Citi, acting through Citibank N.A., has been appointed by Stealth BioTherapeutics Corp. (“Stealth”) as depositary bank for its American Depositary Receipt (“ADR”) programme. Stealth’s ADRs trade on the Nasdaq Global Market under the symbol “MITO.” Each ADR represents 12 ordinary shares of Stealth.

“We are pleased to have been selected by Stealth as depositary bank for its Nasdaq listed ADR programme,” said Dirk Jones, Global Head of Issuer Services, at Citi. “We look forward to supporting the expansion of Stealth’s investor outreach through the expertise of our Investor Relations Advisory team and the breadth of our global equity distribution network.”

For more information on Citi’s Depositary Receipt Services, visit www.citi.com/dr.

About Citi

Citi, the leading global bank, has approximately 200 million customer accounts and does business in more than 160 countries and jurisdictions. Citi provides consumers, corporations, governments and institutions with a broad range of financial products and services, including consumer banking and credit, corporate and investment banking, securities brokerage, transaction services, and wealth management.

Additional information may be found at www.citigroup.com | Twitter: @Citi | YouTube: www.youtube.com/citi | Blog: http://blog.citigroup.com | Facebook: www.facebook.com/citi | LinkedIn: www.linkedin.com/company/citi

About Stealth BioTherapeutics

Stealth BioTherapeutics (“Stealth”) is a clinical-stage biotechnology company focused on the discovery, development and commercialization of novel therapies for diseases involving mitochondrial dysfunction. Mitochondria, found in nearly every cell in the body, are the body’s main source of energy production and are critical for normal organ function. Dysfunctional mitochondria characterize a number of rare genetic diseases, collectively known as primary mitochondrial diseases, and are also involved in many common age-related diseases. Stealth believes their lead product candidate, elamipretide, has the potential to treat both rare genetic and common age-related mitochondrial diseases. Stealth is studying elamipretide in the following primary mitochondrial diseases: primary mitochondrial myopathy, Barth syndrome and Leber’s hereditary optic neuropathy. The company is also studying elamipretide in dry age-related macular degeneration. Stealth’s other pipeline candidates include SBT-20, which is being evaluated for rare peripheral neuropathies, and SBT-272, which is being evaluated for rare neurodegenerative disease indications. The company has optimized its discovery platform to identify novel mitochondrial-targeted compounds, which may be nominated as therapeutic product candidates or utilized as scaffolds to deliver other compounds to mitochondria. Stealth’s mission is to be the leader in mitochondrial medicine, and the company has assembled a highly experienced management team, board of directors and group of scientific advisors to help them achieve this mission.