- the proportion of patients reporting pain in Russo (20%) is too low to incentivise the skilled person to create a new formulation;
- even if he were seeking to address the reported pain, several aspects of an injection are known to influence pain including the needle size and shape, the injection technique and the volume of injected fluid, and so it would not be obvious to increase the concentration to lower the dose volume; and
- the skilled person would have no expectation of success if the concentration were increased because of anticipated side effects, and so it would not be obvious to try increasing the concentration.
- since methotrexate is a generic drug, there was limited commercial interest in investigating new formulations, with research being primarily focussed on new biologics;
- simply that clinicians (and/or nurses depending on the identity of the person administering the drug) who form part of the skilled team might not have been aware of the problem of pain, since most methotrexate administered in the UK before the priority date was taken orally; and
- that Russo might simply not have been read by a skilled person looking to address the issue of the invention, and that this could be the sole reason for it not having been done before. In order for such a “why had it not been done before?” position to have weight, the patentee would need to show that the Russo document had been read and its content appreciated by the skilled person, who had nevertheless not pursued the route taken by the inventors.
The problem with arguments over common general knowledge alone is that the combination of features relied on is always and necessarily one created with hindsight knowledge of the invention, and worse, is one which the person attacking validity has not been able to find as a pre-existing combination in the concrete prior art. If they had they would have relied on that concrete prior art. Either the combination has not been made in the concrete prior art at all or it only appears with additional inconvenient details. If an invention is not obvious over the concrete prior art which is relied on, the court is entitled to be sceptical that an argument that it is nevertheless obvious over common general knowledge alone is correct.
The problem is illustrated in this case. Sometimes an invention belongs to a field which is not well documented but in this case Accord did not lack possible starting points. It has pleaded two documents and could easily have pleaded others…. However the documents contain what might have been thought of as "inconvenient" details. Russo does not mention subcutaneous administration by name and is aimed at JCA rather than RA. Russo is also a small study and was published six years before the priority date. Jansen does mention subcutaneous and is for RA but it does not mention pain…. That the "inconvenient" details in Russo have not led to a finding of non-obviousness is not the point. To invent as a starting point in the prior art an amalgam of the best bits of the two cited documents while leaving out the inconvenient aspects, which is in effect what the argument was, created a combination which did not hitherto exist
If it was not obvious to a skilled person to make a 25 mg dose using a 50 mg/ml concentration in a 0.5 ml volume in order to reduce pain, such a finding would not reveal a sufficiency problem not least because the patent explains that the reduced volume reduces pain. However the position with side effects is different. If it was not obvious to administer a 25 mg dose using a 50 mg/ml concentration in a 0.5 ml volume subcutaneously because of a concern about the risk of side effects, then the patent does not give such a skilled person any comfort at all about that risk. If that skilled person would not administer the formulation to treat [rheumatoid arthritis] due to the risk, they would still not do it after reading the patent, and the claim to the use of that formulation would be insufficient.
[medac’s expert] explained in his evidence that he regarded the invention as plausible because the holder of the patent, medac, was a well respected pharmaceutical company. Medac relied on this evidence. It is not relevant. As a matter of law, the identity of the inventor or patentee cannot have anything to do with sufficiency in general and plausibility in particular. The issue is an objective legal standard. It is based on the technical disclosure only.
This Kat would like to thank his colleague Tim Belcher for authorial assistance with this post.