Wondering how the FDA drug approval process works once a company files its application? A review team checks the evidence, the manufacturing and the label, as part of evaluating the application.
This page is part of our wider coverage of what is drug discovery.
| Item | Value |
|---|---|
| Standard review, initial application | 12 months, including a 60-day filing period |
| Standard review, supplemental application | 10 months |
| Priority review, initial / supplemental | 8 and 6 months |
| Novel drugs approved under priority review, 2014 to 2016 | 64 of 108 |
| Drugs approved in 2020 on a single pivotal trial | 28 of 49 |
Figures come from a published review in PubMed Central and a cohort study in PubMed Central. Review goals and approval patterns can change, so check the source before you rely on them.
What an application contains
After clinical trials, a sponsor files a New Drug Application (NDA). For biological products the equivalent is a biologics license application. The package is large: according to a PubMed Central review of FDA approval pathways, the sponsor “pays an application fee and files a New Drug Application (NDA) that includes extensive information on the drug, the results of all phases of testing, manufacturing and facilities, quality control, labeling, and risk evaluation and mitigation.”
The trials that feed into it are covered in our guide to clinical trial phases explained. The NDA is where all of that evidence is brought together for a regulator to judge.
How the FDA drug approval process unfolds
A review of a new drug application, as one PubMed Central paper describes it, “consists of 6 major steps that include reviewing clinical trial results, planning and execution of the product label, and manufacturing site inspections.”
Review clocks: standard and priority
Timelines are set by the Prescription Drug User Fee Act (PDUFA). The same review states: “the standard review time for an NDA or BLA is 12 months for an initial application and 10 months for a supplemental application (both timelines include a 60‐day filing review period).”
Priority review shortens those goals to 8 and 6 months. To qualify, the application must be for a drug that treats a serious condition and, if approved, “would provide a significant improvement in safety or effectiveness.”
Between 2014 and 2016, 64 of 108 novel drug approvals were approved under priority review, so it is a common route rather than a rare one.
What evidence the agency weighs
The legal bar is “substantial evidence” of safety and efficacy. That was long read as at least two adequate and well-controlled Phase III trials, but practice has shifted. The PubMed Central review reports that the proportion of NDAs including at least 2 controlled trials was 52.8% in the 2015 to 2017 period, down from a previous level of 80%.
A cohort study of 2020 approvals found the 49 novel therapeutics were supported by 75 pivotal trials. More than half of the drugs (28, or 57.1%) rested on a single pivotal trial, and nearly half of the trials (34, or 45.3%) used a surrogate measure as a primary end point.
A surrogate measure, such as a laboratory value, stands in for how a patient feels or survives.
Who pays for the review, and why it matters
The Prescription Drug User Fee Act (PDUFA) is the law behind the review clocks. The PubMed Central paper notes that Congress passed it “to authorize the FDA to collect fees from applicant companies to invest in resources to accelerate FDA review and approval operations.”
Fees support resources intended to accelerate review and approval operations. Critics sometimes ask whether industry funding could shape priorities, which is why the evidence standards, rather than the speed, are the part worth watching.
The deadline is a target for acting on an application, not a promise of a particular answer. A fast decision can still be a rejection.
Reading the numbers with care
Statistics about approvals describe groups of drugs, not any single product. A share such as 64 of 108 priority approvals tells you how often a route is used, not how well those drugs perform in patients.
Three habits help when you read news about a filing or an approval:
- Check whether the application is an initial one or a supplemental one, because the review goals differ.
- Look at the type of end point. A laboratory measure answers a different question than survival or function.
- Note how many pivotal trials supported the decision and whether they had randomized, concurrent controls.
Oncology deserves a separate look. In the 2020 cohort, historical controls and surrogate end points were much more common in cancer approvals, so comparisons across disease areas can mislead.
Limits and uncertainty
An approval is a judgment about benefits and risks at one moment, based on a limited set of trials. It does not predict how any individual would respond, and this site does not offer medical advice.
- Pivotal trials are finite in size and duration, so rare or late effects may appear only after approval.
- Surrogate end points and historical controls were much more common in oncology approvals than in others, which affects how firmly results can be interpreted.
- Published timelines are goals, not guarantees.
Treatment decisions belong with your doctor: consult a physician or other qualified healthcare professional about any medicine, rather than relying on approval statistics.
For readers following AI in drug discovery, the same rules apply to any candidate, however it was found: it must clear the same evidence bar. How other regulators handle this is explained in our ema drug approval process guide.
Frequently asked questions
How long does the FDA take to review a new drug application?
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The published goals are 12 months for an initial application under standard review and 8 months under priority review, both counting a 60-day filing period.
What is a complete response letter?
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To understand a particular complete response letter, read the letter itself alongside the application information. The useful question is what the agency says about that application, rather than what a published review timeline might lead you to expect. Review timing and the assessment of evidence are separate questions. An NDA includes clinical testing results, manufacturing and facilities information, quality control, labeling, and risk evaluation and mitigation. Those categories provide a framework for understanding the application, but they should not be used to guess the contents of a particular letter. Look for the issues actually discussed, and distinguish statements about clinical evidence from statements about manufacturing or labeling. A general account of the review process cannot substitute for the wording of an individual regulatory response.
Does priority review lower the approval standard?
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A shorter review goal should not be interpreted as a lower evidence standard. Priority review concerns the time allocated to review: the published goals are 8 months for an initial application and 6 months for a supplemental application. Eligibility concerns a drug for a serious condition that, if approved, would provide a significant improvement in safety or effectiveness. The phrase “if approved” matters: eligibility describes the proposed benefit, rather than establishing that an approval has already occurred. To assess the evidence behind an approved drug, look at its trials, their end points and their controls, rather than drawing a conclusion from the review category alone. The 2020 approval study illustrates why those details matter: some drugs were supported by a single pivotal trial, and some trials used surrogate measures. Review speed alone does not describe those features of the evidence.
Why do user fees matter?
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PDUFA lets the agency collect fees from applicants to invest in resources intended to accelerate review and approval operations. That explains the role of fees in supporting the review process. It does not mean that payment demonstrates a drug’s safety or effectiveness. Those are questions for the evidence in the application, including the results of clinical testing. When reading about a drug, keep the funding of the review separate from the findings of the trials. The review timelines describe timing, while the trial results describe what was studied and what was observed.
This article is for information only. It is general education about science and the drug industry, and it is not medical, treatment or investment advice.
