Rare disease advocates confused by FDA's mixed messages

Two years ago, Megan Selser was folding clothes with her 7-week-old baby’s head on her chest when the phone rang. When she answered, the person on the other end could hear the heartbreaking voice she used so many times as an ICU nurse to deliver bad news.

It turned out that her son Ben had mucopolysaccharidosis (MPS) type 2, or Hunter syndrome. The disease is among a group of rare diseases that are invisible at birth but can slowly reduce physical and cognitive abilities by the time a child enters kindergarten. Some children die as young as 10 years old.

But there was reason to be hopeful. Ben was discovered early thanks to a newborn screening pilot project in North Carolina. The doctors explained that there are new treatments in clinical trials, including two gene therapies and a protein-based drug. If given early enough, it can change the course of the disease.

This month, those hopes took a big hit. The Food and Drug Administration rejected Regenxbio’s gene therapy, telling the company it needed to collect more data because regulators could delay approval for years.

Regenxbio’s MPS drug is one of at least five cell or gene therapies for deadly rare diseases that officials have rejected or appear to have reversed course in the last year since the Trump administration installed new leadership. Many advocates and executives worry that regulators are backing away from the flexible approach they have promised in recent years.

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