The following discussion and analysis is meant to provide material information relevant to an assessment of the financial condition and results of operations of our company, including an evaluation of the amounts and certainty of cash flows from operations and from outside resources, so as to allow investors to better view our company from management’s perspective. The following discussion of our financial condition and results of operations should be read in conjunction with our financial statements and the notes to those financial statements appearing elsewhere in this Quarterly Report on Form 10-Q and the audited consolidated financial statements and notes thereto and management’s discussion and analysis of financial condition and results of operations for the year ended December 31, 2025 included in our Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 19, 2026, or our 2025 Annual Report. This discussion contains forward-looking statements that involve significant risks and uncertainties. As a result of many factors, such as those set forth in Part I, Item 1A. (Risk Factors) of our 2025 Annual Report, our actual results may differ materially from those anticipated in these forward-looking statements. Our Company We are a global biopharmaceutical company dedicated to the discovery, development and commercialization of clinically differentiated medicines for children and adults living with rare disorders. We are advancing a robust and diversified pipeline of transformative medicines as part of our mission to provide access to best-in-class treatments for patients with unmet medical needs. Our strategy is to leverage our scientific expertise and global commercial infrastructure to optimize value for our patients and other stakeholders. We believe that this allows us to maximize value for all of our stakeholders. We have a diversified therapeutic portfolio 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. Corporate Updates Global Commercial Footprint Sephience™ (sepiapterin) Sephience (sepiapterin) is a product for the treatment of phenylketonuria, or 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, or EC, for the treatment of children and adults living with PKU within the European Economic Area, or EEA. In July 2025, Sephience was approved by the U.S. Food and Drug Administration, or 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, or MHLW, for the treatment of children and adults living with PKU in Japan, where the label includes individuals of all ages and the full spectrum of disease severity. 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. During the three months ended June 30, 2026, we recognized $151.3 million in net sales of Sephience. Global DMD Franchise We have two products, Translarna™ (ataluren) and Emflaza® (deflazacort), for the treatment of Duchenne muscular dystrophy, or 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 of 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, or nmDMD. However, the EC indicated that individual countries within the European Union, or EU, can leverage Articles 117(3) and 5(1) of the EU Directive 2001/83 to allow continued commercial use of Translarna. 36 Table of Contents Translarna is an investigational new drug in the United States. In 2017, we filed a new drug application, or NDA, for Translarna for the treatment of nmDMD over protest with the FDA and 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. We 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, we decided to withdraw the NDA resubmission for Translarna in February 2026. Further development of Translarna for the treatment of nmDMD in the United States is not planned. Translarna has marketing authorization in additional geographies outside of the EEA, though the EC adoption of the CHMP negative opinion and the withdrawal of the Translarna NDA in the United States may affect future reauthorizations. During the three months ended June 30, 2026, we recognized $42.2 million in net sales for Translarna. Emflaza is approved in the United States for the treatment of DMD in patients two years and older. During the three months ended June 30, 2026, we recognized $24.6 million in net sales for Emflaza. We have previously relied on Emflaza’s seven-year marketing exclusivity period in the United States for its approved indications under the provisions of the Orphan Drug Act of 1983, or the Orphan Drug Act, when commercializing Emflaza for the treatment of DMD in patients five years and older, which expired in February 2024. With the expiration of this orphan drug exclusivity, we have seen an increase in competition from generics, which has, and we expect will continue to have, a negative impact on Emflaza net product revenue. Emflaza’s orphan drug exclusivity related to the treatment of DMD in patients two years of age to less than five expired in June 2026. Upstaza™ (eladocagene exuparvovec) / Kebilidi™ (eladocagene exuparvovec-tneq) Upstaza/Kebilidi is a gene therapy for the treatment of Aromatic L Amino Decarboxylase, or AADC, deficiency, a rare central nervous system, or 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 granted accelerated approval of our gene therapy for the treatment of children and adults with AADC deficiency, which is marketed with the brand name Kebilidi in the United States. Tegsedi® (inotersen) and Waylivra™ (volanesorsen) We hold the rights for the commercialization of Tegsedi and Waylivra for the treatment of rare diseases in countries in Latin America and the Caribbean pursuant to a Collaboration and License Agreement, or the Tegsedi-Waylivra Agreement, dated August 1, 2018, by and between us and Akcea Therapeutics, Inc., or Akcea, a subsidiary of Ionis Pharmaceuticals, Inc. Tegsedi has received marketing authorization in the United States, EU, and Brazil for the treatment of stage 1 or stage 2 polyneuropathy in adult patients with hereditary transthyretin amyloidosis, or hATTR amyloidosis. In August 2021, ANVISA, the Brazilian health regulatory authority, approved Waylivra as the first treatment for familial chylomicronemia syndrome, or 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. Evrysdi® (risdiplam) We also have a spinal muscular atrophy, or SMA, collaboration with F. Hoffman-La Roche Ltd. and Hoffman La Roche Inc., which we refer to collectively as Roche, and the Spinal Muscular Atrophy Foundation, or 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 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. 37 Table of Contents Diversified Development Pipeline Splicing Platform In addition to our SMA program, our splicing platform also includes votoplam, which is being developed for the treatment of Huntington’s disease, or HD. We announced the results from our Phase 1 study of votoplam in healthy volunteers in September 2021 demonstrating dose-dependent lowering of huntingtin messenger ribonucleic acid and protein levels, that votoplam efficiently crosses blood brain barrier at significant levels and that votoplam was well tolerated. We 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 September 2024, the FDA granted Fast Track designation to the votoplam program for the treatment of HD. In November 2024, we entered into a License and Collaboration Agreement with Novartis Pharmaceuticals Corporation, or Novartis, relating to our votoplam program, or the Novartis Agreement, which included related molecules. While Novartis has taken over responsibility for the further development of the votoplam program, we continue to collaborate with Novartis on next steps. In May 2025, we 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 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. Also in April 2026, we 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, we are working with Novartis to finalize a plan to engage with FDA to discuss the 24-month results in the second half of 2026. Inflammation and Ferroptosis Platform Our 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 our inflammation and ferroptosis platform is vatiquinone. We announced topline results from a registration-directed Phase 3 trial of vatiquinone in children and young adults with Friedreich’s ataxia, or FA, called MOVE-FA, in May 2023. While the trial 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, we 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, we submitted an NDA to the FDA for vatiquinone for the treatment of children and adults living with FA. 