When is an invention not an invention and so liable to revocation? When it is obvious, says section three of the Patents Act 1977. But what is ‘obvious’?
This apparently simple question is a fundamental issue of patent law and one that has kept patent practitioners and the courts more entertained than perhaps any other single issue. Many sub-tests have evolved and faded away over the years to try to grasp it. One such sub-test is to ask whether the invention was ‘obvious to try’. But this itself has different formulations; some make it easier to show obviousness (and therefore a lack of invention) and others harder.
In recent years patentees, particularly in the originator pharmaceutical industry, have complained that those seeking to invalidate their patents for obviousness currently find it too easy to do so. They say the approach of the courts needs to change if innovation is to be properly protected. So when the House of Lords looked at how obviousness (in particular, the obvious-to-try test) should be assessed in the recent case of Conor Medsystems v Angiotech Pharmaceuticals, the result was keenly awaited. Would the Lords set a new test for obviousness? Would they make it more difficult to pass, and thus strengthen
The answer is not unequivocal, but it seems they may have done both of these things. If so, this is a hugely important result for patent owners.
The Angiotech patent
The patent under attack for obviousness concerned stent technology used in the treatment of angiogenesis — the growth of blood vessels causing arteries to become constricted or ‘stenosed’. This condition can result in angina and heart failure. Stents are small, tubular wire cages, which are pushed into the blocked artery to hold it open. But there is problem with conventional stents: they cannot prevent the further growth of blood vessels into the stent itself — a process known as ‘restenosis’.
However, Angiotech’s patent described a stent coated in a drug called taxol. Taxol is an ‘anti-replicate’ drug for treating or preventing restenosis. When challenged by Conor Medsystems, the patent was found obvious at first instance and in the Court of Appeal. Leave to appeal to the Lords was subsequently granted. Two key issues were identified:
Finding the invention
Before asking whether the invention was obvious, the Lords first needed to identify it. Against the patent, it was argued that there was no invention at all because Angiotech did not show that the claimed stent would reduce restenosis. The Lords agreed that a patent should not be granted for a merely speculative idea, and also that the patent specification did not prove that taxol would actually reduce restenosis. However, this did not matter as
Addressing obviousness
So was it obvious to try taxol on a stent for treatment of restenosis? In particular, was it obvious to try in the light of a publication pre-dating the patent which described unspecified ‘anti-replicate’ drug-eluting stents that might reduce restenosis? On this issue the Lords thought the correct test was to ask if the invention was something that was obvious to try with “a fair expectation of success”.
The necessary level of expectation of success would depend on all the relevant circumstances. These may include factors such as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues for research, and the effort involved in pursuing them.
In this case, even though taxol was one of a number of known anti-replicates, it was held not obvious to try on stents for the treatment of restenosis because there was insufficient expectation that it would work.
Where does this leave patentees? Will patentees now find it easier to obtain and defend patents against obviousness attacks, as they had hoped? The result on the facts, and the statement that there must be a fair expectation of success in obvious-to-try cases, does seem to be a move away from the less patentee-friendly approach adopted in more recent times. Some previous cases have not required any expectation of success that the invention would work and have disregarded the number of other potential avenues for research which might have been taken.
In contrast, the requirement of a fair expectation of success may help protect those inventions that for various reasons were lower on a list of hypothetical alternatives. The Lords themselves seem to think it is a big change: Lord Neuberger, one of the five lords who heard the case, described it as a “significant development” in
It is no doubt an important authority, but its interpretation and application in the
Paul England is a senior associate at Herbert Smith.
