The Company	3 Months Ended
Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The Company PTC Therapeutics, Inc. (the “Company” or “PTC”) is a science-driven global biopharmaceutical company focused on the discovery, development and commercialization of clinically differentiated medicines that provide benefits to patients with rare disorders. The Company’s ability to globally commercialize products is the foundation that drives its continued investment in a robust diversified pipeline of transformative medicines and its mission to provide access to best-in-class treatments for patients who have an unmet medical need. The Company’s strategy is to leverage its strong scientific expertise and global commercial infrastructure to maximize value for its patients and other stakeholders. 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 the European Economic Area (the “EEA”) for the treatment of nonsense mutation Duchenne muscular dystrophy (“nmDMD”) in ambulatory patients aged 2 years and older and in Brazil for the treatment of nmDMD in ambulatory patients aged 5 years and older, subject to annual renewal and other conditions. In July 2020, the European Commission approved the removal of the statement “efficacy has not been demonstrated in non-ambulatory patients” from the indication statement for Translarna. Emflaza is approved in the United States for the treatment of DMD in patients two years and older. 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 “Akcea Collaboration and License Agreement”), dated August 1, 2018, by and between the Company and Akcea Therapeutics, Inc. (“Akcea”). 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”). While the Company is in the process of initiating its commercial launch for Tegsedi for the treatment of hATTR amyloidosis in Latin America, it continues to make Tegsedi available in certain countries within Latin America and the Caribbean through early access programs. Waylivra has received marketing authorization in the EU for the treatment of familial chylomicronemia syndrome (“FCS”). The Company filed for marketing authorization for Waylivra for the treatment of FCS with ANVISA, the Brazilian health regulatory authority, in June 2020 and, subject to potential delays in the review process related to the COVID-19 pandemic, expects a regulatory decision on approval from ANVISA in the third quarter of 2021. 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 United States Food and Drug Administration (“FDA”) in August 2020 for the treatment of SMA in adults and children two months and older and by the European Commission 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 also received marketing authorization for the treatment of SMA in Brazil in October 2020. Additionally, in October 2020, Chugai Pharmaceutical Co., Ltd. (“Chugai”), a subsidiary of Roche, filed a New Drug Application (“NDA”) in Japan for Evrysdi for the treatment of SMA and a regulatory decision on approval is expected in 2021. In addition to the Company’s SMA program, the Company’s splicing platform also includes PTC518, which is being developed for the treatment of Huntington’s disease (“HD”). The Company announced preliminary results from its ongoing Phase 1 study of PTC518 in healthy volunteers in April 2021 demonstrating dose-dependent lowering of huntingtin messenger ribonucleic acid levels and that PTC518 was well tolerated with no safety-related findings. The Company has a pipeline of gene therapy product candidates for rare monogenic diseases that affect the central nervous system (“CNS”) including PTC-AADC for the treatment of Aromatic L-Amino Acid Decarboxylase (“AADC”) deficiency (“AADC deficiency”), a rare CNS disorder arising from reductions in the enzyme AADC that results from mutations in the dopa decarboxylase gene. In January 2020, the Company submitted an MAA to the European Medicines Agency (“EMA”) for PTC-AADC for the treatment of AADC deficiency in the EEA, and the Company expects an opinion from the Committee for Medicinal Products for Human Use (“CHMP”) in the third quarter of 2021. The Company is also preparing a biologics license application (“BLA”) for PTC-AADC for the treatment of AADC deficiency in the United States. The Company anticipates the BLA submission to the FDA to be delayed by at least one quarter. The Company’s Bio-e 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 two most advanced molecules in the Company’s Bio-e platform are vatiquinone and PTC857. The Company initiated a registration-directed Phase 2/3 placebo-controlled trial of vatiquinone in children with mitochondrial disease and associated refractory epilepsy in the third quarter of 2020 and anticipates data from this trial to be available in the third quarter of 2022. The Company also initiated a registration-directed Phase 3 trial of vatiquinone in children and young adults with Friedreich ataxia in the fourth quarter of 2020 and anticipates data from this trial to be available in 2023. In the second quarter of 2020, the Company initiated a Phase 1 trial in healthy volunteers to evaluate the safety and pharmacology of PTC857. This Phase 1 trial was recently completed and the Company expects data to be available in the second quarter of 2021. On May 29, 2020, the Company completed its acquisition of Censa Pharmaceuticals, Inc. (“Censa”) pursuant to an Agreement and Plan of Merger, dated as of May 5, 2020 (the "Censa Merger Agreement"), by and among the Company, Hydro Merger Sub, Inc., the Company’s wholly owned, indirect subsidiary, and, solely in its capacity as the representative, agent and attorney-in-fact