Entry into a Material Definitive Agreement. On August 25, 2026, PTC Therapeutics, Inc. (the “Company”) entered into an asset purchase agreement (the “Asset Purchase Agreement”) with Sangamo Therapeutics, Inc. (“Sangamo”), pursuant to which the Company agreed to acquire from Sangamo, subject to the terms and conditions set forth in the Asset Purchase Agreement, all of Sangamo ’s right, title and interest in and to the assets primarily related to ST-920, a one-time administered AAV gene therapy…

Director — Hege Sollie-Zetlmayer: Ms. Hege Sollie-Zetlmayer was appointed to the board of directors, filling a vacancy.

Results of Operations and Financial Condition. On July 30, 2026, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended June 30, 2026. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this “Report”) and is incorporated by reference into this

Other Events. The Company is using approximately $328.8 million of the net proceeds from the offering to repurchase for cash $222.0 million in aggregate principal amount of the Existing Convertible Notes pursuant to privately negotiated transactions with certain holders entered into concurrently with the pricing of the offering of the Notes. After giving effect to such expected repurchases of the Existing Convertible Notes, the aggregate principal amount outstanding of Existing Convertible No…

Unregistered Sales of Equity Securities. The information set forth in

Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. The information set forth in

Entry into a Material Definitive Agreement. On June 18, 2026, PTC Therapeutics, Inc. (the “Company”) completed its previously announced private offering of $550,000,000 aggregate principal amount of its 0.0% Convertible Senior Notes due 2031 (the “Notes”) and entered into an indenture with U.S. Bank Trust Company, National Association, as trustee (the “Trustee”), governing the Notes (the “Indenture”). The Notes were sold in a private placement under a purchase agreement, dated as of June 15,…

Other Events. On June 15, 2026, PTC Therapeutics, Inc. (the “Company”) issued a press release announcing the pricing of its previously announced offering (the “Offering”) of $500.0 million aggregate principal amount of 0.00% Convertible Senior Notes due 2031 (the “Notes”). The Company also granted the initial purchasers an option to purchase, within the 13-day period beginning on, and including, the date on which the Notes are first issued, up to an additional $50.0 million aggregate principa…

Director — Alethia Young: Ms. Young resigned from the Board to focus on other commitments but will continue as a consultant.

Results of Operations and Financial Condition. On May 7, 2026, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended March 31, 2026. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this "Report") and is incorporated by reference into this

Director — Jessica Chutter: Jessica Chutter was appointed to the board of directors, bringing extensive healthcare investment banking experience.

Results of Operations and Financial Condition. On February 19, 2026, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter and fiscal year ended December 31, 2025. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this "Report") and is incorporated by reference into this

or this Item 7.01, including Exhibits 99.1 and 99.2, 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 Current Report on Form…

Regulation FD Disclosure. On January 12, 2026, the Company also announced financial guidance for its fiscal year ending December 31, 2026 in the press release, including that the Company anticipates (i) full year total product revenues of $700 million to $800 million, excluding Evrysdi ® (risdiplam) royalty revenue and collaboration revenue and (ii) GAAP R&D and SG&A expense for the full year 2026 of $775 million to $815 million with non-GAAP R&D and SG&A expense for the full year 2026 of $68…

Entry into a Material Definitive Agreement. On December 29, 2025, PTC Therapeutics, Inc. (the “Company”), Royalty Pharma Investments 2019 ICAV (“RPI”), and, for the limited purposes set forth in the Purchase Agreement (as defined below), Royalty Pharma plc, entered into an Amendment No. 2 to Amended and Restated Royalty Purchase Agreement (the “Amendment”), which amends that certain Amended and Restated Royalty Purchase Agreement, dated as of October 18, 2023, as amended by Amendment No. 1 da…

Results of Operations and Financial Condition. On November 4, 2025, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended September 30, 2025. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this “Report”) and is incorporated by reference into this

Results of Operations and Financial Condition. On August 7, 2025, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended June 30, 2025. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this “Report”) and is incorporated by reference into this

Entry into a Material Definitive Agreement. On August 5, 2025, PTC Therapeutics, Inc. (the “Company”), certain of the former securityholders of Censa Pharmaceuticals, Inc., a Delaware corporation (“Censa”), and, for the limited purposes set forth in the agreement, Shareholder Representative Services LLC, a Colorado limited liability company (“SRS”), entered into a Rights Satisfaction Agreement (the “Rights Satisfaction Agreement”), pursuant to which such former securityholders of Censa (the “…

Results of Operations and Financial Condition. On May 6, 2025, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended March 31, 2025. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this “Report”) and is incorporated by reference into this

Results of Operations and Financial Condition. On February 27, 2025, PTC Therapeutics, Inc. (the “Company”) announced its financial results for the quarter and fiscal year ended December 31, 2024. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K (this "Report") and is incorporated by reference into this

or this Item 7.01, including Exhibits 99.1 and 99.2, 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 Current Report on Form…

​ ​ 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: January 3, 2025 By: /s/ Pierre Gravier ​ Name: Pierre Gravier ​ Title: Chief Financial Officer ​ ​

Entry Into a Material Definitive Agreement. On December 31, 2024, PTC Therapeutics, Inc. (the “Company”) and Warren CC Acquisitions, LLC, (the “Landlord”) entered into a First Amendment to Lease Agreement (the “Amendment”), which amends that certain Lease Agreement dated as of May 24, 2022 between the Company and the Landlord (the “Lease Agreement”). The Lease Agreement was initially for two entire buildings comprised of approximately 360,000 square feet of shell condition, modifiable space (…

Entry Into a Material Definitive Agreement. On November 27, 2024, PTC Therapeutics, Inc. (the “Company”), PTC Therapeutics HD, Inc. and Novartis Pharmaceuticals Corporation (“Novartis”) entered into a License and Collaboration Agreement (the “Agreement”), relating to the Company’s PTC518 Huntington's disease program which includes related molecules. Under the Agreement, the Company will receive an upfront payment of $1.0 billion on the Effective Date and up to $1.9 billion in development, reg…

Entry Into a Material Definitive Agreement. On November 26, 2024, PTC Therapeutics, Inc. (the “Company”) entered into an asset purchase agreement (the “PRV Transfer Agreement”) with an affiliate of a large pharmaceutical company (the “Buyer”), pursuant to which the Company agreed to sell to the Buyer a Rare Pediatric Disease Priority Review Voucher (“PRV”) for a purchase price equal to $150.0 million, payable in cash, upon the closing of the sale. The Company was awarded the PRV on November 1…