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“Bitter Pill” for ANDA Applicant Duramed Regarding Contraceptive Drug Delivery System

April 01, 2003

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Last Month at the Federal Circuit - May 2003

Judges: Bryson (author), Rader, and Schall

In Bio-Technology General Corp. v. Duramed Pharmaceuticals, Inc., No. 02-1195 (Fed. Cir. Apr. 1, 2003), the Federal Circuit rejected the district court’s claim construction and reversed the district court’s SJ of noninfringement. The Federal Circuit remanded the case with a broader claim construction and held that under this new claim construction, the Plaintiff may be able to prove infringement of its pharmaceutical patent claims.

Bio-Technology General Corporation (“BTG”) is the assignee of reissued U.S. Patent Re. 35,724 (“the ‘724 patent”), a patent covering an oral contraceptive “method of use” and “drug delivery system” in which a woman takes doses of estrogen and/or progestin at different stages of her menstrual cycle. Claim 1 of the ‘724 patent describes a daily oral contraceptive method in which the woman consumes an estrogen compound on days 3 or 4 through day 7 of her menstrual cycle, followed by a progestin-containing compound through day 28 (wherein day 1 is the onset of menses). Claim 18 of the ‘724 patent claims a “drug delivery system” of 24+ separate daily doses in which a woman takes four or five “initial dosage units” of estrogen compound, followed by twentyone doses of progestin-containing compound.

The commercial embodiment of the ‘724 patent is marketed as Mircette®, in which a woman takes 28 pills per 28-day menstrual cycle. The Mircette® dosage package or “blister pack” is arranged such that the first twenty-one pills contain a composition of progestin and estrogen, the next two pills are placebos, and the last five pills contain only estrogen.

Duramed Pharmaceuticals, Inc. (“Duramed”) filed an ANDA and sought FDA approval for a generic version of Mircette®, which Duramed claimed was identical to Mircette® in every material respect. However, in the Duramed “drug delivery system” blister pack, the 21 progestin pills are before the two placebo pills and five estrogen pills (instead of after, as described in claim 1). Duramed certified to the FDA that neither its generic version of the drug nor Mircette® was covered by BTG’s ‘724 patent, and therefore Duramed did not infringe.

BTG sued Duramed for patent infringement under the Hatch-Waxman Act (35 U.S.C. § 271(e)(2)) in the District Court for the District of New Jersey, claiming that Duramed’s proposed contraceptive method infringed both the above described independent claims, as well as several dependent claims. The district court granted SJ of noninfringement because the arrangement of pills in their package by Duramed is reversed from that in the claims, as construed by the court.

The Federal Circuit disagreed, concluding that a contraceptive regimen in which a woman at any time is taking BTG’s described compounds on the prescribed days of her menstrual cycle in the order indicated (placebo, estrogen, progestin), will infringe. The Federal Circuit relied on testimony by BTG’s medical experts, as well as Duramed’s own package insert, which taught that taking the estrogen and progestin-containing pills in the order and duration prescribed in the Duramed system would cause a “menstrual shift.” Expert testimony suggested that after taking 21 days of progestincontaining product followed by placebos (as in the Duramed system), a woman would begin menses again, thereby “restarting” the woman’s menstrual cycle with “day 1.” Continuing with the regimen, the woman is instructed to take several placebo pills, followed by estrogen, followed by progestin again until day 28 of her cycle. In other words, within a short time after a woman began using Duramed’s accused product, she would end up taking the placebo and estrogen pills as recited in the claims. Hence, users of the Defendant’s product would infringe BTG’s ‘724 patent and Duramed could be liable for contributory or induced infringement.

The Federal Circuit also held that the district court’s claim construction of claim 18 was unduly restrictive. The district court had interpreted claim 18 to cover only one month’s worth of pills in a blister pack, with the pills being arranged in a specified order (4/5 estrogen-only pills before 21 progestin-containing pills). The district court ruled that Duramed could not infringe claim 18 because its blister packs had the three rows of progestincontaining pills ahead of the estrogen-only pills. However, the Federal Circuit held that the term “drug delivery system” referred more generally to any system consisting of at least 24 dosage units of the composition type specified in the claim, to be taken in the order specified in the claim. The Court stressed that there was no evidence that the patentee intended claim 18 to be limited in scope to a one-month blister pack of pills, but rather that BTG’s written description repeatedly characterized the “drug delivery system” in terms of the timing of the administration of the dosages of estrogen and progestin in reference to the different stages of the woman’s menstrual cycle (estrogen in the initial stage followed by three weeks of progestin), without limiting that contraceptive regimen to a specific ordering of pills beginning and ending within one blister pack. Given the evidence that a woman’s menstrual cycle would “shift” in such a way that the contraceptive regimen would soon be administering the same type of claimed compounds in the same order claimed by BTG, the Federal Circuit ruled that SJ of noninfringement was not appropriate.