At this point, the developer has all the information it needs about the drug, but the FDA still wants to assess one more thing: the developer’s plans for clinical trials.
The FDA’s primary concern is to protect trial participants. The agency will require that the developer start testing the drug at very low doses to look for any signs of toxicity, often in healthy volunteers instead of people with the disease, before moving up to doses that might be effective. This may seem unnecessary after all the testing in animals, but remember that mice are not humans, and drugs that cause no issues in other animals may be toxic in people.
The FDA also will make sure that the trial is well-designed, so as to have the best chance of yielding useful information about the drug with minimal risk to the trial participants. Developing a trial protocol can take some time, while the drug developer consults with physicians about the best way to run the trial, and what measurements need to be made to give as much information as possible with minimum disruption to patients.