Industry Partner News: Summit Announces PhaseOut DMD Did Not Meet Primary Endpoint

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To the DMD community,

After reviewing the top-line results of PhaseOut DMD, we have made the difficult decision to discontinue the development of ezutromid.

We recognize that this decision will be disappointing for the Duchenne community, but the data from PhaseOut DMD were clear that ezutromid, while well-tolerated, did not provide a benefit to patients with DMD.

These results are not what we had hoped for, and certainly not what we had expected based on the encouraging interim results from PhaseOut DMD. But, they provide a clear answer to the important scientific question of ezutromid’s effect in DMD. The results provided no evidence that ezutromid is having a meaningful effect on slowing DMD progression. We therefore cannot support further development of ezutromid. We are now working with our clinical trial investigators to bring the PhaseOut DMD clinical trial and associated extension phase to a close. Patients in PhaseOut DMD should contact their study doctors for more information.

We sincerely thank the patients, families and clinical trial sites who have been involved in all of our clinical trials of ezutromid. We plan to explore ways that the information gathered as part of PhaseOut DMD can be made available to support other research activities in DMD for the benefit of the entire community.

We are also grateful for the support that we’ve had from patient organizations worldwide in the development of ezutromid.

We believe that the future of Duchenne research is bright. There are numerous clinical trials and research studies taking place in this field, and there is hope on the horizon for all those living with DMD.

If you have further questions, please contact Michelle Avery, PhD, our Director of Patient Engagement, at

Glyn Edwards, CEO of Summit


1.       What do these data mean? We designed PhaseOut DMD to answer if ezutromid is safe and efficacious in patients with DMD. Unfortunately, the results are quite clear that ezutromid is not having a clinical benefit for patients with DMD. It does continue to be well-tolerated, but given the lack of evidence we’ve seen, we have decided to discontinue its development.

2.       Will patients in PhaseOut DMD be allowed to continue to receive ezutromid? We are working with our clinical trial investigators to bring the trial and extension phase to a close, including any patients who have been enrolled into the additional cohort of the trial that was opened in March 2018. We have taken this difficult decision as the data were clear that patients in PhaseOut DMD were not benefitting from ezutromid treatment.

3.       Are you continuing to work on future generation compounds? While we still believe utrophin modulation could have a place in the treatment of DMD and other dystrophinopathies, our focus will be on the development of our new mechanism antibiotic pipeline.

To read the full press release, please visit Summit's website here.