Decoding the Scope of Patent Protection: Singapore after Eli Lilly v. Actavis

Kat friend Arthur Yap from JurisAsia provides an instructive summary of how the Singapore Court of Appeal has charted its own direction on the doctrine of equivalents in light of the decision by the UK Supreme Court in the widely discussed Eli Lilly v. Actavis case.

The UK Supreme Court's decision in Eli Lilly v. Actavis [2017] UKSC 48 is an important development in the law of patents, specifically in relation to determining the scope and ambit of protection conferred to the patentee under his patent. In determining the scope of protection, two very important but contrasting public policies are at play: rewarding the patentee with a monopoly for his invention, and public certainty on the scope of the invention claimed. Striking the right balance to protect both the inventor and the public has always been difficult; and, following the Actavis decision, the question remained as to whether other jurisdictions will similarly embrace the doctrine of equivalents.

Prior to Actavis, the Singapore courts both endorsed and applied the purposive approach to patent construction developed by the UK courts in Catnic Components v. Hill & Smith [1982] RPC 183; Improver Corporation v. Remington [1990] FSR 181; and Kirin-Amgen v. Hoechst [2005] RPC 9 ("Kirin-Amgen"). The adoption of UK jurisprudence was a natural consequence of the close similarities between the governing legislation in Singapore and the UK, respectively, namely the Singapore Patents Act (the "PA") and the UK Patents Act. For example, s 113 of the PA, whose terms are materially similar to s 125 of the UK Patents Act, provides that the invention for a patent shall, unless the context otherwise requires, be taken to be that specified in a claim of the specification as interpreted by the description and any drawings contained in that specification.

Post Actavis, the Singapore Court of Appeal recently had the occasion, in the matter of Lee Tat Cheng v. Maka GPS Technologies Pte Ltd [2018] SGCA 18 ("Lee Tat Cheng"), to determine whether the principles espoused by the UK Supreme Court ought to be similarly applied in Singapore. The Court of Appeal first observed that in Actavis, the UK Supreme Court was bound to give effect to the Protocol on the Interpretation of Article 69 of the EPC (the "Protocol") in interpreting s 125 of the UK Patents Act. In particular, the Court of Appeal noted that Actavis made a distinction between the interpretation of a claim in a patent from the extent of the protection afforded by that patent. This distinction was said to lie in the need to take account of equivalents and represented a significant departure from the established position that the extent of the protection conferred under a claim is exactly what that claim, properly construed, encompasses.

Nevertheless, the Court of Appeal came to the unanimous conclusion that Actavis should not be applied in Singapore for a number of reasons.

First, the approach set out in Actavis is inconsistent with the PA because it allows the extent of the protection conferred by a patent to go beyond the scope of the claims in the patent, purposively construed. S113 of the PA states in no uncertain terms that the extent of the protection conferred by a patent is to be determined by what is specified in the claims, and interpreted in the light of the description and any drawings contained in the patent specification. This does not permit the scope of the protection conferred by a patent to be otherwise determined or to extend beyond what is specified in the claims. While the terms of s113 of the PA is materially similar to s125 of the UK Patents Act, the interpretation of the latter is now governed by the Protocol, which is simply not the legal position here.

Second, there are good reasons why the scope of the protection conferred by a patent should not extend beyond the scope of the claims in that patent, purposively construed. It is fair for a patentee to be bound by the language in which he chooses to frame the claims of his patent. That is how he has chosen to define the scope of his monopoly, and the rest of the world should be entitled to take him at his word.

The purposive approach caters to the limitations of language and helps to militate against potentially harsh results that a strict literal approach might bring about, for instance, by not allowing an imitator to evade the intended monopoly by making minor and immaterial variations just to take his products outside the scope of the literal words of the patent. The purposive approach strikes the right balance between the need to afford fair protection to the patentee so that he is not left without protection against third parties who make immaterial variants to the patented invention, and the need to provide a reasonable degree of certainty to third parties who, in the conduct of their business, rely on patent claims as delimiting the scope of patent protection. Actavis, on the other hand, extends the scope of the protection conferred by a patent beyond its claims and this, according to the Court of Appeal, tilts the balance too far in favour of the patentee and in a manner that is not compatible with the terms of the governing legislation.

Third, if Actavis, which imports the doctrine of equivalents, were to be applied in Singapore, it may give rise to undue uncertainty. The Court of Appeal expressed the same concerns raised by Lord Hoffman in Kirin-Amgen that "once the monopoly has been allowed to escape from the terms of the claims, it is not easy to know where its limits should be drawn". Determining the scope of the monopoly conferred by a patent based on a purposive interpretation of the patent claims gives rise to greater certainty because it is aimed at determining what, based on the language of the claims, the patentee would have objectively meant to include within the scope of his monopoly at the time of the patent application. On the other hand, incorporating the doctrine of equivalents brings with it an element of ex post facto analysis that focuses on how the patented invention works in practice based on the state of developing scientific knowledge at the date of the alleged infringement.

Lee Tat Cheng is significant for being the first apex highest court outside of the EU and the UK to embark on an in-depth analysis of the doctrine of equivalents and it is perhaps even more significant for expressly rejecting the same. It remains to be seen whether jurisdictions that are not obligated to give effect to Article 2 of the Protocol will adopt Actavis and the doctrine of equivalents, or follow Singapore's approach.

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