Taiwan provides patent term extension for pharmaceutical patents. Once a patent term extension is granted, the scope of the extended patent right is limited to the scope defined by the active ingredient and the use (i.e., medical indication) specified in the drug approval. Accordingly, one of the key requirements in determining whether a patent term extension should be granted is whether the active ingredient specified in the drug approval (i.e., marketing approval) falls within the scope of the claims of the patent. In June 2026, the Supreme Administrative Court issued Judgment No. 394 of 2024, which provided clear guidance on the relationship between an active ingredient and a compound claim.
Under the Patent Act, the drug approval relied upon for a patent term extension application must be the first drug approval, meaning that either the active ingredient or the use must be new, i.e., approved for the first time. With respect to determining whether an active ingredient is being approved for the first time, the Patent Term Extension Examination Guidelines revised in 2018 expressly changed the approach adopted in the previous version of the Guidelines. The previous Guidelines considered the active ingredient to be the free form of the compound responsible for the pharmacological activity. The revised Guidelines instead provide that the active ingredient is to be determined based on the active ingredient specified in the drug approval.
Accordingly, when determining whether an active ingredient is covered by the scope of the claims, the relevant active ingredient is the active ingredient itself as specified in the formulation section of the first drug approval, rather than the pharmacologically active portion of the drug in its free form.
The central issue in this case was whether the active ingredient specified in the drug approval relied upon for the patent term extension fell within the scope of the claims. The relevant patent included a compound claim directed to “a compound having a specific general formula or a pharmaceutically acceptable salt thereof.” The claim did not expressly cover solvates or hydrates of the claimed compound. In the formulation section (active ingredient) of the drug approval at issue, the active ingredient was expressly identified as “Upadacitinib Hemihydrate,” i.e., a hemihydrate of the compound.
The appellant first argued that, because the Patent Act had not been amended, the 2018 revision of the Patent Term Extension Examination Guidelines, which defined the active ingredient by reference to the ingredient specified in the drug approval, imposed an additional restriction not found in the Patent Act. The Supreme Administrative Court rejected this argument. The Court held that the purpose of the revision was to ensure that the active ingredient specified in the first drug approval could be properly correlated with the scope of the patent right.
In this case, the formulation section (active ingredient) of the drug approval expressly identified the active ingredient as “Upadacitinib Hemihydrate.” Although the formulation section included the parenthetical statement “Corresponds to upadacitinib 15 mg on an anhydrous basis,” the Court considered this statement to indicate only the amount of the pharmacologically active portion contained in the active ingredient. It did not alter the fact that the active ingredient itself was, in substance, upadacitinib hemihydrate. Accordingly, the active ingredient to be compared with the patent claims was “upadacitinib hemihydrate.” The Court therefore concluded that the revised Guidelines did not impose a restriction beyond what is provided by law.
Another, and perhaps more contentious, issue was whether the claims of the patent covered the hemihydrate of the compound. The relevant compound claim did not expressly include a solvate or hydrate of the claimed compound. Although claim 8 covered the upadacitinib compound itself, its structural definition did not include any water molecule. The Court therefore construed the claim as covering “anhydrous upadacitinib or a pharmaceutically acceptable salt of anhydrous upadacitinib.”
The patent specification did contain a general statement on page 109 that “certain compounds and their salts may also exist in solvated forms, such as hydrates.” However, the specification did not specifically identify which of the numerous disclosed compounds could exist as hydrates, nor did it provide any examples of preparing such hydrates. In the Court’s view, a person skilled in the art could not, without experimentation, directly infer that the compounds in question could form hydrates. The Court therefore concluded that the claims at issue did not cover the hemihydrate.
The appellant further argued that: (1) if a hydrate has the same quality, safety, and efficacy as the compound or other hydrates, the hydrate of the compound would be regarded as the same active ingredient as the compound itself and thus only be granted a drug approval as a “generic drug approval,” rather than a “new drug approval”; and (2) once a compound has obtained patent protection, it would be almost impossible to obtain separate patent protection for the hydrate itself of the same compound through a separate patent application..
The Court rejected both arguments. With respect to the first argument, the Court explained that, under the Patent Act, whether a drug approval constitutes a first drug approval is not determined by whether the approval is a new drug approval or a generic drug approval. As for the second argument, whether a hydrate of a known compound is patentable must still be determined under the applicable patentability requirements. If an applicant can provide sufficient reasons and evidence, a hydrate of a known compound may still be granted patent protection.
The Supreme Administrative Court also rejected the appellant’s argument that a compound and its hydrate constitute a genus-species relationship and that the hydrate should therefore fall within the scope of a claim directed to the compound. The Court explained that, in a hydrate, water molecules are chemically associated with the free-form compound through intermolecular forces, such as hydrogen bonding, in a specific proportion. A hydrate is therefore a chemically combined substance consisting of water molecules and the free-form compound and constitutes a different substance. The two are not in a genus-species relationship. Thus, where a claim merely defines a compound, it should be construed as covering the free-form compound without crystal water and not its hydrated form.
The Supreme Administrative Court thus confirmed the definition of an active ingredient adopted by the Taiwan Intellectual Property Office in the 2018 revision of the Patent Term Extension Examination Guidelines. The Court also confirmed that, where the active ingredient specified in the drug approval is a particular compound in its hemihydrate form, that active ingredient does not fall within a claim directed only to the compound and its salts.
This decision has significant implications for the drafting and claim strategy of compound claims in pharmaceutical patent applications. To obtain appropriate protection for a pharmaceutical compound, it may therefore be advisable to expressly include relevant solvates or hydrates of the compound within the scope of the claims, where appropriate.