PMS22 - MODELING THE BUDGET IMPACT OF AVAILABILITY OF BIOSIMILARS OF INFLIXIMAB AND ADALIMUMAB FOR TREATMENT FOR RHEUMATOID ARTHRITIS USING PUBLISHED CLAIM-BASED ALGORITHM DATA IN THE UNITED STATES

Abstract

FDA is reviewing biosimilars as first-line treatment of moderate-to-severe rheumatoid arthritis (RA) patients. We estimated the budget impact of availability of biosimilars of infliximab and adalimumab in the market by assessing the influence of differences in price, effectiveness, and market share between the original biologics and respective biosimilars. We simulated pre- and post-biosimilar scenarios to assess the impact of biosimilars on the cost per effectively treated patients with RA using a claims-based effectiveness algorithm. For pre-biosimilar scenario, we utilized data from a cohort of patients with RA aged 18-63 years in the IMS PharMetrics Plus database that assessed coverage of biologics including adalimumab, etanercept, golimumab, abatacept and infliximab. For the post-biosimilar basecase scenario, biosimilars of infliximab and adalimumab were included in the analysis for the same patient cohort assuming biosimilars’ market share and price discount at 30% and 25% respectively and no effectiveness deviation with respect to reference biologics. We estimated the impact on annual treatment costs and annual cost of treating a RA patient effectively. Effectiveness was defined based on adherence, medication switching, dose escalation, and treatment modifications in the algorithm. The introduction of biosimilars resulted in an annual cost saving of $6.1 million per 10,000 insured patients. The annual treatment cost per effectively treated patient reduced by 3.5% from $60,660 (pre-biosimilar) to $58,520 (post-biosimilar) for the basecase. One-way sensitivity analyses revealed the budget impact to be affected more by changes in market share and in price discounts of biosimilars, but less so by deviations in effectiveness. Budget impact of biosimilars will likely be driven by factors influencing market share growth, the cumulative price discounts achievable, and the rates of acceptance and adaptation of biosimilars by prescribers and patients. Each of these represents unique challenges for the various stakeholders.