Sarepta and Summit Enter Into Exclusive License Agreement Cambridge, MA, and Oxford, UK, 4 October 2016 - Sarepta Therapeutics (NASDAQ: SRPT) and Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM) today announced that they have entered into an exclusive license and collaboration agreement granting Sarepta rights in Europe, as well as in Turkey and the Commonwealth of Independent States (‘the licensed territory’), to Summit’s utrophin modulator pipeline, including its lead clinical candidate, ezutromid, for the treatment of Duchenne muscular dystrophy (‘DMD’). As part of the agreement, Sarepta also obtains an option to license Latin American rights to Summit’s utrophin modulator pipeline. Summit retains commercialization rights in all other countries. Utrophin modulation is a potential disease-modifying treatment for all patients with the fatal muscle wasting disease DMD, regardless of their underlying dystrophin gene mutation. Ezutromid is currently in a Phase 2 proof of concept trial called PhaseOut DMD. "This partnership with Summit Therapeutics furthers our commitment to invest in innovative approaches to treating Duchenne and supports our common goal of improving the lives of patients with DMD," said Edward Kaye, M.D., Sarepta’s Chief Executive Officer. "Summit’s utrophin modulation technology represents a potentially promising approach to treat DMD, which may complement our current approach of exon skipping therapy.” “Sarepta Therapeutics has paved the way in the development of disease-modifying therapies for DMD with the first FDA-approved drug in this disease area, making them a strong strategic partner to support our utrophin modulator pipeline,” commented Glyn Edwards, Chief Executive Officer of Summit. “This agreement provides us with access toSarepta’s development, regulatory and commercialisation expertise for the continued advancement of our promising utrophin modulator pipeline. We look forward to this partnership and working together to bring great advances to patients and families living with DMD.” Under the terms of the agreement, Summit will receive an upfront fee of $40 million. In addition, Summit will be eligible for future ezutromid related development, regulatory and sales milestone payments totalling up to $522 million, including a $22 million milestone upon the first dosing of the last patient in Summit’s PhaseOut DMD trial, and escalating royalties ranging from a low to high teens percentage of net sales in the licensed territory. Summit will also be eligible to receive development and regulatory milestones related to its next-generation utrophin modulators. Sarepta and Summit will share specified utrophin modulator-related research and development costs at a 45%/55% split, respectively, beginning in 2018. If Sarepta elects to exercise its option for Latin American rights, Summit would be entitled to additional fees, milestones and royalties. Sarepta and Summit will host an update call for the Duchenne community on Monday, October 10 at 12:00 EDT. Details of the call can be accessed by visiting http://www.parentprojectmd.org/communitycall. This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014 (MAR). About Utrophin Modulation in DMD DMD is a progressive muscle wasting disease that is caused by different genetic faults in the gene that encodes dystrophin, a protein that is essential for the healthy function of all muscles. There is currently no cure for DMD and life expectancy is into the late twenties. Utrophin protein is functionally and structurally similar to dystrophin. In preclinical studies, the continued expression of utrophin has a meaningful, positive effect on muscle performance. Summit believes that utrophin modulation has the potential to treat all patients with DMD, regardless of the underlying dystrophin gene mutation. Summit also believes that utrophin modulation could potentially be complementary to other therapeutic approaches for DMD. The Company’s lead utrophin modulator, ezutromid, is an orally administered, small molecule. DMD is an orphan disease, and the US Food and Drug Administration (‘FDA’) and the European Medicines Agency have granted orphan drug status to ezutromid. Orphan drugs receive a number of benefits including additional regulatory support and a period of market exclusivity following approval. In addition, ezutromid has been granted Fast Track designation and Rare Pediatric Disease designation by the FDA. About Summit Therapeutics Summit is a biopharmaceutical company focused on the discovery, development and commercialisation of novel medicines for indications for which there are no existing or only inadequate therapies. Summit is conducting clinical programmes focused on the genetic disease Duchenne muscular dystrophy and the infectious disease C. difficileinfection. Further information is available at www.summitplc.com and Summit can be followed on Twitter (@summitplc). About Sarepta Sarepta Therapeutics is a commercial-stage biopharmaceutical company focused on the discovery and development of unique RNA-targeted therapeutics for the treatment of rare neuromuscular diseases. The Company is primarily focused on rapidly advancing the development of its potentially disease-modifying DMD drug candidates, including EXONDYS 51, designed to skip exon 51 and approved under the accelerated approval pathway. For more information, please visit us at www.sarepta.com.