Are Belated Claim Amendments of Granted Patents Permitted?

Summary

In a recent order dated August 01, 2017, the Singapore Court of Appeal [See end note i], upheld the High Court’s order [See end note ii] rejecting Warner-Lambert Company LLC’s (Warner-Lambert) application in a pending patent infringement suit against Novartis (Singapore) Pte Ltd (Novartis), seeking leave to amend its Patent for the drug “Lyrica” directed to the use of Pregabalin for the treatment of pain under Section 83(1) of the Patents Act (Cap 221, 2005 Rev Ed) [See end note iii] (hereinafter referred to as the Singapore Patents Act). Warner-Lambert sought to amend the claims of its granted patent which were directed to a method of treatment to a “Swiss-style” claim, generally denoted as the following: “the use of compound X in the manufacture of a medicament for a specified (and new) therapeutic use Y”.  The Singapore High Court and the Court of Appeal rejected Warner-Lambert’s application for the post-grant amendment on two grounds.  Firstly, on the ground that the proposed amendments are impermissible under Section 84(3)(b) of the Singapore Patents Act [See end note iv] because they extend the protection conferred by the patent. Secondly, on the ground that Warner-Lambert’s proposed amendments were sought after a lengthy and inexplicable delay.

Therefore, while the amendment per-se is not impermissible, Section 84(3) of the Singapore Patents Act carve out certain exemptions. Further, though the ground of “delay” for disallowing any amendment have not been expressly provided under the Singapore Patents Act, the courts have recognised such a principle as a valid ground.  Such a position exists in India also. Indian courts have recognized the principle of “belated amendment” under the Indian Patents Act, 1970 and in cases where the amendment of granted patents are introduced belatedly without proper justification the same has been refused

Background

Warner-Lambert claims a monopoly by virtue of its granted patent over the use of Pregabalin for the treatment of pain. Under the patent, Warner-Lambert manufactures and distributes the product known as “Lyrica” which has Pregabalin as its active ingredient and the said product is approved by the Singapore Health Sciences Authority (HAS) for use in treating, inter alia, neuropathic pain and chronic pain disorders including fibromyalgia. On 23 March 2015, Warner-Lambert received notice of the Novartis’ applications to the HSA for product licences in respect of pregabalin products under Section 12A(3)(a) of the Medicines Act (Cap 176, 1985 Rev Ed). Vide the said notice, Novartis argued that Warner-Lambert’s patent would not be infringed by the doing of the acts for which the product licences were sought. Thereafter, on 21 April 2015, Warner-Lambert commenced an infringement action against Novartis seeking inter alia a declaration that its patent would be infringed by the doing of the acts for which the product licences were sought. Subsequent thereto, on 5 May, 2015, Warner-Lambert notified Novartis of its intention to apply to amend the patent.

In response to the above, on 2 June 2015, Novartis filed its defence and counterclaim in which it counterclaimed for  revocation of the patent on the basis that the patent is and always has been invalid for the reason that it claims a monopoly over methods of treatment of the human or animal body, which are not patentable under Section 16(2) of the Singapore Patents Act [See end note v]. Thereafter, Warner-Lambert’s proposed amendments were advertised on 29 June 2015, under O 87A r 11(1) of the Singapore Rules of Court and Novartis filed its notice of opposition to Warner-Lambert’s application to amend on 24 July 2015. Finally, on 26 August 2015, Warner-Lambert filed the instant application in dispute to amend the claims in its patent.

The Singapore High Court while dismissing Warner-Lambert’s application for post-grant amendments firstly held that, although the granted claims [See end note 6] refer to the medicament (in terms of a therapeutically effective amount of the disclosed compound), they are directed to the method of treatment viz the administration. The High Court held that the amended claims [See end note vii], which claim a method of manufacture, represent a shift away from the method of treatment. The High Court emphasized that the claims, that is pre and post amendment, despite being broadly connected by the same final objective (of treating pain), the two claims are targeted at different activities. That is, the amended claims cover the making of the compound for the purposes of administration (to treat pain) whereas the granted claims cover only the follow-on act of administration of the compound to treat pain. The High Court held that since Warner-Lambert had chosen to stake its claim on the administration of the compound for treating pain and not on the preceding manufacturing process that produced the compound for that use, it cannot now be allowed to extend the protection conferred by the patent by bringing into its ambit the step of manufacturing the medicament. The High Court thus held that Warner-Lambert’s proposed amendments are impermissible under Section 84(3)(b) of the Singapore Patents Act because they extend the protection conferred by the patent.

