11. Enbrel

Closeup view of hand holding a prefilled syringe of Amgen drug Enbrel
Enbrel posted $6.37 billion in 2020 sales, down from $7.2 billion during the prior year. (Amgen)

2020 sales: $6.37 billion
Diseases: rheumatoid arthritis, plaque psoriasis, psoriatic arthritis, ankylosing spondylitis and juvenile idiopathic arthritis 

Even as Amgen posted a big revenue increase in 2020, its top drug—immunology blockbuster Enbrel—didn't fare as well.

Thanks in part to a pandemic-hit rheumatology market, the medicine's sales slipped to $6.37 billion, down from $7.2 billion during the prior year. The performance came as Amgen as a whole posted $25.4 billion in 2020 revenues, a 9% increase.

Aside from the pandemic's negative effect on Enbrel, Amgen also realized a lower net selling price for the key med last year as payers squeezed out bigger discounts for favorable formulary access. Amgen expects volume and price declines on Enbrel to continue into 2021, according to the company’s annual report.

RELATED: With sales on the upswing, Amgen CEO Bradway scores a $20M pay package for 2020

Amid those challenges, though, Enbrel scored a big patent win last year. In a case against Novartis' Sandoz, the U.S. Federal Appeals Court upheld a 2019 ruling from the New Jersey District Court that pushes Enbrel's patent protections into the late 2020s. 

Sandoz and Samsung Biologics already have FDA approvals for their copycats but haven't been able to launch due to Enbrel's patent protections. If Amgen had lost the case, it'd be staring down early copycats to its top medicine.

RELATED: The top 20 pharma companies by 2020 revenue

Looking forward, as drug pricing threats resurface in Washington, Amgen executives have laid out a strategy to boost the company's revenues by growing volumes. But last year, a Congressional probe found that Amgen repeatedly raised prices on Enbrel to meet financial targets. The company, plus other drugmakers, worked to stifle competition to keep their hold on the market, a congressional committee said in October.

Early this year, Amgen CEO Robert Bradway said the company was excited to work with the Biden Administration on “both sides of the aisle” on healthcare and drug pricing issues.

11. Enbrel