FDA denies Barth syndrome drug approval, suggests accelerated pathway

For the past decade, Stealth BioTherapeutics has ridden a rollercoaster trying to convince the Food and Drug Administration to approve its ultra-rare disease drug. Now, the company has encountered yet another twist — an unexpected regulatory rejection that will not only delay access and strain its finances, but ensure some of the most vulnerable patients are denied the treatment.

At issue is a medication for Barth syndrome, a rare illness that causes an enlarged heart, muscle weakness and a shortened life expectancy. The disease afflicts up to 150 people in the U.S., an extremely small number that has, at times, made it difficult for the company and the FDA to find a way to generate enough of the right kind of study data to make the drug available to patients.

But after bouncing between different agency divisions and nearly ending its development efforts, Stealth last October won a key victory — a majority of panelists on an FDA advisory committee voted to recommend approval. The FDA, however, then missed a previously scheduled deadline this past January to complete its marketing review, pushing a decision to April. But the agency missed that deadline, too, suggesting the vast number of job cuts were a factor.