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. We 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, we 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, we plan 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, we initiated a Phase 1 study of PTC612, our 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 we expect will provide an early view of pharmacokinetics and pharmacodynamics. We also expect to initiate a Phase 2a study of PTC844, our next-generation DHODH inhibitor, in 38 Table of Contents the third quarter of 2026. The PTC844 study will be a 12-week pharmacokinetics and pharmacodynamics study in which we will assess treatment effect on biomarkers related to T-cell and B-cell immunity. We expect that the results of this study will help inform the ultimate target indications for PTC844. Multi-Platform Discovery In addition, we have 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. Funding The success of our products and any other product candidates we may develop depends largely on obtaining and maintaining reimbursement from governments and third-party insurers. Our revenues were primarily generated from sales of Sephience for the treatment of PKU in the U.S. and EEA, Translarna for the treatment of nmDMD in countries where we were able to obtain acceptable commercial pricing and reimbursement terms and in select countries where we are permitted to distribute Translarna under our early access programs, or EAP, programs or through similar styled programs, and from sales of Emflaza for the treatment of DMD in the United States. There is a substantial risk that as a result of the EC’s adoption of the CHMP’s negative opinion we will lose a significant portion of our ability to generate revenue from sales of Translarna in the EEA. We also generated revenue from sales of Upstaza/Kebilidi for the treatment of AADC deficiency in the EEA and in the U.S., and have recognized revenue associated with milestone and royalty payments from Roche pursuant to a License and Collaboration Agreement, or the SMA License Agreement, by and among us, Roche and, for the limited purposes set forth therein, the SMA Foundation, under our SMA program and we have recognized license revenues related to performance obligations completed pursuant to the Novartis Agreement. We have financed our operations to date primarily through the private offerings of convertible senior notes, public and “at the market” offerings of common stock, proceeds from royalty purchase agreements, private placements of our 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 our product candidates. We have relied on revenue generated from net sales of our products. We have also relied on revenue associated with milestone and royalty payments from Roche pursuant to the SMA License Agreement under our SMA program, revenue generated from net sales of Tegsedi and Waylivra in Latin America and the Caribbean, and license revenues related to performance obligations already completed pursuant to the Novartis Agreement. In June 2024, we entered into an amendment with Royalty Pharma Investments 2019 ICAV, or Royalty Pharma, and Royalty Pharma plc, to the Amended and Restated Royalty Purchase Agreement, dated October 18, 2023, or the A&R Royalty Purchase Agreement, which amends and restated in its entirety the Royalty Purchase Agreement with RPI Intermediate Finance Trust, or the Immediate Finance Trust, or the Original Purchase Agreement, and we exercised our first put option in exchange for $241.8 million in cash consideration. In December 2025, we, Royalty Pharma, and, for the limited purposes set forth in Amendment No. 2 (as defined below), Royalty Pharma plc, entered into an Amendment No. 2 to Amended and Restated Royalty Purchase Agreement, or Amendment No. 2, which amends that certain A&R Royalty Purchase Agreement, as amended. Under Amendment No. 2, we sold to Royalty Pharma a certain portion of our right to receive sales-based royalty payments on worldwide net sales of Roche’s Evrysdi® (risdiplam) product and any other product developed pursuant to the License and Collaboration Agreement, dated as of November 23, 2011, by and among us, F. Hoffman-La Roche Ltd, Hoffman-La Roche Inc., together with F. Hoffman-La Roche Ltd, Roche, and, for the limited purposes set forth therein, the Spinal Muscular Atrophy Foundation, such payments, the Royalty. Pursuant to Amendment No. 2, on December 29, 2025, we sold to Royalty Pharma its retained interest in the Royalty in exchange for $240.0 million in upfront cash consideration, and three potential additional cash purchase price payments of $20.0 million each conditioned upon receipt by Royalty Pharma of more than $347.0 million of Assigned Royalty Payments (as defined in the A&R Royalty Purchase Agreement) in respect of Calendar Year Net Sales (as defined in the A&R Royalty Purchase Agreement) arising in 2027, $363.0 million of Assigned Royalty Payments in respect of Calendar Year Net Sales arising in 2028, and $379.0 million of Assigned Royalty Payments in respect of Calendar Year Net Sales arising in 2029, respectively. The retained interest sold by us to Royalty Pharma pursuant to the Amendment No. 2 is equal to 9.5111% of the Royalty before the 2020 Assigned Royalty Cap (as defined in the A&R Royalty Purchase Agreement) has been met, 39 Table of Contents and 16.6666% of the Royalty from and after such time as the 2020 Assigned Royalty Cap has been met. As a result of the sale, Royalty Pharma owns 100% of the Royalty and we own 0% of the Royalty. In November 2024, we entered into the Novartis Agreement relating to our votoplam HD program which includes related molecules. Novartis is responsible for all other development of licensed compounds and licensed products and the manufacture and commercialization of licensed compounds and licensed products worldwide. While Novartis has taken over responsibility for the further development of the votoplam program, we continue to collaborate with Novartis on next steps. Under the Novartis Agreement, and upon the closing of the transaction contemplated by the Novartis Agreement in January 2025, we received an upfront payment of $1.0 billion on the effective date and we are eligible to receive up to $1.9 billion in development, regulatory and sales milestones, a 40% share of U.S. profits and losses, and tiered double-digit royalties on ex-U.S. sales. We have also recognized revenue associated with milestone payments from Novartis pursuant to the Novartis Agreement. In April 2026, Novartis notified us that it had initiated the first Phase 3 clinical trial for a Licensed Product (as defined in the Novartis Agreement), which pursuant to the Novartis Agreement, triggered a $50.0 million milestone payment to us. The $50.0 million development milestone is recorded as collaboration and license revenue for the three and six months ended June 30, 2026. In August 2019, we entered into an At the Market Offering Sales Agreement, or the Sales Agreement, with Cantor Fitzgerald and RBC Capital Markets, LLC, or together, the Sales Agents, pursuant to which, we may offer and sell shares of our common stock, having an aggregate offering price of up to $125.0 million from time to time through the Sales Agents by any method that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, or the Securities Act. During the three and six months ended June 30, 2026, we did not issue or sell any shares of common stock pursuant to the Sales Agreement. The remaining shares of our common stock available to be issued and sold, under the Sales Agreement, have an aggregate offering price of up to $93.0 million as of June 30, 2026. In June 2026, we issued $550.0 million aggregate principal amount of 0% convertible senior notes due 2031, or the 2031 Convertible Notes, which reflects the exercise in full by the initial purchasers of their option to purchase up to an additional $50.0 million in aggregate principal amount of the 2031 Convertible Notes. The 2031 Convertible Notes are governed by an indenture, or the 2031 Convertible Notes Indenture, with U.S. Bank Trust Company, National Association as trustee. The 2031 Convertible Notes bear no regular interest and the principal amounts of the 2031 Convertible Notes will not accrete. The 2031 Convertible Notes may bear special interest under specified circumstances relating to our failure to comply with our reporting obligations under the 2031 Convertible Notes Indenture or if the 2031 Convertible Notes are not freely tradeable as required by the 2031 Convertible Notes Indenture. Special interest, if any, will be payable semiannually in arrears on June 15 and December 15 of each year, beginning on December 15, 2026 (if and to the extent that special interest is payable). The 2031 Convertible Notes will mature on June 15, 2031, unless earlier converted, redeemed or repurchased pursuant to their terms. We received net proceeds of approximately $535.4 million after deducting the initial purchasers’ discounts and commissions and the offering expenses payable by us. Following the issuance of the 2031 Convertible Notes, we used approximately $328.8 million of the net proceeds of the 2031 Convertible Notes to repurchase for cash $222.0 million aggregate principal amount of our outstanding 1.50% convertible senior notes due September 15, 2026, or the 2026 Convertible Notes, pursuant to privately negotiated transactions with certain holders entered into concurrently with the pricing of the offering of the 2031 Convertible Notes. Cash interest payments on the 2026 Convertible Notes were payable on a semi-annual basis in arrears, which will require remaining funding of $0.4 million. The 2026 Convertible Notes are currently convertible at the option of the holders and will mature and become due and payable on September 15, 2026, unless earlier repurchased or converted. As of the quarter ended June 30, 2026, aggregate Sephience global net sales in the prior four consecutive quarters exceeded $250.0 million, which, pursuant to the Agreement and Plan of Merger, dated as of May 6, 2020, or the Censa Merger Agreement, by and among us and Censa Pharmaceuticals, Inc., or Censa, triggered a $30.0 million net sales milestone to the former Censa securityholders. This milestone payment was recorded in accounts payable and accrued expenses on our consolidated balance sheet as of June 30, 2026. As of June 30, 2026, we had an accumulated deficit of $2,883.5 million. We had net income of $80.7 million and $801.7 million for the six months ended June 30, 2026 and 2025, respectively. 