The Company	6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The Company PTC Therapeutics, Inc. (the “Company” or “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. PTC’s strategy is to leverage its scientific expertise and global commercial infrastructure to optimize value for its patients and other stakeholders. PTC has a diversified therapeutic portfolio pipeline that includes several commercial products and product candidates in various stages of development, including clinical, pre-clinical and research and discovery stages, focused on the development of new treatments for multiple therapeutic areas for rare diseases relating to neurology and metabolism. The Company has two products, Translarna™ (ataluren) and Emflaza^® (deflazacort), for the treatment of Duchenne muscular dystrophy (“DMD”), a rare, life-threatening disorder. Translarna has marketing authorization in Russia for the treatment of nonsense mutation Duchenne muscular dystrophy (“nmDMD”) in patients aged two years and older, and in Brazil for the treatment of nmDMD in ambulatory patients two years and older and for continued treatment of patients that become non-ambulatory, as well as in various other countries. Emflaza is approved in the United States for the treatment of DMD in patients two years and older. The Company previously had a marketing authorization for Translarna in the European Economic Area (“EEA”), which had been subject to annual review and renewal by the European Commission (“EC”) following reassessment by the European Medicines Agency (“EMA”) of the benefit-risk balance of the authorization. In September 2022, the Company submitted a Type II variation to the EMA to support conversion of the conditional marketing authorization for Translarna to a standard marketing authorization, which included a report on the placebo-controlled trial of Study 041 and data from the open-label extension. In February 2023, the Company also submitted an annual marketing authorization renewal request to the EMA. In September 2023, the Committee for Medicinal Products for Human Use (“CHMP”), gave a negative opinion on the conversion of the conditional marketing authorization to full marketing authorization of Translarna for the treatment of nmDMD and a negative opinion on the renewal of the existing conditional marketing authorization of Translarna for the treatment of nmDMD. In January 2024, the CHMP issued a negative opinion for the renewal of the conditional marketing authorization following a re-examination procedure. In May 2024, the EC decided not to adopt the CHMP’s negative opinion for the renewal of the conditional marketing authorization of Translarna and returned such opinion to the CHMP for re-evaluation. In June 2024, following the EC’s request for re-review, the CHMP issued a negative opinion on the renewal of the conditional marketing authorization of Translarna for the treatment of nmDMD. In October 2024, the CHMP maintained its negative opinion for the renewal of the conditional marketing authorization following the requested reexamination procedure. In March 2025, the EC adopted the opinion of the CHMP to not renew the authorization of Translarna for the treatment of nmDMD. However, the EC indicated that individual countries within the European Union (“EU”) can leverage Articles 117(3) and 5(1) of the EU Directive 2001/83 to allow continued commercial use of Translarna. Translarna is an investigational new drug in the United States. Following the Company’s announcement of top-line results from the placebo-controlled trial of Study 041 in June 2022, the Company submitted a meeting request to the U.S. Food and Drug Administration (“FDA”) to gain clarity on the regulatory pathway for a potential resubmission of a New Drug Application (“NDA”) for Translarna. The FDA provided initial written feedback that Study 041 does not provide substantial evidence of effectiveness to support an NDA resubmission. The Company held a Type C meeting with the FDA in the fourth quarter of 2023 to discuss the totality of Translarna data. Based on feedback from the FDA, the Company resubmitted the NDA in July 2024, based on the results from Study 041 and from the Company’s international drug registry study for nmDMD patients receiving Translarna. In October 2024, the FDA accepted for review the resubmission of the NDA for Translarna for the treatment of nmDMD. As this was an NDA resubmission following a complete response letter to the NDA which was filed over protest in 2016, the FDA is not obligated to follow the review timelines under Prescription Drug User Fee Act guidelines