351(a) is the traditional pathway for approval of biologics and innovator biologics under the Public Health Service (PHS) act. Under section 351(a), the submitted application must contain all the information regarding the safety and effectiveness of a biological product. It is also known as a “stand alone” application as it doesn’t depend upon any other biological product.

351(k) application is a biologics license application process under the USFDA. The application is submitted by the manufacturers in order to get a product reviewed as a biosimilar or interchangeable which is considered to be “highly similar” to an FDA licensed reference product. The PHS act requires that a 351(K) application should include information explaining that the bio similarity is completely based on the data related to animal studies, clinical studies and analytical studies. However, the FDA will further decide which of the following studies are necessary to be included in the application:  

  1. Analytical Studies – To establish similarity between the biological and reference product, including minor difference in clinically inactive ingredients.
  2. Animal Studies – Includes the evaluation of toxicity.
  3. Clinical Studies – It also includes assessment of immunogenicity and pharmacokinetics (PK) or pharmacodynamics (PD) to ensure safety of the product in the condition of use.

General Requirements of 351(k) pathway

The application must include the following information:

  • Demonstration of the product-in-review to be biosimilar to a reference product
  • Usage of same mechanism(s) of action for the intended condition(s) of use, limiting to the mechanisms of the reference product
  • Previously approved condition(s) of use for labeling
  • Route of administration, dosage form and strength as per the reference product
  • Details regarding the manufacturing of the product to ensure the safety and efficiency of the manufacturing plant and process

351(k) and 351(a) applications are requisite for manufacturers to place their biological products in the US market. To get the customized information and Regulatory support regarding the biological products and their pathways, speak to us at sales@freyrsolutions.com.