Exhibit 99.1
Stealth BioTherapeutics Provides Update on Phase 3 Trial of Elamipretide in Primary Mitochondrial Myopathy
December 20, 2019
BOSTON, Dec. 20, 2019 /PRNewswire/ — Stealth BioTherapeutics (NASDAQ: MITO), a clinical-stage biotechnology company focused on the discovery, development and commercialization of novel therapies for diseases involving mitochondrial dysfunction, today announcedtop-line data from the Phase 3MMPOWER-3 trial evaluating elamipretide for treatment of patients with primary mitochondrial myopathy (PMM). The study did not meet its primary endpoints assessing changes in thesix-minute walk test and Primary Mitochondrial Myopathy Symptom Assessment (PMMSA) Total Fatigue Score. Safety results showed that treatment with elamipretide was well tolerated with most adverse events mild to moderate in severity.
“We are deeply grateful to our patients and families, our investigators and their teams, and our advocacy partners for their support of this study, and share their disappointment that it did not meet the promise of our earlier trials in this indication,” said Chief Executive Officer Reenie McCarthy. “We remain confident in the promise of our platform and committed to our mission of improving the lives of people living with diseases involving mitochondrial dysfunction. We plan to meet with the FDA in early 2020 regarding our Barth syndrome program, where we have observed significant improvement in cardiac stroke volume during open-label extension, and continue to enroll our Phase 2b clinical trial in geographic atrophy associated with dryage-related macular degeneration, in which we observed improvement in visual function during an earlier Phase 1 study. We are also progressing our pipeline of second-generation mitochondrial therapeutics, with lead pipeline compoundSBT-272 entering Phase 1.”
The Company plans to review its operational resources to align them with its near-term priorities of progressing its Barth, AMD and pipeline programs, and expects to provide further guidance next month.
Conference Call Information
Stealth will host a conference call and webcast today at 8:30 a.m. ET to discuss theMMPOWER-3 trial. The call can be accessed by dialing866-939-3921 (domestic) or678-302-3550 (international) and referencing conference ID 49292088. A live audio webcast of the event can be accessed by visiting the Investors & News section of Stealth’s Investor website, https://investor.stealthbt.com/. A replay of the webcast will be archived on Stealth’s website for 30 days following the event.
About theMMPOWER-3 Clinical Trial
MMPOWER-3 was a randomized, double-blind, parallel-group, placebo-controlled trial to evaluate the efficacy and safety of elamipretide over 32 weeks in 218 patients with primary mitochondrial myopathy between the ages of 16 and 80. The trial was conducted at 28 clinical sites across North America, Europe and Australia.
