- The Food and Drug Administration won't allow Voyager Therapeutics to begin a first-in-human trial of an experimental gene therapy for Huntington's disease until the company submits more information on its manufacturing processes.
- The treatment would be Voyager's second to enter clinical testing, joining a Parkinson's disease treatment that's set to be tested in a Phase 3 trial starting next year. Voyager expects to hear more details from the agency within 30 days, the company said Monday.
- Massachusetts-based Voyager joins a list of gene therapy developers that have encountered recent setbacks at the FDA. BioMarin Pharmaceutical, Sarepta Therapeutics, Solid Biosciences and Novartis have all faced delays to various programs.
The first gene therapy to launch in the U.S., Roche's Luxturna, gained FDA approval less than three years ago. The agency's experience with these types of treatment, therefore, is more limited than with other drug classes.
The relative ease with which Luxturna, and then Novartis' Zolgensma, passed regulatory muster may have resulted in misplaced confidence among investors that development of other gene therapies would be as smooth.
Revelations that Novartis' application for approval of Zolgensma contained altered animal testing data, and the FDA's subsequent investigation, have now been followed by closer reviews of several companies' data packages.
Sarepta, for example, was recently asked to use a new test to evaluate the strength of its Duchenne muscular dystrophy gene therapy when produced for commercial use, while a trial of Zolgensma in older patients has been delayed because of an inflammatory response observed in animal studies.
The most notable setback in recent months was to BioMarin's hemophilia A gene therapy, which the FDA rejected outright because it said patients haven't been followed long enough. While some analysts argued the rejection was the result of factors specific to BioMarin's therapy and to hemophilia, others have raised questions about a potential change in the agency's risk tolerance.
In Voyager's case, the company didn't reveal much about the delay beyond indicating the FDA wants to review "certain chemistry, manufacturing and controls matters" — terminology referring to production processes and testing conducted to ensure drug products are consistently safe and effective between batches.
After receiving feedback, the company said it would address the FDA's concerns "promptly" to accelerate work on the Huntington's disease candidate.
If human testing had been cleared to begin, Voyager's gene therapy would have trailed a treatment from rival UniQure by just a few months. Shares in Voyager declined by 6% Tuesday, while UniQure stock slipped downwards by 2%.