The Delhi Patent Office has lately ruled against Pfizer in pre-grant opposition [download] filed by Torrent Pharma Ltd. against the patent application no. 2571/DEL/1998 for therapeutic combination of amlodipine and atorvastatin. The combination is marketed as Caduet by Pfizer and has US Patent No. 6,455,574 listed with Orange Book. The Delhi Patent Office rejected the application on grounds of (1) lack of inventive step under section 25 (1) (e), (2) not patentable under section 25(1)(f) and (3) insufficiency of description under section 25(1)(g). The application is also found not patentable under section 3(d) (lack of enhanced efficacy) and 3(e) (lack of synergy).