Efficacy and safety of guselkumab and adalimumab for pustulotic arthro-osteitis and their impact on peripheral blood immunophenotypes.

Objectives: We compared the treatment effectiveness between guselkumab and adalimumab in patients with pustulotic arthro-osteitis (PAO). In addition, we performed peripheral blood immunophenotyping to elucidate the immunological background and analyzed the impact of therapeutic drugs to verify the validity of immunological phenotypes as therapeutic targets.

Methods: Patients were treated with guselkumab 100 mg (guselkumab group; n = 12) and adalimumab 40 mg (adalimumab group; n = 13). Arthritis disease activity, skin lesion activity, and patient-reported outcomes (PROs) were evaluated and compared between the two groups. The retention rate and adverse events were evaluated. Comprehensive phenotyping of peripheral immune cells was performed in both groups, and phenotypes were compared before and after treatment.

Results: At 6 months, both groups showed significant improvement in arthritis disease activity and PROs. In the guselkumab group, skin symptoms significantly improved. The 6-month continuation rates were 91.7% (11/12) and 69.2% (9/13) in the guselkumab and adalimumab groups, respectively. Adverse events occurred in 2/12 and 5/13 patients in the guselkumab (16.7%) and adalimumab (38.5%) groups, respectively. Peripheral blood immunophenotyping showed that the proportion of activated T helper (Th) 1 cells was significantly lower in patients with PAO than in healthy controls and that the proportion of activated Th17 cells was significantly higher in patients with PAO, which significantly decreased after treatment with guselkumab.

Conclusion: Although guselkumab and adalimumab have comparable efficacy for PAO, their impact on immunophenotypes varies.