How do NDA and BLA differ in the scope of products they regulate?

• A. NDA for biologics; BLA for small-molecule drugs; both require FDA approval
• B. NDA for small-molecule drugs; BLA for biologics; both require FDA approval
• C. NDA and BLA are interchangeable terms with identical scope
• D. NDA is required for all drugs; BLA is optional

Answer: (B)

The main idea is that the licensing path depends on the product type. Small-molecule drugs are evaluated under the New Drug Application path, while biologics—such as vaccines, therapeutic proteins, monoclonal antibodies, and other products derived from living systems—are evaluated under the Biologics License Application path. Both paths require FDA approval before a product can be marketed, after demonstrating safety and efficacy through preclinical and clinical data.

This distinction exists because biologics have different characteristics and manufacturing controls than chemically synthesized drugs, which is why they sit under separate regulatory tracks. For example, small molecules are typically chemically synthesized and reviewed through the NDA process, whereas biologics are complex, often produced in living systems, and reviewed through the BLA process.

So, the correct view is that the NDA covers small-molecule drugs and the BLA covers biologics, with both requiring FDA approval. (The other options imply the roles are the same or reversed or that one path is optional, which isn’t accurate.)