Pharmacoeconomic analysis of biological treatments for psoriatic arthritis

Psoriatic arthritis is an inflammatory and possibly destructive form of arthritis; left untreated, psoriatic arthritis can be a progressively disabling disease. The arthritic manifestations often include debilitating disease of the hands and feet, as well as painful inflammation of the tendon insertions and arthritis of the spine. The most common treatments prescribed for the psoriatic arthritis are nonsteroidal anti-inflammatory drugs (NSAIDs), COX-2 inhibitors, corticosteroids and disease-modifying antirheumatic drugs (DMARDs). Due to a recently suggested role of the tumour necrosis factor (TNFα) in the pathogenesis of psoriatic arthritis, new therapies specifically blocking TNFα have been investigated. Aim of the present study is to compare cost/effectiveness (CEA) and cost/utility (CUA) ratios of anti-TNF medications currently available on the Italian market: etanercept, infliximab and adalimumab. The evaluation was conducted through the development of a single Markov model. Clinical data were obtained from three Phase III trials attesting the clinical efficacy of the biological therapies. Both cost/effectiveness and cost/utility analysis were implemented through the deterministic evaluation and the probabilistic evaluation, in order to assess the convenience for the Italian National Healthcare Service. Adalimumab appears to be cost effective for the treatment of psoriatic arthritis, especially considering the incremental cost/effectiveness ratio (ICER) and the incremental cost/utility ratio (ICUR); the results suggest that ICER and ICUR values of adalimumab over etanercept is definitely lower than the maximum acceptable willingness-to-pay value. Moreover, compared with infliximab, adalimumab is less costly and more effective.