Kirin-Amgen Inc and Others v. Hoechst Marion Roussel Limited and Others [2004] UKHL 46

On 21st October, 2004 Hoechst Marion Roussel Limited and Transkaryotic Therapies Inc (together referred to as "TKT") won their five year battle against Kirin-Amgen Inc ("Amgen").

Background

The dispute between Amgen and TKT relates to the production of erythropoietin ("EPO"). EPO is produced in the kidneys in minute quantities. It was discovered that EPO had the useful property that it stimulated production of red blood cells and as a result it was very valuable for the therapeutic treatment of anaemia.

Amgen invented a process of producing EPO by recombinant DNA technology. For this invention Amgen was granted a European Patent (EP0148605B2). Essentially, Amgen had discovered a way of inserting the genetic code for the expression of EPO (or a part of the EPO protein) into a host cell. The cell would then take the genetic code for EPO and express the protein as part of its natural function. Amgen's patent was directed to this invention.

TKT developed a different method of producing EPO. Almost all cells within the human body contain the full genetic code for the human body. In other words, the cells contains all the information required to produce any protein that the human body requires. However, although each cell is capable of producing any protein the human body requires, the ability of a cell to express most of the proteins is suppressed so that the cell only produces the proteins which are required for that cell's particular function. For example a liver cell will only produce proteins which are required for the functioning of the liver. TKT discovered a way to "switch on" a cell's natural ability to express EPO. This method was unknown at the priority date of the patent.

Hoechst Marion Roussel Limited started importing EPO into the UK. Amgen issued proceedings for infringement of Amgen's patent. As a concerned party TKT also joined the proceedings.

The claims which Amgen claimed were infringed were Claim 19 and 26. However, Claim 26 is a dependent claim based on Claim 1. Therefore the relevant claims were:

Claim 1

"A DNA sequence for use in securing expression in a procaryotic or eucaryotic host cell of a polypeptide product having at least part of the primary structural [conformation] of that of erythropoietin to allow possession of the biological property of causing bone marrow cells to increase production of reticulocytes and red blood cells and to increase [haemoglobin] synthesis or iron uptake, said DNA sequence selected from the group consisting of [certain DNA sequences coding for EPO disclosed in the patent]."

Claim 19

"A recombinant polypeptide having part or all of the primary structural conformation of human or monkey erythropoietin as set [in certain DNA sequences coding for EPO disclosed in the patent] or any allelic variant or derivative thereof possessing the biological property of causing bone marrow cells to increase production of reticulocytes and red blood cells to increase haemoglobin synthesis...