A Study to Evaluate the Efficacy and Safety of Bimekizumab in Study Participants With Palmoplantar Pustulosis

The purpose of this study is to evaluate the efficacy and safety of bimekizumab compared with placebo in participants with palmoplantar pustulosis (PPP).

Inclusion Criteria: * At least 18 years of age inclusive, at the time of signing the informed consent form (ICF) * Have a palmoplantar pustulosis (PPP) diagnosis for at least 24 weeks prior to the Screening Visit * Have PPPASI ≥12 at the Screening Visit and Baseline Visit * Have PPP-IGA ≥3 at the Screening Visit and Baseline Visit * Have pustules on the palms of the hands and/or soles of the feet at the Screening Visit and Baseline Visit, defined as pustule severity ≥2 and having more than 5 active pustules * Participant must be a candidate for systemic therapy or phototherapy Exclusion Criteria: * Has PPP symptoms which improve significantly between the Screening Visit and Baseline Visit, defined as a reduction in the PPPASI score * Has the following: palmoplantar PSO (plaque PSO on palms/soles), guttate PSO, erythrodermic PSO (EP), generalized pustular PSO (GPP), Acrodermatitis continua of Hallopeau (ACH), atopic dermatitis, dyshidrotic eczema or chronic hand eczema. * Has drug-induced PSO (eg, first onset or current exacerbation due to beta blockers, calcium channel inhibitors, lithium, or tumor necrosis factor \[TNF\] inhibitor) or drug-induced pustular PSO (eg, acute generalized exanthematous pustulosis, acute localized exanthematous pustulosis) * Has cutaneous lesions that may interfere with the evaluation of the affected area and/or evaluation of the severity of PPP * Is taking or has taken prohibited or restricted medications without meeting the mandatory discontinuation or stability period relative to the Baseline Visit * Is taking or has ever taken an interleukin (IL)-17A/IL-17F inhibitor, including bimekizumab, or has participated in a bimekizumab investigational study