Case Details
- Citation: [2000] SGCA 39
- Case Number: CA 9/2000
- Decision Date: 28 July 2000
- Court: Court of Appeal of the Republic of Singapore
- Coram: Chao Hick Tin JA; L P Thean JA; Yong Pung How CJ
- Plaintiff/Applicant: Merck & Co, Inc
- Defendant/Respondent: Pharmaforte Singapore Pte Ltd
- Appellants’ Counsel: P Sivakumar and Vicki Heng (Ella Cheong & G Mirandah)
- Respondents’ Counsel: Ranvir Kumar Singh and Vivienne Kaur (Kumar & Loh)
- Tribunal/Court: Court of Appeal
- Judgment Length: 16 pages, 8,967 words
- Legal Areas: Patents and Inventions — Infringement; Patents and Inventions — Validity of patent; Novelty; Inventive step
- Statutes Referenced: English Patents Act; Patents Act 1994 (Singapore)
- Prior Proceedings: Appeal from Lai Kew Chai J (High Court), who dismissed Merck’s infringement claim and held product claims 16–21 invalid; also held the respondents’ manufacturing process differed from process claim 11
- Core Patent Subject-Matter: Process for lactonization of mevinic acids and analogs; product claims for Lovastatin with a dimeric impurity < 0.2%
- Key Alleged Infringing Product: “Apo-Lovastatin” imported into Singapore and manufactured in Canada by Apotex Inc
Summary
Merck & Co, Inc v Pharmaforte Singapore Pte Ltd concerned an alleged patent infringement relating to Lovastatin, a cholesterol-lowering “statin” drug. Merck was the registered proprietor of a Singapore patent covering a process for lactonization of mevinic acids and analogs, together with product claims for Lovastatin characterised by a low level of a specific impurity: a dimeric impurity of less than 0.2%. Pharmaforte imported a competing product, “Apo-Lovastatin”, manufactured in Canada. Merck alleged that Apo-Lovastatin infringed Merck’s product claims (claims 16–21) and also infringed a process claim (claim 11).
The trial judge dismissed Merck’s infringement claim and invalidated the product claims. On appeal, Merck did not pursue the process-claim point, recognising it depended substantially on findings of fact. The Court of Appeal focused on the validity of the product claims, particularly whether the trial judge was correct to treat “utility” as relevant to novelty/patentability and whether the claimed product was novel and involved an inventive step. The Court’s analysis clarified the role of “utility” in patent law under Singapore’s Patents Act 1994 (which is based on the English Patents Act 1977), and it examined how differences in degree of purity and prior disclosures affect novelty and inventive step.
What Were the Facts of This Case?
Merck’s patent in suit (Singapore Patent No 9690405-7, registered on 15 June 1996) was derived from a European patent application and ultimately from a US priority application. The patent concerned lactonization of mevinic acids and analogs, a chemical transformation used to produce Lovastatin in its lactone form. In the background science, statins are marketed in lactone form, which involves a chemical ring structure. Lactonization converts the free acid into the lactone via intramolecular condensation. However, an intermolecular condensation can occur, producing an inactive dimer impurity. Historically, it was believed that dimer formation could not be completely suppressed, and dimer impurity levels of approximately 0.4% to 0.8% were treated as unavoidable.
Merck’s European filing introduced stand-alone product claims to Lovastatin where the dimeric impurity was reduced to less than 0.2%, regardless of the method of manufacture. Merck’s Singapore patent similarly contained both process claims and product claims. The product claims were directed to Lovastatin defined by its impurity profile (dimeric impurity < 0.2%). Merck’s infringement case was therefore not merely about a particular manufacturing method, but about whether the imported Apo-Lovastatin fell within the claimed product definition.
Pharmaforte, the respondent, imported and distributed pharmaceutical products in Singapore, including Apo-Lovastatin. Apo-Lovastatin was manufactured in Canada by Apotex Inc. Merck instituted proceedings because it alleged that Apo-Lovastatin possessed dimeric impurity levels of less than 0.2% and therefore infringed Merck’s product claims. Merck also alleged infringement of the process claim, contending that Apotex’s manufacturing process fell within the scope of Merck’s lactonization process claim.
