By Memorandum Opinion entered by The Honorable Richard G. Andrews in Amgen Inc. v. Hospira, Inc., Civil Action No. 15-839-RGA (D.Del., November 30, 2016), the Court issued its claim constructions for the two phrases in dispute in claims 1 and 8 of U.S. Patent No. 5,856,298 (“the ‘298 patent”) and found that claim 8 of the ‘298 patent is invalid under 35 U.S.C. § 112 because it is a dependent claim that contradicts a limitation of the claim from which it depended – claim 1.

In construing the phrase “an isolated . . . isoform” in claims 1 and 8 of the ‘298 patent, the Court adopted Hospira’s proposal that “an isolated . . . isoform” means only one isoform. Id. at *4-6. In doing so, the Court rejected Amgen’s proposal that the phrase “an isolated . . . isoform” allows for mixtures of at least one isoform. Id. The Court reasoned that Amgen’s proposed construction would render the word “isolated” superfluous and would equate the phrase “an isolated . . . isoform” with “an insoform ”, which would violate the principle that “claims are interpreted with an eye toward giving effect to all terms in the claim.” Bicon, Inc. v. Straumann Co., 441 F.3d 945, 950 (Fed. Cir. 2006).

In construing the phrase “isolated . . . isoform” in claims 1 and 8 of the ‘298 patent, the Court adopted Amgen’s proposal that “isolated . . . isoform” as referred to in claim 1 means “a group of molecules that has a single isoelectric focusing point and a specific number of sialic acids per molecule, and appears as a single band on an isoelectric focusing gel (an example of which is shown in Figure 1 of the ‘298 patent).” Id. at *6-7.

In finding claim 8 (a dependent claim that depends on independent claim 1) invalid under 35 U.S.C. § 112, the Court explained that claim 1 requires only one isoform. “Claim 8 contradicts claim 1’s limitation that the isoform is ‘isolated’ by requiring a mixture ‘consisting essentially of two or three’ isoforms. Claim 8 thus improperly narrows claim 1.” Id. at *8.

A copy of the Memorandum Opinion is attached.

The general take away is that, where the limitation of dependent claim is logically inconsistent with that of the independent claim, it is a problem under 35 U.S.C. § 112.  In other words, something that infringes a dependent claim should necessarily infringe the independent claim from which the dependent claim depends.  When that is not true, there is something wrong with the claim drafting.