Its pretty BS FDA will request phentermine+Lorcaserin data. Its like asking for HCV polymerase+protease inhibitor data when the filing is for the monotherapy + SOC. In fact, ARNA initially wanted to run Lorcaserin+phentermine, but was strongly adviced against by FDA.
I hear you, but it's the FDA. One never knows what they will ask for as a result of an NDA review. That's why I avoid FDA decisions and would only consider ARNA after the FDA decision.