Prior Art Range Encompassing The Claimed Invention Creates A Rebuttable Presumption Of Obviousness

This article previously appeared in Last Month at the Federal Circuit Newsletter, 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...