Exhibit 99.1

Sarepta Therapeutics Announces Strategic Restructuring and Pipeline Prioritization Plan to Maintain Long-term, Sustainable Growth and Provides Update on ELEVIDYS Label

CAMBRIDGE, Mass., July 16, 2025 (BUSINESS WIRE) -- Sarepta Therapeutics, Inc. (NASDAQ:SRPT), the leader in precision genetic medicine for rare diseases, today announced a strategic restructuring plan designed to prioritize high-value, high impact programs, meet its 2027 financial obligations, and support its long-term financial viability. This plan is expected to position the Company for long-term sustainable growth, with an emphasis on near- and mid-term opportunities from the siRNA platform. These decisive changes aim to ensure sustained profitability and preserve the Company’s ability to deliver on its mission of advancing innovative medicines for those with rare genetic diseases.

“Faced with environmental changes, we have decided to act decisively, implementing a focused strategy to ensure Sarepta remains a vibrant, financially enduring, patient-centric organization dedicated to improving the lives of those with rare genetic diseases,” said Doug Ingram, chief executive officer, Sarepta Therapeutics. “These changes will ensure we remain a financially strong and profitable organization built on a sharpened and focused strategy. We will continue to drive performance of ELEVIDYS and our three PMOs in service of the Duchenne community those therapies benefit, and with our financial performance, we will advance our high-value, focused pipeline of programs for rare genetic diseases, primarily relying on the siRNA platform, while ensuring we meet our financial obligations.”

In addition to the restructuring plan, the Company provided an update on activities related to the label updates underway for ELEVIDYS (delandistrogene moxeparvovec), the first and only approved gene therapy for the treatment of Duchenne muscular dystrophy and reported preliminary financial results for the quarter ended June 30, 2025.

ELEVIDYS Label Update and Enhanced Safety Efforts

Following previously communicated steps being taken to strengthen the safety profile of ELEVIDYS, Sarepta is providing an update on on-going engagement with the U.S. Food and Drug Administration (FDA) regarding the ELEVIDYS (delandistrogene moxeparvovec) label. Consistent with other AAV-delivered gene therapies, the FDA has requested that

the label include a black box warning for acute liver injury (ALI) and acute liver failure (ALF). Sarepta agrees with this change, which appears to resolve any material issues with the ambulant portion of the ELEVIDYS label.

Sarepta recently announced that it was pausing shipments of ELEVIDYS for non-ambulant patients while it explored the adoption of additional prophylactic immunosuppression. To that end, Sarepta convened an Expert Committee of neuromuscular specialists, hepatologists, hematologists, and immunologists to review cases of ALF and explore additional immunosuppression regimens. The Committee aligned on an enhanced immunosuppressive regimen with sirolimus for ELEVIDYS in non-ambulant patients. Sarepta will submit the finding of the expert panel and proposed protocol to the FDA imminently and will discuss a proposal to gather data on the regimen in a new cohort (Cohort 8) of the ENDEAVOR study (Study SRP-9001-103) as a pathway to re-establish dosing in the non-ambulant setting. Additionally, Sarepta is assessing real-world data generation opportunities for ambulant patients through investigator-initiated trials.

Strategic Restructuring to Bolster Financial Foundation

Sarepta has initiated immediate changes to reduce operating expenses and align its cost structure with strategic priorities, aiming to enhance financial flexibility and meet its 2027 financial obligations.

Collectively, these measures are projected to deliver approximately $400 million in annual cost reductions, significantly lowering the Company’s average annual non-GAAP R&D and SG&A expenses to between $800 million and $900M starting in 2026.

These include:

This rigorous approach is designed to maintain access to Sarepta’s $600 million revolving credit facility and generate robust cash flow to proactively manage liabilities, including the repayment of the 2027 convertible note.

Preliminary Second Quarter 2025 Financial Highlights

For the second quarter ended June 30, 2025, Sarepta reported preliminary financial results:

These selected financial results are preliminary and subject to adjustment. The Company has not completed its financial closing procedures for the quarter ended June 30, 2025, and its actual results could be materially different from these preliminary financial results. Sarepta will report its final and complete second quarter 2025 financial results in early August 2025.

