UK Supreme Court decision – clarity on patentability of dosage claims?

The UK Supreme Court handed down its second patent decision in 6 months today. The judgment in Actavis Group & ors v ICOS Corporation & anor  (link) concerns the patent protection for Eli Lilly’s drug tadalafil. While it is significantly less lengthy than November’s Lyrica decision, it nonetheless contains some important conclusions of interest to:

• patent heavy industries - the UK test for inventive step
• the life sciences sector - can a patentable invention result from clinical trials?
• all - the basis on which a UK case may be appealed.

Speed read: Lilly’s appeal was unanimously rejected. The patent (to a specific dosage of tadalafil) was obvious. The Court of Appeal had been entitled to re-evaluate the weight attached to various factors in the assessment by the trial judge.

Of relevance to all – can appeal courts interfere with factual findings? The appellants criticised the Court of Appeal for re-examining the application of the legal test (in this case for obviousness) to the factual findings of the trial judge. The Supreme Court held:

1.  An error of principle is not confined to an error of law, but includes errors in the application of a legal standard to the facts of the case during the evaluation of those facts.
2.  That includes the weighing of different factors against each other.
3.  Having re-weighed the relevant factors, the Court of Appeal considered there was a logical failing in the trial judge’s conclusions and was therefore justified in departing from his assessment.

For patent fans - restatement of the test for obviousness: The court has re-emphasised that neither the EPO’s “problem-solution” approach nor the UK’s Windsurfing/Pozzoli test are the sine qua non of inventive step. Neither “should be applied in a mechanistic way” and each is merely a tool by which the statutory question – “was it obvious” – may be assessed [at 62]. That assessment can be multi-factorial.

One factor in the inventive step analysis used was whether the claimed lower dose was “obvious to try”. There is no change to the standard required, but the Court reiterated that the relevance of this question depends on the particular facts of the case and laid down ten factors to consider in the assessment. A step-by-step approach – asking if each step is obvious – may also be used providing the steps are untainted by hindsight. The Court also considered the EPO's parallel “could-would” approach and reached the same conclusion.

How does this affect other inventions made in Phase I-III/IV? The Supreme Court has not closed the door on dosage claims. They remain patentable, but must involve an inventive step. This will be challenging to demonstrate in many cases, but there will continue to be cases where the path of research produces an unexpected and inventive result. However, “bonus” results resulting from routine experiments required for regulatory filings are, without more, unlikely to be held valid. 

Factual background: Lilly (ICOS) in-licensed tadalafil from Glaxo, who had already filed a patent disclosing the molecule, its potency against the physiological target, a wide range of potential dosages and an exemplary dose of 50mg. Lilly progressed the molecule into pre-clinical and clinical trials, and discovered that it could be administered at a low oral dose (5mg) daily whilst retaining its effect and minimising adverse reactions. The patent in suit contained claims to that low dose. A key issue was the extent to which required dose-ranging studies would ordinarily extend to the 5mg dose.