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Prior Art Range Encompassing the Claimed Invention Creates a Rebuttable Presumption of Obviousness

June 22, 2011
Cyr Ph.D., Shana K.

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Last Month at the Federal Circuit - July 2011

Judges: Newman, Bryson (author), Gajarsa

[Appealed from: D.N.J., Judge Chesler]

In Tyco Healthcare Group LP v. Mutual Pharmaceutical Co., No. 10-1513 (Fed. Cir. June 22, 2011), the Federal Circuit affirmed the district court’s SJ invalidating two claims of U.S. Patent No. 5,211,954 (“the ’954 patent”) for obviousness.

The ’954 patent is directed to formulations of the drug temazepam, the relevant claims reciting “6 to 8 milligrams” and “7.5 milligrams” of crystalline temazepam. Temazepam is a hypnotic (sleep-inducing) drug marketed internationally for the treatment of insomnia since the 1970s. Tyco Healthcare Group LP and Mallinckrodt, Inc. (collectively “Tyco”) hold the rights to the ’954 patent and have marketed capsules containing 7.5 mg of temazepam in the United States since 1981 as Restoril®. Mutual Pharmaceutical Company, Inc. (“Mutual”) filed an ANDA with the FDA, seeking approval to manufacture and sell a generic version of the 7.5 mg temazepam capsules, and Tyco sued Mutual for patent infringement.

In the district court, Tyco moved for a preliminary injunction following the FDA’s tentative approval of Mutual’s ANDA. The district court denied Tyco’s motion, finding that Mutual’s proposed product could not literally infringe the asserted claims of the ’954 patent. Mutual then moved for SJ of noninfringement and invalidity. The district court granted Mutual’s motion with respect to invalidity, concluding that Mutual had shown by clear and convincing evidence that the ’954 patent claims were obvious because (1) Restoril® was sold in the United States in 15 and 30 mg capsules for more than a year before the priority date of the ’954 patent; (2) a 1983 British National Formulary (“BNF”) medical reference book directed physicians to use temazepam at a dosage between 5 and 15 mg for treatment of insomnia in the elderly; and (3) the parties did not dispute that physicians always seek to prescribe the lowest effective dose of any medication, particularly hypnotics such as temazepam.

On appeal, the Federal Circuit found that the only claim limitation not disclosed by the prior art Restoril® capsules was the claimed lower dosage of temazepam. The Court noted that the BNF medical reference taught a range of temazepam from 5 to 15 mg, which included the claimed range. The Court reiterated that “where there is a range disclosed in the prior art, and the claimed invention falls within that range, there is a presumption of obviousness” that may be rebutted “either by a showing that the prior art taught away from the invention or by a showing of new and unexpected results relative to the prior art.” Slip op. at 6 (quoting Iron Grip Barbell Co. v. USA Sports, Inc., 392 F.3d 1317, 1322 (Fed. Cir. 2004)).

The Federal Circuit, however, rejected each of Tyco’s arguments. First, Tyco relied on its expert’s declaration in arguing that the BNF reference did not direct a person of ordinary skill in the art to temazepam hard capsules in the 5 to 15 mg range for the effective treatment of insomnia. The Court noted that Tyco’s expert correctly described the contents of the reference, but that the efficacy of the product was irrelevant to the conclusion as to obviousness because the claims did not discuss the intended use of the capsules in a particular treatment regimen (e.g., treating insomnia). The Federal Circuit also rejected Tyco’s argument that the unclaimed property of effectiveness in treating insomnia renders the claims nonobvious, reasoning that “[t]he discovery of a new property or use of a previously known composition, even when the property and use are unobvious from the prior art, can not [sic] impart patentability to the known composition.” Id. at 8 (quoting In re Spada, 911 F.2d 705, 708 (Fed. Cir. 1990)).

Second, the Federal Circuit also rejected Tyco’s argument that the prior art as a whole taught away from a range of 6 to 8 mg. After addressing each reference individually, the Court noted that none of the references addressed the effects of temazepam on elderly patients. Since the BNF reference specifically directed readers to a lower dosage of temazepam for the elderly, even if the other references could be viewed as teaching away from the use of 7.5 mg generally, they would not cast doubt on the BNF reference’s dosage range for elderly patients.

Finally, the Federal Circuit found that Tyco’s arguments for unexpected results and commercial success did not overcome the strong prima facie evidence of obviousness. While Tyco pointed to statements in the ’954 patent specification regarding unexpected results, the Court noted that “[u]nsupported statements in the specification, however, cannot support a finding of unexpected results.” Id. at 14. Additionally, the Court found that Tyco’s other evidence of unexpected results and alleged commercial success of Restoril® did not overcome Mutual’s strong showing of obviousness.

Accordingly, the Federal Circuit affirmed the district court’s SJ that the asserted claims of the ’954 patent were invalid for obviousness.

Summary authored by Shana K. Cyr, Ph.D., Esq.