Priority Review

Priority review is a scheduling designation, not a lower bar. Under the Prescription Drug User Fee Act, FDA works to goal dates: for a new molecular entity, roughly ten months from the sixty-day filing decision for a standard review and roughly six for a priority one. The criterion is that the product, if approved, would significantly improve the safety or effectiveness of treatment, diagnosis or prevention of a serious condition. It is decided at submission, applies to that application rather than to the molecule, and changes nothing about the substantial-evidence standard.

A separate mechanism, the priority review voucher, detaches the benefit from the product that earned it. Congress created voucher programmes for neglected tropical diseases, rare paediatric diseases and medical countermeasures; a sponsor receiving one may apply it to an unrelated application or sell it, and vouchers have sold for sums in the tens to hundreds of millions of dollars. These programmes have lapsed and been reauthorised more than once, so whether one is currently accepting designations should be checked against FDA and the governing statute.

The interpretive point is that priority review reflects a judgement about the condition and the claimed advance, made before the data have been reviewed, and says nothing about the outcome. Applications with priority review are refused.

The usual confusion is with the other expedited programmes, which do different work. Fast track affects communication during development, breakthrough therapy adds intensive guidance, and accelerated approval changes the endpoint a sponsor may rely on; only the last alters what the evidence must show. A press release that runs them together, or treats a goal date as a scheduled approval, describes a queue position as a verdict.