The Delhi Patent Office lately rejected Gilead’s patent application no. 712/DEL/2002 for crystalline adefovir dipivoxil in a pre-grant opposition proceeding filed by Ranbaxy. Ranbaxy challenged the application on the grounds of: (1) the subject matter of the application is not novel, (2) the subject matter of the application lacks inventive step, (3) the invention has no utility, (4) the application could not have been filed under section 5(2) of the previous Act, (5) claims are indefinite, (6) no patent can be granted for a new form of a known substance, and (7) no patent can be granted for a composition. In its [decision], the Patent Office found application lacking inventive step and lacking comparative data with respect to known substance to prove improvement in the therapeutic efficacy. The decision was made on March 18, 2009. Adefovir dipivoxil is a diester prodrug of adefovir marketed by Gilead under the brand name Hepsera having therapeutic activity against human hepatitis B virus (HBV).