This is a Phase 3 study to evaluate the efficacy, safety and long-term safety of the topical administration of FMX-101, 4% minocycline foam for the treatment of moderate-to-severe acne vulgaris. The first 12 weeks of the study involves randomized, double-blind treatment with active FMX-101, 4% or matching vehicle. Subjects who successfully complete the 12-week double blind portion of the study will be offered the opportunity to continue in the trial for up to an additional 40 weeks (for a total of 1 year) and receive open-label treatment with FMX-101, 4%.