40 Table of Contents We anticipate that we will continue to incur significant expenses in connection with our commercialization efforts in the United States, the EEA, Latin America, Japan and other territories, including expenses related to our commercial infrastructure and corresponding sales and marketing, legal and regulatory, and distribution and manufacturing undertakings as well as administrative and employee-based expenses. In addition to the foregoing, we expect to continue to incur significant costs in connection with ongoing, planned and potential future clinical trials and studies for our splicing and inflammation and ferroptosis programs as well as studies in our products for maintaining authorizations, label extensions and additional indications. We may seek to expand and diversify our product pipeline through opportunistically in-licensing or acquiring the rights to products, product candidates or technologies and we may incur expenses, including with respect to transaction costs, subsequent development costs or any upfront, milestone or other payments or other financial obligations associated with any such transaction, which would increase our future capital requirements. We also have certain significant contractual obligations and commercial commitments that require funding and we have disclosed these items under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations-Funding Obligations” in our 2025 Annual Report. There were no material changes to these obligations and commitments during the period ended June 30, 2026. Furthermore, since we are a public company, we have incurred and expect to continue to incur additional costs associated with operating as such including significant legal, accounting, investor relations and other expenses. We will need to generate significant revenues to sustain profitability, and we may never do so. Accordingly, we may need to obtain substantial additional funding in connection with our continuing operations. Adequate additional financing may not be available to us on acceptable terms, or at all. If we are unable to raise capital when needed or on attractive terms, we could be forced to delay, reduce or eliminate our research and development programs or our commercialization efforts. Financial operations overview Revenues Net product revenues. Our net product revenues primarily consist of sales of Sephience for the treatment of PKU. Our net product revenues also consist of sales of Translarna for the treatment of nmDMD in territories outside of the United States, and sales of Emflaza for the treatment of DMD in the United States. We recognize revenue when performance obligations with customers have been satisfied and if it is probable that a significant revenue reversal will not occur. Our performance obligations are to provide products based on customer orders from distributors, hospitals, specialty pharmacies or retail pharmacies. The performance obligations are satisfied at a point in time when our customer obtains control of the product, which is typically upon delivery. We invoice customers after the products have been delivered and invoice payments are generally due within 30 to 90 days of invoice date. We determine the transaction price based on fixed consideration in its contractual agreements. Contract liabilities arise in certain circumstances when consideration is due for goods not yet provided. As we have identified only one distinct performance obligation, the transaction price is allocated entirely to the product sale. In determining the transaction price, a significant financing component does not exist since the timing from when we deliver product to when the customers pay for the product is typically less than one year. Customers in certain countries pay in advance of product delivery. In those instances, payment and delivery typically occur in the same month. We record product sales net of any variable consideration, which includes discounts, allowances, rebates related to Medicaid and other government pricing programs, and distribution fees. We use the expected value or most likely amount method when estimating variable consideration, unless discount or rebate terms are specified within contracts. The identified variable consideration is recorded as a reduction of revenue at the time revenues from product sales are recognized. These estimates for variable consideration are adjusted to reflect known changes in factors and may impact such estimates in the quarter those changes are known. Revenue recognized does not include amounts of variable consideration that are constrained. During the three and six months ended June 30, 2026 and 2025, net product revenues consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 41 Table of Contents ​ ​ ​ 2026 ​ ​ 2025 (in thousands) ​ ​ United States ​ International ​ Total ​ ​ ​ United States ​ International ​ Total Sephience ​ $ 127,550 $ 23,760 $ 151,310 ​ ​ $ — $ — $ — Translarna ​ ​ — ​ 42,217 ​ 42,217 ​ ​ ​ — ​ 59,470 ​ 59,470 Emflaza ​ ​ 24,634 ​ — ​ 24,634 ​ ​ ​ 36,353 ​ — ​ 36,353 Upstaza/Kebilidi ​ ​ — ​ 11,163 ​ 11,163 ​ ​ ​ — ​ 11,889 ​ 11,889 All other products ​ ​ — ​ 9,495 ​ 9,495 ​ ​ ​ — ​ 10,617 ​ 10,617 Total net product revenue ​ $ 152,184 $ 86,635 $ 238,819 ​ ​ $ 36,353 $ 81,976 $ 118,329 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ ​ 2026 ​ ​ 2025 ​ ​ ​ United States ​ International ​ Total ​ ​ ​ United States ​ International ​ Total Sephience ​ $ 239,590 $ 36,271 $ 275,861 ​ ​ $ — $ — $ — Translarna ​ ​ — ​ 101,193 ​ 101,193 ​ ​ ​ — ​ 145,624 ​ 145,624 Emflaza ​ ​ 46,112 ​ — ​ 46,112 ​ ​ ​ 84,142 ​ — ​ 84,142 Upstaza/Kebilidi ​ ​ 2,998 ​ 17,759 ​ 20,757 ​ ​ ​ — ​ 20,547 ​ 20,547 All other products ​ ​ — ​ 20,469 ​ 20,469 ​ ​ ​ — ​ 21,442 ​ 21,442 Total net product revenue ​ $ 288,700 $ 175,692 $ 464,392 ​ ​ $ 84,142 $ 187,613 $ 271,755 ​ Disaggregated net product revenues by country for the three and six months ended June 30, 2026 and 2025, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ Six Months Ended June 30, (in thousands) ​ 2026 ​ 2025 ​ ​ 2026 ​ 2025 United States ​ $ 152,184 ​ $ 36,353 ​ ​ $ 288,700 ​ $ 84,142 Russia ​ ​ 25,581 ​ ​ 18,124 ​ ​ ​ 28,830 ​ ​ 56,638 Brazil ​ ​ 8,210 ​ ​ 40,951 ​ ​ ​ 49,422 ​ ​ 50,456 All other countries ​ ​ 52,844 ​ ​ 22,901 ​ ​ ​ 97,440 ​ ​ 80,519 Total net product revenue ​ $ 238,819 ​ $ 118,329 ​ ​ $ 464,392 ​ $ 271,755 ​ For three and six months ended June 30, 2026, three of our distributors each accounted for over 10% of our net product sales. For three and six months ended June 30, 2025, three and two of our distributors, respectively, each accounted for over 10% of our net product sales. In relation to customer contracts, we incur costs to fulfill a contract but do not incur costs to obtain a contract. These costs to fulfill a contract do not meet the criteria for capitalization and are expensed as incurred. We consider any shipping and handling costs that are incurred after the customer has obtained control of the product as a cost to fulfill a promise. Shipping and handling costs associated with finished goods delivered to customers are recorded as a selling expense. Roche and the SMA Foundation Collaboration. In November 2011, we entered into the SMA License Agreement pursuant to which we are collaborating with Roche and the SMA Foundation to further develop and commercialize compounds identified under our SMA program with the SMA Foundation. The research component of this agreement terminated effective December 31, 2014. We are eligible to receive additional payments from Roche if specified events are achieved with respect to each licensed product, including up to $135.0 million in research and development event milestones, up to $325.0 million in sales milestones upon achievement of specified sales events, and up to double digit royalties on worldwide annual net sales of a commercial product. As of June 30, 2026, we had recognized a total of $310.0 million in milestone payments and $907.7 million in royalties on net sales pursuant to the SMA License Agreement. As of June 30, 2026, there are no remaining research and development event milestones that we can receive. The remaining potential sales milestones as of June 30, 2026 are $150.0 million upon achievement of certain sales events. For the three and six months ended June 30, 2026 and 2025, we did not recognize collaboration revenue related to the SMA License Agreement with Roche. 