The Company	6 Months Ended
Jun. 30, 2026
The Company
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 developed Sephience™ (sepiapterin), a product for the treatment of phenylketonuria (“PKU”), a rare inherited metabolic disease characterized by the body’s inability to break down an essential amino acid called phenylalanine, and which can result in neurological and other symptoms. In June 2025, Sephience was granted marketing authorization by the European Commission (“EC”) for the treatment of children and adults living with PKU within the European Economic Area (“EEA”). In July 2025, Sephience was approved by the U.S. Food and Drug Administration (“FDA”) for the treatment of pediatric and adult patients living with PKU in the United States age one month and above. In December 2025, Sephience was approved by the Japanese Ministry of Health, Labor, and Welfare (“MHLW”) for the treatment of children and adults living with PKU in Japan. In February 2026, Sephience was approved by ANVISA, the Brazilian health regulatory authority, for the treatment of children and adults living with PKU in Brazil. Sephience is also approved in additional geographies. The Company has two products, Translarna™ (ataluren) and Emflaza® (deflazacort), for the treatment of Duchenne muscular dystrophy (“DMD”), a rare, life-threatening disorder. While Translarna previously had conditional approval in the EEA, in March 2025, the EC adopted the negative opinion of the Committee for Medicinal Products for Human Use, or CHMP, of the European Medicines Agency, or EMA, to not renew the conditional marketing authorization of Translarna for the treatment of nonsense mutation Duchenne muscular dystrophy (“nmDMD”). However, the EC indicated that individual countries within the European Union, can leverage Articles 117(3) and 5(1) of the EU Directive 2001/83 to allow continued commercial use of Translarna. Translarna has marketing authorization in additional geographies outside of the EEA, but the EC adoption of the CHMP negative opinion may affect future reauthorizations. Emflaza is approved in the United States for the treatment of DMD in patients two years and older. Translarna is an investigational new drug in the United States. In 2017, the Company filed a new drug application (“NDA”) for Translarna for the treatment of nmDMD over protest with the FDA and the Office of Drug Evaluation I of the FDA issued a complete response letter for the NDA, stating that it was unable to approve the application in its current form. The Company re-submitted the NDA in July 2024 and in October 2024, the FDA accepted for review the resubmission of the NDA for Translarna for the treatment of nmDMD. Following feedback from the FDA, the Company withdrew the NDA resubmission for Translarna in February 2026. Further development of Translarna for the treatment of nmDMD in the United States is not planned. The Company has developed Upstaza™ (eladocagene exuparvovec), a gene therapy used 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 Company’s biologics license application for its gene therapy treatment of AADC deficiency was approved by the FDA. This gene therapy 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. Waylivra has also received marketing authorization in the EU for the treatment of FCS. In December 2022, ANVISA approved Waylivra for the treatment of familial partial lipodystrophy. 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 consisted 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 Neurofilament light (“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. In April 2026, Novartis announced that it had commenced the global Phase 3 clinical trial, which is expected to enroll approximately 770 individuals with early symptomatic disease, randomized 3:2 to receive votoplam 10 milligrams or placebo, and includes an interim analysis. Pursuant to the Novartis Agreement, the initiation of the Phase 3 clinical trial triggered a $50.0 million milestone payment to the Company. The $50.0 million development milestone is recorded as collaboration and license revenue for the three and six months ending June 30, 2026. Also in April 2026, the Company reported positive topline results from the 24-month interim analysis of the PIVOT-HD long-term extension study, with favorable dose-dependent effects on disease progression for Stage 2 HD patients following 24 months of votoplam treatment compared to an external natural history cohort, with 52% slowing of disease progression on the Composite Unified Huntington’s Disease Rating Scale at the 10 milligram dose level. While the Phase 3 clinical trial remains the base case for votoplam approval, Novartis and the Company are finalizing a plan to engage with FDA to discuss the 24-month results in the second half of 2026. 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 and non-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. In August 2025, the FDA issued a complete response letter related to the NDA stating that substantial evidence of efficacy was not demonstrated for vatiquinone and that an additional adequate and well-controlled study would be needed to support NDA resubmission. The Company met with the FDA in the fourth quarter of 2025 to discuss the vatiquinone development program, at which time the FDA suggested an additional study be conducted to support NDA resubmission. In April 2026, the Company again met with FDA to discuss the design of a new trial to provide additional data to support NDA resubmission. Based on the meeting discussion and written feedback, the Company plans to initiate the PROVE-FA open label study using matched natural history control in the third quarter of 2026. This study is expected to enroll approximately 120 patients ages 7 to 21 and the study primary endpoint is the change in mFARS from baseline to month 24. During the quarter ended June 30, 2026, the Company initiated a Phase 1 study of PTC612, its oral NLRP3 inhibitor, and completed several of the single and multiple ascending dose treatment cohorts. Notably, this healthy volunteer study includes a cohort of individuals with obesity and cardiovascular disease, which the Company expects will provide an early view of pharmacokinetics and pharmacodynamics. The Company expects to initiate a Phase 2a study of PTC844, its next-generation DHODH inhibitor, in the third quarter of 2026. The PTC844 study will be a 12-week pharmacokinetics and pharmacodynamics study in which the Company will assess treatment effect on biomarkers related to T-cell and B-cell immunity. The Company expects that the results of this study will help inform the ultimate target indications for PTC844. 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, 2026, the Company had an accumulated deficit of approximately $2,883.5 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 areas addressed by the Company’s product candidates. The Company has also relied on revenue generated from net sales of its products, the 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, and the revenues associated with the Novartis Agreement. The Company expects that cash flows from the sales of its products, 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 after the issuance date of these financial statements.

