Question

After which phase of clinical trials do pharmaceutical companies submit a New Drug Application (NDA) to the regulatory authority?

• A. Phase I
• B. Phase II
• C. Phase III
• D. Phase IV

Hint:

Remember: NDA submission follows successful Phase III trials, while Phase IV studies are post-marketing studies conducted after drug approval.

Answer 1

The Correct Option is C

An NDA is a formal request for marketing approval, and it needs solid, confirmed evidence of both safety and effectiveness before it can be filed.

1. Phase I: Only checks basic safety in a small group of healthy people, far too early for an approval filing.
2. Phase II: Gives an early signal of efficacy in patients but on too small a scale to support approval.
3. Phase III: Provides the large, confirmatory trial data regulators actually require, and once this data is compiled, it forms the core of the NDA submitted for review.
4. Phase IV: Only starts once the drug is already approved and on the market, so it comes after the NDA, not before it.

The NDA is filed right after Phase III trials deliver their confirmatory results.

So the correct answer is Phase III.