Deciding whether an invention is new or inventive and whether it should be patented requires answering some difficult questions. Of particular importance to the patenting of pharmaceutical inventions are new use inventions.
Imagine that a particular product is already known for a particular purpose (e.g. AZT as a cancer drug since the 1960's). Imagine then that a new use is found for this product (e.g. AZT as an antiretroviral drug in the 1980's). Should a patent be granted for this new use? One way of looking at this might be to say that it is the same old product, but that we now know more about it, and someone has discovered (rather than invented) a new therapeutic use of it. Another way of looking at it might be to say that, in terms of its new function in life, the product is brand new, so it should be seen as novel.
The TRIPS Agreement gives no guidance in the matter as it only requires WTO Members to grant patents for products and processes, thereby leaving Members free to determine their own approach. Most experts agree that "even though the TRIPS text does not specify any exception to new uses for known substances, it can be concluded that TRIPS does not require the grant of such patents".
There is no accepted international doctrine on the matter. Some countries have decided to grant patents for new uses as product patents, others as process patents, or as a separate patent category. Others have decided to deny the patentability of such new uses for lack of novelty, inventiveness or industrial applicability, or because such a use may amount to a method of medical treatment (which may be excluded from patentability under TRIPS), or because new uses are just discoveries related to a known product and therefore not real inventions.
The research-based pharmaceutical industry has lobbied strongly for this optional protection, arguing that patent protection of new medical indications will provide them incentive to invest resources in investigating potential new uses of known products, which will be less onerous than searching for new products. In Europe a special novelty exception was created in patent law to allow a first medical use of a known substance to be patented. To allow a second medical use to be patented was widely seen as impossible twenty years ago in Europe and yet a way was found to allow it to happen. An artificial legal construction was invented, the so-called "Swiss claim", to justify the practice. Despite strong opposition many countries have decided that they now believe it, within some limits.
In developing countries this question has been even more debated:
"At the time of the TRIPS negotiations, the patent laws of several developed and developing countries excluded from patentability any new uses for known substances. The search for newer and more effective treatment of diseases has to [be] balanced against the well known exclusion of medical methods of treatment and substances already in the public domain. The implementation of TRIPS in the patent laws of developing countries such as the Andean Group expressly excludes second use of known substances. Others like Brazil and Argentina do not have specific exclusions or inclusions to cover this. This means that they could exclude such "second use" inventions as not being novel or inventive enough to qualify for a patent grant. Korea, on the other hand, explicitly deleted the exclusion of new uses of known chemical substances with effect from 1 July 1987 under its bilateral understanding with the US following action under Section 301". Countries of the Andean Community as well as Kenya have resisted pressure from multinational companies and industrialised countries and expressly excluded new uses from patentability in order to limit the number of patents granted in the pharmaceutical sector. The UK CIPR report recommended that "most developing countries, particularly those without research capabilities, should strictly exclude diagnostic, therapeutic and surgical methods from patentability, including new uses of known products". However, the example below shows that such a political choice can be difficult to maintain in a world where the global tendency, originating from industrialised countries, is to grant patents for most things, including for second medical use inventions.
The right to reject patents for second medical use inventions: The Andean example
According to Article 21 of Decision 486, Common Intellectual Property Regime, of the Andean Community, "products or processes already patented and included in the state of the art … shall not be the subject of new patents on the sole ground of having been put to a use different from that originally contemplated by the initial patent". Despite this exclusion in the common legislation, an unexpected legislative decree was passed in 1997 in Peru, clarifying that patents may be granted for new uses if it complies with the requirements of novelty, inventiveness and industrial applicability. This resulted in the patent office of Peru granting a second medical use patent to Pfizer in 1999 to protect the anti-impotence drug Viagra®. The generic industry association of Peru complained about this patent to the Secretariat of the Andean Community, which brought the dispute to the Andean Tribunal of Justice. Although powerful forces were involved (14 lawyers to defend Pfizer and the Government of Peru against two for the Secretariat of the Andean Community), the Tribunal ruled that the Government of Peru had violated the regional patent legislation in granting such a patent.
Developing countries have the same sovereign right as developed countries to interpret international agreements with regard to their own needs, when these provisions are unclear or not uniformly accepted. It remains to be seen whether similar efforts can be mounted for less lucrative but more essential drugs.