At each study treatment visit, one (for secukinumab 150 mg) or two (for secukinumab 300 mg) s.c. injections in the form of PFS will be administered, since secukinumab is available in 1.0 mL (150 mg) PFSs. Placebo to secukinumab is also available in 1.0 mL to match the active drug.