California-based Biotech Company Gilead Science Inc. has lately lost crucial pre-grant opposition [download] for its anti-influenza drug Oseltamivir Phosphate marketed as Tamiflu. The Delhi Patent Office decided the pre-grant opposition in favor of Cipla Ltd. after it found that the applicant (Gilead) failed to provide any supportive evidence in the specification by means of comparative data or by way of examples which would have supported the inventive merit of Oseltamivir. The Delhi Patent Office particularly relied on the decision of European Board of Appeal (T-0133/01) stating that alleged but unsupported advantages cannot be taken into consideration in respect of the determination of the problem underline the claimed invention. The Delhi Patent Office also found anti-influenza agent Oseltamivir to fall within the provisions of section 3(d) and not patentable. Tamiflu is marketed by Roche in India and in 2005 entered into sub-license agreement with Hyderabad-based Hetero Drugs for the production of oseltamivir.