Secukinumab, a fully human anti-IL-17A monoclonal antibody, neutralizes IL-17A, a key cytokine in the pathogenesis of psoriasis. Efficacy and safety of secukinumab was evaluated in Japanese patients with moderate-to-severe plaque psoriasis as part of a large Phase 3 global study (ERASURE). In this 52-week, double-blind study (ClinicalTrials.gov Identifier: NCT01365455, JapicCTI-111529), 87 patients from Japan (11.8% of 738 patients randomized in the overall study population) were equally randomized to receive secukinumab 300 mg or 150 mg, or placebo once weekly at baseline and at Weeks 1, 2, 3 and 4, then every 4 weeks. Co-primary endpoints (Week 12) were ≥75% improvement in psoriasis area-and-severity index (PASI 75) from baseline and a score of 0 (clear) or 1 (almost clear) on a 5-point Investigator's Global Assessment scale (IGA mod 2011 0/1) versus placebo. PASI 75 and IGA mod 2011 0/1 responses at Week 12 were superior with secukinumab 300 mg (82.8% and 55.2%, respectively) or 150 mg (86.2% and 55.2%, respectively) versus placebo (6.9% and 3.4%, respectively; P < 0.0001 for all). Greater than 90% improvement in PASI (PASI 90) was also superior with secukinumab 300 mg (62.1%) or 150 mg (55.2%) versus placebo (0.0%) at Week 12 (P < 0.0001 for both). Clinical responses were sustained up to Week 52 in the majority of patients. During a 12-week induction period, adverse event incidences were 48.3% with secukinumab 300 mg, 55.2% with 150 mg, and 41.4% with placebo. Secukinumab showed robust and sustainable efficacy in symptom reduction for moderate-to-severe plaque psoriasis in the Japanese patients.