The drug adalimumab, also known as blockbuster drug Humira, manufactured by AbbVie, is set to go off patent in the US in January 2023. With revenue peaking at 20.8 billion dollars in 2021, Humira is considered to be the world's top selling drug and has held that status for the past 8 years. Humira has generated a revenue total of 200 billion dollars over the years, since its release to the market in 2002.

To deter competition with its top seller drug, AbbVie sought to obtain as many patents as it could. Some of the patents claimed Humira, its uses, or its manufacturing processes. Other patents included ingredients, formulations, and/or processes that AbbVie did not use, but which an innovative biosimilar company might employ to make a competitor to Humira. AbbVie sought to patent the entire field of Humira biosimilars so as to foreclose any possible competition. In order to protect Humira's largest market- the US, AbbVie had arranged settlements with 8 manufacturing companies, allowing them to release their biosimilars in the EU in 2018, yet restraining them from releasing in the US until a designated date in 2023.

The first settlement closed was with Amgen regarding their biosimilar Amgevita. AbbVie agreed not to settle with any other manufacturers on terms that would let them enter the market at the same time as Amgen, or for five months thereafter, thus ensuring Amgen with Humira biosimilar exclusivity for the first five months it is on the market. The potential worth of these exclusive five months could mount up to several billions of dollars for Amgen, simply for withholding their version of Humira.

The other settlements that were made also allowed the release of the biosimilars in the EU market in 2018. However, the release date in the US market differs from one settlement to the next. With each settlement closed, the release date was pushed back by a few months, guarantying the former settler a few months of market exclusivity, along with the companies who have made an agreement with AbbVie beforehand.
In this manner, AbbVie had gained complete control over the adalimumab market, merging generics gradually into the market, allowing AbbVie to manipulate their prices and marketing strategies to suit the market they have constructed.

Sample pricing data: US tender (Humira)  vs. Germany (Amgevita)