News & events News Summit opens enrolment for people who have taken part in previous Ezutromid trials Summit Expands Enrolment in PhaseOut DMD Phase 2 Clinical Trial to Include Planned Additional Group · Additional Group is Open to Patients Who Participated in Phase 1 Clinical Trials of Ezutromid · Allows Summit to Gather Additional Safety and Efficacy Data from a Broader Patient Population Summit announces it has opened enrolment in a planned additional group in its Phase 2 open label clinical trial called PhaseOut DMD. Enrolment is open to patients who participated in Phase 1 clinical trials of ezutromid but did not meet the entry criteria for the main PhaseOut DMD cohorts. Patients are eligible to participate regardless of their ambulatory status or age. Study assessments will include functional tests appropriate for the patient’s ambulatory status, cardiac MRI and lung function tests. “We are extremely grateful to the patients who participated in our Phase 1 clinical trials and contributed to ezutromid’s clinical advancement, but were not initially eligible to participate in our Phase 2 clinical trial. Accordingly, we are pleased to open this additional group in our Phase 2 and provide these patients with the opportunity to receive ezutromid treatment,” commented Dr David Roblin, Chief Operating Officer and Medical Officer of Summit. “We expect the data collected from this additional group of patients will help expand our understanding of ezutromid’s safety and efficacy profile across a broader patient population.” Dosing of patients in this additional group will run in parallel to the main part of the ongoing PhaseOut DMD clinical trial. PhaseOut is a multi-centre, 48-week open-label Phase 2 clinical trial that has enrolled 40 ambulant patients with DMD aged between their fifth and tenth birthday. Recently announced positive 24-week interim data from the clinical trial showed that compared to baseline, ezutromid significantly and meaningfully reduced muscle damage, as measured in muscle biopsies. Further, the interim data showed ezutromid significantly reduced muscle inflammation, as measured by MRS transverse relaxation time T2. Summit expects to report top-line data from the full 48-week trial of these 40 patients in the third quarter of 2018. About Utrophin Modulation in DMD Utrophin protein is functionally and structurally similar to dystrophin. In preclinical studies, the continued expression of utrophin had a meaningful, positive effect on muscle performance. Summit believes that utrophin modulation has the potential to slow down or even stop the progression of DMD, regardless of the patient’s underlying dystrophin gene mutation. Summit also believes that utrophin modulation could be complementary to other therapeutic approaches for DMD. The Company’s lead utrophin modulator, ezutromid, is an orally administered, small molecule drug. 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.