The Singapore High Court secondly held an application for patent amendment must be made expeditiously and that the patent proprietor is not entitled to sit on its hands after discovering the need for amendment. The High Court also held that for the delay to be considered undue, the period of the delay need not be long provided that there is no plausible explanation for the delay. Further, the High Court held that a delay may not be held against the applicant if it is able to provide a reasonable explanation for the delay. On the question of what is the extent and quality of the knowledge required by the amending party to start the clock running, the High Court referred to and applied the Australian decision of CSL Limited v Novo Nordisk Pharmaceuticals Pty Ltd (No 2) [2010] FCA 1251 wherein it was held that an applicant’s actual or constructive knowledge of the need to amend should, in appropriate circumstances, suffice to disentitle the applicant to the favourable exercise of the court’s discretion. The High Court thus rejected Warner-Lambert’s proposed amendments on the basis that there has been undue and unreasonable delay on its part in filing the instant amendment application. The High Court held that Warner-Lambert had ample opportunity to amend its patent pre-grant and post-grant, and that its inaction was not adequately explained but for a denial that there was legal advice alerting it to the need to amend. The High Court relied upon the Australian decision and held that the patentee, as the person who has access to all the relevant information, should not wait until a challenge is made by a third party in whatever form of proceedings that may be appropriate in a particular jurisdiction to undertaken necessary amendments.

Warner-Lambert approached the Singapore Court of Appeal challenging the High Court’s decision on both the above-mentioned grounds. The Court of Appeal concurred with the High Court’s reasoning, both on the ground that the proposed amendment extended the scope of protection of the granted patent and on the ground of belated amendments. On the issue of undue delay in seeking the amendments, the Court of Appeal held that constructive knowledge of a patent’s potential invalidity is sufficient. The Court of Appeal held that that it was incumbent on Warner-Lambert to apply to amend the patent at the earliest possible opportunity or, at the very least, to seek legal advice in relation to the issue. The Court of Appeal thus held that the failure to act on this knowledge expeditiously amounted to unreasonable delay.

The Indian perspective

The relevant provisions under the Patents Act, 1970 (hereinafter referred to as the Act) dealing with claim amendments are Section 57 to Section 59 of the Act. Section 57 of the Act pertains to amendment of an application for the patent and specification therein before Controller and Section 58 of the Act pertains to amendment of specification of the granted Patent before the Intellectual Property Appellate Board or the High Court. Section 59 of the Act states that an amendment of an application or a complete specification or any document relating thereto under Section 57 or 58 of the Act shall be made only by way of a disclaimer, correction or explanation. The provision further states that no amendment shall be allowed except for the purpose of incorporation of actual fact and most importantly mandates that no amendment of a complete specification shall be allowed, the effect of which would be that the specification as amended would claim or describe matter not in substance disclosed or shown in the specification before the amendment, or that any claim of the specification as amended would not fall wholly within the scope of a claim of the specification before the amendment. 

The issue as to whether belated amendments of granted patents are permitted came up in the case of AGC Flat Glass Europe SA vs. Anand Mahajan and Ors. 2009 (41) PTC 207 (Del.), wherein the Plaintiff during the course of a patent infringement suit instituted before the Delhi High Court, filed an Interim Application under Sections 57 and 58 of the Patents Act, 1970 read with Section 151 of the Civil Procedure Code, 1908, for an amendment in Claim 1 of its granted patent. The Plaintiff sought to amend its Claim 1 in Indian Patent no. 190380 by inserting "a sensitizing material, typically tin" in clause (ii) of the said Claim. The Plaintiff asserted that the amendment satisfies all the requirements of Section 59 of the Patents Act, 1970 as it is by way of an explanation clarifying the scope of the Plaintiff’s invention in the light of the prior art and also asserted that the amendment pertains to matter already disclosed in the specifications and does not fall outside the scope of the un-amended specification. The Defendants on the other hand contended that with the proposed amendment, the Plaintiff wishes to create a new monopoly as regards a new product as the proposed amendment would result in changing of the product originally patented. The Defendants also asserted that the amendment by the Plaintiff was sought after 12 years of grant of the patent and that the Plaintiff must have had knowledge as regards usage of tin in its product. The Defendant asserted that despite the said knowledge, the Plaintiff chose not to amend its claim previously and proceeded to institute suits for infringement on the basis of the un-amended patent which according to Plaintiff now, is unclear/ambiguous. Although the High Court allowed the Plaintiff’s Application on merits holding that the claim amendment is merely a clarificatory / elaborative that does not alter the scope of the invention, the High Court recognized the principle of not allowing belated amendments and observed that “if the patentee has known of the objection on the prior publication for many years, delay in applying for amendment will itself be ground for refusal.”

Although the Indian Courts have not as yet undertaken a detailed and comprehensive analysis on the issue of belated claim amendments of granted patents as their counterparts in Singapore, it is evident that the principle of not allowing belated amendments of granted patents without proper justification is recognized and will most likely be applied based on the facts and circumstances of each case.