Uptake of tumour necrosis factor-alpha inhibitor biosimilars for psoriasis: a drug utilization study from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR).

BACKGROUND: Tumour necrosis factor-alpha inhibitors (TNFi) have revolutionized the treatment of moderate-to-severe psoriasis. Following patent expiry of the originator biologics, TNFi biosimilars became available, presenting the opportunity for significant reductions in drug costs. OBJECTIVES: To describe the uptake of TNFi biosimilars for psoriasis treatment in the UK and Ireland. METHODS: This observational cohort study utilizes data from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR), a national pharmacovigilance study register for patients with psoriasis on systemic treatments. We analysed biosimilar uptake trends over time in nine geographical regions of England along with Wales, Scotland, Northern Ireland and the Republic of Ireland. We assessed the incidence of switching to biosimilars in an originator-user cohort (switchers). Patients on originators infliximab, etanercept and adalimumab at the time originator patents expired, entered the cohort on 1 February 2015, August 2015 and October 2018, respectively, and were followed up until 31 October 2021. Trends in biosimilar initiations were assessed in an adalimumab-naïve cohort who started adalimumab between 1 October 2018 and 31 July 2019 (starters). We assessed the associations between patient factors and originator-to-biosimilar switching and biosimilar initiation using a multivariable Cox regression model and a multivariable logistic regression model, respectively. RESULTS: Included in the originator-user cohort were 4202 patients (209 on infliximab, 742 on etanercept and 3251 on adalimumab). For infliximab, etanercept and adalimumab, respectively, the cumulative incidence of originator-to-biosimilar switching increased with time to 14.8%, 23.6% and 66.6% after 3 years. Across geographical regions, 3-year switching rates varied from 0% to 43.7% for infliximab; from 0% to 40.4% for etanercept; and from 12.5% to 84.3% for adalimumab. Out of the 528 patients included in the adalimumab-naïve cohort, 67.8% started on biosimilars. Originator-to-biosimilar switching and biosimilar initiation were more common in men and in patients who had lower Psoriasis Area and Severity Index at cohort entry. CONCLUSIONS: The uptake of biosimilars increased over time and varied considerably across the UK and Ireland; adalimumab had the highest biosimilar uptake rate compared with that of other TNFi drugs.

Biosimilars for the Treatment of Psoriasis: A Systematic Review of Clinical Trials and Observational Studies.

Importance: Biosimilars have the potential to reduce costs for the management of moderate-to-severe psoriasis compared with originators. However, the extrapolation of evidence enables the approval of a biosimilar for use in indications held by the originator without directly being studied in clinical trials. Thus, biosimilars can be approved for psoriasis based on extrapolated evidence from other diseases. The availability of evidence for the effectiveness and safety of biosimilars for the treatment of psoriasis is therefore unclear. Objective: To compare the efficacy/effectiveness and safety of biosimilars with originator biologics for the treatment of patients with psoriasis. Evidence Review: MEDLINE, EMBASE, Cochrane Library, ClinicalTrials.gov, and The European Union Clinical Trials Register were searched in August 2022. Eligible studies were appraised using the Cochrane Risk of Bias 2 and ROBINS-I tools. All analyses were conducted from September 2022 to November 2022. Findings: Fourteen trials (10 adalimumab, 2 etanercept, 1 infliximab, and 1 ustekinumab) and 3 cohort studies (1 adalimumab, 1 etanercept, 1 infliximab and etanercept) were included. Twelve trials compared biosimilars with originators in originator-naive patients (starters), and 11 trials compared switching from originator to biosimilar (switchers) with continuous originator treatments. There was no clinically or statistically significant difference in rates of achieving 75% improvement in Psoriasis Area and Severity Index scores and risks of adverse events (AEs) at week 16 and week 52 between the comparators. Two cohort studies showed no difference in effectiveness and safety outcomes between originators and biosimilars, whereas 1 study reported more AEs in patients who switched to biosimilars of adalimumab at 12 months. Three trials showed low risk of bias, whereas 11 trials had moderate risk of bias. All cohort studies had moderate to high risk of bias. Conclusions and Relevance: In this systematic review, there was no clinically or statistically significant difference in the efficacy and safety between biosimilars and originators for the treatment of patients with psoriasis. Most of the available evidence was based on randomized clinical trials, although high-quality real-world evidence was lacking. Future studies are needed to examine the long-term effectiveness and safety of biosimilars for the treatment of patients with psoriasis.

Drug survival and safety of biosimilars and originator adalimumab in the treatment of psoriasis: a multinational cohort study.

INTRODUCTION: Psoriasis is a chronic inflammatory skin disease. Adalimumab is an effective but previously expensive biological treatment for psoriasis. The introduction of biosimilars following the patent expiry of the originator adalimumab Humira has reduced the unit cost of treatment. However, the long-term effectiveness and safety of adalimumab biosimilars for treating psoriasis in real-world settings are uncertain and may be a barrier to widespread usage. METHODS AND ANALYSIS: This study aims to compare the drug survival and safety of adalimumab biosimilars to adalimumab originator for the treatment of psoriasis. We will use both routinely collected healthcare databases and dedicated pharmacovigilance registries from the PsoNet initiative, including data from the UK, France and Spain. We will conduct a cohort study using a prevalent new user design. We will match patients on previous adalimumab exposure time to create two equal-sized cohorts of biosimilar and originator users. The coprimary outcomes are drug survival, defined by the time from cohort entry to discontinuation of the drug of interest; and risk of serious adverse events, defined by adverse events leading to hospitalisation or death. Cox proportional hazards models will be fitted to calculate HRs as the effect estimate for the outcomes. ETHICS AND DISSEMINATION: The participating registries agree with the Declaration of Helsinki and received approval from local ethics committees. The results of the study will be published in scientific journals and presented at international dermatology conferences by the end of 2023.