Enlarge / Dr. Peter Marks, Director of the Center for Biologics Evaluation and Research within the Food and Drug Administration on March 18, 2021 in Washington, DC. (credit: Getty | Susan Walsh)

The Food and Drug Administration (FDA) on Thursday announced expanded approval for a gene therapy to treat Duchenne muscular dystrophy (DMD)—despite the fact that it failed a Phase III clinical trial last year and that the approval came over the objections of three of FDA's own expert review teams and two of its directors.

In fact, the decision to expand the approval of the therapy—called Elevidys (delandistrogene moxeparvovec-rokl)—appears to have been decided almost entirely by Peter Marks, Director of the FDA's Center for Biologics Evaluation and Research.

Elevidys initially gained an FDA approval last year, also over objections from staff. The therapy intravenously delivers a transgene that codes for select portions of a protein called dystrophin in healthy muscle cells; the protein is mutated in patients with DMD. Last year's initial approval occurred under an accelerated approval process and was only for use in DMD patients ages 4 and 5 who are able to walk. In the actions Thursday, the FDA granted a traditional approval for the therapy and opened access to DMD patients of all ages, regardless of ambulatory status.