Measures such as compulsory licenses and parallel imports that may be used to overcome patent barriers, and in particular excessive pricing of medicines under patent, have been hotly debated in recent years, and rightly so. However, there has been less debate about whether or not particular pharmaceutical patents are valid. Yet every patent granted is potentially partially or entirely invalid. A patent is deemed to be valid until stated otherwise by a competent administrative or judicial authority, depending on national/regional laws.
The validity of patents is determined according to the conditions of patentability, as laid down in the national and/or regional patent law, and in accordance with general international rules deriving from TRIPS and other agreements that bind Members. TRIPS Article 27.1 states that "patents shall be available for any inventions provided that they are new, involve an inventive step and are capable of industrial application" (italics added).
As a general convention though, the TRIPS Agreement does not define each of these terms, so it is up to WTO Members to determine how the novelty, inventiveness and industrial applicability of a given invention should be understood. This depends on the objectives of the patent law and on previous practice in each Member State, as well as on the country's own interests. As discussed further below, it is the use that countries make of this freedom that will determine the scope of patentability of pharmaceutical inventions, in conjunction with the possible exclusions of TRIPS Article 27. Whether all or just a selected number of inventions in the pharmaceutical sector are regarded as new, inventive and capable of industrial applications depends on the approach taken in the national law and on the way it is practiced; for instance, in Brazil, the Ministry of Health is involved in evaluating pharmaceutical-related patent applications. The extent of patentability of pharmaceutical inventions in the developing world will have a major impact on access to medicines in the post-TRIPS implementation era.
In summary, a patent might not be valid even though it has been granted by a patent office. This might be for a variety of reasons: the patent office might have made a mistake in applying the national rules of patentability; the patent office might not have examined the patent application (see p. 18); the patent office might have made a judgement which turns out to be incorrect; a document might exist which was unknown to the patent office when it granted the patent, and so on. Patent laws should provide mechanisms to challenge granted patents. If a patent is challenged and found to be invalid by a competent authority, for example a patent office or other administrative body or a court, it should be amended or revoked in whole or in part, depending on what the national law permits. How patents might be challenged is explained on page 18.
It is important that a patent office's decision to grant a patent taken is not seen as final. These decisions are frequently questioned in industrialised countries, and in the final analysis, it is often a court that settles the matter. Asking these questions, or even bringing an action to revoke a patent, is not necessarily a bad reflection on the patent office or its staff but part of a system of necessary checks and balances intended to protect the public interest.
Unfortunately in many countries that do grant patents, few if any patents have ever been challenged, let alone revoked. Why this might be so is discussed in section 3.5.