Treatment of Severe Palmoplantar Pustular Psoriasis With Bimekizumab

Importance: Palmoplantar pustulosis (PPP) and palmoplantar plaque psoriasis with pustules remain challenging to treat. Studies suggest that an interleukin 17 or interleukin 36 loop acts synergistically in these diseases to induce palmoplantar pustules. Objective: To assess the effectiveness of bimekizumab in treating PPP and palmoplantar plaque psoriasis with pustules. Design, Setting, and Participants: This case series involved 21 adults with PPP (11 patients) or palmoplantar plaque psoriasis with pustules (10 patients) treated at 1 of 7 tertiary dermatological centers in France from September 2022 through June 2023. All patients treated with bimekizumab for at least 3 months were included in the analyses. Main Outcomes and Measures: The main outcome was the posttreatment Investigator Global Assessment (IGA), scored as 0 (complete clearance), 1 (almost clear), 2 (mild), 3 (moderate), or 4 (severe). When relevant, evolution of joint pain and nail involvement was reported. Tolerance and potential adverse events were noted. Results: A total of 21 patients (mean [range] age, 46 [24-68] years; 19 females) were included. Eleven patients had isolated PPP, and 10 had palmoplantar plaque psoriasis with pustules. All of them, except 2 who received bimekizumab as first systemic therapy, had not responded to at least 1 systemic treatment (median [range], 3 [1-7] treatments), and/or had adverse events leading to the discontinuation of the treatment. Complete clearance (IGA score, 0) was achieved by 17 patients in 1 to 4 months. Three patients achieved an IGA score of 1, and 1 achieved an IGA score of 2. Three patients with PPP also presented with acrodermatitis continua of Hallopeau. Nail involvement showed 50% to 70% improvement after 4 to 6 months of bimekizumab treatment for these 3 patients. Two patients had SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome; both had complete clearance of skin lesions associated with joint pain improvement. Four patients (19%) with candidiasis were successfully treated with oral antifungal agents. None of the patients had to stop bimekizumab treatment due to adverse events. Conclusions and Relevance: The findings of this case series suggest that bimekizumab could be an appealing approach for treating PPP, palmoplantar plaque psoriasis with pustules, and SAPHO syndrome. Prospective randomized placebo-controlled clinical trials are needed to confirm these encouraging initial results.