Legislation Update - Changes to patent linkage system in Singapore

A number of amendments have been made to the implementing regulations relating to Singapore’s patent linkage system, which are found in Regulation 23 of the Health Products (Therapeutic Products) Regulations 2016 (the “Regulations”), with effect from 1 August 2024. This follows a public consultation that the Singapore Health Sciences Authority (“HSA") had conducted in relation to the proposed amendments earlier this year.

The most important amendment clarifies the types of patents that must be declared when applying for registration of a therapeutic product in Singapore (a.k.a. “marketing approval or MA application”). Additionally, changes have also been made to the steps which the patent owner must take to trigger the 30-month stay on the grant of an MA application.

The amendments lend much needed clarity to the Regulations, which had previously been criticised by some as being unclear and favouring patent owners. However, this is unlikely to be the final word on the topic as there could still be some uncertainty as to the interpretation of the amended Regulations. Also, HSA has announced that it is reviewing other suggestions it has received on possible additional changes to be made to the patent linkage system. As such, this remains a somewhat fluid space.

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The Amendments

Clarity on patents to be declared

Previously, under the Regulations, all “[patents] in force in respect of the therapeutic product” had to be declared. It was not fully clear from this wording whether process patents were covered, and this issue arose in a number of lawsuits before the Singapore courts.

One argument, amongst others, that process patents need not be declared was that Singapore’s patent linkage system was implemented to fulfil our obligation under the US-Singapore Free Trade Agreement, and the US system did not involve process patents being listed in the “Orange Book” (which contained an exhaustive list of the patents that need to be declared when applying for registration of a generic drug). Indeed, in most of the jurisdictions around the world which have implemented patent linkage systems, process patents do not play a role.

In August 2020, the Singapore Court of Appeal in Zyfas Medical Co v Millennium Pharmaceuticals, Inc. [2020] SGCA 84 held that process patents fell within the broad wording of the previous Regulations and had to be declared. Moreover, the court suggested that a process patent must be declared as long as the active ingredient in the therapeutic product which is the subject of the MA application could have been made using the patented process. (See our article on the decision here.) Whilst this decision confirmed that process patents need to be declared, there remained uncertainty given the lack of guidance as to how relevant process patents should be identified in the first place.

Under the amended Regulations, only patents containing the following types of claims need to be declared:

(i)    a claim for an active ingredient of the therapeutic product for which registration is sought;

(ii)   a claim for a formulation or composition of that therapeutic product; and

(iii) a claim for the use of an active ingredient in the manufacture of that therapeutic product for a specific therapeutic, preventive, palliative or diagnostic use.

(each a “restraining patent”).

The amended Regulations also specify, for the avoidance of doubt, patents which do not ned to be declared, namely:

-      a process patent (other than a process patent that contains a claim mentioned in (iii) above);

-      a patent that contains only claims relating to packaging;

-      a patent that contains only claims relating to metabolites; and

-      a patent that contains only claims relating to intermediates.

This amendment brings Singapore’s patent linkage system one step closer to that in the US, where only patents that claim the active pharmaceutical ingredient, drug formulation or composition, and method of use of a compound can be included in the Orange Book. However, since method of use claims are not allowed in Singapore, one notable difference is that this category of claims has been substituted with so-called “Swiss style”…