Humira: the first $20 billion drug.

AbbVie's adalimumab (Humira) is the top-selling pharmaceutical in the world. Due to concerns about government health program spending on Humira, the US House Committee on Oversight and Accountability opened an investigation in 2019 to investigate AbbVie's pricing and marketing practices. We review these reports and describe policy debates surrounding the highest-grossing drug to highlight how the legal landscape enables incumbent manufacturers to block competition in the pharmaceutical market. Tactics include patent thickets, evergreening, Paragraph IV settlement agreements, product hopping, and linking executive compensation to sales growth. These strategies are not unique to AbbVie and shed light on pharmaceutical market dynamics that may be hindering a competitive market. Policy reform and legal initiatives may help reduce anticompetitive behaviors by pharmaceutical manufacturers and increase access to competitive therapeutic options such as biosimilars.