Regulatory glossary

FDA Expedited Programs: Fast Track, Breakthrough, Accelerated Approval

Four FDA programs get called "fast track" in conversation, and they do four different things. Two change how FDA works with you during development, one changes the evidence you may use, and one changes the review clock.

Getting one does not get you the others. They stack, and most successful programmes hold several.

Fast Track

For a drug treating a serious condition where non-clinical or clinical data suggest it addresses an unmet medical need.

What it buys is access: more meetings and more written communication with the review division, and eligibility to submit completed portions of the application as they are ready rather than all at once, which is rolling review.

It does not lower the evidence standard and does not shorten the review clock. Its value is that problems surface in a meeting rather than in a Complete Response Letter.

Breakthrough Therapy

Also for a serious condition, but the bar is higher: preliminary clinical evidence indicating substantial improvement over available therapy on a clinically significant endpoint.

Everything Fast Track offers, plus intensive guidance on efficient development starting as early as Phase 1, and an organisational commitment involving senior FDA managers. In practice the difference from Fast Track is the seniority and intensity of the engagement.

The trade is that FDA is closely involved in your development plan. Sponsors who want to be left alone occasionally find breakthrough designation more supervision than they expected.

Accelerated Approval

The one that changes the evidence rather than the process. It lets FDA approve a drug for a serious condition on a surrogate endpoint, or on an intermediate clinical endpoint, rather than waiting for the clinical outcome itself. A surrogate endpoint is a laboratory measure or physical sign reasonably likely to predict clinical benefit.

The obligation is the point: confirmatory trials are mandatory. Since FDORA in 2022, FDA can require that the confirmatory trial is already underway at the time of accelerated approval, sponsors report progress, and FDA has streamlined authority to withdraw the approval when a confirmatory trial fails or is not completed with due diligence.

Accelerated approval is therefore not a lighter approval. It is an earlier one with a debt attached, and the debt is now enforceable in a way it was not before 2023.

Priority Review

The only one that touches the clock. FDA's goal becomes six months from the filing date instead of ten, for a drug that would be a significant improvement in safety or effectiveness.

It changes nothing about the evidence or the development programme. A priority review application meets exactly the same standard, on a shorter timetable, and an application that is not ready does not become ready by being reviewed faster.

Priority review vouchers, awarded under programmes such as rare paediatric disease, are a separate mechanism: a transferable right to priority review of a future application, which can be sold.

Orphan Drug Designation, which is not an expedited programme

Orphan designation is often listed alongside these and works differently. It is granted for a drug treating a rare disease or condition, defined as affecting fewer than 200,000 people in the US.

It provides development incentives rather than a faster or easier review: tax credits for qualified clinical testing, a waiver of the application user fee, and seven years of marketing exclusivity for the designated indication on approval.

The exclusivity is the valuable part and it is independent of patents. It does not shorten the review, lower the evidence standard, or guarantee approval.

Choosing between them

They are not alternatives and the requests are cheap relative to a development programme. The sequencing that usually makes sense:

1. Orphan designation as early as the prevalence case supports it.
2. Fast Track with or shortly after the IND, on the serious-condition and unmet-need argument.
3. Breakthrough once you have preliminary clinical evidence, if it is strong enough to argue substantial improvement.
4. Accelerated approval discussed at end-of-Phase-2, with the confirmatory trial designed at the same time, not afterwards.
5. Priority review requested with the application.

The one genuine decision is accelerated approval, because it commits you to a confirmatory trial you must be able to fund and enrol. The others add access and optionality.