AbbVie estimates Humira to generate global sales of $21 billion in 2020, higher than $18 billion, predicted previously in 2015. Several companies are working on biosimilar versions of Humira. Though Amgen's ( AMGN - Free Report ) Humira biosimilar received an FDA approval in September 2016, its launch is delayed to 2023 due to settlement of its patent dispute with AbbVie. This will make Humira free from competition for a few more years. Also, AbbVie has a robust intellectual property, which is expected to generate positive sentiments among the investors.