At first instance, Lai Kew Chai J dismissed Merck’s claim. The judge held that the product claims (claims 16–21) were invalid for lack of novelty and lack of inventive step. He also held that the respondents’ manufacturing process differed from the process disclosed in Merck’s process claim (claim 11). On appeal, Merck accepted that the process-claim issue was largely factual and did not pursue it. The appeal therefore concentrated on the validity of the product claims, including the trial judge’s approach to novelty and the relevance of “utility” to patentability.
What Were the Key Legal Issues?
The appeal raised several interrelated issues concerning patent validity. First, the Court had to consider whether the trial judge erred in treating “utility” as an essential ingredient of patentability within a novelty enquiry. Merck argued that the Patents Act 1994, unlike the earlier UK Patents Act 1949, did not contain an express statutory requirement that an invention be “useful” (in the sense of “usefulness” or “utility” as a ground for revocation). Merck contended that the trial judge’s reliance on utility was legally misconceived and that the statutory scheme displaced any residual common law requirement.
Second, the Court had to address whether the claimed product—Lovastatin with a dimeric impurity below 0.2%—was novel over prior art disclosures. This required the Court to consider whether differences in degree of purity (as opposed to differences in kind or type of compound) could support novelty, and whether prior disclosures anticipated the claimed impurity threshold. The Court also had to consider the meaning of “utility” in the context of novelty, if utility remained relevant at all.
Third, the Court had to consider inventive step. The trial judge held that purification of Lovastatin to reduce dimer impurity was an obvious step for the person skilled in the art, using standard techniques. The appeal therefore required an assessment of whether the claimed impurity reduction involved an inventive step, and whether the claimed invention amounted to a mere discovery rather than a patentable advance.
How Did the Court Analyse the Issues?
The Court of Appeal began by addressing the “utility” argument because it went to the legal framework for novelty and patentability. The trial judge had relied on the proposition that, within a novelty enquiry, it was appropriate to assess the utility of the patented product, and he cited the existence of cases imposing utility as a necessary ingredient of patentability notwithstanding its absence as a statutory requirement of novelty. Merck challenged this approach, arguing that the Patents Act 1994 provides a complete code and that utility is not a prerequisite for patentability under section 13.
Section 13(1) of the Patents Act 1994 provides that a patentable invention must satisfy three conditions: it must be new, involve an inventive step, and be capable of industrial application. Section 80(1) provides grounds for revocation, including that the invention is not a patentable invention. Merck’s submission was that, because the Patents Act 1994 does not include a ground equivalent to the old UK “not useful” ground (found in the Patents Act 1949), the courts should not import utility as a novelty requirement. Merck relied on English authority suggesting that the 1977 Act displaced residual common law elements.
The Court of Appeal, however, rejected Merck’s attempt to treat utility as entirely irrelevant. It observed that “inutility” as a ground to revoke a patent was introduced in the 1949 UK Act, and that before then the absence of an express provision had not prevented courts from considering utility in determining patentability. The Court referred to older authorities to show that the concept of usefulness had long been treated as part of the patentability inquiry, even if not expressly stated in the statute. In particular, it cited the Lord Chancellor’s statement in Badische Anilin Und Soda Fabrik v Levinstein that an invention must be useful, even though the word was not found in the statute, and it cited Welsbach Incandescent Gas Light Co Ltd v New Incandescent (Sunlight Patent) Gas Lighting Co Ltd on the meaning of utility in patent law.
Crucially, the Court clarified what “utility” means in this context. It did not treat utility as “commercial utility” or abstract usefulness. Instead, it adopted the older patent-law understanding that utility relates to whether the invention produces a result that is better than the preceding knowledge of the trade in some relevant respect. The Court’s reasoning indicates that the inquiry is not whether the invention is economically attractive, but whether it is capable of producing the claimed result and whether that result is meaningful in the patent sense.
Applying this framework, the Court addressed the trial judge’s view that Lovastatin with a dimeric impurity below 0.2% lacked utility because it did not confer improved therapeutic performance compared with existing statins. The Court’s analysis suggested that this was not the correct way to treat utility for novelty purposes. The Court emphasised that the relevant question is the meaning of utility as understood in the pre-1949 common law, and it drew attention to the principle that a patent claim is for a disclosed result. If the claimed result cannot be produced by the process or if the claimed product does not achieve the promised technical outcome, then the consideration for the grant fails. This approach ties utility to the production of the claimed result rather than to clinical superiority alone.
