Patents – amendment – application to amend to avoid inutility claims – applications limited to deletions of positive statements in the specification concerning the utility of the invention – exercise of discretion

Apotex Pty Ltd v ICOS Corporation [2017] FCA 466

The respondent (ICOS) is a subsidiary of Eli Lilly, and holds three Australian patents for tadalafil, better known as the erectile dysfunction treatment “Cialis”. Apotex has generic tadalafil products registered on the Register of Therapeutic Goods, but has given ICOS assurances that Apotex “has no intention” of marketing or selling those generic products during the term of the first of ICOS’s three patents (the “205 Patent”, relating to the compound itself), nor applying for listing of its products on the Pharmaceutical Benefits Scheme where the listing would take effect during that term.

Apotex has on foot invalidity proceedings in respect of ICOS’s other two patents (the “666 Patent” and the “946 Patent”). By cross-claim, ICOS alleges infringement or threatened infringement of those patents. ICOS sought to amend both patents by an interlocutory application. Of note, the amendments to the 946 Patent were limited to deletions of text from the specification. Among other things, ICOS sought to remove or dilute statements to the effect that the invention (a particular dosage regime for tadalafil) was an effective treatment for erectile dysfunction that: did not have any of the side effects associated with the competing drug, sildenafil “Viagra”); was suitable for patients with particular conditions that meant that use of sildenafil was contraindicated; and was superior to sildenafil in various other respects.

The present decision concerned Apotex’s opposition to the proposed amendments to be made to the 946 Patent, on public policy grounds. In particular, Apotex argued that it would be contrary to public policy to allow a patentee to avoid the consequences of an invention “not meeting the promise of the specification” by deleting the relevant promise after grant, particularly where the patentee had already enjoyed a monopoly over the invention for more than 17 years of its 20 year term and waited over 12 years to seek the deletions.

There is no question that s 105 of the Patents Act 1990 (Cth) permits amendments designed to overcome bases for invalidity. The question was whether the Court should exercise its discretion to allow the amendments. Justice Besanko answered that question in the affirmative.

ICOS led evidence of the events and considerations that led to its application to amend. In effect, the application was made following discussions with Eli Lilly’s patent attorneys (the privilege in respect of which was not maintained by ICOS) prompted by a 2015 decision concerning the Canadian equivalent of the 946 Patent. In that decision, allegations of invalidity for lack of utility were found to be justified such that the Canadian Minister of Health should not be restrained from issuing a “Notice of Compliance” for another generic tadalafil product, but the decision did not of itself amount to a determination of invalidity. Eli Lilly’s internal senior director of its patent division believed that a utility challenge to the 946 Patent could be defended based on clinical data, but nevertheless accepted the advice of its external advisors to amend (particularly given uncertainty under Australian law as to whether all promises in a specification had to be met by the claimed invention).

His Honour was satisfied that in providing this evidence, ICOS had made full disclosure of all relevant matters bearing on the exercise of the s 105 discretion. His Honour also was satisfied that the application to amend had been made without any disentitling delay, as it was made reasonably soon after the Canadian decision; before that decision, neither Eli Lilly nor ICOS ought reasonably to have known of the need to amend.

Apotex also sought to raise a number of other matters for the Court’s consideration, none of which were held to warrant refusal of the application.

First, Apotex argued that the Court should infer from the amendments a failure to “comply with an obligation that crystallised” on the filing of the application or the grant of the patent, namely an obligation to make promises that were, or could be met at that time. His Honour disagreed that, under the law at the time the 946 Patent was filed, ICOS was required to make statements about utility (unlike its obligations with respect to best method and sufficiency).

Secondly, Apotex pointed to statements made by ICOS, when dealing with objections raised to the delegate in 2003, that were to the same effect as statements it now wished to delete from the specification. His Honour was not satisfied, however, that those particular statements were material to overcoming the objections.

Apotex argued that the amendments would remove the “main promises” in the patent. Similarly, Apotex argued that the 946 Patent is a “selection patent” such that the advantages of the invention to the selected beneficiaries was critical to its validity. In both cases, however, his Honour disagreed that the relevant advantages or benefits to be deleted were the only advantages identified.