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Allergan successfully obtains two prohibition orders re: bimatoprost

by Tracey Stott

On June 13, 2014, Justice O’Reilly granted Allergan’s applications for prohibition orders regarding
bimatoprost (Allergan’s LUMIGAN RC) against Cobalt and Apotex: 2014 FC 566 and 2014 FC 567.

Apotex and Cobalt both alleged that Allergan’s patent is obvious, lacks utility and is anticipated. The patent at issue relates to a formulation for eye drops containing bimatoprost and benzalkonium chloride, both within specified concentration ranges. Allergan had a prior patent which the Judge described as covering “a wide range of concentrations of active ingredients and preservatives” and had previously marketed LUMIGAN — another bimatoprost product containing more bimatoprost and less benzalkonium chloride than LUMIGAN RC — which was covered by the prior patent.


As he found the claims clear, Justice O’Reilly did not resort to the specification to construe them. However, he did look to the specification to determine the inventive concept and utility. He held that although “the interpretation of the patent should be as consistent as possible across the various issues in play”, construction of the claims does not necessarily determine the inventive concept in the obviousness analysis. Considering the patent as a whole, Justice O’Reilly found the inventive concept of the claims at issue to be a formulation with reduced bimatoprost but with comparable efficiency to LUMIGAN, achieved by increasing benzalkonium chloride. He found the utility to be that LUMIGAN RC would have a comparable effect to LUMIGAN with less bimatoprost (and therefore, fewer side effects).


In holding that Apotex and Cobalt’s allegations of obviousness were not justified, Justice O’Reilly acknowledged that it was well known that bimatoprost was known to be useful for lowering intraocular pressure and benzalkonium chloride was a well-known preservative at the relevant date. However, he found that reducing bimatoprost would have been expected to lower efficacy (and side effects) and increasing benzalkonium chloride would likely have been a concern. In addition, nothing in the art pointed to benzalkonium chloride as a “penetration enhancer” for bimatoprost. He also pointed to the “numerous tests Allergan conducted” and the “millions of dollars” and “thousands of person-hours” spent on the project as evidence that it was not self-evident that the claimed formulation would work.


Justice O’Reilly rejected Apotex and Cobalt’s allegations that the utility was not soundly predicted, holding that the data in the patent is a factual basis and that the sound line of reasoning “is implicit in the data itself and would be apparent to the skilled reader; it did not have to be explicitly laid out.” The data in the patent indicated the penetration enhancement effect of benzalkonium chloride. The data would have been easily interpretable to predict that a relatively low dose of bimatoprost combined with a relatively high dose of benzalkonium chloride would reduce intraocular pressure compared to LUMIGAN.

He also rejected Apotex and Cobalt’s assertions regarding deficiencies in the data.


Apotex and Cobalt advanced different allegations of anticipation.

In the Apotex case, Justice O’Reilly agreed that Allergan’s prior patent had disclosed active ingredients (including bimatoprost) that could be combined with preservatives (including benzalkonium chloride), in amounts that include the LUMIGAN RC formulation. He also agreed that the formulations in Allergan’s prior patent could be used to treat glaucoma. However, he found that the previous patent did not disclose the special advantage of LUMIGAN RC (lowering intraocular pressure with less bimatoprost than would usually be required for a similar result), and thus the prior patent did not anticipate the claims at issue. He also found that as inventive steps were required to achieve the formulation, there was no enablement.

Justice O’Reilly also rejected Cobalt’s allegation of anticipation. In the Cobalt case, he held that, although the formulation claimed falls within the scope of a prior patent, there is nothing in that prior patent to enable a skilled person to arrive at the invention set out in the claims in issue. Further, nothing in the prior art would have alerted a skilled person to the possibility of developing the claimed formulation with lower bimatoprost and higher benzalkonium chloride to deliver efficacy compared to LUMIGAN.

Apotex has appealed.

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