Canada: LUMIGAN RC Formulation Patent Found Valid And Infringed

In a patent infringement action brought by Allergan and AbbVie under subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations (Regulations), in relation to 0.01% w/v bimatoprost solution for ophthalmic administration (AbbVie's LUMIGAN RC), Justice Pentneyof the Federal Court found Canadian Patent No. 2,585,691 (the 691 Patent) to be valid and granted a declaration of infringement: Allergan Inc v Juno Pharmaceuticals Corp, 2023 FC 1686.

Background

The 691 Patent was previously the subject of invalidity allegations by Cobalt and Apotex in separate applications brought under the pre-amended Regulations. In each decision, the Federal Court found that the allegations of obviousness, anticipation and lack of utility were not justified and Apotex's appeal was dismissed.

LUMIGAN RC is used to treat glaucoma and intraocular hypertension by lowering intraocular pressure (IOP). It is an improvement over a previous formulation (old LUMIGAN) that lowered IOP but had unwanted side effects. The new formulation involved two key changes: a significant reduction in the amount of bimatoprost combined with a significant increase in the amount of the preservative benzalkonium chloride (BAK). Juno sought to obtain approval for a generic equivalent to LUMIGAN RC. Juno conceded that its product would infringe the 691 Patent but argued that the 691 Patent is invalid for obviousness and insufficient disclosure.

Inventive concept informed by specification

In construing the asserted claims, Justice Pentneyheld that the claims should be read in accordance with the plain meaning of their terms. However, as the claims do not reveal the "solution taught by the patent", the interpretation of the inventive concept was based on a reading of the claims informed by the specification. The inventive concepts were found to be a formulation with less bimatoprost but with comparable efficacy to old LUMIGAN, which is achieved by including more BAK than is found in old LUMIGAN (claim 16) and the use of this formulation for the treatment of glaucoma and intraocular hypertension in humans (claim 19). The Court held it was not bound to follow the previous determinations of the inventive concept in the proceedings against Cobalt and Apotex under the pre-amended Regulations.

Claims neither obvious nor obvious to try

The Court held that the state of the art showed that reducing the amount of bimatoprost in the formulation was expected to reduce its IOP lowering efficacy and taught away from increasing the amount of BAK. Justice Pentney held that the steps required to bridge the substantial gap would not have been obvious to the skilled person.

Considering the factors in the "obvious to try" test, Justice Pentneyheld that it was not more or less self-evident that what is being tried ought to work; that the extent, nature and amount of effort required to achieve the invention was extensive; that there was a motive in the prior art to find the solution the patent addresses; and that the actual course of conduct shows that the invention was not reached "quickly, easily, directly and relatively inexpensively" and therefore the invention was not obvious to try.

Claims not invalid for insufficiency of disclosure

Justice Pentney held that the 691 Patent, read as a whole, discloses sufficient information to enable a skilled formulator to make the formulation and a skilled ophthalmologist to administer it to patients with glaucoma or intraocular hypertension and that this is all that the law requires. Arguments advanced by Juno relating to safety and efficacy were held to be irrelevant as the features were not in the claims.

Juno also argued that the 691 Patent does not adequately disclose that 200 ppm BAK was used to increase ocular permeability of 0.01% bimatoprost. However, this was rejected on the basis that this link is clear in the data and a patent does not have to explain how the invention works as long as it explains how to work the invention.

Finally, Juno argued that since Allergan has asserted that data based on rabbit studies cannot be directly extrapolated to the effects on humans, the disclosures in the 691 Patent regarding permeability are not sufficient. However, this was also rejected. Justice Pentney held that while the data based on rabbit studies cannot be expected to show the precise results that will be achieved in humans, it is regularly accepted as a basis for prediction regarding clinical results.

Juno has appealed (A-14-24).

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