The drug: Humira
The companies: Abbott Laboratories/Eisai
Estimated worldwide sales 2012: $9.48 billion

Abbott Laboratories ($ABT) has a lot riding on Humira. The company is spinning off its pharmaceuticals division, and the new company's centerpiece will be none other than the anti-inflammatory drug. Good thing it is poised to become the top-selling drug in the world.

The drug accounted for $7.9 billion of Abbott's 2011 sales, up from $6.5 billion in 2010 and $5.5 billion the year before that. Approved in 2003 for rheumatoid arthritis, Humira has taken billion-dollar leaps with help from a series of new indications: psoriatic arthritis, ankylosing spondylitis, plaque psoriasis, Crohn's disease, and now, ulcerative colitis.  In early October, the FDA approved that 7th indication, in a chronic disease that affects some 620,000 patients in the U.S. Analysts say the ulcerative colitis use could add another $500 million or more to Humira sales.

As that spinoff nears, the company is circling the wagons in an effort to protect Humira from biosimilars. Abbott filed a citizen's petition to hold off copycat versions, claiming FDA would need access to Abbott trade secrets to determine whether those copies were properly rendered. As a bonus legal argument, Abbott also claimed that FDA shouldn't approve copies of any biologic drug approved before biosimilars legislation passed in 2010.

For more:
New use for Humira delayed as Abbott preps for spinoff
Abbott tries to throw up roadblock to Humira biosim
Humira sales leap helps power Abbott earnings
Abbott prevails as Supremes pass on J&J patent suit