of the securityholders of Censa, Shareholder Representative Services LLC (the "Censa Merger"). The transaction was accounted for as an asset acquisition. In connection with the Censa Merger, the Company acquired PTC923, an oral formulation of synthetic sepiapterin, a precursor to intracellular tetrahydrobiopterin, which is a critical enzymatic cofactor involved in metabolism and synthesis of numerous metabolic products. The Company expects to initiate a registration-directed Phase 3 trial for PTC923 for phenylketonuria (“PKU”) in mid-2021. In June 2020, the Company initiated a Phase 2/3 clinical trial evaluating the efficacy and safety of PTC299, a dihydroorotate dehydrogenase inhibitor that the Company has also been developing in oncological indications, in patients hospitalized with COVID-19. The Company expects data from this trial to be available in the second half of 2021. 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, including rare diseases and oncology. The Company’s marketing authorization for Translarna in the EEA is subject to annual review and renewal by the European Commission following reassessment by the EMA of the benefit-risk balance of the authorization, which the Company refers to as the annual EMA reassessment. This marketing authorization is further subject to the specific obligation to conduct and submit the results of a multi-center, randomized, double-blind, 18 month, placebo-controlled trial, followed by an 18 month open-label extension, according to an agreed protocol, in order to confirm the efficacy and safety of Translarna. The final report on the trial and open-label extension is to be submitted by the Company to the EMA by the end of the third quarter of 2022. The Company refers to the trial and open-label extension together as Study 041. The marketing authorization in the EEA was last renewed in June 2020 and is effective, unless extended, through August 5, 2021. In February 2021, the Company submitted a marketing authorization renewal request to the EMA. The renewal was based on the Company’s commitment to conduct Study 041 and the totality of the clinical data available from its trials and studies of Translarna for the treatment of nmDMD, including the safety and efficacy results of the Phase 2b and Phase 3 clinical trials. The primary efficacy endpoint was not achieved in either trial within the pre-specified level of statistical significance. Translarna is an investigational new drug in the United States. During the first quarter of 2017, the Company filed a New Drug Application (“NDA”) over protest with the FDA, for which the FDA granted a standard review. In October 2017, 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. In response, the Company filed a formal dispute resolution request with the Office of New Drugs of the FDA. In February 2018, the Office of New Drugs of the FDA denied the Company’s appeal of the Complete Response Letter. In its response, the Office of New Drugs recommended a possible path forward for the ataluren NDA submission based on the accelerated approval pathway. This would involve a re-submission of an NDA containing the current data on effectiveness of ataluren with new data to be generated on dystrophin production in nmDMD patients’ muscles. The Company followed the FDA’s recommendation and collected, using newer technologies via procedures and methods that the Company designed, such dystrophin data in a new study, Study 045, and announced the results of Study 045 in February 2021. Although Study 045 did not meet its pre-specified primary endpoint, the Company plans to discuss the Study 045 dystrophin results and the totality of existing clinical and real-world data with the FDA to determine if there is a potential path to approval based on these results and data. There is substantial risk that the FDA will determine that the results from the Company’s clinical trials and existing real-world data are not sufficient to support a marketing approval for Translarna for the treatment of nmDMD in the United States. In that case, as the Company expects to have data for Study 041 in the third quarter of 2022, and subject to a positive outcome in that study, the Company would plan to re-submit the NDA at that time. As of March 31, 2021, the Company had an accumulated deficit of approximately $1,702.7 million. The Company has financed its operations to date primarily through the private offerings in September 2019 of 1.50% convertible senior notes due 2026 and in August 2015 of 3.00% convertible senior notes due 2022 (collectively, the “Convertible Notes”) (see Note 9), public offerings of common stock in February 2014, October 2014, April 2018, January 2019, and September 2019, "at the market offerings" of its common stock, its initial public offering of common stock in June 2013, proceeds from a Royalty Purchase Agreement dated as of July 17, 2020, by and among the Company, RPI 2019 Intermediate Finance Trust (“RPI”), and, solely for the limited purposes set forth therein, Royalty Pharma PLC (the “Royalty Purchase Agreement”) (see Note 2), private placements of its convertible preferred stock, collaborations, bank and institutional lender 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. Since 2014, 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, and since May 2017, the Company has generated revenue from net sales of Emflaza for the treatment of DMD in the United States. 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 expects that cash flows from the sales of its products, 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