Refocused Pipeline on siRNA platform

Sarepta’s dedication to advancing genetic medicine remains steadfast. The Company will continue to support its four on-market Duchenne therapies and all associated clinical trial commitments and evidence-generation activities. Revenues from this robust Duchenne portfolio are expected to continue driving profitability and funding a focused pipeline of high-impact development programs primarily leveraging Sarepta’s potentially best-in-class siRNA platform. This strategic pivot emphasizes chronically administered therapies for neurodegenerative and pulmonary diseases.

As a result of this reprioritization, several programs, including most of the gene therapies in development for limb-girdle muscular dystrophy (LGMD), will be paused. Sarepta expects to submit the Biologics License Application for SRP-9003 for LGMD type 2E/R4 in the second half of this year. Sarepta intends to seek strategic alternatives, including partnering, for programs that it no longer intends to fund directly.

The siRNA programs include investigational treatments for:

These programs offer tremendous near-term potential, addressing areas of significant unmet medical need with potentially best-in-class approaches. Sarepta is also pursuing preclinical programs for Spinocerebellar ataxia type 1 (SCA1) and Spinocerebellar ataxia type 3 (SCA3) and has an exclusive collaboration with Arrowhead Pharmaceuticals to develop therapies for skeletal muscle diseases, with plans to pursue up to six discovery targets in muscle or central nervous system disorders.

Executive Leadership Appointments

In conjunction with the restructuring, Sarepta announced key executive appointments:

Investor Webcast Details

Sarepta will be hosting a conference call and webcast to discuss these updates on Wednesday, July 16, 2025, at 4:30 p.m. Eastern time. The event will be webcast live under the investor relations section of Sarepta's website at: https://investorrelations.sarepta.com/events-presentations and following the event a replay will be archived there for one year. Interested parties participating by phone will need to register using this online form. After registering for dial-in details, all phone participants will receive an auto-generated e-mail containing a link to the dial-in number along with a personal PIN number to use to access the event by phone.

Use of Non-GAAP Measures

In addition to the GAAP financial measures set forth in this press release, we have included the following non-GAAP measurements:

The following components are used to adjust our GAAP financial measures into the previously defined non-GAAP measurements:

We use these non-GAAP measures as key performance measures for the purpose of evaluating operational performance and cash requirements internally. We believe these non-GAAP measures increase comparability of period-to-period results and are useful to investors as they provide a similar basis for evaluating our performance as is applied by management. These non-GAAP measures are not intended to be considered in isolation or to replace the presentation of our financial results in accordance with GAAP. Use of the terms non-GAAP research and development expenses and non-GAAP selling, general and administrative expenses may differ from similar measures reported by other companies, which may limit comparability, and are not based on any comprehensive set of accounting rules or principles.

About ELEVIDYS (delandistrogene moxeparvovec-rokl)

ELEVIDYS (delandistrogene moxeparvovec-rokl) is a single-dose, adeno-associated virus (AAV)-based gene transfer therapy for intravenous infusion designed to address the underlying genetic cause of Duchenne muscular dystrophy – mutations or changes in the DMD gene that result in the lack of dystrophin protein – through the delivery of a transgene that codes for the targeted production of ELEVIDYS micro-dystrophin in skeletal muscle.

ELEVIDYS is indicated for the treatment of Duchenne muscular dystrophy (DMD) in individuals at least 4 years of age.

The DMD indication in non-ambulatory patients is approved under accelerated approval based on expression of ELEVIDYS micro-dystrophin in skeletal muscle. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

IMPORTANT SAFETY INFORMATION

CONTRAINDICATION: ELEVIDYS is contraindicated in patients with any deletion in exon 8 and/or exon 9 in the DMD gene.

WARNINGS AND PRECAUTIONS:

Infusion-related Reactions:

Acute Serious Liver Injury:

Immune-mediated Myositis:

Myocarditis:

Preexisting Immunity against AAVrh74:

Adverse Reactions:

Report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088. You may also report side effects to Sarepta Therapeutics at 1-888-SAREPTA (1-888-727-3782).

For further information, please see the full Prescribing Information.

