Glossary · RegulatoryUpdated September 28, 2026

Orphan drug, breakthrough therapy and fast track designations

FDA offers several programmes that encourage and speed up development of treatments for rare or serious conditions. They differ in criteria and benefits, and a single product can hold more than one.

  • Designations in plain language
  • How it works in practice
  • Related terms

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FDA programmes compared
OrphanFast trackBreakthrough
Rare disease required
Serious condition required
Clinical evidence needed
Rolling review
Market exclusivity7 years

Compared

Criteria and benefits

ProgrammeCriteriaMain benefits
Orphan drug designationIntended for a disease affecting fewer than 200,000 people in the US (or with no reasonable expectation of recovering costs)Tax credits for qualified clinical testing, exemption from certain user fees, 7 years of market exclusivity on approval
Fast trackSerious condition and potential to address an unmet medical need, shown by nonclinical or clinical dataMore frequent FDA meetings and communication, rolling review of the application
Breakthrough therapySerious condition and preliminary clinical evidence of substantial improvement over available therapy on a clinically significant endpointAll fast track features plus intensive guidance from early development and organisational commitment
Priority reviewSignificant improvement in safety or effectiveness for a serious conditionFDA goal to act on the application in 6 months instead of 10
Accelerated approvalSerious condition, meaningful advantage, and an effect on a surrogate or intermediate endpoint reasonably likely to predict benefitEarlier approval, with confirmatory trials required

In short

  • Orphan designation is about disease rarity; fast track and breakthrough are about seriousness and unmet need.
  • Designations are requested separately and can be combined; breakthrough status can also be rescinded if later data do not support it.
  • The EU has its own orphan designation (for conditions affecting no more than 5 in 10,000 people) and the PRIME scheme for priority medicines.
  • Expedited programmes shorten review, not the need for reliable evidence. Data quality expectations are unchanged.

Explained

What designations mean for the trial team

Designations change the pace and the conversation with regulators more than the mechanics of the trial. Breakthrough therapy in particular brings frequent interaction and can compress timelines between phases, which puts pressure on study start-up and database build. Rolling review means parts of the application are submitted as they are ready, so data management needs to reach clean, lockable data sooner.

For rare disease sponsors, orphan designation often sits alongside natural history studies and small, long trials. See EDC for rare disease trials and the FDA single pivotal trial guidance explainer for related evidence expectations.

FAQ

Common questions

Something not covered here? Ask us directly.

What is the difference between fast track and breakthrough therapy?

Fast track needs potential to address an unmet need in a serious condition; breakthrough needs preliminary clinical evidence of substantial improvement over available therapy, and adds more intensive FDA guidance.

What does orphan drug designation give?

Tax credits for qualified clinical testing, exemption from certain user fees and seven years of US market exclusivity on approval.

Can a drug have several designations?

Yes. For example, an orphan drug can also have breakthrough therapy designation and priority review.

Is there an EU equivalent?

Yes. The EU has orphan designation and the PRIME scheme for priority medicines.

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