The FDA has made some concessions. Only requiring 50 patients for mdr2+, look at what the other BP had to do below. Also when they noticed the significant efficacy difference between 350mg and 525mg&700mg in mono, they are allowing the p3 trial to stand without a new trial with the higher doses, i.e. they are going to approve a dose not even used in the trial; very unusual for them. They are also allowing additional safety data from the mono trial instead of requiring it in the combo trial, which is not usually done either. And with the stability test, they have allowed a reduction from 6 months to 3 months. I know if feels like forever, but they have made some concessions. If they had wanted to, they could have made different decisions where it could never happen.

Pfizer —Maraviroc 1059 patients in two trials
https://clinicaltrials.gov/show/NCT00098306
https://clinicaltrials.gov/show/NCT00098722

GSK—Aplaviroc 406 patients
https://clinicaltrials.gov/ct2/show/NCT00297076

Merck—vicriviroc 400 patients
https://clinicaltrials.gov/ct2/show/NCT00474370