"Therpeutically Effective Amount" Does Not Require Healing

In Amgen, Inc. v. Hoechst Marion Roussel, Inc. (August 8, 2006) the Federal Circuit disagreed with the district court’s construction of "therapeutically effective amount" in claim 1 of the patent to the extent that it was limited to erythropoietin ("EPO") products that have one of the in vivo effects listed in the specification and that also increase hematocrit. The appellate court also disagreed with the district court’s conclusion that the claim was limited to EPO products that may be used to treat patients with the disorders listed in the specification.

According to Circuit Judge Schall,

Based on a reading of the claims in light of the specification, it appears that the patentee used the words "therapeutically effective" in order to broadly claim a pharmaceutical composition with a wide range of effects. Those effects do not necessarily include curing disease in humans. During the prosecution of the ’422 patent, in an office action response filed October 23, 1997, the patentee noted that recombinant EPO, like that found in the claimed invention, "is the first therapeutic product which can be used to effectively treat hundreds of thousands of patients who suffer from anemia and other disorders involving low red blood cell counts." In our view, this statement merely lists some of the uses of the invention, without restricting the scope of the invention. . . .

On remand, the district court should utilize the following revised construction of "therapeutically effective:"

A therapeutically effective amount is one that elicits any one or all
of the effects often associated with in vivo biological activity of natural EPO, such as those listed in the specification, column 33, lines 16 through 22: stimulation of reticulocyte response, development of ferrokinetic effects (such as plasma iron turnover effects and marrow transit time effects), erythrocyte mass changes, stimulation of hemoglobin C synthesis and, as indicated in Example 10, increasing hematocrit levels in mammals.

In his dissent, Chief Judge Michel argued that the term means more than simply eliciting in vivo biological effects:

Significantly, I note that the words "therapeutically effective" are conventionally employed in the pharmaceutical arts to indicate that the claimed pharmaceutical product has utility in the treatment of a human disease where such treatment tends to cause the "healing" or "curing" of the disease. The patentee, I think, intended to invoke that very convention. While the majority might be correct that the '422 patent is not necessarily limited to the exact class of patients described in the specification (as opposed to other blood disorders associated with low hematocrit levels), the district court correctly recognized that it would be "foolish to construe a term such as 'therapeutically effective,' without reference to a class of patients for which the product is intended to be 'therapeutically effective.'" Amgen III Validity & Literal Infringement Judgment, 339 F. Supp. 2d at 237.

In his view, the claim should therefore have been properly construed as valid over the Goldwasser reference, which describes a prior art compound eliciting biological activity without curing.