Besides growing the tumor, they had to rewrite the original plan to include what the fda requested to be in the test as well. Which they stated that they would like to see several things. That is not just copy and paste from some notebook.
As in one of their conversations with a investor, they were going back and forth with the FDA constantly so they knew exactly what the fda wanted to see for each one of the fdas request.
These plans/reports are extremely detailed per step in the entire process. These just don’t get wrote overnight.