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.
Summit chief operating officer and medical officer David Roblin said: "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.
"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.