Form 8-K
8-K — PTC THERAPEUTICS, INC.
Accession: 0001070081-26-000023
Filed: 2026-09-21
Period: 2026-09-21
CIK: 0001070081
SIC: 2834 (PHARMACEUTICAL PREPARATIONS)
Item: Regulation FD Disclosure
Item: Other Events
Item: Financial Statements and Exhibits
Documents
8-K — tmb-20260921x8k.htm (Primary)
EX-99.1 (tmb-20260921xex99d1.htm)
GRAPHIC (tmb-20260921xex99d1001.jpg)
XML — IDEA: XBRL DOCUMENT (R1.htm)
8-K
8-K (Primary)
Filename: tmb-20260921x8k.htm · Sequence: 1
PTC THERAPEUTICS, INC._September 21, 2026
0001070081false00010700812026-09-212026-09-21
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): September 21, 2026
PTC THERAPEUTICS, INC.
(Exact Name of Company as Specified in Charter)
Delaware
001-35969
04-3416587
(State or Other Jurisdiction
(Commission
(IRS Employer
of Incorporation)
File Number)
Identification No.)
500 Warren Corporate Center Drive
Warren, NJ
07059
(Address of Principal Executive Offices)
(Zip Code)
Registrant’s telephone number, including area code: (908) 222-7000
Not applicable
(Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):
☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Securities registered pursuant to Section 12(b) of the Act:
Title of each class
Trading Symbol(s)
Name of each exchange on which registered
Common Stock, $0.001 par value per share
PTCT
Nasdaq Global Select Market
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
Emerging growth company ☐
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Item 7.01. Regulation FD Disclosure.
On September 21, 2026, PTC Therapeutics, Inc. (the “Company”) issued a press release announcing that it completed the previously announced agreement with Sangamo Therapeutics, Inc. (“Sangamo”) to acquire ST-920, a BLA-stage one-time administered AAV gene therapy product candidate for Fabry disease, (the “Acquisition”). 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 Item 7.01, including 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 8.01. Other Information.
On September 21, 2026, the Company issued a press release announcing it completed the Acquisition. As previously disclosed, a rolling biologics license application (“BLA”) submission to the U.S. Food and Drug Administration for accelerated approval of ST-920 is expected to be completed in the fourth quarter of 2026. The BLA is based on the evidence of meaningful favorable clinical effect on renal function and safety and tolerability profile over 52 weeks in the Phase 1/2 STAAR study of ST-920. The Company expects to also pursue regulatory approval of ST-920 outside of the United States.
Item 9.01. Financial Statements and Exhibits.
(d) Exhibits
Exhibit No.
Description
99.1
Press Release, dated September 21, 2026 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: September 21, 2026
By:
/s/ Pierre Gravier
Name:
Pierre Gravier
Title:
Chief Financial Officer
EX-99.1
EX-99.1
Filename: tmb-20260921xex99d1.htm · Sequence: 2
Exhibit 99.1
PTC Completes Acquisition of ST-920 Fabry Disease Gene Therapy
– Completion of BLA submission expected in Q4 2026 –
WARREN, N.J., Sept. 21, 2026 – PTC Therapeutics, Inc., (NASDAQ: PTCT) today announced that it completed the previously announced agreement with Sangamo Therapeutics, Inc. to acquire ST-920 – a BLA-stage, one-time administered AAV gene therapy for Fabry disease. A rolling BLA submission to FDA for accelerated approval of ST-920 is expected to be completed in Q4 2026.
“Our team looks forward to completing the ST-920 BLA submission and potentially bringing a one-time administered, safe and effective durable disease treatment that addresses the limitations of chronic enzyme replacement therapy to the Fabry community,” said Matthew B. Klein, M.D., Chief Executive Officer.
About ST-920
ST-920 or isaralgagene civaparvovec is a one-time administered AAV gene therapy product candidate for the treatment of Fabry disease. In clinical studies, isaralgagene civaparvovec enabled long-term production of the deficient alpha-galactosidase A (α-Gal A) enzyme and significant reduction in globotriaosylceramide (Gb3) levels with durable clinical benefit and reduction of the burden associated with chronic Enzyme Replacement Therapy (ERT). The FDA has granted Orphan Drug, Fast Track, and RMAT designations to isaralgagene civaparvovec, which has also received Orphan Medicinal Product designation and PRIME eligibility from the European Medicines Agency and Innovative Licensing and Access Pathway from the U.K. Medicines and Healthcare products Regulatory Agency.
About Fabry Disease
Fabry disease is a lysosomal storage disorder caused by mutations in the galactosidase alpha gene (GLA), which leads to deficient alpha-galactosidase A (α-Gal A) enzyme activity, which is necessary for metabolizing globotriaosylceramide (Gb3). The buildup of Gb3 in the cells can cause serious damage to vital organs, including the kidney, heart, nerves, eyes, gut and skin. Symptoms of Fabry disease can include decreased or absent sweat production, heat intolerance, angiokeratoma (skin blemishes), vision problems, kidney disease, heart failure, gastrointestinal disturbance, mood disorders, neuropathic pain and tingling in the extremities.
