Inline XBRL SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned hereunto duly authorized. PTC Therapeutics, Inc. Date: August 19, 2025 By: /s/ Pierre Gravier Name: Pierre Gravier Title: Chief Financial Officer