This study is designed to evaluate the proportion of patients achieving reversal of chronic plaque psoriasis at week 4 and 12 following multiple doses of secukinumab administered subcutaneously (sc) compared to placebo. Starting from week 13, all patients will receive multiple doses of secukinumab up to week 52 to study long term effects of secukinumab. Clinical endpoints including biomarker assessments, PASI, IGA and DLQI will be compared to better understand, why secukinumab may be effective in psoriasis patients.