Humira: the impending patent battles over adalimumab biosimilars.

The world's top selling drug, adalimumab (AbbVie's Humira), generated sales in excess of US$13 billion in 2015. The primary product patent expires in 2016 in the USA and 2018 in Europe. This has resulted in a rush by companies to develop adalimumab biosimilars and Amgen submitted regulatory filings for its product ABP-501 in late 2015 in both the USA and Europe. AbbVie has claimed its patent portfolio provides product protection until 2022, but an increasing number of patent challenges are being made and the filings for approval of biosimilars will see more challenges made over the next few years.