and an action date has not been provided. The Company has developed Sephience™ (sepiapterin), a product for the treatment of phenylketonuria (“PKU”), a rare inherited metabolic disease which affects the brain. On July 28, 2025, Sephience™ was approved by the FDA for the treatment of pediatric and adult patients living with PKU in the United States. On June 19, 2025, Sephience was granted marketing authorization by the EC for the treatment of children and adults living with PKU within the EEA. The Company also made a regulatory submission for Sephience for the treatment of PKU in Brazil in the third quarter of 2024, with a regulatory decision expected in the second half of 2025, and in Japan in the fourth quarter of 2024, with a regulatory decision expected in the fourth quarter of 2025. The Company has developed Upstaza™ (eladocagene exuparvovec), a gene therapy for the treatment of Aromatic L-Amino Acid Decarboxylase (“AADC”) deficiency (“AADC deficiency”), a rare central nervous system (“CNS”) disorder arising from reductions in the enzyme AADC that results from mutations in the dopa decarboxylase gene. In July 2022, the EC approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA. In November 2022, the Medicines and Healthcare Products Regulatory Agency approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the United Kingdom. In November 2024, the FDA approved the Company’s gene therapy treatment of AADC deficiency, which is marketed under the brand name Kebilidi™ in the United States. The Company holds the rights for the commercialization of Tegsedi^® (inotersen) and Waylivra^® (volanesorsen) for the treatment of rare diseases in countries in Latin America and the Caribbean pursuant to the Collaboration and License Agreement (the “Tegsedi-Waylivra Agreement”), dated August 1, 2018, by and between the Company and Akcea Therapeutics, Inc. (“Akcea”), a subsidiary of Ionis Pharmaceuticals, Inc. Tegsedi has received marketing authorization in the United States, the European Union (the “EU”) and Brazil for the treatment of stage 1 or stage 2 polyneuropathy in adult patients with hereditary transthyretin amyloidosis (“hATTR amyloidosis”). In August 2021, ANVISA, the Brazilian health regulatory authority, approved Waylivra as the first treatment for familial chylomicronemia syndrome (“FCS”) in Brazil. In December 2022, ANVISA approved Waylivra for the treatment of familial partial lipodystrophy (“FPL”). Waylivra has also received marketing authorization in the EU for the treatment of FCS. The Company also has a spinal muscular atrophy (“SMA”) collaboration with F. Hoffman-La Roche Ltd and Hoffman-La Roche Inc. (referred to collectively as “Roche”) and the Spinal Muscular Atrophy Foundation (“SMA Foundation”). The SMA program has one approved product, Evrysdi^® (risdiplam), which was approved by the FDA in August 2020 for the treatment of SMA in adults and children two months and older and by the EC in March 2021 for the treatment of 5q SMA in patients two months and older with a clinical diagnosis of SMA Type 1, Type 2 or Type 3 or with one to four SMN2 copies. Evrysdi has also received marketing authorization for the treatment of SMA in over 100 countries. In May 2022, the FDA approved a label expansion for Evrysdi to include infants under two months old with SMA. In August 2023, the EC approved an extension of the Evrysdi marketing authorization to include infants under two months old in the EU. In addition to the Company’s SMA program, the Company’s splicing platform also includes votoplam (PTC518), which is being developed for the treatment of Huntington’s disease (“HD”). The Company initiated a Phase 2 study of votoplam for the treatment of HD in the first quarter of 2022, which consists of an initial 12-week placebo-controlled phase focused on safety, pharmacology and pharmacodynamic effects followed by a nine-month placebo-controlled phase focused on votoplam biomarker effect. In June 2024, the Company announced interim results from the full Phase 2 study of votoplam. At month 12, votoplam treatment demonstrated durable dose-dependent lowering of mutant HTT (“mHTT”) protein in the blood and dose-dependent lowering of mHTT protein in the cerebrospinal fluid in the interim cohort of stage 2 patients. In addition, favorable trends were demonstrated on several relevant HD clinical assessments. Furthermore, following 12 months of treatment, votoplam continued to be well tolerated. In September 2024, the FDA granted Fast Track designation to the votoplam program for the treatment of HD. In December 2024, the Company held a Type C