42 Table of Contents ​ For the three and six months ended June 30, 2026, we recognized $71.1 million and $117.9 million of royalty revenue, respectively, related to Evrysdi. For the three and six months ended June 30, 2025, we recognized $57.6 million and $94.0 million of royalty revenue, respectively, related to Evrysdi. Novartis Collaboration for votoplam HD. In November 2024, we entered into the Novartis Agreement with Novartis related to our votoplam HD program. Upon the closing of the transaction contemplated by the Novartis Agreement in January 2025, we received an upfront payment of $1.0 billion on the effective date and are eligible to receive up to $1.9 billion in development, regulatory and sales milestones, a 40% share of U.S. profits and losses, and tiered double-digit royalties on ex-U.S. sales. During the three and six months ended June 30, 2026, we recognized $50.6 million and $50.7 million in license revenues, respectively, primarily related to a development milestone pursuant to our Novartis Agreement for Novartis’s initiation of the first Phase 3 clinical trial for a Licensed Product (as defined in the Novartis Agreement), which triggered a $50.0 million milestone payment to us. During the three and six months ended June 30, 2025, we recognized $2.9 million and $992.7 million in license revenues, respectively, related to performance obligations completed pursuant to the Novartis Agreement. Collaboration and license revenue during the three months ended June 30, 2025, was partially offset by $3.5 million related to a refund for a prior collaboration arrangement in relation to votoplam. Research and development expense Research and development expenses consist of the costs associated with our research activities, as well as the costs associated with our drug discovery efforts, conducting preclinical studies and clinical trials, manufacturing development efforts and activities related to regulatory filings. Our research and development expenses consist of: ●external research and development expenses incurred under agreements with third-party contract research organizations and investigative sites, third-party manufacturing organizations and consultants; ●employee-related expenses, which include salaries and benefits, including share-based compensation, for the personnel involved in our drug discovery and development activities; and ●facilities, depreciation and other allocated expenses, which include direct and allocated expenses for rent and maintenance of facilities, IT, human resources and other support functions, depreciation of leasehold improvements and equipment, and laboratory and other supplies. We use our employee and infrastructure resources across multiple research projects, including our drug development programs. We track expenses related to our clinical programs and certain preclinical programs on a per project basis. We expect our research and development expenses to fluctuate in connection with our ongoing activities, particularly in connection with our activities under our splicing and inflammation and ferroptosis programs and performance of our post-marketing requirements imposed by regulatory agencies with respect to our products. The timing and amount of these expenses will depend upon the outcome of our ongoing clinical trials and the costs associated with our planned clinical trials. The timing and amount of these expenses will also depend on the costs associated with potential future clinical trials of our products or product candidates and the related expansion of our research and development organization, regulatory requirements, advancement of our preclinical programs, and product candidate manufacturing costs. 43 Table of Contents The following table provides research and development expense for our most advanced principal product development programs, for the three and six months ended June 30, 2026 and 2025. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ (in thousands) ​ Sephience ​ $ 22,078 ​ $ 26,741 ​ Inflammation & Ferroptosis platform ​ ​ 5,571 ​ ​ 9,186 ​ Global DMD ​ ​ 2,988 ​ ​ 8,318 ​ Gene Therapy ​ ​ 169 ​ ​ 3,465 ​ Other development programs ​ ​ 224 ​ ​ 3,440 ​ Total Development ​ ​ 31,030 ​ ​ 51,150 ​ Research ​ ​ 18,331 ​ ​ 15,691 ​ Payroll, benefits, and share-based stock compensation ​ ​ 40,096 ​ ​ 36,995 ​ Facilities and other indirect costs ​ 9,693 ​ 9,154 ​ Total research and development ​ $ 99,150 ​ $ 112,990 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ (in thousands) Sephience ​ $ 44,704 ​ $ 50,882 Inflammation & Ferroptosis platform ​ 11,235 ​ 15,290 Global DMD ​ 4,358 ​ 15,695 Gene Therapy ​ ​ 3,842 ​ ​ 8,246 Other development programs ​ ​ 1,170 ​ ​ 8,886 Total Development ​ ​ 65,309 ​ ​ 98,999 Research ​ ​ 31,213 ​ ​ 29,538 Payroll, benefits, and share-based stock compensation ​ 83,554 ​ 75,229 Facilities and other indirect costs ​ 19,947 ​ 18,197 Total research and development ​ $ 200,023 ​ $ 221,963 ​ Development. Consists of costs incurred for product candidates following initiation of a clinical trial. ​ For the three and six months ended June 30, 2026, compared to the three and six months ended June 30, 2025, the changes reflect progressing through different phases of studies as we continue to focus our resources on our differentiated, high potential research and development programs. The decrease is primarily due to a decrease in costs relating to Global DMD, Gene Therapy, Splicing platform, Inflammation & Ferroptosis platform, and Sephience related development. ​ Research. Consists of costs incurred for product candidates before initiation of a clinical trial. ​ For the three and six months ended June 30, 2026, compared to the three and six months ended June 30, 2025, the increase in research expenses primarily related to increased investment in research programs and advancement of the clinical pipeline. ​ Payroll, benefits, and share-based stock compensation. Consists of costs incurred for salaries and wages, bonus, payroll taxes, benefits and share-based stock compensation associated with employees involved in research and development activities. Share-based stock compensation may fluctuate from period to period based on factors that are not within our control, such as our stock price on the dates share-based grants are issued. ​ For the three and six months ended June 30, 2026, compared to the three and six months ended June 30, 2025, the increase in payroll, benefits, and share-based stock compensation expenses primarily related to an increase in share-based stock compensation, and increases in salaries due to annual merit increases for the three and six months ended June 30, 2026 compared to the three and six months ended June 30, 2025. 44 Table of Contents ​ Facilities and other indirect costs. Consists of indirect costs incurred for the benefit of multiple programs, including information technology, and other facility-based expenses, such as rent expense. ​ For the three months ended June 30, 2026, compared to the three months ended June 30, 2025, the change in facilities and other indirect costs was relatively flat. For the six months ended June 30, 2026, compared to the six months ended June 30, 2025, the change in facilities and other indirect costs was related to new leases that commenced in the second half of 2025. ​ The successful development of our products and product candidates is highly uncertain. This is due to the numerous risks and uncertainties associated with developing drugs, including the uncertainty of: ● the scope, rate of progress and expense of our clinical trials and other research and development activities; ● the potential benefits of our products and product candidates over other therapies; ● our ability to market, commercialize and achieve market acceptance for any of our products or product candidates that we are developing or may develop in the future, including our ability to negotiate pricing and reimbursement terms acceptable to us; ● clinical trial results; ● the terms and timing of regulatory approvals; and ● the expense of filing, prosecuting, defending and enforcing patent claims and other intellectual property rights. A change in the outcome of any of these variables with respect to the development of our products or product candidates could mean a significant change in the costs and timing associated with the development of those products or product candidates. For example, if the EMA or the FDA or other regulatory authority were to require us to conduct clinical trials beyond those which we currently anticipate will be required for the completion of clinical development of any of our products or product candidates or if we experience significant delays in enrollment in any of our clinical trials, we could be required to expend significant additional financial resources and time on the completion of clinical development. Selling, general and administrative expense Selling, general and administrative expenses consist primarily of salaries and other related costs for personnel, including share-based compensation expenses, in our executive, legal, business development, commercial, finance, accounting, information technology and human resource functions. Other selling, general and administrative expenses include facility-related costs not otherwise included in research and development expense; advertising and promotional expenses; costs associated with industry and trade shows; and professional fees for legal services, including patent-related expenses, accounting services and miscellaneous selling costs. We expect that selling, general and administrative expenses will increase in future periods in connection with our continued efforts to commercialize our products, including increased payroll, expanded infrastructure, commercial operations, increased consulting, legal, accounting and investor relations expenses. Interest expense, net Interest expense, net consists of interest expense from the liability for the sale of future royalties related to the A&R Royalty Purchase Agreement, the 2026 Convertible Notes outstanding, and the 2031 Convertible Notes outstanding, partially offset by interest income earned on investments. 