Pharmaceuticals – European patents – Incentive step – Prior art

Conor Medsystems Inc v (1) Angiotech Pharmaceuticals Inc (2) British Columbia University: HL (Lord Hoffmann, Lord Scott of Foscote, Lord Walker of Gestingthorpe, Baroness Hale of Richmond, Lord Neuberger of Abbotsbury): 9 July 2008

The appellant patentees (X) appealed against a decision ([2007] EWCA Civ 5, [2007] RPC20) that their patent was invalid for obviousness. X held a European patent which included a claim for a stent coated with taxol, an anti-proliferative drug, which were used together to treat or prevent restenosis. The respondent competitor (C) had applied in both the UK and the Netherlands for revocation of the patent, arguing that X’s patent merely asserted that taxol was worth trying, and did not show it actually worked.

The UK courts accepted C’s argument. The Court of Appeal found that X’s claim added nothing to existing knowledge and was obvious. The courts in the Netherlands found that it was sufficient for X to indicate that taxol would work and C’s application failed. X appealed on the basis that the decision of the Dutch court was correct and its patent was valid.

Held: (1) European patents took effect as a bundle of national patents over which the national courts had jurisdiction. It was inevitable that they occasionally gave inconsistent decisions about the same patent. However, when the question was one of principle, it was desirable that there should be uniformity in the way the national courts and the European Patent Office interpreted the European Patent Convention 2000.

In the present case the principle at stake was how to identify the concept in the invention which constituted the ‘inventive step’ for the purposes of section 1(1)(b) of article 56 of the Convention and the Patents Act 1977.

(2) The invention was the product specified in a claim and X was entitled to have the question of obviousness determined by reference to its claim. The alleged inventiveness lay in the claim that the product had a particular property, namely to prevent or treat restenosis. There was no requirement in the convention or the 1977 act that the specification had to demonstrate, by experiment, that the invention worked, or to explain why it worked. X’s specification said very little about the details of how or why taxol would be efficacious in preventing restenosis, but if the invention worked it did not matter why. The specification would be sufficient if, for whatever reason, taxol-coated stents possessed the claimed property of preventing or treating restenosis.

(3) The question was whether X’s solution was obvious and not whether it was obvious that taxol (among many other products) might have the effect claimed. A patent would not be granted for an idea which was mere speculation, unsupported by anything disclosed in the specification. However, there was enough in X’s specification to demonstrate that it was plausible that taxol would work, and X had disclosed the results of its tests, AGREVO/Triazole sulphonamides (T939/92) (1996) EPOR 171 EPO (Technical Bd App) and JOHN HOPKINS/Factor-9 (T1329/04) (2006) EPOR 8 EPO (Technical Bd App) considered. There was no reason as a matter of principle why, if a speculation passed the threshold test of disclosing enough to make the invention plausible, the question of obviousness should be subject to a different test according to the amount of evidence which the patentee presented to justify a conclusion that his patent worked.

(4) The prior art mentioned taxol as one of an undifferentiated number of drugs which could be tried. Those disclosures left one with the knowledge that the solution may lie somewhere in the large number of drugs which could be tried, but was insufficient to make it obvious that taxol would prevent restenosis, Johns Manville Corp’s Patent (1967) FSR 327 CA (Civ Div) and Generics (UK) Ltd v H Lundbeck A/S [2007] EWHC 1040 (Pat), (2007) RPC 32 considered. The Court of Appeal had therefore failed to answer the correct question, namely whether it was obvious to use a taxol-coated stent to prevent restenosis.

Appeal allowed.

Antony Watson QC, Andrew Waugh QC, Colin Birss QC (instructed by Howrey) for the appellants; Michael Tappin, Jessie Bowhill (instructed by the Treasury Solicitor) for the ­respondents.