ViiV Healthcare Company v Gilead Sciences Pty Limited (No 2)

[2020] FCA 1455

This is the second reported interlocutory dispute between the parties over infringement and validity of a patent directed to compounds possessing HIV integrase inhibitory activity – essentially anti-HIV agents.

Previously, Gilead had unsuccessfully complained that ViiV’s amended position statement on infringement insufficiently detailed how the infringement claim was put: ViiV Healthcare Company v Gilead Sciences Pty Limited [2020] FCA 594. On this occasion, Beach J considered ViiV Healthcare’s assertion that Gilead’s particulars of invalidity concerning lack of utility should be struck out because they were insufficiently particularised. His Honour also addressed an application for discovery made by Gilead which would support its lack of utility case.

In short, Gilead’s particulars of lack of utility were not struck out, but its application for discovery was only partially successful, with the categories of discovery ViiV was ordered to give being significantly limited in some respects. Beach J considered that, while the particulars of invalidity were broad, that was in part due to the broad nature of the patent claims. His Honour observed that “Gilead will not be in a position to put forward more complete particulars of inutility until discovery has occurred and/or any experiments have been completed.” Nevertheless, Gilead’s application for discovery needed to be related to work that was said in the patent to have been performed by ViiV, not to work at large, and if that meant Gilead would need to perform experiments to make out its case, as Beach J observed: “so be it”.

His Honour appears to have taken the pragmatic view that it is not unreasonable for ViiV to remain somewhat in the dark regarding the case put against its patent until Gilead files its evidence on chief regarding validity, and that Gilead’s case on invalidity need not crystalise until it has inspected discovery on matters concerning the alleged lack of utility and run any necessary experiments and filed evidence resulting therefrom. His Honour also observed, however, that by that time, any remaining uncertainty of the lack of utility claim would likely be struck out.

Turning back to the detail of the dispute, claim 1 of the patent in issue is to a compound of which a primary formula can have various substituents. Beach J observed that the claim encompassed “a vast range of optional substitutions” – producing many millions of compounds that would fall within the claim. This becomes an important matter for the purposes of dealing with ViiV’s strike out application, as we will see, shortly.

Gilead asserts by way of its particulars of invalidity that the patent promises that the compounds of the invention will have anti-HIV activity or has potent HIV integrase inhibitory activity. It then asserts that the patent does not teach how to make a range of theoretical compounds that fall within claim 1 simply, and that the skilled person could not do so without undue experimentation.

As an aside, that complaint appears more akin to a claim of lack of full description under section 40(2)(a) of the Patents Act 1990 (Cth) rather than lack of utility, but it may be that lack of sufficiency is not available because the requirement (pre-Raising the Bar amendments) can be met if the skilled person can make something (one thing) within the claim, whereas utility requires the promise to be met across the scope of the claim. It seems that Gilead’s point is that, if the skilled person cannot make (without undue burden) a theoretical compound that falls within the claim, then ipso facto, that person cannot meet the promise of the invention of having, for example, potent HIV integrase inhibitory activity. But for that argument to work, it seems that the promise of the patent must include (at least implicitly) that the skilled person in the art can make all theoretical compounds falling within the claim. It will be interesting to see how the argument is developed at trial.

ViiV’s complaint on Gilead’s particulars as to lack of utility was that the compounds which it is asserted the patent fails to teach how to be made, and which the skilled person could not make without undue experimentation, are characterised as having certain features such as “bulky substituents” in certain positions. That, necessarily, covers a huge number of possible compounds. Furthermore, Gilead’s particulars stated that the compounds which were inutile “included” those described generally – which meant they were not confined to such compounds. Indeed, Gilead’s particulars provided that further compounds may be particularised in future.

His Honour accepted that Gilead’s particulars of invalidity did not “currently comply with r 34.46(3) because the particulars of inutility are not limited to identified compounds”. But his Honour considered that the breadth of the patent claim, along with the ability of Gilead to better explain its case by way of its evidence in chief, meant that “this is an appropriate case to allow the amended particulars to stand until Gilead files its evidence in chief on inutility and amends the amended particulars to conform with that evidence”.

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