Pfizer’s patent US No. 6,469,012 relates to its best selling drug “Viagra”. Following patent infringement claims by Pfizer against Eli Lilly, Lilly ICOS (makers of “Cialis”) and Bayer (maker of “Levitra”) had sought for re-examination of Pfizer’s ‘012 Patent.
The claim that is said to cover both “Levitra” and “Cialis” is claim 24.
24. A method of treating erectile dysfunction in a male human, comprising orally administering to a male human in need of such treatment an effective amount of a selective CGMP PDE sub-v inhibitor, or a pharmaceutically acceptable salt thereof, of a pharmaceutical composition containing either entity.