NCT02641730 Guselkumab.

Methods	Randomized, double‐blind, placebo‐controlled study Thirty‐three centres in Japan Period of inclusion: January 2016 to January 2018
Participants	Inclusion criteria of the trial Diagnosis of palmoplantar pustulosis (with or without pustulotic arthro‐osteitis, concurrent extra‐palmoplantar lesions) for at least 24 weeks before screening PPPASI total score ≥ 12 at screening and at baseline Moderate or more severe pustules/vesicles on the palms or soles (≥ 2 PPPASI severity score) at screening and at baseline Inadequate response to treatment with topical steroid and/or topical vitamin D3 derivative preparations and/or phototherapy and/or systemic etretinate before or at screening. Inadequate response is defined as a case judged by the investigator Before first administration of study drug, a woman must be not of childbearing potential; premenarchal; postmenopausal; or of childbearing potential and practicing a highly effective method of birth control Twenty years of age or older Exclusion criteria of the trial Diagnosis of plaque‐type psoriasis Obvious improvement during screening (≥ 5 PPPASI total score improvement during screening) History or current signs or symptoms of severe, progressive, or uncontrolled renal, cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurological, haematological, rheumatological, psychiatric, or metabolic disturbances Unstable cardiovascular disease, defined as recent clinical deterioration (e.g. unstable angina, rapid atrial fibrillation) in the last 12 weeks or cardiac hospitalisation within the last 12 weeks before screening Currently with malignancy or with a history of malignancy within 5 years before screening (with the exception of a non‐melanoma skin cancer that has been adequately treated with no evidence of recurrence for at least 12 weeks before screening, or cervical carcinoma in situ that has been treated with no evidence of recurrence for at least 12 weeks before screening) Baseline data: participants were randomised to placebo (n = 53) or guselkumab 100 mg (n = 54) or guselkumab 200 mg (n = 52) for up to 16 weeks Mean age, years: 53/54/52 Male/female: 9/44, 8/46, 16/36 Mean PPPASI score: not specified Total pustule count: not specified Proportion of participants with psoriatic lesions elsewhere: not specified Withdrawal: placebo n = 2 (adverse event n = 2); guselkumab 100 n = 1 (adverse event n = 1); guselkumab 200 n = 2 (adverse event n = 2)
Interventions	Intervention 1 A: guselkumab 200 mg at weeks 0, 4, 12 Intervention 2 B: guselkumab 100 mg at weeks 0, 4, 12 Intervention 3 C: placebo at weeks 0, 4, and 12 At week 16, placebo participants will be randomised in a 1:1 ratio to guselkumab 200 mg arm or 100 mg arm for 44‐week open‐label extension
Outcomes	Primary outcome Change from baseline in Palmo‐Plantar Area and Severity Index (PPPASI) total score at week 16. The PPPASI is a system used for assessing and grading the severity and area of palmoplantar pustulosis lesions and their response to therapy. The PPPASI produces a numerical score that can range from 0 to 72. Higher score indicates worsening Secondary outcome Change from baseline in Palmo‐Plantar Severity Index (PPSI) total score at week 16. The PPSI assesses the severity of palmoplantar pustulosis lesions and their response to therapy with a score ranging from 0 to 12. Higher score indicates worsening Percentage of participants who achieve a PPPASI of 50 at week 16
Notes	Funding: Janssen Pharmaceutical K.K.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomised" Comment: results from clinicaltrials.gov, which give no methodological details
Allocation concealment (selection bias)	Unclear risk	Quote: "randomised" Comment: results from clinicaltrials.gov, which give no methodological details
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "double blind" Comment: results from clinicaltrials.gov; no methodological details but placebo‐controlled, so assumed blinding of participants and personnel was probably done
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "double blind" Comment: results from clinicaltrials.gov; no methodological details but placebo‐controlled, so assumed blinding of outcome assessment was probably done
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised participants were analysed. Missing data were imputed or 'last observation carried forward' was considered
Selective reporting (reporting bias)	High risk	Percentage of participants who achieved a PPPASI‐50 response at week 16 was one of the outcomes described in study details, and this outcome was reported for 12 and 20 weeks but not for 16 weeks