FDA Drug Approval Process: Timeline, Phases, and Data

The full timeline: 10-15 years on average

Getting a new drug from initial discovery to FDA approval takes an average of 12 years and costs $1-2 billion. Most candidates fail. Only about 12% of drugs entering Phase I trials eventually receive approval.

Stage	Duration	Success Rate
Preclinical (lab/animal)	3-6 years	~1 in 5,000 compounds advance
Phase I (safety)	1-2 years	63% proceed to Phase II
Phase II (efficacy)	2-3 years	31% proceed to Phase III
Phase III (large trials)	3-4 years	58% proceed to NDA
FDA Review (NDA/BLA)	6-12 months	85% of submitted NDAs approved

Preclinical: before human testing

Before any human receives a drug, the sponsor must demonstrate safety in laboratory and animal studies. This stage produces the pharmacokinetics (how the body processes the drug) and toxicology data that FDA requires before allowing clinical trials.

The sponsor files an Investigational New Drug (IND) application. The FDA has 30 days to review. If no clinical hold is issued, trials can begin.

Phase I: first-in-human safety

Phase I trials enroll 20-80 healthy volunteers (or patients for cancer drugs). The goals are narrow:

• Determine safe dosage range
• Identify side effects
• Understand absorption, distribution, metabolism, excretion (ADME)

These trials are not designed to test whether the drug works. They answer: "Is it safe enough to keep testing?"

Phase II: does it work?

Phase II trials enroll 100-300 patients with the target condition. These are typically randomized controlled trials comparing the drug to placebo or standard of care.

Goals:

• Demonstrate preliminary efficacy
• Refine dosing
• Identify common adverse reactions
• Establish endpoints for Phase III

This is where most drugs fail. The 31% success rate from Phase II to Phase III reflects how many compounds show activity in small trials but fail to demonstrate clinically meaningful benefit.

Phase III: large-scale confirmation

Phase III trials enroll 1,000-5,000+ patients across multiple sites. They generate the pivotal data that FDA uses for approval decisions.

Characteristics:

• Randomized, double-blind, placebo-controlled (usually)
• Multi-site (often international)
• Pre-specified primary endpoints
• Statistical analysis plans filed before unblinding

The sponsor typically runs two adequate and well-controlled Phase III trials. One positive trial is sometimes sufficient for rare diseases or breakthrough therapies.

NDA submission and FDA review

After successful Phase III trials, the sponsor submits a New Drug Application (NDA) for small molecules or a Biologics License Application (BLA) for biologics.

An NDA package contains:

• Full clinical trial data from all phases
• Chemistry, manufacturing, and controls (CMC)
• Proposed labeling
• Risk evaluation and mitigation strategy (REMS) if needed

FDA assigns a review division and a target action date:

• Standard review: 10 months
• Priority review: 6 months (for drugs offering significant improvement over existing treatments)

Expedited pathways

Four programs can accelerate the timeline:

Program	Benefit	Criteria
Fast Track	More frequent FDA meetings, rolling review	Serious condition, unmet need
Breakthrough Therapy	All Fast Track benefits + intensive guidance	Preliminary evidence of substantial improvement
Accelerated Approval	Approval based on surrogate endpoint	Serious condition, meaningful advantage
Priority Review	6 months instead of 10	Significant improvement in safety/efficacy

A drug can qualify for multiple programs simultaneously. Breakthrough therapy designation is the most impactful: drugs with this designation have a 70%+ approval rate.

Where to find approval data

Drugs@FDA (accessdata.fda.gov/scripts/cder/daf): Searchable database of all approved drugs with review documents, labeling, and approval letters.

openFDA drugsfda endpoint:

# Search for recent approvals
curl "https://api.fda.gov/drug/drugsfda.json?search=submissions.submission_type:\"ORIG\"+AND+submissions.submission_status_date:[20260101+TO+20261231]&limit=10"

FDA Orange Book: Lists approved drug products with therapeutic equivalence evaluations. Useful for identifying generic equivalents.

ClinicalTrials.gov: The trial registry tracks all phases. Each entry links to published results and FDA review documents when available.

2026 approval trends

Through the first seven months of 2026, the FDA's Center for Drug Evaluation and Research (CDER) has approved approximately 25 novel drugs. This pace is consistent with the 50-55 novel approvals per year seen in 2023-2025.

Notable trends:

• GLP-1 receptor agonists continue expanding indications (MASH, cardiovascular risk reduction)
• Gene therapy approvals accelerating (4 in first half of 2026)
• AI-designed molecules reaching approval for the first time
• Oncology remains the largest therapeutic area for new approvals

FAQ

What is the difference between NDA and BLA? NDA covers small-molecule drugs (chemical compounds). BLA covers biologics (proteins, antibodies, gene therapies, vaccines). The review process is similar, but manufacturing requirements differ significantly.

Can a drug be sold before full approval? Under accelerated approval, yes. The drug reaches market based on surrogate endpoints, with a requirement to complete confirmatory trials post-approval. If those trials fail, FDA can withdraw approval.

How much does an NDA submission cost? The Prescription Drug User Fee Act (PDUFA) fee for a new NDA is approximately $4.0 million in 2026. This fee funds FDA reviewer positions.

What percentage of approved drugs get withdrawn later? About 3-4% of approved drugs are eventually withdrawn from market for safety reasons. Post-market surveillance catches risks that pre-approval trials missed due to limited sample sizes.

Where can I track drugs currently under FDA review? The FDA publishes PDUFA action dates (target decision dates) for drugs under review. These appear on the FDA website and in industry tracking databases.