In which phase do researchers primarily evaluate if new treatments are more effective than existing ones?

The phase in which researchers primarily evaluate whether new treatments are more effective than existing ones is Phase 3. This phase is designed to compare the new treatment directly against the standard of care or placebo in a larger population. During this phase, the efficacy and safety of the treatment are rigorously tested to determine if there are significant improvements over current treatment options.

Phase 3 trials often involve a greater number of participants than earlier phases, providing a clearer picture of how the new therapy performs in a real-world setting. This stage is critical as it helps to establish the treatment’s benefits and risks in a manner that informs clinical practice and regulatory approval.

Earlier phases, such as Phase 1 and Phase 2, are primarily focused on determining dosage, safety, and the preliminary efficacy of the treatment rather than direct comparisons with existing therapies. Phase 4, also known as post-marketing surveillance, involves ongoing monitoring of the treatment's effectiveness and safety after it has already been approved for public use, but it does not focus on comparative effectiveness against existing options.