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Submission & Approval

505(b)(2) Application

A 505(b)(2) application is a New Drug Application that relies partly on FDA's findings for an already-approved listed drug or on published literature, unlike a 505(b)(1) NDA built entirely on the applicant's own studies.

Usage Examples

  • The 505(b)(2) relied on published literature for the active ingredient's safety profile and added bridging PK studies.
  • We sized the pivotal trial down because FDA's prior findings on the listed drug already answered most of the efficacy question.
  • Our paragraph IV certification drew suit inside 45 days, so approval is stayed 30 months.

What is 505(b)(2) Application?

A 505(b)(2) application is a New Drug Application that relies partly on FDA's findings for an already-approved listed drug or on published literature, unlike a 505(b)(1) NDA built entirely on the applicant's own studies.

505(b)(2) applications exist to fill the gap between the two other US drug pathways. The FD&C Act does not permit approval of an ANDA for a new indication, nor for other changes to a listed drug when investigations beyond bioavailability or bioequivalence are essential. Without this route, every modified version of an approved drug would repeat a full development programme.

A 505(b)(2) application covers changes an ANDA cannot carry: new indications, new dosage forms, new routes of administration, and other modifications requiring investigations beyond bioequivalence. The pathway does not cover a product whose active ingredient is absorbed to a lesser extent than the listed drug, or unintentionally more slowly. A pure duplicate of a listed drug still belongs in an ANDA.

A 505(b)(2) application is planned backwards from these constraints. Teams map the listed drug's Orange Book patents and exclusivity before designing the bridging programme, because a five-year new chemical entity bar blocks submission outright and a paragraph IV certification that draws suit adds 30 months to the approval date. The clinical package is sized to what the reliance leaves unanswered.

Not to be confused with

505(b)(1) NDA
a 505(b)(1) rests entirely on investigations the applicant conducted or holds a right of reference to. A 505(b)(2) rests, at least in part, on data the applicant neither generated nor owns, which is the whole reason its development programme is smaller.
ANDA (505(j))
an ANDA establishes sameness through bioequivalence and cannot carry a new indication or any change requiring investigations beyond bioavailability or bioequivalence. The moment such investigations become essential, the ANDA route closes and 505(b)(2) is the only remaining option.
Supplemental NDA
a supplement changes an application the sponsor already holds; a 505(b)(2) is a new application built on someone else's approved product. Both can earn three-year exclusivity, but only the 505(b)(2) creates a new NDA.
Paragraph IV certification
the certification is a filing element inside a 505(b)(2) or an ANDA, not a pathway of its own. It determines whether approval is stayed, not which application type you file.

The obligations that actually shape a 505(b)(2) programme come from Part 314.

What you must do

  1. 1Submit under 505(b)(2) rather than an ANDA whenever investigations other than bioavailability or bioequivalence studies are essential to approving the change from the listed drug21 CFR 314.54(a)
  2. 2Do not use the 505(b)(2) route for a product whose active ingredient is absorbed to a lesser extent, or unintentionally at a lesser rate, than the listed drug21 CFR 314.54(b)
  3. 3Plan approval timing around a 30-month stay running from the later of the dates the patent owner or the NDA holder received the paragraph IV certification notice21 CFR 314.107(b)(3)
  4. 4Hold the 505(b)(2) submission for 5 years from the approval date of a listed drug that contained a new chemical entity approved after 24 September 198421 CFR 314.108(b)(2)
  5. 5Expect FDA to withhold approval for 3 years where the earlier application reported new clinical investigations, conducted or sponsored by that applicant, that were essential to its approval21 CFR 314.108(b)(4)

Common mistakes

  • Filing a 505(b)(2) when an ANDA would have worked

    If nothing beyond bioavailability or bioequivalence is essential to the change, the product belongs in an ANDA. Choosing 505(b)(2) anyway commits the sponsor to a new-drug review it never needed, and to the certification and exclusivity machinery that comes with it.

  • Designing the bridging programme before mapping exclusivity

    A five-year new chemical entity bar prevents submission at all for five years from the listed drug's approval date. A programme timed to finish inside that window has nowhere to file, and the spend sits idle. Check Orange Book exclusivity before the first bridging study is designed.

  • Modelling the 30-month stay as a fixed, known date

    The stay runs from the later of two notice-receipt dates, not from your filing, and a court can extend it where a party fails to cooperate reasonably in expediting the action. Both the start point and the length can move, so a launch forecast anchored to a single hard date is a forecast that will slip.

When This Matters

  • The 505(b)(2) relied on published literature for the active ingredient's safety profile and added bridging PK studies.
  • We sized the pivotal trial down because FDA's prior findings on the listed drug already answered most of the efficacy question.
  • Our paragraph IV certification drew suit inside 45 days, so approval is stayed 30 months.

Frequently Asked Questions

File a 505(b)(2) when investigations other than bioavailability or bioequivalence studies are essential to approving your change from the listed drug. FDA cannot approve an ANDA for a new indication, or for other changes that require such investigations, so a new dosage form, route, or indication forces the 505(b)(2) route.

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