Claim Construction of a "Mixture" and Infringement of a process claim
In Amgen v Hospira the FC, affirming the DC, held that Hospira's method of manufacture of erythropoietin (EPO) would infringe the asserted claims of Amgen's patent related to 'preparing a mixture of two or more EPO isoforms'.
At issue was the Claim 27 of the ’298 patent which recited "A method for obtaining an erythropoietin composition having a predetermined in vivo specific activity comprising preparing a mixture of two or more erythropoietin isoforms of claim 1"
while the claim 1 recited "An isolated biologically active erythropoietin isoform having a single isoelectric point and having a specific number of sialic acids per molecule ... " [Emphasis added]
Neither party had disputed [!!!] that though claim 27 refers to claim 1, it is independent claim. It was surprising that, at least, Hospira did not contested to qualify claim 27 as dependent on claim 1 and/or read all the limitations of claim 1 in to the claim 27, had it been contested, Hospira would have had a favourable construction, at least.
Hospira argued that the claim 27 requires mixing two or more 'isolated' isoforms of EPO; and the argument was supported by the fact that the inventor of the alleged invention had himself testified that his invention was 'to separate the isoforms and then recombine them or mix the fractions back together' to make a composition. Hospira's process did not involve mixing isolated isoforms, rather all the isoforms of the Hospira product eluted together off an ion exchange column.
However, Amgen's contentions were that the claim was directed to "preparing a mixture" (of isoforms) and not limited to "mixing" (the isoforms), though preparing the mixture could be accomplished by mixing individual isoforms.
Court agreed with Amgen that "preparing a mixture of two or more EPO isoforms of claim 1" does not require that the mixture is prepared in any particular way. There was nothing in the claim or the specification that would limit the claim 27 to 'mixing' individual isoforms and hence Hospira infringed.
What, most probably, went in favour of Amgen's- and against the Hospira's proposed construction is the fact that the specification at one point suggested that the mixture can be produced by isolating the isoforms simultaneously - "methods include isolation of individual isoforms by ... preparation of mixtures of isoforms having a predetermined number of sialic acids per molecule by techniques such as ion exchange chromatography or chromatofocusing.”
But, no matter what the specification 'disclosed', what was important was the fact that the claim 27 was 'dependent' on claim 1; the claim 27 'required' preparing a mixture of two or more isoforms of claim 1 and the claim 1 was directed to isolated isoforms. Could "disclosure-dedication" doctrine have invoked? So what if the specification provided multiple methods of preparation of mixture, what was claimed was 'preparing a mixture of two or more isoforms of 'isolated' isoforms. Answer to this, probably, could have been better obtained had the claim 27 was contested to be a dependent claim.
DISCUSSION ON THE SECOND ASPECT OF THE DECISION - "THE SCOPE OF SAFE HARBOR" IS IN A SEPARATE POST.