Background: Psoriasis is a chronic, incurable, and immune-mediated skin disorder that is characterized by erythematous scaly papules and plaques. Understanding of psoriasis at the molecular level has led to the development of biologic agents that target disease-specific inflammatory mediators in psoriatic lesions. Biologic agents have become important components of the psoriasis armamentarium, but some patients become refractory to these agents over time or fail to respond to subsequent biologics.
Objectives: To (a) evaluate demographic and clinical characteristics of psoriasis patients who have treatment patterns suggestive of failure to a newly initiated biologic agent (treatment-regimen failures) compared with those who do not (non-treatment-regimen failures) and (b) to assess health care-related resource utilization and costs in non-treatment-regimen failures and treatment-regimen failures.
Methods: In this retrospective observational cohort study, patients were selected from the MarketScan claims database of commercially insured individuals and individuals with Medicare supplemental insurance. The index event was a newly initiated biologic agent for the treatment of psoriasis (etanercept, adalimumab, ustekinumab, or infliximab) between January 2010 and December 2011. The analysis included psoriasis patients aged ≥ 18 years with ≥ 1 prescription claim for a biologic and continuous enrollment 12 months pre- and post-index date. Patients with claims for a biologic in the pre-index period were excluded. Patients were divided into treatment-regimen-failure and non-treatment-regimen-failure groups based on their treatment patterns post-index date. The treatment-regimen-failure group included patients who switched to another biologic, discontinued the biologic without restarting, increased the dose of the biologic, or augmented treatment with a nontopical psoriasis medication during the post-index period. Between-group patient characteristics and medication use were compared using analysis of variance for continuous variables and chi-square tests for categorical variables without adjustment. Cost differences were compared using the propensity score-adjusted bin bootstrapping method.
Results: Overall, 2,146 patients met the enrollment criteria. The mean age was 45.1 years. Of these patients, 41.5% were considered treatment-regimen failures. Among treatment-regimen failures, 53% were females, and among non-treatment-regimen failures, 61% were male. Patients who experienced treatment-regimen failure had higher incidences of comorbid cerebrovascular disease, hypertension, chronic pulmonary disease, depression, and anxiety in the pre-index period and were more likely to use concomitant topicals (67.0% vs. 58.4%; P < 0.001), methotrexate (20.2% vs. 7.3%; P < 0.001), and cyclosporine (3.1% vs. 1.0%; P < 0.001) in the post-index period. Mean total all-cause health care costs were higher in patients with treatment-regimen failure versus non-treatment-regimen failure during the pre-index period ($8,024 vs. $6,637; P = 0.002), but patients with non-treatment-regimen failure had higher all-cause costs ($30,759 vs. $28,012; P = 0.002) and psoriasis-related costs ($25,286 vs. $19,625; P < 0.001) during the post-index period.
Conclusions: The results of the current study demonstrated that psoriasis patients with treatment patterns suggestive of treatment-regimen failure on an index biologic had different characteristics and incurred higher all-cause health care costs than did patients without treatment-regimen failure during the pre-index period. This study was supported by Eli Lilly and Company. Foster, Zhu, Guo, Nikai, Malatestinic, Ojeh, and Goldblum are full-time employees and stockholders of Eli Lilly and Company. Kornberg is a full-time employee of INC Research, which was contracted by Eli Lilly to assist with medical writing. Wu has received research funding from AbbVie, Amgen, Coherus Biosciences, Eli Lilly, Janssen, Merck, Novartis, Pfizer, Regeneron, and Sandoz; he is a consultant for AbbVie, Amgen, Celgene, Dermira, DUSA Pharmaceuticals, Eli Lilly, and Pfizer. Study concept was developed by Foster, Ojeh, Malatestinic, and Goldblum. Zhu and Guo, along with Foster, took the lead in data collection, and data interpretation was performed by Nikai, Wu, and Foster, with assistance from the other authors. The manuscript was primarily written by Kornberg, along with Foster, with assistance from the other authors. All of the authors were involved with manuscript revision.