c) The right of the prior user referred to in subsection (b)(v) of this Section may be transferred or devolve only together with the enterprise or business, or with that part of the enterprise or business, in which the use or preparations for use have been made. §13.12. Duration; Annual Fees; Restoration a) Subject to subsection (b), a patent shall expire 20 years after the filing date of the patent application. b) In order to maintain the patent or the patent application, as the case may be, an annual fee as prescribed shall be paid in advance to the Liberia Intellectual Property Office for each year, starting one year after the filing date of the application for grant of the patent. A period of grace of six months shall be allowed for the late payment of the annual fee on payment of the prescribed surcharge. If an annual fee is not paid in accordance with this subsection, the patent application shall be deemed to have been withdrawn or the patent shall lapse, as the case may be §13.13. Compulsory Licenses (Other use without authorization of the right holder) a) The Director General or the court may grant, upon request, a compulsory license where: the public interest, in particular, national security or cases of national emergency or other circumstances of extreme urgency, including those involving nutrition or health, so requires; or i. a court or administrative body has determined that the manner of exploitation of the patented invention, by the holder of the patent or someone acting under his authorization or with his consent, is anti-competitive, and that the exploitation of the invention in accordance with this subsection would remedy such practice; or ii. the holder of the patent is abusing his exclusive rights or neglecting to take measures to prevent someone acting under his authorization or with his consent from abusing the exclusive rights conferred by the patent; or iii. after the expiration of a period of four years from the date of filing of the patent application or three years from the date of the grant of the patent, whichever period expires last, the patented invention is not exploited or is insufficiently exploited, by working the invention in Liberia. Notwithstanding this, a compulsory license shall not be issued if the owner of the patent demonstrates that legitimate reasons such as force majeure exist which justify the non-exploitation or insufficient exploitation of the patented invention in Liberia; iv. a patent (the “second patent”) claiming an invention that involves an important technical advance of considerable economic significance in relation to an invention claimed in an earlier patent (the “first patent”) cannot be exploited without infringing the earlier patent; or v. the patent owner has refused to grant a voluntary license to a third party on reasonable commercial terms and conditions. 75