meeting with the FDA to discuss whether huntingtin protein lowering could be considered a surrogate endpoint for accelerated approval of votoplam. The FDA was aligned on the scientific rationale and asked to see additional data supportive of an association between huntingtin protein lowering and changes in clinical outcome scores. In May 2025, the Company announced that the Phase 2 study of votoplam met its primary endpoints of blood HTT lowering and safety. The results on the full study population are consistent with the previously reported evidence of dose-dependent HTT lowering, favorable safety profile and early signals of dose-dependent clinical effect at 12 months in Stage 2 patients. In addition, at 24 months of treatment, there were continued trends of dose-dependent favorable clinical effect relative to a propensity-matched natural history cohort as well as dose-dependent NfL lowering. In November 2024, the Company entered into a License and Collaboration Agreement (the “Novartis Agreement”) with Novartis Pharmaceuticals Corporation (“Novartis”), relating to its votoplam HD program which included related molecules. This transaction closed in January 2025, triggering a $1.0 billion upfront cash payment to the Company. The Company continues to collaborate with Novartis on next steps for votoplam and aims to meet with FDA in the fourth quarter of 2025 to discuss Phase 3 clinical trial design and potential accelerated approval pathway. The Company’s inflammation and ferroptosis platform consists of small molecule compounds that target oxidoreductase enzymes that regulate oxidative stress and inflammatory pathways central to the pathology of a number of CNS diseases. The most advanced molecule in the Company’s inflammation and ferroptosis platform is vatiquinone. The Company announced topline results from a registration-directed Phase 3 trial of vatiquinone in children and young adults with Friedreich’s ataxia (“FA”), called MOVE-FA, in May 2023. While the study did not meet its primary endpoint, vatiquinone treatment did demonstrate significant benefit on key disease subscales, including the upright stability subscale, as well as on other disease relevant endpoints. In October 2024, the Company announced that the pre-specified endpoint for two different FA long-term extension studies was met, with statistically significant evidence of durable treatment benefit on disease progression. In December 2024, the Company submitted an NDA to the FDA for vatiquinone for the treatment of children and adults living with FA. In February 2025, the FDA accepted for filing the NDA and granted priority review with a target regulatory action date of August 19, 2025. In addition, the Company has a pipeline of product candidates and discovery programs that are in early clinical, pre-clinical and research and development stages focused on the development of new treatments for multiple therapeutic areas for rare diseases. As of June 30, 2025, the Company had an accumulated deficit of approximately $2,845.2 million. The Company has financed its operations to date primarily through the private offerings of convertible senior notes (see Note 9), public and “at the market offerings” of common stock, proceeds from royalty purchase agreements (see Note 9), private placements of its convertible preferred stock and common stock, collaborations, bank and institutional lender debt, other convertible debt, grant funding and clinical trial support from governmental and philanthropic organizations and patient advocacy groups in the disease area addressed by the Company’s product candidates. The Company has also relied on revenue generated from net sales of Translarna for the treatment of nmDMD in territories outside of the United States since 2014, Emflaza for the treatment of DMD in the United States since 2017, and Upstaza for the treatment of AADC deficiency in the EEA since 2022. The Company has also relied on revenue associated with milestone and royalty payments from Roche pursuant to the License and Collaboration Agreement (the “SMA License Agreement”) dated as of November 23, 2011, by and among the Company, Roche and, for the limited purposes set forth therein, the SMA Foundation, under its SMA program. The Company also relies on revenues associated with the Novartis Agreement. The Company expects that cash flows from the sales of its products, royalty payments from Roche, and milestone payments from Novartis, together with the Company’s cash, cash equivalents and marketable securities, will be sufficient to fund its operations for at least the next twelve months.

