Eli Lilly and Actavis have been battling over the patent on Lilly's Alimta product since 2012. Fieldfisher went to the UK Supreme Court from 4 - 6 April 2017 to hear the latest round of the proceedings.
The Supreme Court will rule on two issues of fundamental importance in patent cases: (1) the extent of protection conferred by patents in respect of "equivalent products"; and (2) the correct approach to determining indirect infringement in circumstances where an end user may use the "equivalent product" in a way that falls directly within the patent claims.
Lilly's Alimta product for the treatment of lung cancer is marketed as a freeze-dried powder which must be reconstituted and diluted with saline before being administered to patients. Eli Lilly is appealing the Court of Appeal's decision that Actavis' proposed competing product does not directly infringe Lilly's patent on Alimta (the Patent). The Patent covers the use of pemetrexed disodium in combination with B12 and folic acid to treat cancer.The Court of Appeal held that Actavis' pemetrexed product - comprising dipotassium rather than disodium - would not infringe the Patent directly but that indirect infringement would occur when medical practitioners dilute it with saline (containing sodium ions). Actavis is cross-appealing the Court of Appeal's decision on indirect infringement.
The dispute as to direct infringement hinges on whether the skilled person would consider that the potassium salt used in Actavis' product is an obvious non-material variant to disodium. If so, use of the 'equivalent' salt would be covered by the Patent.
The question on indirect infringement is whether Actavis may be liable for sales of its pemetrexed product in view of the likelihood that medical practitioners will dilute that product with saline (containing sodium ions). Does this mean that Actavis is thereby "supplying 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"?
Direct infringement
Counsel for Eli Lilly argued that the Patent covered all salt variants which would have been obvious to the skilled person at the priority date of the Patent. It was common general knowledge at that time that salts other than disodium could be used with pemetrexed. Although the skilled person would not know which of those salts were soluble, routine tests could be used to establish this. Counsel for Lilly also suggested that the current approach in UK case law focused too much on the literal meaning of the language of the claims.
Counsel for Actavis argued that Eli Lilly's prosecution history showed that the EPO had rejected Eli Lilly's claim for pemetrexed diacid. Eli Lilly had then limited its Patent to cover pemetrexed disodium only. Counsel suggested that this clear limitation of the claims had the effect of excluding equivalents from the scope of the Patent monopoly. Counsel also submitted that the questions asked in the UK case of Improver were the appropriate questions for determining the scope of the claims.
Indirect infringement
Counsel for Actavis advocated that the focus for determining indirect infringement should be on the manner in which Actavis produced its product and how this differed from Eli Lilly's production process. Counsel for Eli Lilly disagreed contending that the focus should be on the nature of the product actually administered to patients. Once sodium ions are added to Actavis' product by medical practitioners, this amounted to the administration to patients of a product falling with the scope of the claim. Dilution on this basis was reasonably foreseeable thereby amounting to indirect infringement of the Patent by Actavis.
The decision in this case will have potentially far-reaching consequences for patent owners and users, well beyond the pharmaceutical sector in which this battle is being fought. We will report on the Supreme Court's decision as soon as it becomes available.
With thanks to Amelia Thomson for her contribution to this article.