Last year we reported that the UK High Court had ruled that Actavis UK Ltd would not infringe Eli Lilly & Company’s European patent EP1313508 by launching a generic pemetrexed product. In that Decision Mr Justice Arnold construed the claims using the prosecution history and concluded that claims directed to pemetrexed disodium in combination with vitamin B12 excluded any one of the active ingredients pemetrexed diacid, dipotassium or ditromethamine which Actavis were seeking to launch (see here). The Court of Appeal has now confirmed that pemetrexed salts other than pemetrexed disodium would not constitute a direct infringement of Lilly’s claims, but has dismissed the weight given to the prosecution history by Mr Justice Arnold at First Instance. Further, in a Decision contrary to the First Instance Decision, the Court of Appeal has concluded that there would be indirect infringement and declined to issue a declaration of non-infringement relating to direct infringement alone (Actavis UK Limited & Ors v Eli Lilly & Company  EWCA 555 (Civ), here).
At First Instance Mr Justice Arnold used “the Improver questions” (Improver Corp v Remington Consumer Products Ltd  FSR 181, set out here) to decide that a medical use claim directed to pemetrexed disodium in combination with vitamin B12 for use in inhibiting tumour growth did not extend protection to the use of pemetrexed diacid, pemetrexed dipotassium or pemetrexed ditromethamine. As expected by most, the Court of Appeal has now confirmed that Mr Justice Arnold’s use of the Improver questions to conclude that there was no direct infringement was correct, but in presenting the leading judgement Lord Justice Floyd criticised the emphasis placed upon the prosecution history and confirmed that the doctrine of file wrapper estoppel used in the US does not apply in the UK. This reasoning is likely to offer some comfort to Patentees and Patent Attorneys alike who, under Arnold’s previous reasoning, may have been concerned that any amendments made during prosecution of a patent application could be seen as admissions during subsequent litigation of a granted patent if the prosecution history suggested that an amendment was intended to be limiting.
Having confirmed that Actavis’ proposed product would not constitute a direct infringement of Lilly’s claims, the Court of Appeal turned its attention to indirect infringement which is covered by Section 60(2) of the UK Patents Act (UKPA), and requires that:
… a person (other than the proprietor of the patent) also infringes a patent for an invention if, while the patent is in force and without the consent of the proprietor, he supplies or offers to supply in the United Kingdom a person other than a licensee or other person entitled to work the invention with any of the means, relating to an essential element of the invention, for putting the invention into effect when he knows, or it is obvious to a reasonable person in the circumstances, that those means are suitable for putting, and are intended to put, the invention into effect in the United Kingdom.
In considering the issue of indirect infringement, Lord Justice Floyd gave particular weight to the procedure required for reconstitution of pemetrexed prior to administration by injection, and concluded that reconstitution of any pemetrexed salt in saline (composed of sodium chloride solution) would provide pemetrexed disodium, as required by Lilly’s claims. On this basis, and since the skilled person would understand the reconstitution should be performed in saline, any of the pemetrexed salts proposed by Actavis would constitute a “means relating to an essential element of the invention”, as required by Section 60(2) UKPA, resulting in indirect infringement of Lilly’s claim. This is in contrast to the reasoning provided at First Instance where the essential element was considered to be the sodium salt of pemetrexed, leading to a finding that there was no indirect infringement. On this point the Court of Appeal appears to have got to the heart of the indirect infringement issue since it must be correct to assess the nature of the active agent following administration when considering the essential elements of the invention.
In view of the finding of indirect infringement, Lord Justice Floyd concluded that Actavis was not entitled to a declaration of non-infringement and refrained from issuing a declaration relating to direct infringement only or issuing a declaration limited by reconstitution method. This has left the door open for Actavis to start new proceedings at First Instance requesting a declaration of non-infringement for a different reconstitution method, and their post-appeal submissions suggest that they will take this route. We therefore expect to see more on this issue in the near future as the UK Court seeks to confirm whether a finding of indirect infringement can be avoided by specifying a reconstitution method, even in the knowledge that the end user may disregard such directions.
If you need further information please contact Nina White or your usual Boult Wade Tennant adviser.