Submission & ApprovalLast reviewed April 2026

505(b)(2) Application(505(b)(2))

A US NDA pathway that relies, at least in part, on FDA's findings of safety and effectiveness for a previously approved drug or published literature.

Usage Examples

The 505(b)(2) relied on published literature for the active ingredient's safety profile and included bridging PK studies.
The pivotal trial was reduced in size because FDA's prior findings on the reference product addressed most efficacy questions.
Paragraph IV certification triggered a 30-month stay pending patent litigation.

What is 505(b)(2)?

A 505(b)(2) application is a New Drug Application submitted under section 505(b)(2) of the FDCA that permits the sponsor to rely in whole or in part on data not developed by the sponsor — typically FDA's findings for a previously approved product and/or published scientific literature. This contrasts with 505(b)(1) NDAs, which require full studies conducted or sponsored by the applicant, and 505(j) ANDAs, which rely entirely on the RLD's data through a bioequivalence demonstration.

505(b)(2) is the correct pathway for new drug products that differ from the reference product in ways an ANDA cannot accommodate — different dosage forms, new indications, new routes of administration, combinations, or modifications — while still leveraging existing safety and efficacy knowledge to reduce clinical development cost and timeline.

The pathway triggers patent and exclusivity considerations similar to ANDAs: Paragraph IV certifications to Orange Book-listed patents, potential 30-month stays of approval during patent litigation, and potential 3-year new clinical investigation exclusivity or 5-year new chemical entity exclusivity on approval.

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 FDCA SECTION 505B2, 21 CFR 314.

FDAICHEMA

When This Matters

The 505(b)(2) relied on published literature for the active ingredient's safety profile and included bridging PK studies.
The pivotal trial was reduced in size because FDA's prior findings on the reference product addressed most efficacy questions.
Paragraph IV certification triggered a 30-month stay pending patent litigation.

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Using outdated guidance references across modules and summaries.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

FDCA SECTION 505B221 CFR 314

Frequently Asked Questions

When the product differs meaningfully from any approved drug (preventing an ANDA) but significantly overlaps a reference product's known safety and efficacy profile. Typical use cases include new dosage forms, new indications, new routes of administration, fixed-dose combinations, and prodrugs of approved active ingredients.

A 505(b)(2) approval may receive 3-year new clinical investigation exclusivity if approved based on new clinical studies essential to approval, 5-year new chemical entity exclusivity if the active moiety has not been previously approved, 7-year orphan drug exclusivity if designated, or pediatric exclusivity extensions.

Yes. Like ANDAs, 505(b)(2) applications must certify the status of Orange Book-listed patents for the reference product. Paragraph IV certifications can trigger a 45-day notice, patent litigation, and a 30-month stay of approval.