This was a prospective, multicenter, open-label, non-control group design Phase 3 clinical study. Approximately 880 subjects who were to complete former studies in this program (370 subjects from studies MRZ 60201-0520/1 (8) and MRZ 60201-0527/1 (8) as well as approximately 510 subjects from studies MRZ 60201-0724/1 (10) and MRZ 60201-0741/1) (11) were expected to enroll in this study in 26 centers in the United States, Canada and Germany. Subjects with moderate to severe glabellar frown lines at maximum frown who completed participation in one of these four "feeder" studies in the frown line program were eligible to participate in this repeated dose study.