In this parallel-group , relapse prevention , phase-3 study ( screening [ 14-day ] , pali ER open-label run-in [ 8-week ] and stabilization [ 6-week ] phases , and double-blind ( DB ) treatment [ variable duration ] , and open-label extension phases [ 24-week ] ) , 136/201 patients with schizophrenia were randomized ( 1:1 ) to pali ER ( 3-12 mg ) or placebo during the DB phase .