High Court of England and Wales Upholds Dosage-Regime Patent

The case of Teva v ICOS concerns the validity and infringement of two patents for tadalafil, and gives a good example of how the Court applies the fair expectation of success ' test for inventive step. If something is obvious to test in a research program with a fair expectation of success then it will likely be found to be obvious by the Court. However, if there is low expectation of success then there is a better chance of the Court finding inventive step.

EP (UK) 1 173 181 claimed administration of tadalafil up to a maximum total dose of 5mg per day, and was held to be valid. The prior art dose was 50mg and the Court recognised that a team engaged in commercialising the product would have conducted a clinical programme which would likely have included a 5mg dose in a dose ranging study. However, the team would not have had a reasonable expectation that 5mg would produce a clinically relevant effect nor one with minimal side effects. This is a positive decision for patentees who might have come to fear that if something was obvious to test then the Court would find it lacking inventive step.

Conversely, EP (UK) 1 200 092 which claimed a free drug particulate form of tadalafil in which at least 90% of the particles have a particle size of less than about 40 microns was held to be obvious. The claimed form of the drug provided improved rates of uptake, but it was found that the skilled team would test micronisation in the expectation that it would improve bioavailability.

The present judgment illustrates the practical approach taken by the High Court in the assessment of inventive step and how the actions of the skilled team and the expectation of success are considered in determining obviousness.

A link to the judgment is here.