Lyrica continues – The Court of Appeal considers infringement and validity of Pfizer’s second medical use patent


On 13 October 2016 the Court of Appeal handed down judgment in relation to a second medical use patent with claims in the Swiss form. As readers may know the patent was owned by Warner-Lambert (Pfizer) and covered a compound called pregabalin for the treatment of pain. Pregabalin is sold by Pfizer as “Lyrica”. Previous articles on earlier decisions of the Court in relation to this patent can be found here and here
Of interest are the Court of Appeal’s comments on plausibility, construction and infringement of Swiss-type claims, and whether it is an abuse of process to rewrite claims after a judgment at first instance.
Floyd LJ confirmed that the test for plausibility is a low threshold test and is designed to prohibit speculative claiming. He noted that “claims will easily be seen not to be speculative where the inventor provides a reasonably credible theory as to why the invention will or might work. The same is true where the data in the specification is such that the reader is encouraged to try the invention.” Floyd LJ also confirmed that the test for plausibility is not the same as the test for whether an invention would be “obvious to try” i.e. for a claim to be plausible, there is no need for a reasonable expectation of success.
On the facts of this case, Floyd LJ held that it was not plausible that pregabalin would treat “central neuropathic pain”. This was because there was no data in the patent from which the skilled person could make predictions about that type of pain. He held that a claim to a different type of neuropathic pain, peripheral neuropathic pain, would be plausible, even though the data presented would not have enabled a firm prediction of efficacy to be made. This was because the skilled team would be encouraged by the data in the patent to carry out simple tests to confirm the suitability of pregabalin for the treatment of peripheral neuropathic pain. However, there was no independent unifying characteristic to make a claim to all neuropathic pain plausible. Hence a claim to neuropathic pain was insufficient for being over broad.
Abuse of process
Floyd LJ agreed with Arnold J’s decision in the High Court that Warner-Lambert’s application to amend claim 3 from neuropathic pain to peripheral neuropathic pain was an abuse of process. This application was only filed after Arnold J’s judgment on validity had been handed down (and in response to the finding that a narrower claim to “peripheral neuropathic pain” would be plausible). The latest that Warner-Lambert should have raised this was the start of trial.
As the patent was held to be invalid, the commentary on infringement is strictly obiter but clearly of importance.
Whilst noting the reluctance of Arnold J to follow the Court of Appeal’s interpretation of Swiss-type claims as set out in an earlier decision within the pregabalin saga, and acknowledging that infringement of Swiss-type claims is a difficult issue, Floyd LJ confirmed what had been said on construction in the previous Court of Appeal decision. This means that the relevant test for infringement is an objective not subjective one. The word “for” in Swiss-type claims should be interpreted as requiring that a manufacturer knows or can reasonably foresee the ultimate intentional use for the patented indication. Floyd LJ also confirmed that this objective intention can be “negatived” if the manufacturer shows that he has taken “all reasonable steps within his power” to prevent the infringement occurring.
On indirect infringement, Floyd LJ noted that there is a danger in translating the statutory test into a requirement for a “downstream act of manufacture”. From this, he appears to mean that there is no need to stretch the “manufacturing” element of a Swiss-type claim to include steps taken downstream which are clearly not “manufacturing” in the normal sense. Instead, the test is whether means are provided which are suitable for putting the invention into effect, i.e. indirect infringement could occur if the generic manufacturer supplies generic pregabalin and the invention is then put into effect by the pharmacist ascribing the patented purpose to that generic medicine.

Robert Bond