Humira

Drug: Humira
Company: AbbVie
Use: Arthritis, ankylosing spondylitis, Crohn's disease
Amount spent on doctor payments: $5.58 million

Humira raked in $11.02 billion last year, topping the list of the world's best-selling drugs. But AbbVie ($ABBV) could face a few obstacles after its patent expires in 2016. Humira already has a biosimilar challenger in India from Zydus Cadila. Novartis' ($NVS) Sandoz unit and Boehringer Ingelheim are working on their own versions of the drug. AbbVie needs to get as many patients onto its brand as possible before biosimilars make their debut and start eating away market share. With its broad array of approved uses, AbbVie can send out doctor-speakers to talk up the latest on the drug.

But even in light of new competition, Humira is slated to remain the biggest global brand in the market in the years ahead. Approved to treat rheumatoid arthritis, Crohn's disease and ulcerative colitis, Humira posted double-digit sales leaps for the company during last year's first three quarters. Evaluate Pharma forecasts that the drug will bring in $12.7 billion in 2020--a 15% increase from 2013.

Meanwhile, AbbVie continues to prime its new all-oral hep C regimen Viekira Pak to take the sting out of any lost sales after the end of Humira's blockbuster reign. Analysts expect $3 billion for the drug, which competes head-to-head with Gilead's ($GILD) own blockbuster-in-the-making, Harvoni. -- Emily Wasserman (email | Twitter)

For more:
Special Report: The 10 best-selling drugs of 2013 - Humira
Generics could sink AbbVie below analysts' 2015 estimates
AbbVie needs more than its hep C nod to backfill Humira's looming patent loss
AbbVie's Humira competition begins with Cadila's biosimilar launch in India

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