Sarepta Investor Contact: Erin Cox 857.242.3714 ecox@sarepta.com Sarepta Media Contact: Jim Baker 857.242.3710 jbaker@sarepta.com Sarepta Therapeutics Announces Second Quarter 2013 Financial Results and Recent Corporate

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Sarepta Media Contact:

Sarepta Therapeutics Announces Second Quarter

2013 Financial Results and Recent Corporate Developments

of New Drug Application for Eteplirsen Planned for First Half of 2014

Preparations for Confirmatory Eteplirsen

Study and Manufacturing

Scale Up Remain On Track

Well Capitalized with $164.0 Million in Cash and Other Investments with an Additional $37.9 Million Raised Post-Quarter End

CAMBRIDGE, MA, August 8, 2013 Sarepta Therapeutics, Inc. (NASDAQ: SRPT), a developer of innovative RNA-based

therapeutics, today reported financial results for the three months and six months ended June 30, 2013, and provided an update of recent corporate developments.

We are excited that the FDA is open to an NDA filing for our drug eteplirsen for the treatment of Duchenne muscular dystrophy and the organization is focused on all of the activities necessary for a

successful NDA submission in the first half of next year, said Chris Garabedian, president and chief executive officer of Sarepta Therapeutics. The Sarepta team is planning for success as we continue activities related to our eteplirsen

confirmatory study and our manufacturing scale up, while we begin pre-commercial activities to prepare for the potential approval of eteplirsen.

For the second quarter of 2013, Sarepta reported a Non-GAAP net loss of

$14.6 million, or $0.46 per share, compared to a Non-GAAP net loss of $5.0 million for the second quarter of 2012, or $0.22 per share. The incremental loss is primarily the result of an $8.3 million decrease in government contract revenues as well

as a $1.2 million increase in Non-GAAP operating expenses.

On a GAAP basis, the net loss for the second quarter of 2013 was $19.1 million, or $0.60 per share

(including $2.5 million of stock-based employee compensation expense and restructuring expense), compared with a net income of $8.0 million for the second quarter of 2012, or $0.35 per diluted share (including $0.4 million of stock-based employee

compensation expense). The incremental loss is the result of a $15.4 million change in warrant valuation, an $8.3 million decrease in government contract revenues and a $3.3 million increase in operating expenses.

Revenue for the second quarter of 2013 was $3.0 million, down from $11.2 million for the second quarter of 2012. The $8.3 million decrease was primarily

due to the August 2012 stop-work-order and subsequent termination for convenience of the Ebola portion of the Ebola-Marburg U.S. government contract due to a lack of available U.S. government funding. The termination of the Ebola portion did not

impact the Marburg portion of the contract. Revenues from the Marburg portion of the contract also decreased during the second quarter of 2013 due to the timing of activities throughout the normal progression of the contract. These decreases were

partially offset by revenue from the intramuscular administration (IM) contract with the U.S. government for the Marburg virus that started in August 2012.

Non-GAAP research and development expenses were $12.2 million for the second quarter of 2013, compared to $13.6 million for the second quarter of 2012, a decrease of $1.4 million. GAAP research and

development expenses were $13.0 million for the second quarter of 2013 (including $0.8 million of stock-based employee compensation expense and restructuring expense), compared to $13.8 million for the second quarter of 2012 (including $0.3 million

of stock-based employee compensation expense), a decrease of $0.8 million.

Non-GAAP general and administrative expenses were $5.3 million for

the second quarter of 2013, compared to $2.7 million for the second quarter of 2012, an increase of $2.6 million. GAAP general and administrative expenses were $7.1 million for the second quarter of 2013 (including $1.7 million of stock-based

employee compensation expense and restructuring expense), compared to $2.9 million for the second quarter of 2012 (including $0.2 million of stock-based employee compensation expense), an increase of $4.2 million.

The increased operating expenses were primarily caused by corporate growth as the Company continues the

development of its programs in Duchenne muscular dystrophy and infectious diseases.

Sarepta had cash, cash equivalents and restricted

investments related to our letters of credit of $164.0 million as of June 30, 2013 compared to $187.7 million as of December 31, 2012, a decrease of $23.7 million. The cash was used to fund our ongoing operations in 2013. Subsequent to

second quarter end and up to August 7, the Company raised $37.9 million in proceeds and issued approximately 1.0 million shares of common stock under the At-The- Market (ATM) equity financing that was put in place in July 2013.

In connection with prior equity financings, Sarepta issued warrants that are classified as current liabilities and are adjusted to fair value on a

quarterly basis with the change in fair value being included in net loss. The amount included in net loss is a non-cash item as Sarepta is not required to expend any cash to settle the warrant liability. The warrant liability is primarily affected

by changes in Sarepta s stock price. In the second quarter of 2013, the appreciation in Sarepta s stock price caused the warrant valuation to increase, which resulted in other expense of $1.9 million. In the second quarter of 2012, a

decrease in Sarepta s stock price resulted in other income of $13.5 million. In the first six months of 2013, the change in the warrant liability resulted in a $28.9 million non-cash charge to other non-operating loss and resulted in a $2.6

million non-cash increase in other non-operating income in the comparable period in 2012. The warrant valuation gain or losses as well as stock-based employee compensation expense and restructuring costs related to our corporate move to Cambridge,

are excluded from our Non-GAAP results.

