The Indian Patent Office has denied Gilead Science Inc. patent rights for its anti-influenza drug oseltamivir phosphate marketed as Tamiflu, in India.
India’s generic firm Cipla Ltd had earlier opposed granting of patents rights to Gilead’s Tamiflu did not have inventive step – a pre-requisite for products to gain patents in India.
The Mumbai-based Cipla filed a pre grant opposition suit with the Indian Patent Office against the applicant Gilead alleging that Tamiflu did not have the inventive step or obviousness. Tamiflu is only a derivative and pharmaceutically acceptable salts, solvates and derivatives, dissolved enantiomers and purified diastereomers in the claimed composition are clearly not patentable under section 3(d) of the Indian Patent Act.
The Patent Office in Delhi decided against Gilead as 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.
While declaring the decision in favour of Cipla’s pre-grant opposition terms in favour of Cipla Ltd. after it found anti-influenza agent oseltamivir to fall within the provisions of section 3(d) and not patentable.
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.
Pre-Grant Opposition in India
The provision of Pre-Grant Opposition has been incorporated as one of the provision for opposing the grant of a new patent into Indian Patent Laws, which came into practice on January 1,2005. Opposition to grant of patent is a provision for hearing at pre-grant opposition stage has been made in the rules.
A pre-grant opposition can be filed for an application for a patent which has been published but a patent has not been granted.
Any person may, in writing, represent the opposition to the controller against the grant of patent within a minimum period of 6 months, from the date of publication is provided for making representation as against the present period of 3 months, for filing pre-grant opposition.
The grounds of pre-grant opposition in the Ordinance were novelty, inventive step and industrial applicability, non-disclosure or wrongful mentioning of source and geographical origin of biological material and anticipation of invention by knowledge, oral or otherwise, available in public domain.
Oseltamivir is an antiviral drug that is used in the treatment and prophylaxis of both Influenzavirus A and Influenzavirus B. Like zanamivir, oseltamivir is a neuraminidase inhibitor. It acts as a transition-state analogue inhibitor of influenza neuraminidase, preventing progeny virions from emerging from infected cells.
Oseltamivir was the first orally active neuraminidase inhibitor commercially developed. It is a prodrug, which is hydrolysed hepatically to the active metabolite, the free carboxylate of oseltamivir (GS4071).
Oseltamivir is generally available by prescription only.
The usual adult dosage for treatment of influenza is 75 mg twice daily for 5 days, beginning within 2 days of the appearance of symptoms and with decreased doses for children and patients with renal impairment.
Oseltamivir may be given as a preventive measure either during a community outbreak or following close contact with an infectedindividual. Standard prophylactic dosage is 75 mg once daily for patients aged 13 and older, which has been shown to be safe andeffective for up to six weeks.
The importance of early treatment is that the NA protein inhibition is more effective within the first 48 hours. If the virus has replicated and infected many cells the effectiveness of this medication will be severely diminished, especially over time.
Roche estimates that 50 million people have been treated with oseltamivir. The majority of these have been in Japan, where an estimated 35 million have been treated.
With increasing fears about the potential for a new influenza pandemic,oseltamivir governments, corporations, and even some private individuals are stockpiling oseltamivir.
In October 2005, the Indian drug company Cipla announced their plan tobegin manufacture of generic oseltamivir without license from Roche.
Patent laws allow governments to authorise supply from generic companies, subject to remuneration to patent owners to address public health problems, including emergencies.
However, Roche wanted to remain the sole supplier of the drug. Cipla argued that it can legally sell oseltamivir to India and 49 other developing countries.
As the dispute continued, Roche granted a sub-license to the Hyderabad-based Hetero Drugs for the production of oseltamivir (Tamiflu), in December 2005.The agreement with Hetero is focused on providing oseltamivir for government pandemic use and will have an immediate effect on the availability in India and developing countries – both directly and through further agreements with local companies.
However, Cipla received marketing approval from the drug controller-general of India in January 2006.The drug will be priced at about Rs 1,000 per strip of 10 75 mg tablets – less than half the current Tamiflu market price of $60.
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.