Submission & ApprovalLast reviewed April 2026

Orphan Drug Designation(ODD)

A status granted to drugs intended to treat rare diseases affecting fewer than 200,000 people in the US.

Usage Examples

The enzyme replacement therapy received Orphan Drug Designation.
Orphan exclusivity prevents generic approval for 7 years.
FDA granted orphan designation for the rare pediatric indication.

What is ODD?

Orphan Drug Designation (ODD) is granted by FDA to drugs intended to treat, diagnose, or prevent rare diseases or conditions affecting fewer than 200,000 people in the US (or where there's no reasonable expectation of recovering development costs).

Benefits include 7 years of market exclusivity upon approval, tax credits for qualified clinical trials, waiver of PDUFA application fees, and FDA assistance in protocol design. The Orphan Drug Act (1983) created these incentives.

Orphan designation is distinct from approval. Products must still demonstrate safety and effectiveness. Multiple products may receive orphan designation for the same condition.

Regulatory Context

This term appears most often in submission & approval workflows where submission quality, regulatory evidence, and audit readiness depend on consistent language. It is commonly referenced alongside ORPHAN DRUG ACT, 21 CFR 316.

FDAICHEMA

When This Matters

The enzyme replacement therapy received Orphan Drug Designation.
Orphan exclusivity prevents generic approval for 7 years.
FDA granted orphan designation for the rare pediatric indication.

Common Mistakes

Treating submission readiness as a formatting-only check without lifecycle validation.
Using outdated guidance references across modules and summaries.
Missing cross-functional review between RA, CMC, and quality before submission.

Related Regulations

ORPHAN DRUG ACT21 CFR 316

How to Request FDA Orphan Drug Designation

Submit a request for Orphan Drug Designation to qualify for tax credits, user fee waivers, and 7-year market exclusivity for rare disease therapeutics.

1
Verify eligibility
Confirm: (1) prevalence <200,000 in the US OR no reasonable expectation of recovering development costs, AND (2) a scientifically credible medical plausibility for the drug in the rare indication. Both criteria must be met.
2
Gather prevalence evidence
Document US prevalence from published literature, disease registries, published epidemiologic studies, or sponsor-generated data. CDC, NIH, and peer-reviewed sources are preferred. Estimates must be current and methodology transparent.
3
Build the scientific rationale
Demonstrate the drug's medical plausibility for the orphan indication through nonclinical pharmacology, available clinical experience, and mechanism-of-action argument. The standard is scientific credibility, not proof of efficacy.
4
Prepare the designation request
Per 21 CFR 316.20: drug description, proposed indication and prevalence analysis, medical plausibility, summary of available data, regulatory strategy. Concise, typically 20-40 pages with supporting references.
5
Submit to Office of Orphan Products Development
File through FDA OOPD directly (not through IND). FDA has 90 days to respond with designation, denial, or request for additional information.
6
Respond to any information requests
FDA commonly requests additional prevalence evidence or scientific clarification. Responses should be prompt and focused on the specific question. Additional evidence submitted extends the 90-day clock.
7
Leverage designation benefits
If granted: 7-year market exclusivity from approval, 50% tax credit on qualifying clinical trial costs, user fee waivers (NDA/BLA filing), eligibility for Orphan Grants program, and FDA's structured engagement during development.