This is a landmark patent case heard in the Singapore High Court by Justice George Wei. The plaintiff’s patent contained method of treatment (MOT) claims which are not patentable under Singapore Law. The plaintiff sought the Court’s leave to amend the MOT claims to Swiss-style claims, and the defendant opposed the amendment.

 

The plaintiff, Warner-Lambert Company (WLC), is the owner of Singapore Patent SG 61244, for the use of Pregabalin for the treatment of pain. The defendant, Novartis (Singapore), applied for a product licence to market a generic form of Pregabalin in Singapore.

 

As required by the Medicines Act, Novartis served WLC with a notice of its product licence application. WLC sued Novartis, alleging that the acts for which the licence was sought would infringe its patent. Novartis sought to revoke the patent on the ground that the granted MOT claims were not patentable for lack of industrial applicability.

 

In response, WLC applied to the High Court for leave to amend the patent’s claims, post-grant, from MOT claims to Swiss-style claims.

 

The two main issues in the case were whether the proposed amendments extended the scope of protection conferred by the patent; and whether the Court should exercise its discretion to disallow the amendment because there was undue delay in seeking the amendment.

 

In respect of the judge’s decision on the law, he held that:

 

1. A mere change in claim category (for example, from MOT to swiss-style claims) does not necessarily extend the scope of protection.

 

2. A useful test of determining whether the scope of protection was being extended was the infringement test, i.e. whether a matter which fell outside the scope of the claims (properly interpreted) and was hence not an infringing act on its own (preamendment), now falls within the claims such that it becomes an infringing act (post-amendment).

 

3. A purposive approach was to be adopted in construing the patent claims. If, upon proper construction of the claims, a matter which was not an infringement pre-amendment became an infringement post-amendment, the scope of protection would be extended.

 

In respect of the judge’s decision on the facts, he held that the proposed amendments extended the scope of protection of the patent. He found it clear that the granted MOT claims were only targeted at the administration of the medicament.

 

The amended swiss-style claims, while being connected by the same final objective (i.e. the treatment of pain), represented a shift away from the method of treatment to a method of manufacture.

 

Applying the infringement test, since the plaintiff had chosen to stake its claim on the administration of the compound for treating pain, and not the manufacturing process which produced the compound for that use, the judge held that the plaintiff should not be allowed to extend the protection conferred by bringing into its ambit of infringement, the step of manufacture.

 

In respect of the judge’s decision on the law, he held that a patentee who has actual or constructive knowledge of the invalidity of the patent in question has the duty to at least seek legal advice for compliance with the requirements of patentability. This was especially so in the case of patents granted under Singapore’s self-assessment system, which placed a responsibility on a patentee to have regard to the validity of its patent before proceeding to grant.

 

The judge held that under the selfassessment system, it behoved the plaintiff to have regard to the validity of the patent before proceeding to grant. He found that there were several circumstances showing that the plaintiff understood that methods of treatment were precluded from patent protection in Singapore. For example, many years before the amendment was filed, the plaintiff had amended the patent’s corresponding European application, and other Singapore patents in its portfolio, from MOT to swiss-style claims, but failed to do the same in respect of the patent in suit.

Therefore, he held that the plaintiff, being a well-established pharmaceutical company, which owns a good number of patents similar to the one in suit, must have appreciated that the preclusion against MOT claims would likely extend to other patents in its portfolio (including the patent in suit).

Accordingly, he found that the plaintiff had been guilty of unreasonable delay in taking out the amendment application. Despite having ample opportunity to amend its patent pre-grant and postgrant, the plaintiff’s inaction had not been adequately explained, save for a denial that it had received legal advice alerting it of the need to amend.

This is a landmark decision. The judgment sheds light on the permissibility of amending method of treatment claims (post-grant), and clarifies the state of knowledge required to put a proprietor on notice of the need to amend, especially in the context of patents granted under Singapore’s previous self-assessment system.

The Singapore Patent Registry has introduced new criteria for assessing the post-grant amendments, in particular, whether there was any unreasonable delay in seeking amendments.

WLC has appealed against the judgment, and the matter is now pending before the Court of Appeal.

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