The Company

6 Months Ended

Jun. 30, 2026

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 developed Sephience™ (sepiapterin), a product for the treatment of phenylketonuria (“PKU”), a rare inherited metabolic disease characterized by the body’s inability to break down an essential amino acid called phenylalanine, and which can result in neurological and other symptoms. In June 2025, Sephience was granted marketing authorization by the European Commission (“EC”) for the treatment of children and adults living with PKU within the European Economic Area (“EEA”). In July 2025, Sephience was approved by the U.S. Food and Drug Administration (“FDA”) for the treatment of pediatric and adult patients living with PKU in the United States age one month and above. In December 2025, Sephience was approved by the Japanese Ministry of Health, Labor, and Welfare (“MHLW”) for the treatment of children and adults living with PKU in Japan. In February 2026, Sephience was approved by ANVISA, the Brazilian health regulatory authority, for the treatment of children and adults living with PKU in Brazil. Sephience is also approved in additional geographies.

The Company has two products, Translarna™ (ataluren) and Emflaza® (deflazacort), for the treatment of Duchenne muscular dystrophy (“DMD”), a rare, life-threatening disorder. While Translarna previously had conditional approval in the EEA, in March 2025, the EC adopted the negative opinion of the Committee for Medicinal Products for Human Use, or CHMP, of the European Medicines Agency, or EMA, to not renew the conditional marketing authorization of Translarna for the treatment of nonsense mutation Duchenne muscular dystrophy (“nmDMD”). However, the EC indicated that individual countries within the European Union, can leverage Articles 117(3) and 5(1) of the EU Directive 2001/83 to allow continued commercial use of Translarna. Translarna has marketing authorization in additional geographies outside of the EEA, but the EC adoption of the CHMP negative opinion may affect future reauthorizations. Emflaza is approved in the United States for the treatment of DMD in patients two years and older.

Translarna is an investigational new drug in the United States. In 2017, the Company filed a new drug application (“NDA”) for Translarna for the treatment of nmDMD over protest with the FDA and the Office of Drug Evaluation I of the FDA issued a complete response letter for the NDA, stating that it was unable to approve the application in its current form. The Company re-submitted the NDA in July 2024 and in October 2024, the FDA accepted for review the resubmission of the NDA for Translarna for the treatment of nmDMD. Following feedback from the FDA, the Company withdrew the NDA resubmission for Translarna in February 2026. Further development of Translarna for the treatment of nmDMD in the United States is not planned.

The Company has developed Upstaza™ (eladocagene exuparvovec), a gene therapy used 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 Company’s biologics license application for its gene therapy treatment of AADC deficiency was approved by the FDA. This gene therapy 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. Waylivra has also received marketing authorization in the EU for the treatment of FCS. In December 2022, ANVISA approved Waylivra for the treatment of familial partial lipodystrophy.

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 consisted 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 Neurofilament light (“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. In April 2026, Novartis announced that it had commenced the global Phase 3 clinical trial, which is expected to enroll approximately 770 individuals with early symptomatic disease, randomized 3:2 to receive votoplam 10 milligrams or placebo, and includes an interim analysis. Pursuant to the Novartis Agreement, the initiation of the Phase 3 clinical trial triggered a $50.0 million milestone payment to the Company. The $50.0 million development milestone is recorded as collaboration and license revenue for the three and six months ending June 30, 2026. Also in April 2026, the Company reported positive topline results from the 24-month interim analysis of the PIVOT-HD long-term extension study, with favorable dose-dependent effects on disease progression for Stage 2 HD patients following 24 months of votoplam treatment compared to an external natural history cohort, with 52% slowing of disease progression on the Composite Unified Huntington’s Disease Rating Scale at the 10 milligram dose level. While the Phase 3 clinical trial remains the base case for votoplam approval, Novartis and the Company are finalizing a plan to engage with FDA to discuss the 24-month results in the second half of 2026.

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 and non-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. In August 2025, the FDA issued a complete response letter related to the NDA stating that substantial evidence of efficacy was not demonstrated for vatiquinone and that an additional adequate and well-controlled study would be needed to support NDA resubmission. The Company met with the FDA in the fourth quarter of 2025 to discuss the vatiquinone development program, at which time the FDA suggested an additional study be conducted to support NDA resubmission. In April 2026, the Company again met with FDA to discuss the design of a new trial to provide additional data to support NDA resubmission. Based on the meeting discussion and written feedback, the Company plans to initiate the PROVE-FA open label study using matched natural history control in the third quarter of 2026. This study is expected to enroll approximately 120 patients ages 7 to 21 and the study primary endpoint is the change in mFARS from baseline to month 24.

During the quarter ended June 30, 2026, the Company initiated a Phase 1 study of PTC612, its oral NLRP3 inhibitor, and completed several of the single and multiple ascending dose treatment cohorts. Notably, this healthy volunteer study includes a cohort of individuals with obesity and cardiovascular disease, which the Company expects will provide an early view of pharmacokinetics and pharmacodynamics. The Company expects to initiate a Phase 2a study of PTC844, its next-generation DHODH inhibitor, in the third quarter of 2026. The PTC844 study will be a 12-week pharmacokinetics and pharmacodynamics study in which the Company will assess treatment effect on biomarkers related to T-cell and B-cell immunity. The Company expects that the results of this study will help inform the ultimate target indications for PTC844.

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, 2026, the Company had an accumulated deficit of approximately $2,883.5 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 areas addressed by the Company’s product candidates. The Company has also relied on revenue generated from net sales of its products, the 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, and the revenues associated with the Novartis Agreement. The Company expects that cash flows from the sales of its products, 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 after the issuance date of these financial statements.