On Oct. 18, 2006, ICOS announced it had signed an agreement to be acquired by Eli Lilly and Company. ICOS and Lilly had a joint venture that manufactured, marketed and sold ICOS’ leading product, Cialis, which treats erectile dysfunction. On Jan. 29, 2017, Eli Lilly announced it had completed its acquisition of ICOS Corp. for $2.3 billion or $34 per share.

ICOS was founded in 1991 by David and Isaac Blech, Robert Nowinski, Christopher Henney, and George Rathmann. The company was focused on discovering, developing and commercializing treatments for inflammation and other serious diseases. On Nov. 21, 2003, Cialis (tadalafil), a PDE5 inhibitor discovered through a Glaxo Wellcome (GlaxoSmithKline) ICOS partnership, was approved by the FDA for treating erectile dysfunction (ED) under the name trade name Cialis.