KIRIN-AMGEN INC V. HOECHST MARION ROUSSEL LIMITED [2004] UKHL 46
FACTS
Kirin Amgen Inc a pharmaceutical company, invented a process of producing erythropoietin (EPO) by recombinant DNA technology and for its invention it was granted a European Patent (EP0148605B2). Amgen’s invention of EPO was an advance in the treatment of anaemia and marketed the EPO under the name of Epogen.
Transkaryotic Therapies Inc (TKT) another corporation also developed a method of making EPO, and markets it under the name Dynepo. It uses a process called gene activation and the product was named as GA-EPO. Thus it used a different method as compared to that of Amgen. Hoechst Marion Roussel Ltd ("Hoechst") another pharmaceutical company proposed to import GA-EPO into the United Kingdom.
The essential difference between both the drugs namely Epogen and GA-EPO is that the former is made by an exogenous DNA sequence coding for EPO which has been introduced into an host cell and the latter is made by an endogenous DNA sequence coding for EPO in a human cell into which an exogenous upstream control sequence has been inserted.
Procedural History: Amgen’s claims were the following:
DNA sequence for use in securing the expression of EPO in a host cell,
(19) EPO which is characterized by being the product of eucaryotic expression of an exogenous DNA sequence with further characteristics that made it different from pre-existing EPO, and
(26) EPO, which is the product of the expression in a host cell of a DNA, sequence according to claim 1.
The trial judge held that claim 19 was invalid for insufficiency but that claim 26 was valid and infringed. The Court of Appeal held that both claims were valid but that neither was infringed. Both sides appealed, Amgen against the decision that, as a matter of construction, the TKT process is not within the claims and TKT against the rejection of its attack on the claims for insufficiency and anticipation.
ISSUE
Whether TKT's EPO fell outside the claims of Amgen's patent suit because of the difference in the way it was made?
HELD
Until the Patents Act 1977, which gave effect to the European Patent Convention ("EPC") the patent protection under UK law was limited to what was written or stated in the claim. Article 69 of the EPC states that “ The extent of the protection conferred by a European patent or a European patent application shall be determined by the terms of the claims. Nevertheless, the description and drawings shall be used to interpret the claims."
As an invention is protected only if a reference is made in the claim it becomes important in determining what falls within the scope of the claims.
As this was leading to injustice, the court in this case considered interpretation of Article 69 and came up with the Protocol on the Interpretation of Article 69 (the "Protocol") which requires that Article 69 should not be read as to mean that the claims are given a literal meaning nor should the claims be treated a mere guidelines. Rather the correct treatment is a position between the two extremes, which provides a fair protection for the patentee with a reasonable degree of certainty for third parties.
The Protocol is intended to give the patentee the full extent, but not more than the full extent, of the monopoly, which a reasonable person skilled in the art, reading the claims in context, would think, he was intending to claim.
In interpreting the claims, another approach is to take the objective test or the purposive interpretation. The purposive interpretation laid down three questions, does the variant have a material effect upon the way the invention works, if no, does the variant that did not have material effect had been obvious at the time of filing the patent to a reader skilled in the art and thirdly whether a reader skilled in art would have understood through the language of the claim whether the patentee intended strict compliance of the claim or not.
The method used by both the companies was different to arrive to the same production of drug. Thus there was no material effect on the result, but it was not obvious for the person skilled in art to think that there was an obvious alternative method at the time of filing of the claim. Thus the endogenous method introduced by TKT did not infringe Amgen’s claim.
In relation to the purposive construction, the doctrine of equivalents was also laid down in the case. Doctrine of equivalents is a legal rule that allows a court to hold a party liable for patent infringement even though the infringing device or process does not fall within the literal scope of a patent claim, but nevertheless is equivalent to the claimed invention.
The effect of the doctrine of equivalents is to extend protection to something outside the claims that performs substantially the same function in substantially the same way to obtain the same result.
Amgen’s claims are concerned with the expression of EPO by a gene, which is exogenous to the cell. But the genes, which express EPO in cells by the TKT process, are not exogenous.
The court concluded that TKT did not infringe any of Amgen’s claims and dismissed the appeal.
Doctrine of equivalent and purposive construction which states that a claim should not be limited to literal interpretation and a party can be held liable for patent infringement even though the infringing device or process does not fall within the literal scope of the claim. Thus the doctrine of equivalent allows the patentee to extend his monopoly beyond the claims.
It was held by the court that TKT did not infringe any of the claims of Amgen. As the method used by TKT was different from the method used by Amgen in the production of the same drug. The person skilled in the art would also not come to the conclusion that the production of GA-EPO is same as that of EPO.