3 Months Ended

Mar. 31, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. The Company

PTC Therapeutics, Inc. (the “Company” or “PTC”) is a science-driven global biopharmaceutical company focused on the discovery, development and commercialization of clinically differentiated medicines that provide benefits to patients with rare disorders. The Company’s ability to globally commercialize products is the foundation that drives its continued investment in a robust diversified pipeline of transformative medicines and its mission to provide access to best-in-class treatments for patients who have an unmet medical need. The Company’s strategy is to leverage its strong scientific expertise and global commercial infrastructure to maximize value for its patients and other stakeholders.

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 the European Economic Area (the “EEA”) for the treatment of nonsense mutation Duchenne muscular dystrophy (“nmDMD”) in ambulatory patients aged 2 years and older and in Brazil for the treatment of nmDMD in ambulatory patients aged 5 years and older, subject to annual renewal and other conditions. In July 2020, the European Commission approved the removal of the statement “efficacy has not been demonstrated in non-ambulatory patients” from the indication statement for Translarna. Emflaza is approved in the United States for the treatment of DMD in patients two years and older.

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 “Akcea Collaboration and License Agreement”), dated August 1, 2018, by and between the Company and Akcea Therapeutics, Inc. (“Akcea”). 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”). While the Company is in the process of initiating its commercial launch for Tegsedi for the treatment of hATTR amyloidosis in Latin America, it continues to make Tegsedi available in certain countries within Latin America and the Caribbean through early access programs. Waylivra has received marketing authorization in the EU for the treatment of familial chylomicronemia syndrome (“FCS”). The Company filed for marketing authorization for Waylivra for the treatment of FCS with ANVISA, the Brazilian health regulatory authority, in June 2020 and, subject to potential delays in the review process related to the COVID-19 pandemic, expects a regulatory decision on approval from ANVISA in the third quarter of 2021.

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 United States Food and Drug Administration (“FDA”) in August 2020 for the treatment of SMA in adults and children two months and older and by the European Commission 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 also received marketing authorization for the treatment of SMA in Brazil in October 2020. Additionally, in October 2020, Chugai Pharmaceutical Co., Ltd. (“Chugai”), a subsidiary of Roche, filed a New Drug Application (“NDA”) in Japan for Evrysdi for the treatment of SMA and a regulatory decision on approval is expected in 2021. In addition to the Company’s SMA program, the Company’s splicing platform also includes PTC518, which is being developed for the treatment of Huntington’s disease (“HD”). The Company announced preliminary results from its ongoing Phase 1 study of PTC518 in healthy volunteers in April 2021 demonstrating dose-dependent lowering of huntingtin messenger ribonucleic acid levels and that PTC518 was well tolerated with no safety-related findings.

The Company has a pipeline of gene therapy product candidates for rare monogenic diseases that affect the central nervous system (“CNS”) including PTC-AADC for the treatment of Aromatic L-Amino Acid Decarboxylase (“AADC”) deficiency (“AADC deficiency”), a rare CNS disorder arising from reductions in the enzyme AADC that results from mutations in the dopa decarboxylase gene. In January 2020, the Company submitted an MAA to the European Medicines Agency

(“EMA”) for PTC-AADC for the treatment of AADC deficiency in the EEA, and the Company expects an opinion from the Committee for Medicinal Products for Human Use (“CHMP”) in the third quarter of 2021. The Company is also preparing a biologics license application (“BLA”) for PTC-AADC for the treatment of AADC deficiency in the United States. The Company anticipates the BLA submission to the FDA to be delayed by at least one quarter.

The Company’s Bio-e 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 two most advanced molecules in the Company’s Bio-e platform are vatiquinone and PTC857. The Company initiated a registration-directed Phase 2/3 placebo-controlled trial of vatiquinone in children with mitochondrial disease and associated refractory epilepsy in the third quarter of 2020 and anticipates data from this trial to be available in the third quarter of 2022. The Company also initiated a registration-directed Phase 3 trial of vatiquinone in children and young adults with Friedreich ataxia in the fourth quarter of 2020 and anticipates data from this trial to be available in 2023. In the second quarter of 2020, the Company initiated a Phase 1 trial in healthy volunteers to evaluate the safety and pharmacology of PTC857. This Phase 1 trial was recently completed and the Company expects data to be available in the second quarter of 2021.

