OBJECTIVES:

Rheumatoid arthritis (RA) as a chronic autoimmune disease is correlated with a substantial economic burden. Whilst, conventional synthetic DMARDs such as methotrexate (MTX) are often the first-line treatments of RA, about one-third of RA patients are gone to an add-on therapy with biologic DMARDs due to lack of responsiveness or severe adverse effects of MTX. Anti TNF-alpha biologic DMARDs like Adalimumab (ADL) and anti-IL6 Tocilizumab (TCZ), are often prescribed for MTX intolerant patients. In this study we aimed to evaluate the cost-utility of TCZ compared to ADL in MTX intolerant, biologic naïve RA patients.

METHODS:

An individual microsimulation Markov model was developed to compare TCZ with ADA over a lifetime horizon. Treatment efficacy was estimated based on American College of Rheumatology [ACR] response improvement criteria in 24 weeks. ACR responses caused changes in the Health Assessment Questionnaire (HAQ) score. Then, HAQ scores were mapped onto utility values to calculate outcomes in terms of QALYs. Direct medical costs were taken from national databases. Uncertainty in model parameters was evaluated by sensitivity analyses Costs and outcomes are discounted at 7.2% and 5%, respectively.

RESULTS:

Over a life time horizon, TCZ was more costly than adalimumab (17578 USD versus 16914 USD). Nevertheless, tocilizumab is more effective than adalimumab (QALY of 4.42 versus 4.25). Incremental cost-effective ratio (ICER) is approximately 3905 USD per QALYs gained that is lower that Iranian threshold (1 GDP/capita in Iran: 4200 $) . The results of sensitivity analysis demonstrated that the model is mostly sensitive to the price of TCZ, price of ADL, and probability of no response to ADL.

CONCLUSIONS:

Since the calculated ICER is below the accepted cost-effectiveness threshold, TCZ (162 mg pre-filled syringe) is considered as the cost-effective strategy.