About Sarepta Therapeutics

Sarepta is on an urgent mission: engineer precision genetic medicine for rare diseases that devastate lives and cut futures short. We hold leadership positions in Duchenne muscular dystrophy (Duchenne) and limb-girdle muscular dystrophies (LGMDs) and are building a robust portfolio of programs across muscle, central nervous system, and cardiac diseases. For more information, please visit www.sarepta.comor follow us on LinkedIn, X, Instagramand Facebook.

Internet Posting of Information

We routinely post information that may be important to investors in the 'For Investors' section of our website at www.sarepta.com. We encourage investors and potential investors to consult our website regularly for important information about us.

Forward-Looking Statements

This press release contains “forward-looking statements.” Any statements that are not statements of historical fact may be deemed to be forward-looking statements. Words such as “believe,” “anticipate,” “plan,” “expect,” “will,” “may,” “intend,” “prepare,” “look,” “potential,” “possible” and similar expressions are intended to identify forward-looking statements. These forward-looking statements include, without limitation, statements relating to our financial results and projections and future operations; our pipeline and priorities; ELEVIDYS and the potential benefits of our proposed enhanced regimen; our ongoing and planned clinical trials; the reduction in force and our revised cost structure; the potential for our restructuring activities to help us meet our 2027 financial obligations, sustain profitability and position us for long-term sustainable growth; our expectation that the label for ELEVIDYS will include a black box warning for acute liver injury and acute liver failure; and expected plans and milestones, including our intention to seek alignment with the FDA to test our enhanced regimen in a new cohort of the ENDEAVOR study, submitting the BLA for SRP-9003 later this year, potentially seeking additional strategic alternatives for programs no longer directly funded, and near-term opportunities from the siRNA platform.

Actual results could materially differ from those stated or implied by these forward-looking statements as a result of such risks and uncertainties. Known risk factors include the following: our products or product candidates may be perceived as insufficiently effective, unsafe or may result in unforeseen adverse events; our products or product candidates may cause undesirable side effects that result in significant negative consequences following any marketing approval; we may not be able to comply with all FDA requests in a timely manner or at all; the reduction in force may take longer or result in more significant charges or cash expenditures than anticipated or otherwise negatively impact the Company and its business plans during and after the period during which the reduction in force is being executed; we may not be able to meet expectations with respect to sales of our products or maintain profitability; the estimates and judgments the Company makes, or the assumptions on which it relies, in preparing its financial statements could prove inaccurate; we may not be able to advance all of our programs, and we may use our financial and human resources to pursue particular programs and fail to capitalize on programs that may be more profitable or for which there is a greater likelihood of success; different methodologies, assumptions and applications we use to assess particular safety or efficacy parameters may yield different statistical results, and even if we believe the data collected from clinical trials are positive, these data may not be sufficient to support approval; success in clinical trials, especially if based on a small patient sample, does not ensure that later clinical trials will be successful, and the results of future research may not be consistent with past positive results or with advisory committee recommendations, or may fail to meet regulatory approval requirements for the safety and efficacy of product candidates; failure to retain our key personnel or an inability to attract and retain additional qualified personnel could present a challenge to our business objectives; our existing and any future indebtedness could adversely affect our ability to operate our business; our revenues and operating results could fluctuate significantly, which may adversely affect our stock price and our ability to maintain profitability; the possible impact of regulations and regulatory decisions by the FDA and other regulatory agencies on our business; and those risks identified under the heading “Risk Factors” in our most recent Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) as well as other SEC filings made by the Company, which you are encouraged to review.

Any of the foregoing risks could materially and adversely affect the Company’s business, results of operations and the trading price of Sarepta’s common stock. For a detailed description of risks and uncertainties Sarepta faces, you are encouraged to review the SEC filings made by Sarepta. We caution investors not to place considerable reliance on the

forward-looking statements contained herein. Sarepta does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof, except as required by law.

Source: Sarepta Therapeutics, Inc.

Investor Contact:

Ian Estepan

617-274-4052

iestepan@sarepta.com

Media Contacts:

Tracy Sorrentino

617-301-8566

tsorrentino@sarepta.com

Kara Hoeger

617-710-3898

KHoeger@sarepta.com