About PTC Therapeutics, Inc.
PTC is a global biopharmaceutical company dedicated to the discovery, development and commercialization of clinically differentiated medicines for children and adults living with rare disorders. PTC is advancing a robust and diversified pipeline of transformative medicines as part of its mission to provide access to best-in-class treatments for patients with unmet medical needs. The company’s strategy is to leverage its scientific expertise and global commercial infrastructure to optimize value for patients and other stakeholders.
For more information please contact:
Investors:
Ellen Cavaleri
+1 (615) 618-6228
ecavaleri@ptcbio.com
Media:
Jeanine Clemente
+1 (908) 912-9406
jclemente@ptcbio.com
Forward-Looking Statements:
This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. All statements contained in this release, other than statements of historic fact, are forward-looking statements, including the Company’s expectations regarding the anticipated benefits of ST-920; the timing of and potential for regulatory submissions and potential commercial launch for ST-920; and PTC’s strategy, future operations, future financial position, future revenues, projected costs; and the objectives of management. Other forward-looking statements may be identified by the words, “guidance,” “plan,” “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue,” “aim,” and similar expressions.
PTC’s actual results, performance or achievements could differ materially from those expressed or implied by forward-looking statements it makes as a result of a variety of risks and uncertainties, including those related to: PTC’s ability to complete the BLA submission and obtain regulatory approval for and then commercialize ST-920; the outcome of pricing, coverage and reimbursement negotiations with third party payors for PTC’s products or product candidates that PTC commercializes or may commercialize in the future; expectations with respect to Sephience, including commercialization and the potential achievement of sales milestones and contingent payments that PTC may be obligated to make; PTC’s ability to maintain its marketing authorization of Translarna for the treatment of nmDMD in geographies in which it has been approved and the effect of the European Commission’s adoption of the negative opinion from the Committee for Medicinal Products for Human Use (CHMP) on Translarna and the withdrawal of the Translarna NDA in the US on other regulatory bodies; expectations with respect to PTC’s license and collaboration agreement with Novartis Pharmaceuticals Corporation for votoplam for the treatment of Huntington’s disease including its right to receive development, regulatory and sales milestones, profit sharing and royalty payments from Novartis, the design and expected timing of clinical trials and studies, the availability of data, and regulatory submissions and responses, including potential accelerated approval; expectations with respect to ST-920, including the potential achievement of regulatory milestone payments that PTC may be obligated to make; expectations with respect to Upstaza/Kebilidi, including commercialization, manufacturing capabilities, and the potential achievement of sales milestones and contingent payments that PTC may be obligated to make;
expectations with respect to vatiquinone, including with respect to the design and expected timing of clinical trials and studies, the availability of data, and regulatory submissions and responses and potential approvals and other matters; expectations with respect to the commercialization of Evrysdi under PTC’s SMA collaboration; expectations with respect to the commercialization of Tegsedi and Waylivra; expectations regarding PTC’s product candidates, including the timing of clinical trials and studies; significant business effects, including the effects of industry, market, economic, political or regulatory conditions; changes in tax and other laws, regulations, rates and policies; the eligible patient base and commercial potential of PTC’s products and product candidates; PTC’s scientific approach and general development progress; PTC’s ability to satisfy its obligations under the terms of its lease agreements; the sufficiency of PTC’s cash resources and its ability to obtain adequate financing in the future for its foreseeable and unforeseeable operating expenses and capital expenditures; and the factors discussed in the “Risk Factors” section of PTC’s Annual Report on Form 10-K, as well as any updates to these risk factors filed from time to time in PTC’s other filings with the SEC. You are urged to carefully consider all such factors.
As with any pharmaceutical under development, there are significant risks in the development, regulatory approval and commercialization of new products. There are no guarantees that any product will receive or maintain regulatory approval in any territory, or prove to be commercially successful, including Sephience, Translarna, Emflaza, Upstaza, Kebilidi, Evrysdi, Tegsedi, Waylivra or ST-920.
The forward-looking statements contained herein represent PTC’s views only as of the date of this press release and PTC does not undertake or plan to update or revise any such forward-looking statements to reflect actual results or changes in plans, prospects, assumptions, estimates or projections, or other circumstances occurring after the date of this press release except as required by law.
GRAPHIC
GRAPHIC
Filename: tmb-20260921xex99d1001.jpg · Sequence: 3
Binary file (5563 bytes)
Download tmb-20260921xex99d1001.jpg
XML — IDEA: XBRL DOCUMENT
XML
Filename: R1.htm · Sequence: 9
v3.26.3
Document and Entity Information
Sep. 21, 2026
Document and Entity Information [Abstract]
Document Type
8-K
Document Period End Date
Sep. 21, 2026
Entity File Number
001-35969
Entity Registrant Name
PTC THERAPEUTICS, INC.