Although the judgment extract provided is truncated, the Court’s approach is clear from the portion quoted: it treated utility as a concept linked to whether the claimed invention is capable of producing the result for which protection is sought, and it cautioned against importing an irrelevant or overly broad notion of utility. The Court’s reasoning thus reoriented the novelty analysis away from a purely therapeutic-comparative metric and towards the patent-law concept of whether the claimed product achieves the technical effect disclosed and claimed.
On novelty and inventive step, the Court also engaged with the trial judge’s conclusion that differences in degree of purity were not patentable unless they amounted to a patentable distinction in kind or effect. The Court considered whether a reduction in dimer impurity from previously known levels to below 0.2% could be treated as a novel and inventive advance. The trial judge had found anticipation by prior disclosures and held that purification to achieve the lower impurity threshold was obvious. The Court’s analysis therefore involved assessing whether prior art already disclosed Lovastatin with dimer impurity below the claimed threshold, and whether the skilled person could, using standard techniques, purify Lovastatin to reach the claimed impurity level.
Finally, the Court addressed the “mere discovery” concern embedded in the inventive step analysis. In pharmaceutical chemistry, where compounds may be known but purified to different degrees, the line between a patentable invention and an unpatentable discovery often turns on whether the claimed advance is non-obvious and whether it reflects a technical contribution beyond routine optimisation. The Court’s reasoning, as reflected in the trial judge’s findings and the appeal submissions, focused on whether the skilled person would have had a clear and predictable route to the claimed impurity reduction using existing methods.
What Was the Outcome?
The Court of Appeal dismissed the appeal. The practical effect was that Merck’s product claims (claims 16–21) remained invalid, meaning Merck could not rely on those claims to establish infringement against Pharmaforte’s imported Apo-Lovastatin. Since Merck did not pursue the process-claim issue on appeal, the trial judge’s finding that the respondents’ process differed from claim 11 also stood.
Accordingly, the respondents were not found liable for patent infringement. The decision upheld the trial judge’s approach to novelty and inventive step, while the Court’s discussion of utility clarified the legal meaning of utility in patentability analysis under the Singapore Patents Act 1994 and its English statutory lineage.
Why Does This Case Matter?
This case is significant for patent practitioners because it addresses the interface between statutory patentability requirements and older common law concepts, particularly “utility.” Even though the Patents Act 1994 does not expressly include a “usefulness” ground equivalent to the old UK 1949 Act, the Court’s discussion shows that courts may still consider utility-like concepts when assessing whether the claimed invention satisfies the patentability bargain. For applicants, this underscores the importance of ensuring that claims are supported by a credible technical result and not merely by an asserted clinical or commercial advantage.
Merck & Co v Pharmaforte also provides guidance on how courts evaluate novelty and inventive step where the claimed product is defined by purity or impurity thresholds. The decision reflects judicial caution about treating incremental improvements in degree (for example, lowering an impurity from one percentage range to another) as inherently patentable. Practitioners should therefore expect that, unless the impurity reduction is tied to a non-obvious technical contribution and not merely routine purification, claims may be vulnerable to invalidation for lack of novelty or inventive step.
From a litigation strategy perspective, the case illustrates the importance of claim construction and the evidential burden in pharmaceutical patent disputes. Where infringement turns on whether an imported product meets a specific impurity threshold, the validity of the product claim becomes central. The decision also demonstrates that appeals may narrow substantially when issues depend on factual findings, such as whether a manufacturing process falls within a process claim.
Legislation Referenced
- Patents Act 1994 (Singapore), s 13(1) (patentable invention: novelty, inventive step, industrial application)
- Patents Act 1994 (Singapore), s 80(1) (revocation grounds)
- English Patents Act 1977 (as the statutory basis for the Singapore Patents Act 1994)
- English Patents Act 1949 (historical “not useful” ground for revocation, referenced for context)
Cases Cited
- Genentech Inc’s Patent [1989] RPC 147
- Unilever Ltd (Davis’s) Application [1983] RPC 219
- Badische Anilin Und Soda Fabrik v Levinstein [1887] 4 RPC 449
- Welsbach Incandescent Gas Light Co Ltd v New Incandescent (Sunlight Patent) Gas Lighting Co Ltd [1900] 17 RPC 237
- Alsop’s Patent [1907] 24 RPC 733
- [2000] SGCA 39 (the present case)
Source Documents
This article analyses [2000] SGCA 39 for legal research and educational purposes. It does not constitute legal advice. Readers should consult the full judgment for the Court's complete reasoning.