On May 29, 2020, the Company completed its acquisition of Censa Pharmaceuticals, Inc. (“Censa”) pursuant to an Agreement and Plan of Merger, dated as of May 5, 2020 (the "Censa Merger Agreement"), by and among the Company, Hydro Merger Sub, Inc., the Company’s wholly owned, indirect subsidiary, and, solely in its capacity as the representative, agent and attorney-in-fact of the securityholders of Censa, Shareholder Representative Services LLC (the "Censa Merger"). The transaction was accounted for as an asset acquisition. In connection with the Censa Merger, the Company acquired PTC923, an oral formulation of synthetic sepiapterin, a precursor to intracellular tetrahydrobiopterin, which is a critical enzymatic cofactor involved in metabolism and synthesis of numerous metabolic products. The Company expects to initiate a registration-directed Phase 3 trial for PTC923 for phenylketonuria (“PKU”) in mid-2021.

In June 2020, the Company initiated a Phase 2/3 clinical trial evaluating the efficacy and safety of PTC299, a dihydroorotate dehydrogenase inhibitor that the Company has also been developing in oncological indications, in patients hospitalized with COVID-19. The Company expects data from this trial to be available in the second half of 2021.

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, including rare diseases and oncology.

The Company’s marketing authorization for Translarna in the EEA is subject to annual review and renewal by the European Commission following reassessment by the EMA of the benefit-risk balance of the authorization, which the Company refers to as the annual EMA reassessment. This marketing authorization is further subject to the specific obligation to conduct and submit the results of a multi-center, randomized, double-blind, 18 month, placebo-controlled trial, followed by an 18 month open-label extension, according to an agreed protocol, in order to confirm the efficacy and safety of Translarna. The final report on the trial and open-label extension is to be submitted by the Company to the EMA by the end of the third quarter of 2022. The Company refers to the trial and open-label extension together as Study 041.

The marketing authorization in the EEA was last renewed in June 2020 and is effective, unless extended, through August 5, 2021. In February 2021, the Company submitted a marketing authorization renewal request to the EMA. The renewal was based on the Company’s commitment to conduct Study 041 and the totality of the clinical data available from its trials and studies of Translarna for the treatment of nmDMD, including the safety and efficacy results of the Phase 2b and Phase 3 clinical trials. The primary efficacy endpoint was not achieved in either trial within the pre-specified level of statistical significance.

Translarna is an investigational new drug in the United States. During the first quarter of 2017, the Company filed a New Drug Application (“NDA”) over protest with the FDA, for which the FDA granted a standard review. In October 2017, 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. In response, the Company filed a formal dispute resolution request with the Office of New Drugs of the FDA. In February 2018, the Office of New Drugs of the FDA denied the Company’s appeal of the Complete Response Letter. In its response, the Office of New Drugs recommended a possible path forward for the ataluren NDA submission based on the accelerated approval pathway. This would involve a re-submission of an NDA

containing the current data on effectiveness of ataluren with new data to be generated on dystrophin production in nmDMD patients’ muscles. The Company followed the FDA’s recommendation and collected, using newer technologies via procedures and methods that the Company designed, such dystrophin data in a new study, Study 045, and announced the results of Study 045 in February 2021. Although Study 045 did not meet its pre-specified primary endpoint, the Company plans to discuss the Study 045 dystrophin results and the totality of existing clinical and real-world data with the FDA to determine if there is a potential path to approval based on these results and data. There is substantial risk that the FDA will determine that the results from the Company’s clinical trials and existing real-world data are not sufficient to support a marketing approval for Translarna for the treatment of nmDMD in the United States. In that case, as the Company expects to have data for Study 041 in the third quarter of 2022, and subject to a positive outcome in that study, the Company would plan to re-submit the NDA at that time.

As of March 31, 2021, the Company had an accumulated deficit of approximately $1,702.7 million. The Company has financed its operations to date primarily through the private offerings in September 2019 of 1.50% convertible senior notes due 2026 and in August 2015 of 3.00% convertible senior notes due 2022 (collectively, the “Convertible Notes”) (see Note 9), public offerings of common stock in February 2014, October 2014, April 2018, January 2019, and September 2019, "at the market offerings" of its common stock, its initial public offering of common stock in June 2013, proceeds from a Royalty Purchase Agreement dated as of July 17, 2020, by and among the Company, RPI 2019 Intermediate Finance Trust (“RPI”), and, solely for the limited purposes set forth therein, Royalty Pharma PLC (the “Royalty Purchase Agreement”) (see Note 2), private placements of its convertible preferred stock, collaborations, bank and institutional lender 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. Since 2014, 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, and since May 2017, the Company has generated revenue from net sales of Emflaza for the treatment of DMD in the United States. 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 expects that cash flows from the sales of its products, 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.