In Teva Pharmaceutials USA, Inc. v. Sandoz, Inc., Nos. 12-1567, -1568, -1569, -1570 (Fed. Cir. July 26, 2013), the Federal Circuit affirmed the district court's judgments of infringement and no invalidity with respect to one set of claims, reversed its judgment of no invalidity with respect to another set of claims, and remanded for further proceedings.
Teva Pharmaceuticals USA, Inc. ("Teva") markets Copaxone®, a drug used for treating multiple sclerosis. Sandoz, Inc. ("Sandoz") and Mylan Pharmaceuticals Inc. ("Mylan") (collectively "Defendants") submitted ANDAs to the FDA seeking approval to market generic versions of Copaxone®. Teva sued the Defendants for infringement of the patents listed in the Approved Drug Products with Therapeutic Equivalence Evaluations ("Orange Book") entry for Copaxone®.
The patents-in-suit include claims reciting a product called copolymer-1, which consists of four different amino acids combined in a specific ratio. Samples of copolymer-1 consist of a mixture of molecules that have varying molecular weights. Two different methods exist for measuring the distribution of molecular weights in a given sample. The first method uses statistical measures, including the peak average molecular weight (Mp), number average molecular weight (Mn), and weight average molecular weight (Mw). In a typical sample, these three measures have different values. The second method measures a sample by the number of molecular weights falling within an arbitrarily set range. For example, a sample may be described as having 99% of its mole fraction within the molecular weight range of 1 kilodalton (kDa) and 100 kDa. Teva asserted claims using both types of measurement against Sandoz and Mylan. Claims using the first method of measurement are termed "Group I" claims and those using the second method are categorized as "Group II." Both methods of claims contain the term "molecular weight."
In its claim construction order, the district court did not distinguish between the different contexts (Group I or Group II) when construing the term "molecular weight." It construed "molecular weight" to mean Mp and rejected arguments that the claims were indefinite. After a bench trial, the district court found the asserted claims valid and infringed by the accused Sandoz and Mylan products. Sandoz and Mylan appealed.
On appeal, the Federal Circuit first addressed this issue of definiteness. The Court found the term "molecular weight" ambiguous in the context of the Group I claims, rendering the Group I claims indefinite. The plain language of the Group I claims does not indicate which molecular weight measure is intended: Mp, Mn, or Mw. The Court noted that in overcoming one rejection during prosecution, Teva stated that molecular weight meant Mp, but in overcoming a separate rejection in a related application, Teva argued that molecular weight meant Mw. Rejecting Teva's reliance on the prosecution history to resolve the ambiguity, the Court determined that the two definitions could not be reconciled and held that the contradiction rendered the ambiguity insoluble.
"It is undisputed that Group I claims contain an ambiguity because their plain language does not indicate which average molecular weight measure is intended. Teva's attempt to resolve this ambiguity hinges in part on the prosecution history. But two of its prosecution statements directly contradict each other and render the ambiguity insoluble." Slip op. at 8.
The Court's reasoning did not apply to the Group II claims. The Court explained that, in contrast to the Group I claims, which recite average molecular weight values, the Group II claims recite the percentage of copolymer-1 falling within a set molecular weight range. Thus, the numbers setting the boundaries in those claims set precise points on the "molecular weight" scale. Because the claims refer to exact values rather than statistical measures, the scope of the Group II claims is readily ascertainable and not indefinite.
The Court continued its analysis of the Group II claims, considering whether they were sufficiently enabled. The district court found that the claims were sufficiently enabled because a person of skill in the art would be able to measure the claimed molecular weight using known calibration methods. The Federal Circuit agreed, finding no clear error on the part of the district court. The Court reasoned that Teva's expert testified at length that it would have been routine for a skilled artisan to measure the molecular weight of copolymer-1 and that the district court did not err in finding the testimony more convincing than the testimony offered by opposing experts. Accordingly, the Court affirmed the district court's finding of no invalidity for lack of enablement.
The Federal Circuit also affirmed the district court's finding in favor of Teva on the issue of obviousness. The district court found that the asserted claims would not have been obvious in view of copolymer-1 compounds with a molecular weight higher than 10 kDa, as disclosed in the prior art. The district court found that prior art references explicitly taught away from the claimed lower molecular weight copolymer-1 and that various secondary considerations indicated nonobviousness. The Federal Circuit agreed, holding that the district court did not clearly err when it found that the prior art expressed a preference for higher molecular weight copolymer-1, thereby teaching away from the claimed invention, or when finding that secondary considerations supported a finding of nonobviousness. Accordingly, the Court affirmed the district court's finding of no invalidity for obviousness.
Finally, the Federal Circuit addressed infringement. The district court construed "copolymer-1" to mean a mixture of polypeptides composed of alanine, glutamic acid, lysine, and tyrosine in a molar ratio of approximately 6:2:5:1, a construction that was not in dispute. In considering infringement, the district court determined that an accused product meets the claim limitations as long as its amino acid composition does not vary from the "ideal" percentages by an aggregate of more than 12%. Finding that the accused products from both Sandoz and Mylan vary by less than 5%, the district court ruled that both products infringed literally. The Court held that the district court did not err in its methodology, noting that the conclusion was supported by prior art examples of copolymer-1, which showed that even when one of the amino acids differs from its ideal percentage by more than 5%, the material is still considered "copolymer-1."
The Court also rejected the argument that Teva surrendered claims to copolymer-1 with a molecular weight greater than 10 kDa, as measured by Mw. The Court reasoned that the phrase "molecular weight of 10 kilodaltons" does not expressly refer to any specific molecular weight measurement. This finding, the basis for finding the Group I claims indefinite, also resulted in a finding that the connection between Teva's statement and the prior art was too attenuated to limit the scope of the claims to copolymer-1 with Mw less than 10 kDa. Thus, the Court affirmed the infringement finding.
Judges: Rader, Moore (author), Benson (sitting by designation)
[Appealed from S.D.N.Y., Judge Jones]
This article previously appeared in Last Month at the Federal Circuit, August 2013
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