Taiwan's Patent Act provides a patent term extension system for pharmaceuticals, allowing extension of the term of a patent covering a drug if the drug has obtained its first marketing approval, with the maximum extension period being five years. Whether the marketing approval qualifies as "first" is determined based on the combination of the active ingredient(s) and use specified in the marketing approval issued by the Taiwan FDA. Once an application for patent term extension is approved, the scope of the patent rights during the extended period would extend to the scope limited by the active ingredient(s) and use specified in the marketing approval.
Recently, the Taiwan IPO rejected an application for a patent term extension. The primary reason for rejection was that the active ingredient indicated in the marketing approval was not covered by the patent for which an extension application was filed. The key issue was whether or not the active ingredient, a hydrate of a specific compound, falls within the scope of the compound claim in the patent.
In this case, the active ingredient specified in the marketing approval is a tosylate monohydrate of a specific compound (hereinafter referred to as the "compound hydrate"). The patent for which an extension was sought included both compound claims and its use claims. The dispute centered on whether the language of the compound claim — "the compound or its pharmaceutically acceptable salts, stereoisomers, or tautomers" — encompasses the compound hydrate. During the examination, the patentee pointed out that the marketing approval falls under the category of approval for a new compound, with the main component being the specific compound (free base); although the compound hydrate is specified as the active ingredient in the marketing approval, the relevant descriptions in the leaflet, as well as the dosage and the mechanism of action, are all directed to the compound (free base) per se. Furthermore, the patentee asserted that some passages in the patent specification disclose that the invention covers solvates, such as hydrates, and emphasized that a person skilled in the art would have appreciated, based on the contexts, that the compound obtained in one of the examples in the specification would be the compound hydrate. Therefore, the compound hydrate should be interpreted as being encompassed by the compound claims.
The Taiwan IPO did not accept the patentee’s viewpoint, referencing a prior ruling by the Supreme Administrative Court. The Court established that whether the patent scope covers the active ingredient in the first marketing approval depends solely on the active ingredient described in that marketing approval — in this case, the specific compound tosylate monohydrate (i.e., the compound hydrate), whereas the compound claim, as interpreted by the literal wording thereof, specifies salts, stereoisomers, or tautomers of the compound but does not include hydrates. Therefore, the Taiwan IPO ultimately rejected the application for patent term extension, concluding that the active ingredient specified in the first marketing approval is not covered by the patent claims. This case is currently under administrative proceedings for a remedy, and the final determination awaits further developments.