Direct comparison
505(b)(2) vs NDA, BLA & ANDA Pathways
Compare FDA's four marketing-application routes -- NDA, 505(b)(2), BLA, ANDA -- by data required, patent certification, exclusivity, and review timeline.
Ask about 505(b)(2) vs NDA, BLA & ANDA Pathways
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How do Full NDA (505(b)(1)), 505(b)(2) NDA, BLA (PHS Act §351), ANDA (505(j)) compare side by side?
The table below compares Full NDA (505(b)(1)), 505(b)(2) NDA, BLA (PHS Act §351), ANDA (505(j)) across 8 procurement-relevant dimensions, from statutory basis through typical post-approval exclusivity.
Side-by-side comparison
| Dimension | Full NDA (505(b)(1)) | 505(b)(2) NDA | BLA (PHS Act §351) | ANDA (505(j)) |
|---|---|---|---|---|
| Statutory basis | FD&C Act §505(b)(1), 21 U.S.C. 355(b)(1) | FD&C Act §505(b)(2), 21 U.S.C. 355(b)(2) | PHS Act §351(a), 42 U.S.C. 262(a); defined at 21 CFR 601.2 | FD&C Act §505(j), 21 U.S.C. 355(j) |
| What it's for | A new drug, typically a new molecular entity, backed entirely by the applicant's own data | A changed version of an already-approved drug (new form, route, strength, combination, indication, or Rx-to-OTC switch) | A biological product -- protein, antibody, vaccine, cell/gene therapy, or blood product | A generic duplicate of an already-approved drug -- same active ingredient, strength, dosage form, and route |
| Safety/efficacy data required | Full reports of the applicant's own investigations | New studies for the changed feature, plus reliance on FDA's prior finding for the earlier drug and/or published literature | Full reports of the applicant's own investigations, plus manufacturing/potency/purity data | No new clinical trials -- bioequivalence data only |
| Right of reference to underlying studies | Yes -- applicant owns or holds a right of reference to all pivotal data | No, for the relied-upon portion -- that is the pathway's defining feature | Yes, for its own product-specific data | Not applicable -- relies on the reference drug's approval, not its investigation data |
| Patent certification against another product's patents | Not required -- applicant lists its own new patents | Required when relying on a listed drug -- Paragraph I-IV certification against its Orange Book patents | Biosimilars use the separate BPCIA patent-dance process, not Hatch-Waxman certification | Required -- Paragraph I-IV certification against the reference listed drug's Orange Book patents |
| Reviewing FDA center | CDER | CDER | CBER for most biologics; CDER for many therapeutic proteins/monoclonal antibodies since a 2003 transfer | CDER |
| User fee program | PDUFA | PDUFA | PDUFA (BsUFA for biosimilars) | GDUFA |
| Typical post-approval exclusivity | Up to 5 years New Chemical Entity exclusivity (longer with orphan or pediatric add-ons) | Commonly 3 years, tied to the new clinical investigations for the changed feature | Up to 12 years reference-product exclusivity under the BPCIA | None of its own; first Paragraph IV filer can earn 180 days of generic marketing exclusivity |
Common questions
Common questions about Full NDA (505(b)(1)) vs 505(b)(2) NDA vs BLA (PHS Act §351) vs ANDA (505(j))
What does 505(b)(2) mean in FDA terms?
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It refers to Section 505(b)(2) of the FD&C Act (21 U.S.C. 355(b)(2)): an NDA where at least part of the safety/effectiveness case relies on investigations the applicant did not conduct and does not hold a right of reference to -- typically FDA's prior finding for an already-approved drug, published literature, or both -- combined with new data the applicant does generate for whatever is different about its product.
Is a 505(b)(2) application the same as a generic drug application (ANDA)?
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No. Both can rely on FDA's prior findings about an already-approved drug, but an ANDA is for a like-for-like copy (same active ingredient, strength, dosage form, and route) supported only by bioequivalence data. A 505(b)(2) application is for a product that changes something clinically meaningful -- a new dosage form, route, strength, combination, or indication -- and requires new clinical or nonclinical data for that change, not just bioequivalence.
Can a 505(b)(2) applicant use another company's clinical trial data without permission?
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The applicant does not need permission from the company that generated the data, but it also cannot cite that company's actual study reports as its own -- what it relies on is FDA's own prior conclusion (based on that data) that the earlier drug is safe and effective, or published literature describing the findings, rather than a right to the underlying dossier itself.
Do biologics ever use the 505(b)(2) pathway?
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No. Biologics are approved under a Biologics License Application governed by the Public Health Service Act (PHS Act §351), a different statute from the FD&C Act Section 505 framework that governs NDAs, 505(b)(2) applications, and ANDAs. A biosimilar has its own distinct abbreviated pathway under PHS Act §351(k), not 505(b)(2).
How long does FDA typically take to review these applications?
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For NDAs, 505(b)(2) applications, and BLAs, FDA's standard practice is to decide within 60 days of submission whether to file the application for review, with substantive review commonly taking roughly 6 to 10 months from filing under the applicable PDUFA goal date. ANDAs run under GDUFA's own separate performance-goal timeline. These are program goals, not guarantees.