45 Table of Contents ​ Critical accounting policies and significant judgments and estimates Our management’s discussion and analysis of our financial condition and results of operations is based on our financial statements, which we have prepared in accordance with generally accepted accounting principles in the United States. The preparation of these financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported revenues and expenses during the reporting periods. Actual results may differ from these estimates under different assumptions or conditions. During the three and six months ended June 30, 2026, there were no material changes to our critical accounting policies as reported in our 2025 Annual Report. Results of operations Three months ended June 30, 2026 compared to the three months ended June 30, 2025 The following table summarizes revenues and selected expense and other income data for the three months ended June 30, 2026 and 2025. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ ​ ​ June 30, ​ Change (in thousands) ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ 2026 vs. 2025 Net product revenue ​ $ 238,819 ​ $ 118,329 ​ $ 120,490 Collaboration and license revenue ​ ​ 50,595 ​ ​ 2,941 ​ ​ 47,654 Royalty revenue ​ ​ 71,105 ​ ​ 57,605 ​ ​ 13,500 Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets ​ 19,921 ​ 11,420 ​ ​ 8,501 Amortization of acquired intangible assets ​ 11,841 ​ 4,061 ​ ​ 7,780 Research and development expense ​ 99,150 ​ 112,990 ​ ​ (13,840) Selling, general and administrative expense ​ 80,630 ​ 85,262 ​ ​ (4,632) Tangible asset impairment and losses on transactions, net ​ ​ — ​ ​ 99 ​ ​ (99) Interest expense, net ​ (48,481) ​ (30,358) ​ ​ (18,123) Other expense, net ​ (2,951) ​ (5,737) ​ ​ 2,786 Income tax (expense) benefit ​ ​ (14,049) ​ ​ 6,203 ​ ​ (20,252) ​ Net product revenue. Net product revenue was $238.8 million for the three months ended June 30, 2026, an increase of $120.5 million, or over 100%, from $118.3 million for the three months ended June 30, 2025. The increase in net product revenue was primarily due to an increase in net product sales of $151.3 million for Sephience, which is in the first year of its launch, partially offset by a decrease in net product sales of $11.7 million for Emflaza and $17.3 million for Translarna. The decrease in Emflaza sales is primarily driven by additional generic competition. The decrease in Translarna sales is primarily due to the EC’s adoption of the CHMP’s negative opinion. Collaboration and license revenue. Collaboration and license revenue was $50.6 million for the three months ended June 30, 2026, an increase of $47.7 million, or over 100%, from $2.9 million for the three months ended June 30, 2025. For the three months ended June 30, 2026, we recognized $50.6 million, primarily related to a development milestone. In April 2026, Novartis notified the Company that it had initiated the first Phase 3 clinical trial for a Licensed Product (as defined in the Novartis Agreement). Pursuant to the Novartis Agreement, this triggered a $50.0 million milestone payment to us. For the three months ended June 30, 2025, we recognized $2.9 million related to license revenue from the Novartis Agreement for performance obligations completed during the period. Royalty revenue. Royalty revenue was $71.1 million for the three months ended June 30, 2026, an increase of $13.5 million, or 23%, from $57.6 million for the three months ended June 30, 2025. The increase in royalty revenue was due to higher Evrysdi sales in the three months ended June 30, 2026 as compared to the three months ended June 30, 2025. In 46 Table of Contents accordance with the SMA License Agreement, we are entitled to recognize royalties on worldwide annual net sales of the product. See “Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations—Overview—Corporate Updates—Funding.” Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets. Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets was $19.9 million for the three months ended June 30, 2026, an increase of $8.5 million, or 74%, from $11.4 million for the three months ended June 30, 2025. Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets consists primarily of the costs associated with the Novartis agreement, royalty payments associated with Sephience and Upstaza/Kebilidi net product sales, costs associated with Sephience, Translarna, Upstaza/Kebilidi, and Emflaza product sold during the period, as well as the production costs associated with these products. The increase was primarily driven by the increase in net product sales, which impacted the cost for products sold and royalty expense for the period. Amortization of acquired intangible assets. Amortization of acquired intangible assets was $11.8 million for the three months ended June 30, 2026, an increase of $7.8 million, or over 100%, from $4.1 million for the three months ended June 30, 2025. The increase to the intangible assets balance was primarily related to Upstaza/Kebildi and Sephience intangible assets recorded as a result of the regulatory approvals and net sales milestones as well as the Censa Rights Satisfaction Agreement, which increased the corresponding amortization for those assets. ​ Research and development expense. Research and development expense was $99.2 million for the three months ended June 30, 2026, a decrease of $13.8 million, or 12%, from $113.0 million for the three months ended June 30, 2025. The decrease in research and development expenses primarily related to decreases in development program spend as we continued to focus our resources on our differentiated, high potential research and development programs. Selling, general and administrative expense. Selling, general and administrative expense was $80.6 million for the three months ended June 30, 2026, a decrease of $4.6 million, or 5%, from $85.3 million for the three months ended June 30, 2025. The decrease is primarily due to a decrease in selling expenses related to prelaunch activities for Sephience. ​ Tangible asset impairment and losses on transactions, net. Tangible asset impairment and losses on transactions, net decreased $0.1 million, or 100%, from $0.1 million for the three months ended June 30, 2025. The decrease in tangible asset impairment and losses on transactions primarily related to no impairments and gains or losses during the three months ended June 30, 2026 as compared to $0.1 million related to fixed asset impairments in the three months ended June 30, 2025. Interest expense, net. Interest expense, net was $48.5 million for the three months ended June 30, 2026, an increase of $18.1 million, or 60%, from $30.4 million for the three months ended June 30, 2025. The increase in interest expense, net was primarily due to an increase in interest expense related to the liability for the sale of future royalties related to the A&R Royalty Purchase Agreement. Other expense, net. Other expense, net was $3.0 million for the three months ended June 30, 2026, a decrease of $2.8 million, or 49%, from other expense, net of $5.7 million for the three months ended June 30, 2025. The decrease in other expense, net, primarily relates to net realized and unrealized gains from foreign currency of $0.4 million for the three months ended June 30, 2026, compared to net realized and unrealized losses from foreign currency of $8.7 million for the three months ended June 30, 2025. This decrease was partially offset by an inducement expense of $3.4 million related to the repurchase of a portion of the 2026 Convertible Notes and other items of $2.8 million. Income tax (expense) benefit. Income tax expense was $14.0 million for the three months ended June 30, 2026, a change of $20.3 million, or over 100%, compared to income tax benefit of $6.2 million for the three months ended June 30, 2025. The change in income tax (expense) benefit was driven by the recognition of revenue associated with the A&R Royalty Purchase Agreement. Six months ended June 30, 2026 compared to the six months ended June 30, 2025 47 Table of Contents The following table summarizes revenues and selected expense and other income data for the six months ended June 30, 2026 and 2025. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ ​ ​ ​ June 30, ​ Change (in thousands) ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ 2026 vs. 2025 Net product revenue ​ $ 464,392 ​ $ 271,755 ​ $ 192,637 Collaboration and license revenue ​ 50,738 ​ 989,172 ​ ​ (938,434) Royalty revenue ​ ​ 117,940 ​ ​ 94,044 ​ ​ 23,896 Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets ​ 47,949 ​ 24,282 ​ ​ 23,667 Amortization of acquired intangible assets ​ 23,422 ​ 7,859 ​ ​ 15,563 Research and development expense ​ 200,023 ​ 221,963 ​ ​ (21,940) Selling, general and administrative expense ​ 166,813 ​ 166,223 ​ ​ 590 Change in the fair value of contingent consideration ​ — ​ (800) ​ ​ 800 Tangible asset impairment and losses on transactions, net ​ ​ 927 ​ ​ 176 ​ ​ 751 Interest expense, net ​ (97,511) ​ (64,450) ​ ​ (33,061) Other expense, net ​ (1,342) ​ (12,042) ​ ​ 10,700 Income tax expense ​ ​ (14,396) ​ ​ (57,063) ​ ​ 42,667 ​ Net product revenue. Net product revenue was $464.4 million for the six months ended June 30, 2026, an increase of $192.6 million, or 71%, from $271.8 million for the six months ended June 30, 2025. The increase in net product revenue was primarily due to an increase in net product sales of $275.9 million for Sephience, which is in the first year of its launch, partially offset by a decrease in net product sales of $38.0 million for Emflaza and $44.4 million for Translarna. The decrease in Emflaza sales is primarily driven by additional generic competition. The decrease in Translarna sales is primarily due to the EC’s adoption of the CHMP’s negative opinion. Collaboration and license revenue. Collaboration and license revenue was $50.7 million for the six months ended June 30, 2026, a decrease of $938.4 million, or 95%, from $989.2 million for the six months ended June 30, 2025. The decrease in collaboration and license revenue was due to the receipt of the $1.0 billion upfront payment upon the effective date of the license and collaboration agreement with Novartis related to our votoplam HD program for the six months ended June 30, 2025. For the six months ended June 30, 2026, we recognized $50.7 million primarily related to a development milestone pursuant to our Novartis Agreement for Novartis’s initiation of the first Phase 3 clinical trial for a Licensed Product (as defined in the Novartis Agreement), which triggered a $50.0 million milestone payment to us. For the six months ended June 30, 2025, we recognized $992.7 million related to license revenue from the Novartis Agreement which was partially offset by $3.5 million related to a refund for a prior collaboration arrangement in relation to votoplam. Royalty revenue. Royalty revenue was $117.9 million for the six months ended June 30, 2026, an increase of $23.9 million, or 25%, from $94.0 million for the six months ended June 30, 2025. The increase in royalty revenue was due to higher Evrysdi sales in the six months ended June 30, 2026 as compared to the six months ended June 30, 2025. In accordance with the SMA License Agreement, we are entitled to recognize royalties on worldwide annual net sales of the product. Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets. Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets was $47.9 million for the six months ended June 30, 2026, an increase of $23.7 million, or 97%, from $24.3 million for the six months ended June 30, 2025. Cost of product, collaboration and license sales, excluding amortization of acquired intangible assets consists primarily of the costs associated with the Novartis agreement, royalty payments associated with Sephience and Upstaza/Kebilidi net product sales, costs associated with Sephience, Translarna, Upstaza/Kebilidi, and Emflaza product sold during the period, as well as the production costs associated with these products. The increase was primarily driven by the increase in net product sales, which impacted the cost for products sold and royalty expense for the period. Amortization of acquired intangible assets. Amortization of acquired intangible assets was $23.4 million for the six months ended June 30, 2026 an increase of $15.6 million, or over 100%, from $7.9 million for the six months ended June 30, 2025. 48 Table of Contents The increase to the intangible assets balance was primarily related to Upstaza/Kebildi and Sephience intangible assets recorded as a result of the regulatory approvals and net sales milestones as well as the Censa Rights Satisfaction Agreement, which increased the corresponding amortization for those assets. Research and development expense. Research and development expense was $200.0 million for the six months ended June 30, 2026, a decrease of $21.9 million, or 10%, from $222.0 million for the six months ended June 30, 2025. The decrease in research and development expenses related to decreases in development program spend as we continued to focus our resources on our differentiated, high potential research and development programs. Selling, general and administrative expense. Selling, general and administrative expense was $166.8 million for the six months ended June 30, 2026, an increase of $0.6 million, or 0%, from $166.2 million for the six months ended June 30, 2025. The increase reflected our continued investment to support our commercial activities including our expanding commercial portfolio. Change in the fair value of contingent consideration. There was no change in the fair value of contingent consideration for the six months ended June 30, 2026, a change of $0.8 million, or 100%, from a gain of $0.8 million for the six months ended June 30, 2025. During the first quarter of 2025, the probability of triggering the remaining contingent consideration was determined to be remote, and therefore the balance was written down to zero. Tangible asset impairment and losses on transactions, net. Tangible asset impairment and losses on transactions, net was $0.9 million for the six months ended June 30, 2026, an increase of $0.8 million, or over 100%, from $0.2 million for the six months ended June 30, 2025. The increase was primarily driven by a $0.8 million loss related to inventory impairments during the six months ended June 30, 2026. During the six months ended June 30, 2025, we recorded $0.1 million related to fixed asset impairments and $0.1 million related to losses on the sale of fixed assets. Interest expense, net. Interest expense, net was $97.5 million for the six months ended June 30, 2026, an increase of $33.1 million, or 51%, from $64.5 million for the six months ended June 30, 2025. The increase in interest expense, net was primarily due to an increase in interest expense related to the liability for the sale of future royalties related to the A&R Royalty Purchase Agreement. Other expense, net. Other expense, net was $1.3 million for the six months ended June 30, 2026, a decrease of $10.7 million, or 89%, from other expense, net of $12.0 million for the six months ended June 30, 2025. The decrease in other expense, net, primarily relates to net realized and unrealized gains from foreign currency of $1.8 million for the six months ended June 30, 2026, compared to net realized and unrealized losses from foreign currency of $15.0 million for the six months ended June 30, 2025. This decrease was partially offset by an inducement expense of $3.4 million related to the repurchase of a portion of the 2026 Convertible Notes and other items of $2.7 million. Income tax expense. Income tax expense was $14.4 million for the six months ended June 30, 2026, a decrease of $42.7 million, or 75%, compared to income tax expense of $57.1 million for the six months ended June 30, 2025. The decrease in income tax expense was driven by the projected utilization of additional tax attributes in 2026 as a result of the provisions within the One Big Beautiful Bill Act. Liquidity and capital resources Sources of liquidity While we have generated net income in the six months ended June 30, 2026 and 2025, we have historically incurred significant operating losses. As a growing commercial-stage biopharmaceutical company, we are engaging in significant commercialization efforts for our products while also devoting a substantial portion of our efforts on research and development related to our products, product candidates and other programs. Our product revenue primarily consists of sales of Sephience for the treatment of PKU. Our product revenues also consist of sales of Translarna for the treatment of nmDMD in territories outside of the United States and from Emflaza for the treatment of DMD in the United States. Our ability to generate product revenue 49 Table of Contents from any of our products will largely depend on the coverage and reimbursement levels set by governmental authorities, private health insurers and other third-party payors, as the case may be, depending on the country in which our products are marketed, and the rate and degree of market acceptance and clinical utility of any of our products. Additionally, for Emflaza, its seven-year period of orphan drug exclusivity related to the treatment of DMD in patients five years and older expired in February 2024. With the expiration of this orphan drug exclusivity, we have seen an increase in competition from generics, which has, and we expect will continue to have, a negative impact on Emflaza net product revenue. Emflaza’s orphan drug exclusivity related to the treatment of DMD in patients two years of age to less than five expired in June 2026. Additionally, for Translarna, our ongoing ability to generate revenue from sales of Translarna for the treatment of nmDMD is dependent upon our ability to maintain our marketing authorizations