Stealth BioTherapeutics, a Massachusetts-based biotech, has had its elamipretide treatment request rejected by the FDA after a 16.5-month priority review cycle. The company plans to resubmit for approval using data from a phase 2 trial that showed significant improvements in knee extensor muscle strength. The biotech aims to capitalize on the FDA’s agreement to consider this endpoint as part of its accelerated approval process. Elamipretide targets Barth syndrome, a rare genetic condition affecting boys and causing various metabolic issues, including heart failure and reduced life expectancy.
Stealth had initially presented data to the FDA in 2019 but faced multiple delays and setbacks before finally filing for standard review in March 2024. The company secured priority review designation two months later but missed its revised deadline due to FDA delays. An advisory committee voted in favor of the filing, but the agency ultimately rejected it, citing exploratory data on muscle strength changes.
To conserve cash for a resubmission, Stealth has laid off 30% of its staff. The biotech plans to file again once the new data is available and will focus on demonstrating the correlation between knee extensor muscle strength improvements and positive outcomes in patients with Barth syndrome. The cycle, which included multiple delays, took 16.5 months, exceeding the initial PDUFA date of late September 2024.
Source: https://www.fiercebiotech.com/biotech/stealth-bombs-fda-receiving-rejection-twice-delayed-filing-and-laying-staff