SIGNIFICANT AGREEMENTS	9 Months Ended
Sep. 30, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
SIGNIFICANT AGREEMENTS	3. SIGNIFICANT AGREEMENTS University of Western Australia In April 2013, the Company and UWA entered into an agreement under which an existing exclusive license agreement between the Company and UWA was amended and restated (the “Amended and Restated UWA License Agreement”). The Amended and Restated UWA License Agreement grants the Company specific rights to the treatment of DMD by inducing the skipping of certain exons. EXONDYS 51 falls under the scope of the license agreement. Under the Amended and Restated UWA License Agreement, the Company may be required to make payments of up to $6.0 million in aggregate to UWA based on the successful achievement of certain development and sales milestones relating to EXONDYS 51 and up to five additional product candidates. The Company may also be obligated to make payments to UWA of up to $20.0 million upon the achievement of certain sales milestones. Additionally, the Company may also be required to pay a low-single-digit percentage royalty on net sales of products covered by issued patents licensed from UWA during the term of the Amended and Restated UWA License Agreement. However, the Company has the option to purchase future royalties up-front. Under this option, prior to the First Amendment (defined below), the Company could be required to make a one-time royalty payment of $30.0 million to UWA. In June 2016, the Company and UWA entered into the first amendment to the Amended and Restated UWA License Agreement (the “First Amendment”). Under the First Amendment, the Company was obligated to make an up-front payment of $7.0 million to UWA upon execution of the amendment. Under the terms of the First Amendment, UWA has waived certain rights and amended the timing of certain payments under the Amended and Restated UWA License Agreement, including lowering the up-front payment that is due by the Company upon exercise of the option to purchase future royalties up-front. Upon exercise of the option to purchase future royalties up-front, the Company would still be obligated to make up to $20.0 million in payments to UWA upon achievement of certain sales milestones. For the three and nine months ended September 30, 2016, the Company recorded $0.3 million and $7.3 million, respectively, relating to the development milestone and up-front payments to UWA as research and development expense in the unaudited condensed consolidated statement of operations and comprehensive loss. Additionally, corresponding to the FDA approval and the subsequent commercial sale of EXONDYS 51, as defined in the Amended and Restated UWA License Agreement, the Company recorded a $1.0 million milestone as an in-license right in the unaudited condensed consolidated balance sheets as of September 30, 2016.

3. SIGNIFICANT AGREEMENTS

University of Western Australia

In April 2013, the Company and UWA entered into an agreement under which an existing exclusive license agreement between the Company and UWA was amended and restated (the “Amended and Restated UWA License Agreement”). The Amended and Restated UWA License Agreement grants the Company specific rights to the treatment of DMD by inducing the skipping of certain exons. EXONDYS 51 falls under the scope of the license agreement. Under the Amended and Restated UWA License Agreement, the Company may be required to make payments of up to $6.0 million in aggregate to UWA based on the successful achievement of certain development and sales milestones relating to EXONDYS 51 and up to five additional product candidates. The Company may also be obligated to make payments to UWA of up to $20.0 million upon the achievement of certain sales milestones. Additionally, the Company may also be required to pay a low-single-digit percentage royalty on net sales of products covered by issued patents licensed from UWA during the term of the Amended and Restated UWA License Agreement. However, the Company has the option to purchase future royalties up-front. Under this option, prior to the First Amendment (defined below), the Company could be required to make a one-time royalty payment of $30.0 million to UWA.

In June 2016, the Company and UWA entered into the first amendment to the Amended and Restated UWA License Agreement (the “First Amendment”). Under the First Amendment, the Company was obligated to make an up-front payment of $7.0 million to UWA upon execution of the amendment. Under the terms of the First Amendment, UWA has waived certain rights and amended the timing of certain payments under the Amended and Restated UWA License Agreement, including lowering the up-front payment that is due by the Company upon exercise of the option to purchase future royalties up-front. Upon exercise of the option to purchase future royalties up-front, the Company would still be obligated to make up to $20.0 million in payments to UWA upon achievement of certain sales milestones.

For the three and nine months ended September 30, 2016, the Company recorded $0.3 million and $7.3 million, respectively, relating to the development milestone and up-front payments to UWA as research and development expense in the unaudited condensed consolidated statement of operations and comprehensive loss.

Additionally, corresponding to the FDA approval and the subsequent commercial sale of EXONDYS 51, as defined in the Amended and Restated UWA License Agreement, the Company recorded a $1.0 million milestone as an in-license right in the unaudited condensed consolidated balance sheets as of September 30, 2016.