in other geographies and secure market access through commercial programs following the conclusion of pricing and reimbursement terms at sustainable levels in the member states of the EEA or through EAP programs or similar styled programs in the EEA and other territories. While Translarna previously had conditional approval in the EEA, in March 2025, the EC adopted the negative opinion of the CHMP of the EMA to not renew the conditional marketing authorization of Translarna for the treatment of nmDMD. However, the EC indicated that individual countries within the EU can leverage Articles 117(3) and 5(1) of the EU Directive 2001/83 to allow continued commercial use of Translarna. There is a substantial risk that as a result of the EC’s adoption of the CHMP’s negative opinion we will lose a significant portion of our ability to generate revenue from sales of Translarna in the EEA. Additionally, the loss of the Translarna marketing authorization in the EEA and the withdrawal of the Translarna NDA in the United States may influence regulatory entities in other jurisdictions in which Translarna has been approved to reassess such approvals. There is substantial risk that we will be unable to maintain our marketing authorizations in these countries. Even in countries where our marketing authorization is maintained, there may be an impact on pricing and reimbursement of Translarna within those countries. We have financed our operations to date primarily through private offerings of convertible senior notes, public and “at the market” offerings of common stock, proceeds from royalty purchase agreements, private placements of our 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 our product candidates. We expect to continue to incur significant expenses for at least the next fiscal year. The net income and losses we incur may fluctuate significantly from quarter to quarter. In August 2019, we entered into the Sales Agreement, pursuant to which, we may offer and sell shares of our common stock, having an aggregate offering price of up to $125.0 million from time to time through the Sales Agents by any method that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act. See “Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations—Overview—Corporate Updates — Funding” for additional information. We have received fundings from Royalty Pharma under the A&R Royalty Purchase Agreement in July 2020, October 2023, June 2024 and December 2025, totaling $2.1 billion. In exchange for these fundings, we sold Royalty Pharma 100% of our right to receive sales-based royalty payments on worldwide net sales of Roche’s Evrysdi® (risdiplam) product and any other product developed pursuant to the SMA collaboration with us, Roche, and the SMA Foundation. In November 2024, we and Novartis entered into the Novartis Agreement relating to our votoplam HD program which includes related molecules. Pursuant to the Novartis Agreement, we were responsible for conducting the Phase 2A clinical trial of votoplam, which is complete, and have transitioned sponsorship of the ongoing open-label extension clinical trial to Novartis. Novartis will be responsible for all other development of licensed compounds and licensed products and the manufacture and commercialization of licensed compounds and licensed products worldwide. Under the Novartis Agreement, and upon the closing of the transaction contemplated by the Novartis Agreement in January 2025, we received an upfront payment of $1.0 billion on the effective date and are eligible receive up to $1.9 billion in development, regulatory and sales milestones, a 40% share of U.S. profits and losses, and tiered double-digit royalties on ex-U.S. sales. In April 2026, Novartis notified us that it had initiated the first Phase 3 clinical trial for a Licensed Product (as defined in the Novartis Agreement), which, pursuant to the Novartis Agreement, triggered a $50.0 million milestone payment to us. 50 Table of Contents In September 2019, we issued $287.5 million aggregate principal amount of 2026 Convertible Notes, which included an option to purchase up to an additional $37.5 million in aggregate principal amount of the 2026 Convertible Notes, which was exercised in full by the initial purchasers. We received net proceeds of $279.3 million after deducting the initial purchasers’ discounts and commissions and the offering expenses payable by us. The 2026 Convertible Notes bear cash interest at a rate of 1.50% per year, payable semi-annually on March 15 and September 15 of each year, beginning on March 15, 2020. The 2026 Convertible Notes will mature on September 15, 2026, unless earlier repurchased or converted. The 2026 Convertible Notes are currently convertible at the option of the holder. During the three months ended June 30, 2026, a holder converted $10.0 million principal value of 2026 Convertible Notes in exchange for $12.9 million in cash and 3,506 shares of our common stock. We recorded a $10.0 million reduction to the carrying value of the convertible notes, and the excess of $2.9 million was recognized as a reduction in additional paid-in capital within our statement of stockholders’ deficit. In June 2026 we closed a private offering of $550.0 million aggregate principal amount of 0% convertible senior notes due 2031, which reflects the exercise in full by the initial purchasers of their option to purchase up to an additional $50.0 million in aggregate principal amount of the 2031 Convertible Notes. The 2031 Convertible Notes bear no regular interest and the principal amounts of the 2031 Convertible Notes will not accrete. The 2031 Convertible Notes may bear special interest under specified circumstances relating to our failure to comply with our reporting obligations under the 2031 Convertible Notes Indenture or if the 2031 Convertible Notes are not freely tradeable as required by the 2031 Convertible Notes Indenture. Special interest, if any, will be payable semiannually in arrears on June 15 and December 15 of each year, beginning on December 15, 2026 (if and to the extent that special interest is payable). The 2031 Convertible Notes will mature on June 15, 2031, unless earlier converted, redeemed or repurchased pursuant to their terms. We received net proceeds of approximately $535.4 million after deducting the initial purchasers’ discounts and commissions and the offering expenses payable by us. Following the issuance of the 2031 Convertible Notes, we used approximately $328.8 million of the net proceeds of the 2031 Convertible Notes to repurchase for cash $222.0 million aggregate principal amount of our 2026 Convertible Notes pursuant to privately negotiated transactions with certain holders entered into concurrently with the pricing of the offering of the 2031 Convertible Notes. After giving effect to the repurchases of the 2026 Convertible Notes, the aggregate principal amount outstanding of 2026 Convertible Notes is $55.5 million. The repurchase of the 2026 Convertible Notes was accounted for as an induced conversion. The excess of the fair value of the repurchase price over the if-converted value was $3.4 million and was recorded as inducement expense within other expense, net on the consolidated statements of operations. The net carrying amount of the repurchased 2026 Convertible Notes was derecognized, and the difference between the if-converted value and the net carrying amount of $102.7 million was recognized as a reduction in additional paid-in capital within the consolidated statement of stockholders’ deficit. Cash flows As of June 30, 2026, we had cash, cash equivalents and marketable securities of $2.23 billion. The following table provides information regarding our cash flows and our capital expenditures for the periods indicated. ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended ​ ​ ​ June 30, ​ (in thousands) ​ ​ ​ 2026 ​ ​ ​ 2025 ​ Cash provided by (used in): ​ ​ ​ Operating activities ​ 70,071 ​ 811,770 ​ Investing activities ​ (216,292) ​ (606,369) ​ Financing activities ​ 218,281 ​ 13,371 ​ ​ Net cash provided by operating activities was $70.1 million for the six months ended June 30, 2026, and $811.8 million for the six months ended June 30, 2025. The net cash provided by operating activities for the six months ended June 30, 2026, primarily relates to the $50.0 million in cash received from Novartis for initiating the first Phase 3 clinical trial for a Licensed Product. The net cash provided by operating activities for the six months ended June 30, 2025, was 51 Table of Contents primarily related to the upfront payment of $1.0 billion in cash received upon the closing of the Novartis Agreement in January 2025, partially offset by spend supporting clinical development and commercial activities. Net cash used in investing activities was $216.3 million for the six months ended June 30, 2026, compared to $606.4 million for the six months ended June 30, 2025. Cash used in investing activities for the six months ended June 30, 2026 and 2025, was primarily related to the purchases of marketable securities, acquisition of product rights, and purchases of fixed assets, offset by sales of marketable securities. Net cash provided by financing activities was $218.3 million for the six months