What is the primary purpose of Phase 3 clinical trials?

Phase 3 clinical trials are designed to confirm the effectiveness of a drug and to monitor its side effects in a larger population. By this stage, the researcher has already established preliminary evidence of a drug's efficacy and safety from earlier trials (Phase 1 and Phase 2). In Phase 3, the focus shifts to obtaining further data on the drug’s effectiveness, collecting information about the overall benefit-risk relationship, and assessing both the drug’s side effects and how it performs compared to standard treatments or placebos.

Successful completion of Phase 3 trials is essential for supporting the drug's application for regulatory approval, as it provides the comprehensive data needed to demonstrate that the medication can deliver the desired health outcomes in a broader, more diverse population. This extensive proof of performance is crucial in ensuring that healthcare professionals can safely prescribe the medication.

In terms of other options, testing drug interactions typically occurs in earlier phases or specific studies designed for that purpose, while determining dosage is generally a focus of Phase 1 clinical trials. The assessment of the manufacturing process is more relevant to regulatory compliance and good manufacturing practices rather than the primary aims of Phase 3 trials.