Entity Incorporation, State or Country Code
DE
Entity Tax Identification Number
04-3416587
Entity Address, Address Line One
500 Warren Corporate Center Drive
Entity Address, City or Town
Warren
Entity Address, State or Province
NJ
Entity Address, Postal Zip Code
07059
City Area Code
908
Local Phone Number
222-7000
Written Communications
false
Soliciting Material
false
Pre-commencement Tender Offer
false
Pre-commencement Issuer Tender Offer
false
Title of 12(b) Security
Common Stock, $0.001 par value per share
Trading Symbol
PTCT
Security Exchange Name
NASDAQ
Entity Emerging Growth Company
false
Entity Central Index Key
0001070081
Amendment Flag
false
X
- Definition
Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.
+ References
No definition available.
+ Details
Name:
dei_AmendmentFlag
Namespace Prefix:
dei_
Data Type:
xbrli:booleanItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Area code of city
+ References
No definition available.
+ Details
Name:
dei_CityAreaCode
Namespace Prefix:
dei_
Data Type:
xbrli:normalizedStringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Cover page.
+ References
No definition available.
+ Details
Name:
dei_CoverAbstract
Namespace Prefix:
dei_
Data Type:
xbrli:stringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.
+ References
No definition available.
+ Details
Name:
dei_DocumentPeriodEndDate
Namespace Prefix:
dei_
Data Type:
xbrli:dateItemType
Balance Type:
na
Period Type:
duration
X
- Definition
The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.
+ References
No definition available.
+ Details
Name:
dei_DocumentType
Namespace Prefix:
dei_
Data Type:
dei:submissionTypeItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Address Line 1 such as Attn, Building Name, Street Name
+ References
No definition available.
+ Details
Name:
dei_EntityAddressAddressLine1
Namespace Prefix:
dei_
Data Type:
xbrli:normalizedStringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Name of the City or Town
+ References
No definition available.
+ Details
Name:
dei_EntityAddressCityOrTown
Namespace Prefix:
dei_
Data Type:
xbrli:normalizedStringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Code for the postal or zip code
+ References
No definition available.
+ Details
Name:
dei_EntityAddressPostalZipCode
Namespace Prefix:
dei_
Data Type:
xbrli:normalizedStringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Name of the state or province.
+ References
No definition available.
+ Details
Name:
dei_EntityAddressStateOrProvince
Namespace Prefix:
dei_
Data Type:
dei:stateOrProvinceItemType
Balance Type:
na
Period Type:
duration
X
- Definition
A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2
+ Details
Name:
dei_EntityCentralIndexKey
Namespace Prefix:
dei_
Data Type:
dei:centralIndexKeyItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Indicate if registrant meets the emerging growth company criteria.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2
+ Details
Name:
dei_EntityEmergingGrowthCompany
Namespace Prefix:
dei_
Data Type:
xbrli:booleanItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.
+ References
No definition available.
+ Details
Name:
dei_EntityFileNumber
Namespace Prefix:
dei_
Data Type:
dei:fileNumberItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Two-character EDGAR code representing the state or country of incorporation.
+ References
No definition available.
+ Details
Name:
dei_EntityIncorporationStateCountryCode
Namespace Prefix:
dei_
Data Type:
dei:edgarStateCountryItemType
Balance Type:
na
Period Type:
duration
X
- Definition
The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2
+ Details
Name:
dei_EntityRegistrantName
Namespace Prefix:
dei_
Data Type:
xbrli:normalizedStringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2
+ Details
Name:
dei_EntityTaxIdentificationNumber
Namespace Prefix:
dei_
Data Type:
dei:employerIdItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Local phone number for entity.
+ References
No definition available.
+ Details
Name:
dei_LocalPhoneNumber
Namespace Prefix:
dei_
Data Type:
xbrli:normalizedStringItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 13e
-Subsection 4c
+ Details
Name:
dei_PreCommencementIssuerTenderOffer
Namespace Prefix:
dei_
Data Type:
xbrli:booleanItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 14d
-Subsection 2b
+ Details
Name:
dei_PreCommencementTenderOffer
Namespace Prefix:
dei_
Data Type:
xbrli:booleanItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Title of a 12(b) registered security.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b
+ Details
Name:
dei_Security12bTitle
Namespace Prefix:
dei_
Data Type:
dei:securityTitleItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Name of the Exchange on which a security is registered.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection d1-1
+ Details
Name:
dei_SecurityExchangeName
Namespace Prefix:
dei_
Data Type:
dei:edgarExchangeCodeItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 14a
-Subsection 12
+ Details
Name:
dei_SolicitingMaterial
Namespace Prefix:
dei_
Data Type:
xbrli:booleanItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Trading symbol of an instrument as listed on an exchange.
+ References
No definition available.
+ Details
Name:
dei_TradingSymbol
Namespace Prefix:
dei_
Data Type:
dei:tradingSymbolItemType
Balance Type:
na
Period Type:
duration
X
- Definition
Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Securities Act
-Number 230
-Section 425
+ Details
Name:
dei_WrittenCommunications
Namespace Prefix:
dei_
Data Type:
xbrli:booleanItemType
Balance Type:
na
Period Type:
duration