Stealth BioTherapeutics (Stealth), a US-based clinical-stage biopharmaceutical firm, has begun a longitudinal extension Phase II trial (MMPOWER-2) for evaluating elamipretide in primary mitochondrial disease.
The company's lead candidate Elamipretide is an investigational drug with the potential to modify disease by preserving energetics and restoring normal energy production in mitochondria, while decreasing oxidative stress.
Stealth noted that the randomised, double-blind, placebo-controlled crossover MMPOWER-2 study will be limited to patients who completed the initial MMPOWER Phase II trial.
Positive data from MMPOWER was announced in June this year, showing a statistically significant improvement in distance walked within six minutes.
Stealth chief executive officer Reenie McCarthy said: "Patients with rare primary mitochondrial diseases have no FDA-approved treatment options to address their needs.
"We're committed to helping fill these significant gaps in care through our study of elamipretide.
"Following the promising results from our Phase II MMPOWER study, we're happy to announce the initiation of MMPOWER-2, which will help us better understand the effects of longer treatment with elamipretide for these patients, who often face severe challenges completing even simple daily activities."
MMPOWER-2 is designed to evaluate the safety, tolerability and efficacy of four weeks' treatment with once-daily subcutaneous (SC) injections of elamipretide in patients with genetically confirmed mitochondrial disease previously treated in the MMPOWER study.
Genetic mitochondrial diseases are a diverse group of rare inherited disorders characterised by systemic mitochondrial dysfunction that impairs patient health and well-being.
Stealth chief medical officer Doug Weaver said: "We look forward to the results of this follow-on study and hope to use these results, along with the positive data from MMPOWER, to engage in discussions with regulators to develop the design for a Phase III trial in primary mitochondrial disease."
It is reported that subjects treated in the MMPOWER-2 trial will be randomised (1:1) to receive either four weeks' treatment with 40mg elamipretide administered once daily SC in Treatment Period 1, followed by four weeks of treatment with placebo administered once daily SC in Treatment Period 2 or vice versa.
Both treatment periods will be separated by a four-week washout period.
The trial’s primary endpoint is change in distance walked within six minutes after four weeks, while secondary endpoints include safety and tolerability assessments, patient-reported outcomes and improvements in mobility and movement patterns.