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The Concentration Range in an Independent Claim Must Include the Concentrations in the Dependent Claims

August 08, 2012
Duszczyszyn Ph.D., Danielle A.

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Last Month at the Federal Circuit - September 2012

Judges: Prost, Moore (author), O'Malley

[Appealed from: S.D. Ind., Judge Young]

In Alcon Research, Ltd. v. Apotex Inc., No. 11-1455 (Fed. Cir. Aug. 8, 2012), the Federal Circuit reversed the district court’s holding that claims 1-3 and 5-7 of U.S. Patent No. 5,641,805 (“the ’805 patent”) would not have been obvious over the prior art, and affirmed the district court’s holding that claims 4 and 8 are not invalid.

The ’805 patent is directed to a method for treating allergic eye disease in humans comprising stabilizing conjunctival mast cells, the primary cells involved in allergic reactions, by topically administering an olopatadine composition. Both the olopatadine compound itself and a method of treating allergies using the class of chemicals that encompasses olopatadine were already patented at the time of invention. Distinguishing itself from the prior art, the specification states that a compound’s activity in a rodent’s conjunctival mast cells or in mast cells located elsewhere in the body cannot predict its ability to stabilize mast cells in the human eye. The ’805 patent is listed in the Orange Book for Patanol®, which is marketed by Alcon Research, Ltd. et al. (collectively “Alcon”).

Apotex Inc. and Apotex Corp. (collectively “Apotex”) submitted an ANDA to the FDA seeking approval to market a generic version of Patanol®. Alcon sued Apotex for patent infringement under 35 U.S.C. § 271(e)(2)(A), asserting claims 1-8 of the ’805 patent. In a bench trial, the district court found that the ’805 patent was enforceable and not invalid, and that Apotex’s generic product infringed the asserted claims. The district court granted a permanent injunction against Apotex, and Apotex appealed.

On appeal, the Federal Circuit stated that it “must determine what olopatadine concentrations constitute a ‘therapeutically effective amount,’” and that “[t]he dependent claims are a starting point for ascertaining the concentration of olopatadine covered by claim 1.” Slip op. at 10. “Because [the dependent claims] set forth a concentration range, that range at a minimum must be included in claim 1, whatever its limitations.” Id. at 12.

The Federal Circuit rejected Alcon’s argument that the inoperative portion of the range would not be covered by the claim by virtue of the limitation requiring mast cell stabilization to a clinically relevant extent. “This is not how patent law works. . . . [Y]ou can’t simply disavow the invalid portion and keep the valid portion of the claim.” Id. at 11. The prior art expressly disclosed eye drops with olopatadine concentrations covered by claims 1-3 and 5-7, and thus overlapped with the ranges disclosed in the ’805 patent. The Court held that “if prior art discloses a portion of the claimed range, the entire claim is invalid.” Id. at 11-12.

The Federal Circuit then found there was motivation to adapt the formulation disclosed in the prior art, which was tested in guinea pigs, for use in treating allergic eye disease in humans. Explaining that “[t]he district court’s error stemmed from its refusal to look at any motivation beyond that articulated by the patent,” the Federal Circuit stated that it had “repeatedly held that the motivation to modify a prior art reference to arrive at the claimed invention need not be the same motivation that the patentee had.” Id. at 12-13 (citing KSR Int’l Co. v. Teleflex, Inc., 55 U.S. 398, 420 (2007); In re Kahn, 441 F.3d 977, 990 (Fed. Cir. 2006); DyStar Textilfarben GmbH v. C.H. Patrick Co., 464 F.3d 1356, 1361 (Fed. Cir. 2006)). The Federal Circuit found motivation to adapt the prior art’s antihistamine formulation for human use because it proved effective in guinea pigs and these animal models are predictive of antihistaminic efficacy in humans.

After weighing the district court’s fact-findings on objective secondary considerations against the strong evidence of obviousness, the Federal Circuit concluded that claims 1-3 and 5-7 were obvious over the prior art, which disclosed every limitation of those claims except that the formulation can be used to treat eye allergies in humans.

The Federal Circuit affirmed the district court’s finding of nonobviousness for claims 4 and 8. The Court reasoned that these claims were limited to formulations with a concentration outside the range disclosed in the prior art. The Court noted that the concentrations tested in the prior art were substantially lower than that of claims 4 and 8, and that a person of ordinary skill in the art would have been concerned that olopatadine might be biphasic at the increased concentration, and thus would not have tried such formulations.

The Court also held that the district court did not clearly err by finding that a skilled artisan would not arrive at the claimed concentration by substituting olopatadine for the active compound used in the ophthalmic formulation disclosed in a prior art patent. The Court agreed with the district court that a person of ordinary skill in the art would have known that one could not simply substitute one active ingredient for another without adjusting the concentration.

Finally, the Federal Circuit found that objective evidence of outstanding commercial success and widespread praise within the industry further supported the district court’s decision, noting that the olopatadine concentration recited in claims 4 and 8 is the one used in Patanol®. The Court thus affirmed the district court’s decision that claims 4 and 8 would not have been obvious.

Summary authored by Danielle A. Duszczyszyn, Ph.D., Esq.