Trends in list prices, net prices, and discounts of self-administered injectable tumor necrosis factor inhibitors.

List prices of tumor necrosis factor (TNF) inhibitors drastically increased during the last decade, but previous research has shown that half of these increases were offset by rising manufacturer discounts. It remains unclear to what extent manufacturers' discounts have offset increases in list prices of each self-administered injectable TNF inhibitor. Evaluating trends in net prices and discounts at the product level will be paramount in understanding the role of competition in the biologic market. To (a) describe product-level changes in net prices of each self-administered injectable TNF inhibitor available in 2007-2019 and (b) quantify to what extent manufacturer discounts have offset increases in list prices. We obtained 2007-2019 pricing data for etanercept, adalimumab, certolizumab, and golimumab from the investment firm SSR Health, which uses company-reported sales to estimate net prices and discounts for brand products manufactured by publicly traded companies. For each drug and year, we calculated annual costs of treatment for patients with rheumatoid arthritis based on list and net prices and discounts in Medicaid and other payers. From 2007-2019, list prices of etanercept and adalimumab increased by 293% and 295%, respectively; however, discounts offset 47% and 45% of these increases, leading to net price increases of 171% and 203%. List prices of golimumab and certolizumab increased by 183% and 182%, respectively, but with discounts offsetting 58% and 59% of these increases, net prices increased by 103% and 109%. Net prices of golimumab started to decrease after 2016, while net prices of adalimumab and certolizumab experienced their first drop in 2019. Across the study period, discounts in Medicaid and in other payers increased, respectively, from 21% to 85% and 6% to 32% for etanercept; from 26% to 88% and 19% to 35% for adalimumab; from 28% to 63% and 22% to 46% for golimumab; and from 29% to 83% and 27% to 47% for certolizumab. Despite growing manufacturer discounts, net prices of self-administered injectable TNF inhibitors still increased at a mean annual rate of 9.6% in 2007-2019. This led to net prices tripling for adalimumab and more than doubling for etanercept, golimumab, and certolizumab. This study was funded by the Myers Family Foundation. Hernandez is funded by the National Heart, Lung and Blood Institute (grant number K01HL142847). Funding sources had no role in design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. Hernandez has served on Pfizer's scientific advisory board. The other authors have nothing to disclose.