Abstract
BACKGROUND: Guselkumab is a drug used to treat moderate to severe plaque psoriasis. However, real-life clinical data on its off-label use are limited, especially regarding the optimal drug dosage regimen for different patient profiles. OBJECTIVE: The main objective of this real-world, single-centre, retrospective study was to identify the off-label guselkumab dosing regimen used in clinical practice. The study also aimed to evaluate the drug's efficacy, safety, and survival, as well as the proportion of super-responders (SR) based on a newly proposed definition. METHODS: The study included 69 patients who started treatment with guselkumab between March 2019 and July 2021. Patients were followed up until April 2022, during which time their efficacy, safety, persistence, and use of guselkumab were recorded. Patients were aged ≥ 18 years and had moderate to severe plaque psoriasis. RESULTS: The mean disease duration was 18.6 years, and 59% of patients had received at least one biologic treatment before guselkumab with a mean of 1.3 biologics per patient. The initial absolute Psoriasis Area and Severity Index (PASI) was 10.1 and decreased to 2.1 between Week 11-20 without significant changes in the PASI value throughout the 90 weeks of follow-up. The cumulative probability of drug survival was 93.5% at Week 52. No differences were found in terms of efficacy and survival associated with the off-label drug dosage regimens compared to the doses described in the Summary of Product Characteristics (SmPC). The greatest adjustments in the drug administration regimen were achieved in the subgroups of bio-naïve and SR patients, with a reduction in the number of administrations by 40% and 47% compared to the regimen described in the SmPC. Super-response to guselkumab was mainly associated with patients naïve to previous biologic treatment. CONCLUSION: The study demonstrated that off-label use of guselkumab was safe and effective in real-life clinical practice. The findings suggest that adjustments to the drug administration regimen may be necessary to optimise its use in different patient profiles, especially in SR and bio-naïve patients. Further studies are needed to confirm these findings.