ORGANIZATION AND BASIS OF PRESENTATION	9 Months Ended
Sep. 30, 2013
Accounting Policies [Abstract]
ORGANIZATION AND BASIS OF PRESENTATION	1. ORGANIZATION AND BASIS OF PRESENTATION *Business* Sarepta Therapeutics, Inc. and its wholly-owned subsidiaries (“Sarepta” or the “Company”) is a biopharmaceutical company focused on the discovery and development of unique RNA-based therapeutics for the treatment of rare and infectious diseases. Applying the Company’s proprietary platform technologies, the Company is able to target a broad range of diseases and disorders through distinct RNA-based mechanisms of action. The Company is focused on advancing the development of its Duchenne muscular dystrophy (DMD) drug candidates, including its lead product candidate, eteplirsen, for which the Company is currently conducting an ongoing open label extension study following completion of its initial Phase IIb clinical trials. The Company is also focused on developing therapeutics for the treatment of infectious diseases, including its lead infectious disease program aimed at the development of a drug candidate for the Marburg hemorrhagic fever virus for which the Company has historically received significant financial support from U.S. government research contracts. The accompanying unaudited condensed consolidated financial statements reflect the accounts of Sarepta and its consolidated subsidiaries. The accompanying unaudited condensed consolidated balance sheet data as of December 31, 2012 was derived from audited financial statements not included in this report. The accompanying unaudited condensed consolidated financial statements were prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) and the rules and regulations of the U.S. Securities and Exchange Commission (SEC) pertaining to interim financial statements. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the financial statements and the notes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2012. The results of operations for the interim periods presented are not necessarily indicative of the results to be expected for the full year. Management has determined that the Company operates in one segment: the development of pharmaceutical products on its own behalf or in collaboration with others. Since its inception in 1980, the Company has incurred losses of $534.4 million, substantially all of which resulted from expenditures related to research and development, general and administrative charges and losses on change in warrant valuation partially offset by revenue generated from research contracts with and grants primarily from the U.S. Department of Defense (DoD). As of September 30, 2013, the Company has completed all of its contracts with the DoD except for the July 2010 contract for the development of therapeutics against the Marburg virus. The period of performance for the Company’s August 2012 contract with the DoD related to the Marburg virus concluded in the third quarter of 2013. In November 2012, the Company entered into an agreement with the European Commission (EC) Health Innovation for development and study related activities for a DMD therapeutic. The Company has not generated any material revenue from product sales to date, and there can be no assurance that revenue from product sales will be achieved. Moreover, even if the Company does achieve revenue from product sales, the Company is likely to continue to incur operating losses in the near term. As of September 30, 2013, the Company had $281.4 million of cash, cash equivalents and invested cash, comprised of $273.6 million of cash and cash equivalents and $7.8 million of restricted investments. The Company believes its cash, cash equivalents and invested cash is sufficient to fund the Company’s current operational plan for the next twelve months. Should the Company’s funding from the DoD cease or be delayed, the Company would likely curtail certain of its infectious disease research and development efforts unless additional funding was obtained. The Company is also likely to pursue additional cash resources through public or private financings, seeking additional government contracts, and from establishing collaborations or licensing its technology to other companies. *Estimates and Uncertainties* The preparation of financial statements in conformity with GAAP requires management 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 and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. *Commitments and Contingencies* In the normal course of business, the Company may from time to time be named as a party to various legal claims, actions and complaints, including matters involving employment, intellectual property, and effects from the use of therapeutics utilizing its technology, professional services or others. Although there are significant inherent uncertainties in connection with these legal matters, management believes the resolution of current matters will not have a material impact on the Company’s financial position, results of operations or cash flows. In February 2013, the Company issued two letters of credit totaling $7.3 million to a contract manufacturing vendor in connection with certain manufacturing agreements. The obligations secured by the letters of credit are fulfilled upon payment for certain minimum volume commitments that the Company expects to occur within the next twelve months. To meet the requirement of the letters of credit, the Company purchased $7.3 million in certificates of deposit with April 2014 maturity dates in February 2013. The Company has recorded this $7.3 million as restricted investments in the condensed consolidated balance sheet as of September 30, 2013. In April 2013, the Company and the University of Western Australia (UWA) entered into an agreement under which an existing exclusive license agreement between the Company and UWA was amended and restated. Under the terms of this agreement, UWA granted the Company an exclusive license to certain UWA intellectual property rights in exchange for up to $7.1 million in upfront and development milestone payments. In April 2013, the Company recognized expense of $1.0 million relating to certain upfront payments required under the agreement within research and development in the condensed consolidated statement of operations. In June 2013, the Company entered into a lease agreement for its Cambridge, Massachusetts location. The agreement calls for a security deposit in the form of a letter of credit totaling $0.6 million. The Company purchased a certificate of deposit to meet the requirement. The initial term of the lease agreement is for seven years with an average base rent of approximately $2.4 million per year. At September 30, 2013, the Company recorded construction in progress related to the lease totaling $4.7 million in property and equipment in the condensed consolidated balance sheet of which $3.7 million was paid by the landlord as part of a tenant improvement allowance which is recorded in other long-term liabilities.

