Igarashi 2012.

Study characteristics
Methods	RCT, placebo‐controlled, double‐blind trial Date of study: March 2008 ‐ March 2010 Location: 35 centres in Japan
Participants	Randomised: 160 participants (age median 45 years, 126 male) Inclusion criteria Participants with moderate‐severe psoriasis Authors' assessment > 6 months, PASI ≥ 12, BSA > 10% Age > 20 years Non‐response to topical treatment Non‐response to phototherapy Number of allowed previous treatment line: 2 Exclusion criteria Pregnancy Had an active infection Had past history of malignant tumours Dropouts and withdrawals 10/160 (6.2%) Withdrawn before treatment (2) Ustekinumab 45 mg group (64): discontinued (0) Ustekinumab 90 mg group (62): discontinued (4) Placebo (32): discontinued (4)
Interventions	Intervention A. Ustekinumab (n = 64), SC, 45 mg, weeks 0 ‐ 4, every 12 weeks, 64 weeks Control intervention B. Ustekinumab (n = 62), SC, 90 mg, weeks 0 ‐ 4, every 12 weeks, 64 weeks C. Placebo (n = 32), SC, weeks 0 ‐ 4, every 12 weeks, 64 weeks
Outcomes	Assessments at 12 weeks Primary outcomes of the trial PASI 75 Secondary outcomes of the trial Proportion of participants with PGA 0/1 at week 12 Change in DLQI from baseline at 12 weeks Improvement from baseline to week 12 through 64 in NAPSI and joint pain, as measured by the change in VAS
Notes	Funding source, Quote (p 242): "This study was supported by Janssen pharmaceutical KK, a part of the Johnson & Johnson family of companies. Declarations of interest (p 242): "Igarashi has served as a consultant and speaker for Janssen Pharmaceutical K.K.; H. Nakagawa has served as a consultant for Abbott Japan and Tanabe Mitsubishi, and as a consultant and speaker for Janssen Pharmaceutical K.K.; M. Song is an employee of Centocor Research & Development, Inc., a division of Johnson & Johnson Pharmaceutical Research & Development, L.L.C., and owns stock in Johnson & Johnson; T. Kato and M. Kato are employees of Janssen Pharmaceutical K.K. and own stock in Johnson & Johnson."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote (p 244): “randomised” Comment: no description of the method used to guarantee random sequence generation
Allocation concealment (selection bias)	Unclear risk	Quote (p 244): “randomised” Comment: no description of the method used to guarantee allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote (p 243): “double‐blind placebo‐control” Comment: used a placebo without visible side effect
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote (p 243): “double‐blind placebo‐control” Comment: used a placebo without visible side effect
Incomplete outcome data (attrition bias) All outcomes	Low risk	160 randomised, 157 analysed (2 did not received a dose of the drug and 1 was excluded in the placebo group due to lack of efficacy data after receiving a single dose) Methods for dealing with missing data Quote (p 244): “Efficacy analyses were based on all randomised patients with efficacy data after randomisation... Patients who discontinued the study... were considered as treatment failures” Comment: few lost at follow‐up, well‐balanced number and reasons between groups.
Selective reporting (reporting bias)	Unclear risk	Comment: no protocol was available The prespecified outcomes mentioned in the Methods section appeared to have been reported