Allergan, Inc & Anor v Aspire Pharma Ltd

In assessing obviousness, the court must consider whether the claimed invention was technically obvious to the skilled person. Commercial cost or difficulty is not the test. The court may use the structured approach in Windsurfing International Inc v Tabur Marine (Great Britain Ltd and Pozzoli SPA v BDMO SA, while weighing all relevant circumstances, including motivation, possible research routes, effort and expectation of success.

An invention may be obvious to try where there is a sufficient likelihood of success. Multiple possible routes do not prevent one route from being obvious. Applying those principles, a formulation containing lower-dose bimatoprost and 200 ppm benzalkonium chloride was obvious. The patent was therefore invalid.

Allergan, Inc owned a European patent for an ophthalmic formulation containing bimatoprost and benzalkonium chloride. Allergan marketed the formulation for glaucoma treatment.

Aspire Pharma Ltd and Accord Healthcare Ltd had obtained marketing authorisations for generic products. They accepted that their intended dealings would infringe, but challenged the patent’s validity for obviousness over Laibovitz et al, alternatively for insufficiency. Allergan applied unconditionally to amend the patent by adding claim 18.

The principal issue was whether a formulation containing 0.01% bimatoprost and 0.02% benzalkonium chloride was obvious in light of the prior clinical study and the skilled team’s common general knowledge.

1. Obviousness. The court applied the principles recently reviewed in Actavis Group PTC EHC v ICOS Corp. The structured approach from Windsurfing International Inc v Tabur Marine (Great Britain Ltd, as reformulated in Pozzoli SPA v BDMO SA, may be used but is not mandatory. The question remains whether the claimed invention was obvious from a technical point of view.
2. The relevant circumstances included the motive to solve the problem, the number and extent of possible research avenues, the effort involved and the expectation of success. Cost was not relevant insofar as it did not bear on technical obviousness. A trial may be obvious to try where there is a sufficient likelihood of success, although some experiments may be obvious even without a particular expectation as to the result.
3. The existence of several research routes did not make an otherwise obvious route less obvious. The skilled team would have been motivated to investigate a lower bimatoprost dose to reduce hyperaemia. Repeating the prior study with improved methodology and a larger patient group was obvious.
4. Use of a preserved formulation was also obvious. Benzalkonium chloride was the usual preservative, and the skilled team would regard concentrations between 50 and 200 ppm as technically available, safe and tolerable. There was no technical reason to limit the formulation to the minimum preservative concentration.
5. Alternatively, increasing benzalkonium chloride from 50 ppm to 200 ppm to enhance corneal penetration and bioavailability was obvious to try, with a good expectation of success. The claimed formulation was therefore obvious over Laibovitz et al.
6. Claim 18 was invalid, as were all the granted claims. The insufficiency case was relied on only as a squeeze on obviousness and therefore fell away. The court nevertheless observed that, if safety concerns had made the use of 200 ppm non-obvious, the patent contained nothing to dispel those concerns.

First-instance decision of the High Court (Patents Court). No earlier appellate decision is stated in the judgment.