In addition to the GAAP financial measures set forth in this press release, the Company has included

certain non-GAAP Measurements: non-GAAP research and development expenses, non-GAAP general and administrative expenses, non-GAAP net loss, and non-GAAP basic and diluted net loss per share, which present operating results on a basis adjusted for

certain items. The Company uses these non-GAAP measures as key performance measures for the purpose of evaluating performance internally. We also believe these non-GAAP measures provide our investors with useful information regarding our historical

operating results. These non-GAAP measures are not intended to replace the presentation of our financial results in accordance with GAAP. Use of the terms non-GAAP research and development expenses, non-GAAP general and administrative expenses,

non-GAAP net loss, and non-GAAP basic and diluted net loss

per share may differ from similar measures reported by other companies. All relevant non-GAAP measures are reconciled from their respective GAAP measures in the attached table

Reconciliation of GAAP to Non-GAAP net loss.

Recent Corporate Developments

Duchenne Muscular Dystrophy Program

The conference call may

be accessed by dialing 888.895.5271 for domestic callers and 847.619.6547 for international callers. The passcode for the call is 35366636. Please specify to the operator that you would like to join the Sarepta Second Quarter Earnings

Call. The conference call will be webcast live under the investor relations section of

Sarepta s website at www.sarepta.com and will be archived there following the call for 90 days. Please connect to Sarepta s website several minutes prior to the start of the broadcast

to ensure adequate time for any software download that may be necessary. An audio replay will be available through August 22, 2013 by calling 888.843.7419 or 630.652.3042 and entering access code 35366636.

About Sarepta Therapeutics

Therapeutics is focused on developing first-in-class RNA-based therapeutics to improve and save the lives of people affected by serious and life-threatening rare and infectious diseases. Sarepta s diverse pipeline includes its lead program

eteplirsen, for Duchenne muscular dystrophy, as well as potential treatments for some of the world s most lethal infectious diseases. Sarepta aims to build a leading, independent biotech company dedicated to translating its RNA-based science

into transformational therapeutics for patients who face significant unmet medical needs. For more information, please visit us at www.sarepta.com.

Forward-Looking Statements and Information

In order to provide Sarepta s

investors with an understanding of its current results and future prospects, this press release contains statements that are forward-looking. Any statements contained in this press release that are not statements of historical fact may be deemed to

be forward-looking statements. Words such as believes, anticipates, plans, expects, will, intends, potential, possible and similar expressions are

intended to identify forward-looking statements. These forward-looking statements include statements about the potential for dystrophin as a surrogate marker, the amount and type of data as well as our ability to provide the data that will be

necessary for the FDA s regulatory determinations regarding eteplirsen, the safety, efficacy, development and potential of Sarepta s product candidates, the potential and timing for regulatory submissions and meetings, the potential and

timing for regulatory filings, review and approval of Sarepta s product candidates (including potentially under Subpart H Accelerated Approval), Sarepta s ability to establish and protect intellectual property rights, Sarepta s timing

and ability to manufacture product candidates and Sarepta s estimates regarding its future revenue, operating loss, cash reserves and expenses and expectations regarding future success and funding from government and other sources.

These forward-looking statements involve risks and uncertainties, many of which are beyond Sarepta s control. Actual results

could materially differ from these forward-looking statements as a result of such risks and uncertainties. Known risk factors include, among others: clinical trials may not demonstrate safety and efficacy of any of Sarepta s drug candidates

and/or Sarepta s antisense-based technology platform;

development of any of Sarepta s drug candidates may not result in funding from the U.S. government in the anticipated amounts or on a timely basis, if at all; scale-up of manufacturing may

not be successful and any of Sarepta s drug candidates may fail in development, may not receive required regulatory approvals (including potentially under Subpart H Accelerated Approval), or be delayed to a point where they do not become

commercially viable; Sarepta may need additional funds to conduct research and development efforts; and those risks identified under the heading Risk Factors in Sarepta s Quarterly Report on Form 10-Q for the quarter ended

June 30, 2013, and filed with the Securities and Exchange Commission, as well as the other information we file with the SEC.

of the foregoing risks could materially and adversely affect Sarepta 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 official corporate documents filed with the Securities and Exchange Commission. Sarepta does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof.

Sarepta Therapeutics, Inc.

(A Development-Stage Company)

(in thousands, except per share amounts)

Sarepta Therapeutics, Inc.

(A Development-Stage Company)

Reconciliation of GAAP to Non-GAAP Net Loss

(in thousands, except per share

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