• By Anni Griswold
    Stealth BioTherapeutics

    Stealth BioTherapeutics has gained the fast-track designation for elamipretide, an eye drop for Leber’s hereditary optic neuropathy (LHON). If approved, the treatment could benefit an estimated 35,000 people who carry the mitochondrial DNA mutation worldwide, according to Stealth.

    "Elamipretide offers hope for patients suffering from this rare ophthalmic disease, for which there is no FDA-approved treatment. The loss of vision can be sudden and devastating, often occurring in both eyes within a few weeks' time. Unfortunately, the resulting vision loss is usually permanent, underscoring the desperate need for effective treatment options," said Alfredo Sadun, MD, PhD, UCLA Doheny Eye Institute, the primary investigator for the study.

    Elamipretide uniquely targets the inner mitochondrial membrane to restore electron transport, improve cellular energy production and reduce oxidative stress created by the over-production of reactive oxygen species.

    Stealth is currently conducting a phase 2 study of the safety, tolerability and efficacy of elamipretide eye drops in 12 adults with LHON.  The company plans to announce top-line results from the LHON trial, dubbed ReSIGHT, in mid-2018.

    The FDA has also expedited review of elamipretide for the treatment of 2 other rare mitochondrial conditions: primary mitochondrial myopathy and Barth syndrome. The drug is undergoing phase 2/3 trials in patients with those conditions, as well as phase 1 studies for dry AMD.

    The fast track designation hastens the regulatory review of drugs intended to treat serious medical conditions that have few other treatment options. With this designation in hand, drug companies can seek incremental FDA approval during each stage of development, rather than waiting until development is complete to submit a new drug application. Expedited drugs may also undergo priority review and accelerated approval.