Is it better than current treatments? The FDA and the drug’s sponsor work together to design the phase 3 studies. They might study the drug on different populations at different dosages, and in combination with other drugs. These are often double-blind studies where neither the participants nor researchers know who received the active drug. Phase 3 trials are large in scope—sometimes involving tens of thousands of people around the world but according to the FDA, most are not larger than 3,000. If the drug is found to benefit the patient more than other drugs, and the side effects are manageable, a new drug application is filed.