BACKGROUND: 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. OBJECTIVES: 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.

Objectives: To describe trends in list prices, net prices, and discounts for selfadministered disease-modifying therapies (DMTs) for multiple sclerosis (MS) from 2007-2019. Methods: We obtained 2007-2019 pricing data for dimethyl fumarate, fingolimod, glatiramer acetate, interferon beta-1A, interferon beta-1B, peginterferon beta-1A, and teriflunomide from SSR Health, which provides quarterly estimates of list prices, net prices, and discounts in Medicaid and other payers for branded products manufactured by publicly traded companies. For each drug and year, we calculated average list and net annual costs of treatment based on FDA-approved dosing; and average discounts in Medicaid and other payers. Results: From 2007-2019, list prices of self-administered MS DMTs increased by 4.