The purpose of this study is to demonstrate the efficacy of Adapalene 0.1% /Benzoyl Peroxide 2.5% Gel compared to its Vehicle Gel as an acne maintenance treatment in Subjects previously treated with Adapalene-BPO Gel or Adapalene-BPO Vehicle Gel both associated with Doxycycline Hyclate 100 mg. The safety of the two investigational treatments will also be assessed.