The Company

6 Months Ended

Jun. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. The Company

PTC Therapeutics, Inc. (the “Company” or “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. PTC’s strategy is to leverage its scientific expertise and global commercial infrastructure to optimize value for its patients and other stakeholders. PTC has a diversified therapeutic portfolio pipeline that includes several commercial products and product candidates in various stages of development, including clinical, pre-clinical and research and discovery stages, focused on the development of new treatments for multiple therapeutic areas for rare diseases relating to neurology and metabolism.

The Company has two products, Translarna™ (ataluren) and Emflaza^® (deflazacort), for the treatment of Duchenne muscular dystrophy (“DMD”), a rare, life-threatening disorder. Translarna has marketing authorization in Russia for the treatment of nonsense mutation Duchenne muscular dystrophy (“nmDMD”) in patients aged two years and older, and in Brazil for the treatment of nmDMD in ambulatory patients two years and older and for continued treatment of patients that become non-ambulatory, as well as in various other countries. Emflaza is approved in the United States for the treatment of DMD in patients two years and older.

The Company previously had a marketing authorization for Translarna in the European Economic Area (“EEA”), which had been subject to annual review and renewal by the European Commission (“EC”) following reassessment by the European Medicines Agency (“EMA”) of the benefit-risk balance of the authorization. In September 2022, the Company submitted a Type II variation to the EMA to support conversion of the conditional marketing authorization for Translarna to a standard marketing authorization, which included a report on the placebo-controlled trial of Study 041 and data from the open-label extension. In February 2023, the Company also submitted an annual marketing authorization renewal request to the EMA. In September 2023, the Committee for Medicinal Products for Human Use (“CHMP”), gave a negative opinion on the conversion of the conditional marketing authorization to full marketing authorization of Translarna for the treatment of nmDMD and a negative opinion on the renewal of the existing conditional marketing authorization of Translarna for the treatment of nmDMD. In January 2024, the CHMP issued a negative opinion for the renewal of the conditional marketing authorization following a re-examination procedure. In May 2024, the EC decided not to adopt the CHMP’s negative opinion for the renewal of the conditional marketing authorization of Translarna and returned such opinion to the CHMP for re-evaluation. In June 2024, following the EC’s request for re-review, the CHMP issued a negative opinion on the renewal of the conditional marketing authorization of Translarna for the treatment of nmDMD. In October 2024, the CHMP maintained its negative opinion for the renewal of the conditional marketing authorization following the requested reexamination procedure. In March 2025, the EC adopted the opinion of the CHMP to not renew the authorization of Translarna for the treatment of nmDMD. However, the EC indicated that individual countries within the European Union (“EU”) can leverage Articles 117(3) and 5(1) of the EU Directive 2001/83 to allow continued commercial use of Translarna.

Translarna is an investigational new drug in the United States. Following the Company’s announcement of top-line results from the placebo-controlled trial of Study 041 in June 2022, the Company submitted a meeting request to the U.S. Food and Drug Administration (“FDA”) to gain clarity on the regulatory pathway for a potential resubmission of a New Drug Application (“NDA”) for Translarna. The FDA provided initial written feedback that Study 041 does not provide substantial evidence of effectiveness to support an NDA resubmission. The Company held a Type C meeting with the FDA in the fourth quarter of 2023 to discuss the totality of Translarna data. Based on feedback from the FDA, the Company resubmitted the NDA in July 2024, based on the results from Study 041 and from the Company’s international drug registry study for nmDMD patients receiving Translarna. In October 2024, the FDA accepted for review the resubmission of the NDA for Translarna for the treatment of nmDMD. As this was an NDA resubmission following a complete response letter

to the NDA which was filed over protest in 2016, the FDA is not obligated to follow the review timelines under Prescription Drug User Fee Act guidelines and an action date has not been provided.

