Are all dosage patents obvious? Actavis v ICOS in the Supreme Court

Unlike some other recent Supreme Court rulings, the decision in Actavis v ICOS does not strike out in a new direction. There is only one judgment, rather than several conflicting ones as in last year’s Warner-Lambert case. But this decision does cast a shadow over pharmaceutical patenting, making it more likely that patents resulting from the standard process of pharmaceutical research – especially dosage patents - will be considered uninventive by the courts.

The case involves claims to a low level dose of the erectile dysfunction treatment tadalafil. Both Swiss-form and EPC 2000 treatment claims were used. The key prior art document, a 1997 GSK patent referred to as “Daugan”, described tadalafil and another compound that could be used for the oral treatment of erectile dysfunction.

At trial, the judge came to the conclusion that the dosage patent was valid, but the Court of Appeal disagreed. The dose that ICOS had identified (5mg) was low, but not outside the range suggested in Daugan. A 5mg does would not have been within the scope of the first dose-ranging study that a skilled team would have carried out. But having found a therapeutic plateau in initial studies, the team would have extended the testing range to include lower doses.

What is the right approach? 

In its analysis, the Supreme Court sets out the various approaches to assessing obviousness and the factors to be taken into account. It does not designate a single approach that should always be followed. Instead it explores how the UK’s Windsurfing/Pozzoli approach and the European Patent Office’s “problem-and-solution” approach can be used. However, it explains that these are only ways of getting to an answer to the statutory question of whether there is an inventive step having regard to the state of the art (Article 56 of the European Patent Convention and s.3 of the UK Patents Act). 

A shopping list of relevant factors 

The Supreme Court lists ten different factors that it considers relevant. Briefly:

• was it “obvious to try”?
• was the research routine or an established practice?
• was the research burdensome and costly?
• what value judgments would the research team have to make?
• were there alternative paths of research?
• would there have been a motive to carry out the research?
• were the results unexpected or surprising?
• is knowledge of the endpoint necessary to drive the direction of the research (the danger of hindsight)?
• does the invention provide a “golden bonus” to work that would have been carried out anyway?
• in the case of a dosage patent, is there an unusual feature that would not have followed from standard dose ranging studies?

Taking account of these different factors the Supreme Court concludes that the Court of Appeal was right. The patent is invalid for obviousness. The skilled team would have followed standard industry procedures to find the 5mg dose. The failure of the initial dose ranging studies would not have deterred them from going on to explore lower dosage ranges. 

When are dosage patents inventive?

The answer to the question, "Are all dosage patents obvious?" is no, but patentees will need something out of the ordinary to support inventiveness. For example, in a 2008 case (Actavis v Merck), treatment for androgenic alopecia with finasteride had ceased to be worth investigating with any dosage regime, and so it was inventive to explore it further. Does this rather narrow approach offer appropriate support for continuing research to realise the full benefit of a medicinal product? The Supreme Court clearly feels that it does, although we are not convinced.

More broadly, this ruling from the highest court in the land shakes up the established approach to understanding inventiveness. Given the long list of factors that a court might take into account, and the different possible approaches it might take, we think it will now be more difficult to make a clear assessment of whether the test is met.

Do pharmaceutical companies need to rethink? 

This case does not necessarily mean a change of direction for patent filing. Dosage patents can still be valid and a worthwhile means of protecting continuing research on a known drug. But they are clearly vulnerable to an obviousness attack. Patent applicants should focus on any unusual features in their research programme and emphasise these where possible.

James Fry and Isabel Teare