Cost per responder of TNF-α therapies in Germany.

Tumor necrosis factor α (TNF-α) inhibitors ranked highest in German pharmaceutical expenditure in 2011. Their most important application is the treatment of rheumatoid arthritis (RA). Our objective is to analyze cost per responder of TNF-α inhibitors for RA from the German Statutory Health Insurance funds' perspective. We aim to conduct the analysis based on randomized comparative effectiveness studies of the relevant treatments for the German setting. For inclusion of effectiveness studies, we require results in terms of response rates as defined by European League Against Rheumatism (EULAR) or American College of Rheumatology (ACR) criteria. We identify conventional triple therapy as the relevant comparator. We calculate cost per responder based on German direct medical costs. Direct clinical comparisons could be identified for both etanercept and infliximab compared to triple therapy. For infliximab, cost per responder was 216,392 euros for ACR50 and 432,784 euros for ACR70 responses. For etanercept, cost per ACR70 responder was 321,527 euros. Cost was lower for response defined by EULAR criteria, but data was only available for infliximab. Cost per responder is overestimated by 40% due to inclusion of taxes and mandatory rebates in German drugs' list prices. Our analysis shows specific requirements for cost-effectiveness analysis in Germany. Cost per responder for TNF-α treatment in the German setting is more than double the cost estimated in a similar analysis for the USA, which measured against placebo. The difference in results shows the critical role of the correct comparator for a specific setting.