The Company has developed Sephience™ (sepiapterin), a product for the treatment of phenylketonuria (“PKU”), a rare inherited metabolic disease which affects the brain. On July 28, 2025, Sephience™ was approved by the FDA for the treatment of pediatric and adult patients living with PKU in the United States. On June 19, 2025, Sephience was granted marketing authorization by the EC for the treatment of children and adults living with PKU within the EEA. The Company also made a regulatory submission for Sephience for the treatment of PKU in Brazil in the third quarter of 2024, with a regulatory decision expected in the second half of 2025, and in Japan in the fourth quarter of 2024, with a regulatory decision expected in the fourth quarter of 2025.

The Company has developed Upstaza™ (eladocagene exuparvovec), a gene therapy for the treatment of Aromatic L-Amino Acid Decarboxylase (“AADC”) deficiency (“AADC deficiency”), a rare central nervous system (“CNS”) disorder arising from reductions in the enzyme AADC that results from mutations in the dopa decarboxylase gene. In July 2022, the EC approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the EEA. In November 2022, the Medicines and Healthcare Products Regulatory Agency approved Upstaza for the treatment of AADC deficiency for patients 18 months and older within the United Kingdom. In November 2024, the FDA approved the Company’s gene therapy treatment of AADC deficiency, which is marketed under the brand name Kebilidi™ in the United States.

The Company holds the rights for the commercialization of Tegsedi^® (inotersen) and Waylivra^® (volanesorsen) for the treatment of rare diseases in countries in Latin America and the Caribbean pursuant to the Collaboration and License Agreement (the “Tegsedi-Waylivra Agreement”), dated August 1, 2018, by and between the Company and Akcea Therapeutics, Inc. (“Akcea”), a subsidiary of Ionis Pharmaceuticals, Inc. Tegsedi has received marketing authorization in the United States, the European Union (the “EU”) and Brazil for the treatment of stage 1 or stage 2 polyneuropathy in adult patients with hereditary transthyretin amyloidosis (“hATTR amyloidosis”). In August 2021, ANVISA, the Brazilian health regulatory authority, approved Waylivra as the first treatment for familial chylomicronemia syndrome (“FCS”) in Brazil. In December 2022, ANVISA approved Waylivra for the treatment of familial partial lipodystrophy (“FPL”). Waylivra has also received marketing authorization in the EU for the treatment of FCS.

The Company also has a spinal muscular atrophy (“SMA”) collaboration with F. Hoffman-La Roche Ltd and Hoffman-La Roche Inc. (referred to collectively as “Roche”) and the Spinal Muscular Atrophy Foundation (“SMA Foundation”). The SMA program has one approved product, Evrysdi^® (risdiplam), which was approved by the FDA in August 2020 for the treatment of SMA in adults and children two months and older and by the EC in March 2021 for the treatment of 5q SMA in patients two months and older with a clinical diagnosis of SMA Type 1, Type 2 or Type 3 or with one to four SMN2 copies. Evrysdi has also received marketing authorization for the treatment of SMA in over 100 countries. In May 2022, the FDA approved a label expansion for Evrysdi to include infants under two months old with SMA. In August 2023, the EC approved an extension of the Evrysdi marketing authorization to include infants under two months old in the EU.

In addition to the Company’s SMA program, the Company’s splicing platform also includes votoplam (PTC518), which is being developed for the treatment of Huntington’s disease (“HD”). The Company initiated a Phase 2 study of votoplam for the treatment of HD in the first quarter of 2022, which consists of an initial 12-week placebo-controlled phase focused on safety, pharmacology and pharmacodynamic effects followed by a nine-month placebo-controlled phase focused on votoplam biomarker effect. In June 2024, the Company announced interim results from the full Phase 2 study of votoplam. At month 12, votoplam treatment demonstrated durable dose-dependent lowering of mutant HTT (“mHTT”) protein in the blood and dose-dependent lowering of mHTT protein in the cerebrospinal fluid in the interim cohort of stage 2 patients. In addition, favorable trends were demonstrated on several relevant HD clinical assessments. Furthermore, following 12 months of treatment, votoplam continued to be well tolerated. In September 2024, the FDA granted Fast Track designation to the votoplam program for the treatment of HD. In December 2024, the Company held a Type C meeting with the FDA to discuss whether huntingtin protein lowering could be considered a surrogate endpoint for accelerated approval of votoplam. The FDA was aligned on the scientific rationale and asked to see additional data supportive of an association between huntingtin protein lowering and changes in clinical outcome scores. In May 2025, the Company announced that the Phase 2 study of votoplam met its primary endpoints of blood HTT lowering and safety. The results on the full study population are consistent with the previously reported evidence of dose-dependent HTT lowering, favorable safety profile

