Patentability of New Use of a Drug

Pharmaceutical companies employ time, money and labour to discover new use of a known drug. They claim patent for this new use and to establish ‘Novelty of Purpose’. The format which is used to claim such new use is called ‘Swiss type claim’ format.

 According to sec. 2 (6) of the UK Patents act, 1977:
"the fact that an invention consisting of a substance or composition for use in a method of medical treatment forms part of the state of the art, shall not prevent the invention from being taken to be new, if the use of the substance or composition in any such method does not form part of the state-of-the-art."

The provision confers novelty for a known drug in form of discovery of a new purpose. The plain reading of this provision states that only first use may be patented but not the second and subsequent use of a known drug as it lacks novelty. EPO has confirmed that Article 54(5) of the European Patents Convention applies to second and subsequent medical uses of a drug given the claims are drafted in ‘swiss format’. In Wyeth's Application [1985] RPC 545 one of the claims was written in Swiss format and the examiner refused to grant. On appeal the UK Patents Court allowed the grant of a patent.

According to section 3 (d) of the Indian Patents act “the mere discovery of any new property or mere new use for a known substance or of the mere use of a known process, machine or apparatus” is not an invention unless such known process results in a new product or employs at least one new reactant.”

So to get a patent for second and subsequent use the efficacy must be enhanced and a new reactant must be employed. We don’t have provisions like section 2 (6) of the patents act, 1977 (UK) and article 54(5) of the EPC which allow second and subsequent use.

Having a  patent for first use and then claiming patent for second and subsequent use in order to extend term of protection is called ‘Ever greening’. US, UK and Australia allow patents for second and subsequent use.

 It seems reasonable that when a pharmaceutical company has invested time, money and intellect in discovering a new use of a known drug it must be protected which is purpose of IPR laws but on the other hand if it is allowed then patents will never expire and people will be required to purchase expensive patented drugs which is really harmful for public interest.

Now when the Mashelkar committee report has been discarded as a whole it will be interesting to see what policy makers decide about the section 3 (d) of the Indian patents act in context of new use of a drug.