Although Sarepta initially appeared to have avoided the worst possible outcome for Elevidys—a market withdrawal—thanks to the gene therapy’s new black box warning, the FDA is signaling stronger misgivings about the approved drug in the wake of the death of a third patient who received one of the company's gene therapies.

But uncertainty remains around the FDA's decision-making and whether patient demand for Elevidys will remain, the analysts said. The company voluntarily paused Elevidys shipments for ambulatory patients last week after previously rejecting the FDA's request that it do so.