FreeBioListCompany announcements are full of designations: Fast Track, Breakthrough Therapy, Priority Review, Accelerated Approval. They sound like stages of a single process, but they're separate tools for drugs that treat serious conditions. Two of them change how development works, one changes the length of the review, and one changes what evidence an approval can rest on. None of them lowers the standard for approval or predicts the outcome.
The FDA's own summary page and its 2014 guidance, Expedited Programs for Serious Conditions – Drugs and Biologics, are the primary sources for everything below.
Fast Track: more contact, rolling submission
What it's for: drugs for a serious condition that show the potential to address an unmet medical need. The evidence bar is relatively low; depending on the stage, animal or early clinical data can be enough.
What it gives: more frequent meetings and written communication with the FDA during development, and the option of a rolling submission, where completed sections of the application go in as they're ready. It can also make the drug eligible for priority review and accelerated approval later, if it meets their criteria.
What it doesn't do: shorten the review once the application is complete. A Fast Track designation early in development says little about the eventual result.
Breakthrough Therapy: intensive guidance
What it's for: drugs for a serious condition where preliminary clinical evidence suggests a substantial improvement over existing treatment on a clinically significant endpoint. Created by Congress in 2012, it needs human data, not just animal data, so it's harder to get than Fast Track.
What it gives: everything Fast Track gives, plus intensive FDA guidance on an efficient development programme from as early as Phase 1, and the involvement of senior FDA staff.
What it doesn't do: guarantee approval, or even guarantee the improvement holds up in larger trials. The FDA can withdraw the designation if later data no longer support it.
Cell and tissue therapies have a parallel designation, Regenerative Medicine Advanced Therapy (RMAT), created by the 21st Century Cures Act in 2016, with similar benefits.
Priority Review: a shorter clock
What it's for: applications for drugs that, if approved, would be a significant improvement in the safety or effectiveness of treating a serious condition.
What it gives: a 6-month review goal instead of the standard 10. For a new molecular entity, that's measured from the 60-day filing date, so roughly 8 months from submission rather than 12. The FDA decides on priority review when it files the application, and the company usually announces it together with the PDUFA date.
What it doesn't do: change the evidence required. A priority review is the same review, faster.
Priority review can also be bought, in effect, with a priority review voucher, which some programmes award for developing drugs in neglected areas such as tropical diseases. Vouchers can be sold to other companies, which redeem them to turn a standard review into a priority one.
Ionis's 8-K for bepirovirsen in chronic hepatitis B reported that it was "Granted Priority Review in the U.S. and PDUFA target action date of October 26, 2026" (8-K exhibit, 29 July 2026). The two pieces of news arriving together is typical. See the Ionis page.
Accelerated Approval: approval on a surrogate endpoint
What it's for: drugs for serious conditions with unmet need, where waiting for a clinical outcome such as survival would take too long. The FDA can approve based on a surrogate endpoint, a measurement such as tumour shrinkage or a lab value that is "reasonably likely" to predict real clinical benefit, or on an intermediate clinical endpoint. The rules are in 21 CFR Part 314, Subpart H for drugs and Part 601, Subpart E for biologics.
What it requires: confirmatory trials after approval to show the predicted benefit is real. Since the Food and Drug Omnibus Reform Act of 2022, the FDA can require those trials to be under way before it grants approval, and has a faster process for withdrawing an indication if they fail or aren't done with due diligence.
What it means for you: an accelerated approval is a real approval, and the drug can be sold. But it carries an open question that a later trial will answer, and indications have been withdrawn when confirmatory trials failed.
Vera Therapeutics' atacicept received accelerated approval on 7 July 2026 "to reduce proteinuria" in IgA nephropathy (8-K). Proteinuria, protein leaking into the urine, is the surrogate; slowing kidney decline is the benefit it's expected to predict. Inovio's INO-3107 BLA is under review "under the Agency's accelerated approval program" with a PDUFA date of 30 October 2026 (Inovio page), and PMV Pharmaceuticals and Lexeo both guide to submissions under the same pathway.
A newer option: national priority vouchers
In June 2025 the FDA launched a pilot, the Commissioner's National Priority Voucher programme, which aims to reach a decision within one to two months of a complete application for a small number of products the agency selects as aligned with national health priorities. The first recipients were named in October 2025. Because it's a pilot with few participants, a voucher is a notable disclosure when a company has one.
How they fit together
- During development: Fast Track, Breakthrough Therapy or RMAT.
- At filing: Priority Review, or Standard.
- At approval: traditional approval, or Accelerated Approval with confirmatory obligations.
A single drug can collect several of these. A Breakthrough-designated drug that files with priority review and receives accelerated approval is common in oncology.
Reading designation announcements
- A designation is the FDA agreeing a drug qualifies for a process. It isn't a view on whether the drug will be approved.
- Fast Track is common; Breakthrough is more selective; Priority Review is decided only once a complete application exists.
- Look at what the designation actually changes for the next date on the tracker. Only Priority Review (and the new vouchers) change the length of the review itself.