1. ORGANIZATION AND BASIS OF PRESENTATION

Business

Sarepta Therapeutics, Inc. and its wholly-owned subsidiaries (“Sarepta” or the “Company”) is a biopharmaceutical company focused on the discovery and development of unique RNA-based therapeutics for the treatment of rare and infectious diseases. Applying the Company’s proprietary platform technologies, the Company is able to target a broad range of diseases and disorders through distinct RNA-based mechanisms of action. The Company is focused on advancing the development of its Duchenne muscular dystrophy (DMD) drug candidates, including its lead product candidate, eteplirsen, for which the Company is currently conducting an ongoing open label extension study following completion of its initial Phase IIb clinical trials. The Company is also focused on developing therapeutics for the treatment of infectious diseases, including its lead infectious disease program aimed at the development of a drug candidate for the Marburg hemorrhagic fever virus for which the Company has historically received significant financial support from U.S. government research contracts.

The accompanying unaudited condensed consolidated financial statements reflect the accounts of Sarepta and its consolidated subsidiaries. The accompanying unaudited condensed consolidated balance sheet data as of December 31, 2012 was derived from audited financial statements not included in this report. The accompanying unaudited condensed consolidated financial statements were prepared in conformity with accounting principles generally accepted in the United States of America (GAAP) and the rules and regulations of the U.S. Securities and Exchange Commission (SEC) pertaining to interim financial statements. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the financial statements and the notes thereto included in the Company’s annual report on Form 10-K for the year ended December 31, 2012. The results of operations for the interim periods presented are not necessarily indicative of the results to be expected for the full year.

Management has determined that the Company operates in one segment: the development of pharmaceutical products on its own behalf or in collaboration with others.

Since its inception in 1980, the Company has incurred losses of $534.4 million, substantially all of which resulted from expenditures related to research and development, general and administrative charges and losses on change in warrant valuation partially offset by revenue generated from research contracts with and grants primarily from the U.S. Department of Defense (DoD). As of September 30, 2013, the Company has completed all of its contracts with the DoD except for the July 2010 contract for the development of therapeutics against the Marburg virus. The period of performance for the Company’s August 2012 contract with the DoD related to the Marburg virus concluded in the third quarter of 2013. In November 2012, the Company entered into an agreement with the European Commission (EC) Health Innovation for development and study related activities for a DMD therapeutic. The Company has not generated any material revenue from product sales to date, and there can be no assurance that revenue from product sales will be achieved. Moreover, even if the Company does achieve revenue from product sales, the Company is likely to continue to incur operating losses in the near term.

As of September 30, 2013, the Company had $281.4 million of cash, cash equivalents and invested cash, comprised of $273.6 million of cash and cash equivalents and $7.8 million of restricted investments. The Company believes its cash, cash equivalents and invested cash is sufficient to fund the Company’s current operational plan for the next twelve months. Should the Company’s funding from the DoD cease or be delayed, the Company would likely curtail certain of its infectious disease research and development efforts unless additional funding was obtained. The Company is also likely to pursue additional cash resources through public or private financings, seeking additional government contracts, and from establishing collaborations or licensing its technology to other companies.

Estimates and Uncertainties

The preparation of financial statements in conformity with GAAP requires management 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 and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

Commitments and Contingencies

In the normal course of business, the Company may from time to time be named as a party to various legal claims, actions and complaints, including matters involving employment, intellectual property, and effects from the use of therapeutics utilizing its technology, professional services or others. Although there are significant inherent uncertainties in connection with these legal matters, management believes the resolution of current matters will not have a material impact on the Company’s financial position, results of operations or cash flows.

In February 2013, the Company issued two letters of credit totaling $7.3 million to a contract manufacturing vendor in connection with certain manufacturing agreements. The obligations secured by the letters of credit are fulfilled upon payment for certain minimum volume commitments that the Company expects to occur within the next twelve months. To meet the requirement of the letters of credit, the Company purchased $7.3 million in certificates of deposit with April 2014 maturity dates in February 2013. The Company has recorded this $7.3 million as restricted investments in the condensed consolidated balance sheet as of September 30, 2013.

In April 2013, the Company and the University of Western Australia (UWA) entered into an agreement under which an existing exclusive license agreement between the Company and UWA was amended and restated. Under the terms of this agreement, UWA granted the Company an exclusive license to certain UWA intellectual property rights in exchange for up to $7.1 million in upfront and development milestone payments. In April 2013, the Company recognized expense of $1.0 million relating to certain upfront payments required under the agreement within research and development in the condensed consolidated statement of operations.

In June 2013, the Company entered into a lease agreement for its Cambridge, Massachusetts location. The agreement calls for a security deposit in the form of a letter of credit totaling $0.6 million. The Company purchased a certificate of deposit to meet the requirement. The initial term of the lease agreement is for seven years with an average base rent of approximately $2.4 million per year. At September 30, 2013, the Company recorded construction in progress related to the lease totaling $4.7 million in property and equipment in the condensed consolidated balance sheet of which $3.7 million was paid by the landlord as part of a tenant improvement allowance which is recorded in other long-term liabilities.