A multicenter study conducted in patients with OABS comprising a 2-week single blind placebo run-in period followed by an 8-week randomized, double-blind, placebo controlled treatment period with patients randomized to receive 20 mg, 40 mg, 80 mg or 120 mg SMP 986 or placebo in a 1:1:1:1:1 ratio in parallel groups on an outpatient basis with study center visits.