Update: see our article here regarding the dismissal of ViiV's appeal.


On April 6, 2020, the Federal Court granted Gilead's motion for summary trial and dismissed ViiV's action: ViiV Healthcare Company v Gilead Sciences Canada, Inc, 2020 FC 486. ViiV claimed Gilead infringed Patent No. 2,606,282 (282 Patent) by selling bictegravir as one of three medicinal ingredients in BIKTARVY. The trial judge, Manson J., found that a summary trial was both appropriate and timely. Justice Manson dismissed ViiV's action, holding that bictegravir sodium did not fall within the scope of the 282 Patent claims.

The 282 Patent relates to compounds possessing inhibitory activity against HIV integrase. It contains 437 claims. However, only claims 1, 11 and 16 (the Claims) were at issue. Each refers to a genus of compounds and their pharmaceutically acceptable salts or solvates that are of a general structure, including a ring described as "Ring A". At issue was the purposive construction of Ring A and whether bictegravir's "bridged" ring falls within the scope of the Claims.

Summary Trial

The Federal Courts Rules (Rule 216) permit a party to bring a motion for a summary trial. If a party serves all the evidence on which it seeks to rely and "[i]f the Court is satisfied that there is sufficient evidence for adjudication, regardless of the amounts involved, the complexities of the issues and the existence of conflicting evidence, the Court may grant judgment either generally or on an issue, unless the Court is of the opinion that it would be unjust to decide the issues on the motion". Gilead's motion for the summary trial and the summary trial itself were heard over five days. Five experts (in total) were cross-examined at trial.

Gilead bore the burden of demonstrating that a summary trial was appropriate and to prove non-infringement.

ViiV argued against a summary trial, alleging that there was a lack of expert opinion evidence. However, Manson J. held the five expert witnesses provided all the necessary expert evidence to construe Ring A and determine whether Gilead had made out its case of non-infringement. ViiV also argued summary trial was inappropriate because it will result in litigating in slices. However, Manson J. found that the disposition of the claim construction issue would provide efficiencies. Even if the motion was not entirely dispositive of ViiV's claim, disposition of the claim construction issue would provide greater certainty and clarity for a trial of the remaining issues, including validity.

Claim Construction

Counsel for ViiV acknowledged that Ring A is an essential element of the Claims. While the definitions for Ring A vary between the Claims, each includes the feature of an "optionally substituted heterocycle". Bictegravir has a bridged bicyclic ring at the Ring A position. The sole issue was whether the skilled person would have understood Ring A to include bridged bicyclic rings.

Justice Manson held that the skilled person would have understood that a heterocycle is a cyclic structure that includes one or more non-carbon atoms, also known as heteroatoms, as part of the ring and that such rings can be joined together to form bicyclic or polycyclic ring structures. He also acknowledged that there are only three ways in which rings can be joined and that the skilled person would have known that the three categories of bicyclic compounds are bridged (as in bictegravir), "spiro" and "fused". Gilead argued that as the patent disclosure made specific reference to spiro and fused rings, but not bridged rings, Ring A must be limited to spiro and fused rings.

In the chemical structures depicted in the Claims, Ring A is defined by a semicircular arc. While it appears only to depict a single ring in the structure, the experts agreed that the skilled person, based on their common general knowledge, and reading the patent as a whole, would understand that additional rings are possible beyond a monocyclic Ring A.

In claim 1, Ring A is defined as an "optionally substituted heterocycle" without further limitations. Justice Manson acknowledged that this expression appears on its face to be clear and unambiguous. However, he accepted that recourse to the disclosure was necessary to understand the meaning given to these words by the inventors and the intended scope of this claim language. Both parties' chemistry experts referred to the disclosure to understand the claim terms. Justice Manson noted that bridged ring structures are never mentioned in the patent. The disclosure only refers specifically to spiro and fused ring structures in the preferred embodiments. Justice Manson ultimately held that a reasonable and fair construction of claim 1 therefore does not include bridged bicyclic Ring A structures. Similar findings were made for Ring A in claims 11 and 16.

Conclusion

As bictegravir includes a bridged ring at the Ring A position and the Claims were construed to only encompass fused or spiro rings, Manson J. held that bictegravir fell outside the scope of the Claims and Gilead did not infringe. He accordingly granted Gilead's motion for summary trial and dismissed ViiV's action, granting a lump sum award of 30% of actual costs plus reasonable disbursements. ViiV may appeal as of right.

Originally published 30 April, 2020

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