Despite proposals to the contrary, the TRIPS Agreement did not require the protection of pharmaceutical inventions in preparation in these countries at the time of the entry into force of the WTO. (3) However, since that date (1 January 1995), developing and least-developed countries that have not already provided patent protection for medicinal products are required to prepare a system for filing patent applications for pharmaceutical inventions (often referred to as letterbox systems). These applications had to be considered by developing countries only after 1 January 2005 and, in the case of LDCs, they do not need to be considered until 1 January 2016. If it turns out that a patent is patentable by reference to the filing date (or priority date), it should be granted for the remainder of the patent term, counted from the filing date.