Pink Sheet infographic looks at the nascent space of gene therapy accelerated approvals, where confirmatory trial timelines can run many years beyond approval due to disease rarity and a focus on durability of response.

Three of the accelerated approvals were for CAR-T products, a class that the agency considers to be gene therapies. The FDA’s September approval of bluebird bio’s Skysona for cerebral adrenoleukodystrophy was the lone non-cancer product in the group. Pink Sheet infographic tracks the required confirmatory studies and timelines for all four products.

The long-term follow-up requirements expected for many gene therapies could raise consent and drop-out issues, which could hinder efforts to track safety and efficacy.

Vertex is closing in on annual revenues of $10bn from its cystic fibrosis drugs, but non-opioid pain therapy candidate VX-548 could open up a whole new blockbuster revenue stream if Phase III studies go to plan.