When does the patent on Humira expire?

Answer 1

According to the link shown below, the United States Patent and Trademark Office lists the expiration date as October 23, 2012.

http://www.fda.gov/OHRMS/DOCKETS/dailys/04/july04/071504/99e-1086-let00003-vol1.pdf

Answer 2

Humira has been on the market for eight years now, so it has about 12 years to go on it's initial patent.