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Back to Basics: 505(b)(2) FAQs Part 1

As the 505(b)(2) expert, Premier Consulting is frequently asked questions about how to get a product approved via the 505(b)(2) regulatory pathway and if this pathway is appropriate. Given the growing popularity of the 505(b)(2) pathway for approval of repurposed, reformulated, or unapproved marketed products, we thought it would be worth providing a refresher. Here are questions that Strategic Advisor Ken Phelps recently answered at a webinar focused on the 505(b)(2) pathway. The topic of this post will be general 505(b)(2) questions, including what is and is not allowed for an approval via the 505(b)(2) regulatory pathway. Stay tuned to this blog for more FAQs and Premier Consulting’s responses in the coming weeks. But first, why the name? 505b2

Where does the name “505(b)(2)” come from?

The “505(b)(2)” name comes from Section 505 of the Federal Food, Drug, and Cosmetic Act. Section 505(b)(2) was added by the Drug Price Competition and Patent Term Restoration Act of 1984 (Hatch-Waxman Amendments). Section 505 has subsections that describe 3 types of applications:

  1. 505(b)(1) – new molecular entity containing full reports of safety and efficacy
  2. 505(b)(2) – applications in which some of the information required for approval comes from sources other than sponsor studies, or for which the sponsor has not obtained a right of reference
  3. 505(j) – generics: the application provides proof that the product is identical to a previously approved product

Now to the questions asked by Ken’s audience:

Q1: Can you change the indication and dosage form at the same time for an approved drug with 505(b)(2)?

Yes. A product that is appropriate for approval via the 505(b)(2) pathway may differ from approved products in multiple attributes, including dosage form, strength, route of administration, formulation, dosage regimen, indication, or even active ingredient. Changes to any of these attributes will usually affect the safety or efficacy of the proposed product. Therefore, the 505(b)(2) application for the proposed product will need to demonstrate adequate safety and efficacy for the indication.

In addition, a 505(b)(2) application need not refer to any approved product, or listed drug. If the information in the literature is appropriate and of a standard acceptable to the FDA, it is possible to leverage this information for approval of a new product.

Q2: Do “Pre-DESI” products fall under 505(b)(2) or a new (molecular entity) NDA?

Many products that are marketed unapproved (so-called “DESI” or “pre-DESI”), are suitable for approval via the 505(b)(2) pathway. This is because there is often existing information on these products that can be used to support their safety and efficacy. This information may include studies reported in the literature or information retained in the manufacturer’s own database. In many cases, this information can be used to reduce the size or scope of the development program required to get the product approved.

See our previous blog post on unapproved or so-called “DESI” products for more information.

Q3: Does a 505(b)(2) require a proprietary name?

Drug products, including those approved via the 505(b)(2) pathway, do not require a proprietary name. However, if a Sponsor would like to include a proprietary name in the labeling, the proposed name must be assessed for appropriateness by the FDA’s Office of Medication Error Prevention and Risk Management before the final labeling can be approved. Conditional approval of the name may be obtained earlier in the process. Until the proprietary name is approved, the product may be referred to in submissions and studies by any name or number that the Sponsor chooses.

Once approved, a proprietary name is important in distinguishing and promoting a product approved via the 505(b)(2) pathway, similar to that of a 505(b)(1), or new molecular entity.

Q4: Is the 505(b)(2) pathway available for approval of biologics that are similar?

No. Products that are similar to biologics approved via a Biologics License Application (BLA), known as a “biosimilars,” are approved via Section 351(k) of the PHS Act (42 U.S.C. 262(k)), added by the Biologics Price Competition and Innovation Act of 2009 (BPCI Act). Whereas a 505(b)(2) product requires an NDA submission to the FDA’s Center for Drug Evaluation and Research (CDER), biosimilars require submission of a 351(k) BLA to the Center for Biologics Evaluation and Research (CBER).


Products that are suitable for approval via the 505(b)(2) regulatory pathway include drug products for which existing information can be leveraged to reduce the time and cost for approval. For an assessment of whether your product is appropriate for approval via the 505(b)(2) pathway or to learn more about ways, Premier Consulting’s multi-disciplinary team can help you get your product approved with a minimal development program, read more here or contact us.

Other installments in “Back to Basics: 505(b)(2) FAQs”:


Angela Drew, Ph.D.
Product Ideation Consultant