ended June 30, 2026, compared to $13.4 million for the six months ended June 30, 2025. Cash provided by financing activities for the six months ended June 30, 2026, was primarily attributable to cash received from the exercise of options, proceeds from employee stock purchase plan, proceeds from the issuance of the 2031 Convertible notes, offset by the debt issuance costs related to the 2031 convertible notes, and the repurchase and conversion of the 2026 Convertible Notes. Cash provided by financing activities for the six months ended June 30, 2025, was primarily attributable to proceeds from our employee stock purchase plan and proceeds from the exercise of options, partially offset by payments on contingent consideration obligation. Funding requirements We anticipate that we will continue to incur significant expenses in connection with our commercialization efforts in the United States, the EEA, Latin America, Japan and other territories, including expenses related to our commercial infrastructure and corresponding sales and marketing, legal and regulatory, and distribution and manufacturing undertakings as well as administrative and employee-based expenses. In addition to the foregoing, we expect to continue to incur significant costs in connection with ongoing, planned and potential future clinical trials and studies for our splicing and inflammation and ferroptosis programs as well as studies in our products for maintaining authorizations, label extensions and additional indications. These efforts may significantly impact the timing and extent of our commercialization and manufacturing expenses. We 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, we 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, we plan to initiate the PROVE-FA open label study using matched natural history control in the third quarter of 2026. In addition, our expenses will increase if and as we: ● seek to satisfy contractual and regulatory obligations that we assumed through our acquisitions and collaborations; ● execute our commercialization strategy for our products, including initial commercialization launches of our products, label extensions or entering new markets; ● are required to complete any additional clinical trials, non-clinical studies or Chemistry, Manufacturing and Controls, or CMC, assessments or analyses in order to advance our products or product candidates in the United States or elsewhere; ● initiate or continue the research and development of our splicing and inflammation and ferroptosis programs as well as studies in our products for maintaining authorizations, label extensions and additional indications; ● seek to discover and develop additional product candidates; ● seek to expand and diversify our product pipeline through strategic transactions; ● maintain, expand and protect our intellectual property portfolio; and 52 Table of Contents ● add operational, financial and management information systems and personnel, including personnel to support our product development and commercialization efforts. We believe that our cash flows from product sales and milestone payments from Novartis, together with existing cash and cash equivalents, and marketable securities, will be sufficient to fund our operating expenses and capital expenditure requirements for at least the next twelve months. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect. Our future capital requirements will depend on many factors, including: ● our ability to commercialize and market our products and product candidates that may receive marketing authorization; ● our ability to negotiate, secure and maintain adequate pricing, coverage and reimbursement terms, on a timely basis, with third-party payors for our products and product candidates; ● our plans for vatiquinone including with respect to the expected timing of clinical trials and studies, availability of data, regulatory submissions and responses, meetings with regulatory agencies, and other matters; ● our ability to successfully complete all post-marketing requirements imposed by regulatory agencies with respect to our products; ● the progress and results of activities for our splicing and inflammation and ferroptosis programs as well as studies in our products for maintaining authorizations, label extensions and additional indications; ● the scope, costs and timing of our commercialization activities, including product sales, marketing, legal, regulatory, distribution and manufacturing, for any of our products and for any of our other product candidates that may receive marketing authorization; ● the costs, timing and outcome of regulatory review of our splicing and inflammation and ferroptosis programs and Sephience, Translarna and Upstaza/Kebilidi in other territories; ● our ability to satisfy our obligations under the indenture governing the 2026 Convertible Notes; ● our ability to satisfy our obligations under the indenture governing the 2031 Convertible Notes; ● the timing and scope of any potential future growth in our employee base; ● the scope, progress, results and costs of preclinical development, laboratory testing and clinical trials for our other product candidates, including those in our splicing and inflammation and ferroptosis programs; ● revenue received from commercial sales of our products or any of our product candidates; ● our ability to obtain additional and maintain existing reimbursed named patient and cohort EAP programs for Translarna for the treatment of nmDMD on adequate terms, or at all; ● the ability and willingness of patients and healthcare professionals to access Translarna through alternative means if pricing and reimbursement negotiations in the applicable territory do not have a positive outcome; ● the costs of preparing, filing and prosecuting patent applications, maintaining, and protecting our intellectual property rights and defending against intellectual property-related claims; 53 Table of Contents ● the extent to which we acquire or invest in other businesses, products, product candidates, and technologies, including the success of any acquisition, in-licensing or other strategic transaction we may pursue, and the costs of subsequent development requirements and commercialization efforts, including with respect to our acquisitions of Emflaza, Agilis, our inflammation and ferroptosis platform and Censa and our licensing of Tegsedi and Waylivra; ● our ability to establish and maintain collaborations, including our collaborations with Roche and the SMA Foundation, and our ability to obtain research funding and achieve milestones under these agreements. ● the progress and results of activities for our votoplam program, including our right to receive any development, regulatory and sales milestones, profit sharing and royalty payments from Novartis; and ● unexpected decreases in revenue or increase in expenses resulting from geopolitical events, global economic developments and public health pandemics or epidemics. With respect to our outstanding 2026 Convertible Notes, cash interest payments are payable on a semi-annual basis in arrears, which will require remaining funding of $0.4 million through maturity. As of the quarter ended June 30, 2026, aggregate Sephience global net sales in the prior four consecutive quarters exceeded $250.0 million, which, pursuant to the Censa Merger Agreement, triggered a $30.0 million net sales milestone payment to the former Censa securityholders. This milestone payment was recorded in accounts payable and accrued expenses on our consolidated balance sheet as of June 30, 2026. We also have certain significant contractual obligations and commercial commitments that require funding and we have disclosed these items under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations-Funding Obligations” in our 2025 Annual Report. There were no material changes to these obligations and commitments during the period ended June 30, 2026. We will need to generate significant revenues to achieve and sustain profitability and we may never do so. We may need to obtain substantial additional funding in connection with our continuing operations. Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs primarily through a combination of equity offerings, debt financings, collaborations, strategic alliances, grants and clinical trial support from governmental and philanthropic organizations and patient advocacy groups in the disease areas addressed by our product and product candidates and marketing, distribution or licensing arrangements. Adequate additional financing may not be available to us on acceptable terms, or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, our stockholders ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our common stockholders. Debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through collaborations, strategic alliances or marketing, distribution or licensing arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or product candidates or to grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity, debt or other financings when needed or on attractive terms, we may be required to delay, limit, reduce or terminate our product development or commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.