and early signals of dose-dependent clinical effect at 12 months in Stage 2 patients. In addition, at 24 months of treatment, there were continued trends of dose-dependent favorable clinical effect relative to a propensity-matched natural history cohort as well as dose-dependent NfL lowering. In November 2024, the Company entered into a License and Collaboration Agreement (the “Novartis Agreement”) with Novartis Pharmaceuticals Corporation (“Novartis”), relating to its votoplam HD program which included related molecules. This transaction closed in January 2025, triggering a $1.0 billion upfront cash payment to the Company. The Company continues to collaborate with Novartis on next steps for votoplam and aims to meet with FDA in the fourth quarter of 2025 to discuss Phase 3 clinical trial design and potential accelerated approval pathway.

The Company’s inflammation and ferroptosis platform consists of small molecule compounds that target oxidoreductase enzymes that regulate oxidative stress and inflammatory pathways central to the pathology of a number of CNS diseases. The most advanced molecule in the Company’s inflammation and ferroptosis platform is vatiquinone. The Company announced topline results from a registration-directed Phase 3 trial of vatiquinone in children and young adults with Friedreich’s ataxia (“FA”), called MOVE-FA, in May 2023. While the study did not meet its primary endpoint, vatiquinone treatment did demonstrate significant benefit on key disease subscales, including the upright stability subscale, as well as on other disease relevant endpoints. In October 2024, the Company announced that the pre-specified endpoint for two different FA long-term extension studies was met, with statistically significant evidence of durable treatment benefit on disease progression. In December 2024, the Company submitted an NDA to the FDA for vatiquinone for the treatment of children and adults living with FA. In February 2025, the FDA accepted for filing the NDA and granted priority review with a target regulatory action date of August 19, 2025.

In addition, the Company has a pipeline of product candidates and discovery programs that are in early clinical, pre-clinical and research and development stages focused on the development of new treatments for multiple therapeutic areas for rare diseases.

As of June 30, 2025, the Company had an accumulated deficit of approximately $2,845.2 million. The Company has financed its operations to date primarily through the private offerings of convertible senior notes (see Note 9), public and “at the market offerings” of common stock, proceeds from royalty purchase agreements (see Note 9), private placements of its convertible preferred stock and common stock, collaborations, bank and institutional lender debt, other convertible debt, grant funding and clinical trial support from governmental and philanthropic organizations and patient advocacy groups in the disease area addressed by the Company’s product candidates. The Company has also relied on revenue generated from net sales of Translarna for the treatment of nmDMD in territories outside of the United States since 2014, Emflaza for the treatment of DMD in the United States since 2017, and Upstaza for the treatment of AADC deficiency in the EEA since 2022. The Company has also relied on revenue associated with milestone and royalty payments from Roche pursuant to the License and Collaboration Agreement (the “SMA License Agreement”) dated as of November 23, 2011, by and among the Company, Roche and, for the limited purposes set forth therein, the SMA Foundation, under its SMA program. The Company also relies on revenues associated with the Novartis Agreement. The Company expects that cash flows from the sales of its products, royalty payments from Roche, and milestone payments from Novartis, together with the Company’s cash, cash equivalents and marketable securities, will be sufficient to fund its operations for at least the next twelve months.