Comparisons of efficacy and cost-effectiveness of topical immunomodulators in the management of atopic dermatitis

Abstract

SUMMARYThe availability of new topical immunomodulators greatly improves treatment options for patients with atopic dermatitis (AD). Unfortunately, head-to-head studies have not been conducted to allow comparisons in treatment efficacy and cost-effectiveness. The study aims to compare the efficacy and cost-effectiveness of tacrolimus ointment and pimecrolimus cream as monotherapy for the treatment of AD patients with moderate disease, who are not responsive to or not well-controlled with topical corticosteroids. In the absence of head-to-head comparative data, relative treatment efficacy was estimated based on existing outcomes, which were reported in the published literature and data from clinical trials. Comparisons were made between Eczema Area and Severity Index (EASI) scores and converted to disease-controlled days (DCDs) on treatment. Other assumptions about resource utilization, changes in management and patient outcomes were based on opinions of a physician panel and from previously published reports. Medical resources costs were derived from fee schedules and product average wholesale prices (AWPs). A Markov model was developed to determine the cost-effectiveness ratios for each treatment. Sensitivity analyses were conducted for key variables to assess their impact on the results. Study designs and efficacy endpoints differed between tacrolimus and pimecrolimus clinical studies. In tacrolimus studies, a quantitative physician global assessment was performed, which tracked percentage improvement relative to baseline. In contrast, pimecrolimus studies relied on investigator global assessments scored on a Likert scale. Studies of both agents used the Eczema Area and Severity Index (EASI). A comparison of EASI scores for tacrolimus and pimecrolimus found that pimecrolimus was approximately 60% as efficacious as tacrolimus after 2 to 4 weeks of treatment. Based on these efficacy rates, average cost-effectiveness ratios were estimated at $7.34 per DCD for tacrolimus and $11.34 per DCD for pimecrolimus. Sensitivity analyses found that pimecrolimus would only be cost-effective if its efficacy approached 90% of tacrolimus efficacy or if the costs of the products were significantly different than current AWPs. Although head-to-head comparative studies have not been completed to date, there are likely to be differences in efficacy between topical immunomodulators. Based on published data, we estimate that the efficacy of pimecrolimus to be 60% of the efficacy of tacrolimus and therefore, tacrolimus to be more cost-effective for the treatment of moderate AD. Sensitivity analyses revealed that pimecrolimus cream would need to be 90% as efficacious as tacrolimus ointment in order to be cost-effective in this patient population.