A 505(b)(2) product can provide an efficient development pathway when a sponsor can rely, in part, on information from studies not conducted by or for the applicant, or on FDA’s previous findings of safety or effectiveness. However, the pathway does not eliminate the need for an appropriately designed Investigational New Drug (IND) submission when clinical investigation of the product requires an IND. A successful strategy must connect the product’s regulatory basis, nonclinical package, clinical rationale, CMC information, and eventual 505(b)(2) NDA strategy. FDA describes a 505(b)(2) application as an NDA supported partly by investigations for which the applicant does not have a right of reference or use. The first step is to establish why the proposed product is appropriately positioned for the 505(b)(2) regulatory pathway rather than a 505(b)(1) or ANDA pathway. This assessment should consider the proposed active ingredient, dosage form, route of administration, strength, formulation, indication, and the extent to which existing FDA findings or published literature can support development. FDA’s August 2026 draft guidance, which would replace the 2019 guidance if finalized, specifically addresses how sponsors should determine whether an ANDA or 505(b)(2) application is appropriate. Because it is currently a draft, sponsors should distinguish its recommendations from binding statutory or regulatory requirements.

For an IND application, FDA expects sufficient information to determine whether the proposed clinical investigation may proceed without unreasonable risk to participants. Under 21 CFR Part 312, an IND generally includes administrative information, introductory material and general investigational-plan information, investigator information, protocols, chemistry, manufacturing and controls, pharmacology and toxicology information, previous human experience where applicable, and additional relevant information. FDA emphasizes that an IND should be complete and well organized in accordance with the applicable requirements. For a 505(b)(2) development program, the submission should clearly explain how the proposed product relates to the relied-upon reference information and why the proposed clinical and nonclinical program is scientifically justified.

A particularly important issue is the regulatory bridge between the existing information and the proposed product. Sponsors should avoid assuming that reliance on a previously approved product automatically reduces every evidentiary requirement. Differences in formulation, dosage form, route, strength, delivery technology, excipients, exposure, or intended population may create new questions regarding safety, pharmacokinetics, tolerability, or efficacy. The IND should therefore present a logical evidence package showing what is already known, what can reasonably be bridged, and what must be demonstrated through new studies. Where appropriate, FDA has also recognized that generally accepted scientific knowledge may contribute to meeting certain nonclinical requirements, although the applicability of such information must be scientifically justified for the specific product. The CMC strategy is another critical component. Even when a sponsor relies on existing clinical or safety information, FDA still expects adequate information concerning the identity, quality, purity, strength, manufacturing process, specifications, analytical methods, packaging, and stability of the investigational product appropriate to the stage of development. Manufacturing changes made during development should be evaluated for their potential effect on product quality and clinical comparability. Weak or incomplete CMC information can create regulatory questions and, depending on the circumstances, contribute to delays or clinical development restrictions.

The clinical development plan should be equally disciplined. Sponsors need to establish appropriate objectives, endpoints, study populations, dosing rationale, safety monitoring, and statistical considerations based on the product-specific development question. For products that modify an existing therapy, clinical studies may need to address differences that cannot be adequately supported through prior knowledge alone. FDA’s current IND resources continue to emphasize appropriate clinical protocols, safety monitoring, manufacturing information, and supporting preclinical evidence. Recent FDA activity also reinforces the importance of regulatory planning early in development. In August 2026, FDA issued a new draft guidance on determining whether a product should follow the ANDA or 505(b)(2) NDA pathway, signaling continued attention to pathway selection and the quality of abbreviated application strategies. FDA has also issued updated guidance affecting IND development, including its May 2026 final guidance on assessing food effects for orally administered drugs developed under INDs and NDAs. Such developments demonstrate why sponsors should continuously monitor FDA guidance rather than rely solely on older regulatory assumptions. Common compliance risks include selecting the wrong regulatory pathway, inadequately documenting reliance on existing information, conducting studies without sufficient scientific justification, overlooking product-specific nonclinical requirements, providing incomplete CMC information, and failing to align the IND strategy with the eventual NDA. A pre-IND meeting can be particularly valuable when the development program involves complex bridging questions or uncertainty regarding the proposed clinical and nonclinical package. FDA notes that such interactions can help sponsors identify unnecessary studies, improve study design, obtain regulatory insight, and potentially reduce the risk of a clinical hold.

For pharmaceutical and biotech companies developing reformulations, new dosage forms, combinations, alternative routes, or other products based partly on existing information, an effective FDA IND submission strategy should therefore be built backward from the intended 505(b)(2) NDA. Every study and regulatory argument should have a defined purpose: establish safety, characterize exposure, demonstrate the relevance of existing evidence, address product-specific uncertainties, or support the eventual approval package. This integrated approach can make development more efficient while maintaining the level of scientific and regulatory rigor expected by FDA.