Appeal from the United States District Court for the District of Columbia (No. 04cv00605)
Before: Edwards, Sentelle, and Randolph, Circuit
The opinion of the court was delivered by: Edwards, Circuit Judge
Since December 2002, the District Court has issued three decisions in connection with disputes between Apotex, Inc. ("Apotex") and Purepac Pharmaceutical Co. ("Purepac") over the marketing of a generic version of the drug gabapentin. The Food and Drug Administration ("FDA" or"agency") has approved gabapentin, sold by Pfizer, Inc. ("Pfizer") under the brand name Neurontin, for the treatment of epilepsy. The first two decisions, Purepac Pharmaceutical Co. v. Thompson, 238 F. Supp. 2d 191 (D.D.C. 2002) (" Purepac I"), and TorPharm, Inc. v. Thompson, 260 F. Supp. 2d 69 (D.D.C. 2003) (" TorPharm"), were affirmed by this court in a consolidated appeal. See Purepac Pharm. Co. v. Thompson, 354 F.3d 877 (D.C. Cir. 2004) (" Purepac II").
At issue in this case is a dispute over the proper interpretation and application of the pre-amended version of the 180-day generic marketing exclusivity provision of the Federal Food, Drug, and Cosmetic Act ("FDCA"), 21 U.S.C. § 355(j)(5)(B)(iv) (2000) (amended 2003). The parties disagree over whether the pre-2003 version of this statutory provision adopts a"patent-based" approach or"first-filer" approach in establishing the 180-day period for generic marketing exclusivity. Applying a patent-based interpretation of § 355(j)(5)(B)(iv), FDA awarded Purepac two separate periods of 180-day exclusivity for the same generic gabapentin drug. Purepac's first exclusivity period has expired. But the second exclusivity period, which FDA awarded on the basis of a laterlisted patent, is now running and will not expire until April 2005. Meanwhile, FDA has delayed final approval of Apotex's application to market its generic version of gabapentin pending the expiration of Purepac's period of marketing exclusivity. Apotex claims that FDA erred in awarding multiple 180-day periods of marketing exclusivity for the same drug when, in its view, the statute allows only awards for a single period of exclusivity to the first applicant.
Apotex filed the present suit in District Court against FDA and federal officials (collectively"federal appellees"), advancing Apotex's interpretation of § 355(j)(5)(B)(iv) and seeking an injunction directing FDA to issue final approval for Apotex's gabapentin application. Purepac intervened as a defendant. After consolidating Apotex's motion for a preliminary injunction and defendants' motions to dismiss or for summary judgment, the District Court granted summary judgment to defendants. The District Court's judgment rested on two grounds. First, the District Court ruled that res judicata barred Apotex's action, because the parties in this case are the same parties who appeared in TorPharm; a final judgment was rendered against Apotex in TorPharm; the causes of action in this case and TorPharm share a common nucleus of facts; there has been no intervening change in the law; and there have been no material changes in the facts since the judgment in TorPharm. In the alternative, the District Court held that, even if res judicata did not apply, the defendants would be entitled to summary judgment, because FDA's interpretation of § 355(j)(5)(B)(iv) was reasonable and thus entitled to deference.
We agree that res judicata bars Apotex from bringing this suit. Therefore, we affirm the judgment of the District Court on this ground alone. We vacate the District Court's alternative holding reaching the merits of whether FDA's interpretation of 21 U.S.C. § 355(j)(5)(B)(iv) is reasonable.
A. Statutory and Regulatory Framework
The FDCA requires that companies seeking to market a drug that has not previously been approved by FDA submit a New Drug Application ("NDA") to FDA. See 21 U.S.C. § 355(b)(1) (2000), amended by Pediatric Research Equity Act of 2003, Pub. L. No. 108-155, § 2(b), 117 Stat. 1936, 1941 (2003). NDAs are usually lengthy, and they must include, among other things, evidence surrounding the drug's safety and information about any patents that cover or might cover the drug. Purepac Pharm. Co. v. Thompson, 354 F.3d 877, 879 (D.C. Cir. 2004) (" Purepac II") (citing 21 U.S.C. § 355(b)(1)).
In 1984, Congress passed the Hatch-Waxman Amendments to the FDCA. See Drug Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417, 98 Stat. 1585 (1984) ("Hatch-Waxman"). Hatch-Waxman eased the process of generic drug approval by allowing companies seeking to market generic versions of approved drugs to submit Abbreviated New Drug Applications ("ANDAs"). ANDAs must contain, among other things, information demonstrating that the generic version is the bioequivalent of the approved version of the drug. See 21 U.S.C. § 355(j)(2)(A)(iv) (2000).
ANDAs must also address patents that apply or might apply
to the drug for which the ANDA is submitted. ANDA
applicants can satisfy this requirement by making one of four
certifications with regard to the patent's claim on the drug. Id.
§ 355(j)(2)(A)(vii). The relevant certification for the purposes
of this case, known as a"paragraph IV certification," requires
an ANDA applicant to certify that"such patent is invalid or will
not be infringed by the manufacture, use, or sale of the new drug
for which the application is submitted." Id. §
355(j)(2)(A)(vii)(IV). When an ANDA includes a paragraph IV
certification, the ANDA applicant must notify the owner of the
patent and the holder of the NDA for the approved drug. See id.
§ 355(j)(2)(B)(i). If a patent infringement lawsuit is brought
against the ANDA applicant within 45 days from the date notice
is received, FDA's approval of the ANDA is automatically
stayed for 30 months. See id. § 355(j)(5)(B)(iii).
An ANDA applicant who submits a paragraph IV certification is entitled under certain circumstances to a 180-day period of generic marketing exclusivity during which no other company can market a generic version of the drug. See id. § 355(j)(5)(B)(iv). This exclusivity provision was amended in 2003, but this case arose under § 355(j)(5)(B)(iv) as it existed prior to the 2003 Amendments. See Medicare Prescription Drug, Improvement, and Modernization Act of 2003, Pub. L. No. 108-173, § 1102, 117 Stat. 2066, 2457-60 (2003) ("2003 Amendments"). All references to § 355(j)(5)(B)(iv) are to the statute as it existed prior to the 2003 Amendments.
Because we conclude that Apotex is barred by res judicata from bringing this case, we need not provide an elaborate discussion of this generic marketing exclusivity provision. Rather, what is important here is that the parties have advanced competing interpretations of § 355(j)(5)(B)(iv). These competing interpretations emanate from the fact that NDA holders may receive additional patents that claim an approved drug, or that claim a method of use for the drug, after the approval of their NDAs. Thus, an ANDA applicant who filed the first ANDA with a paragraph IV certification for a particular drug may not be the first ANDA applicant to file paragraph IV certifications for all patents that claim the drug.
Consistent with FDA's determination in this case, the federal appellees and Purepac understand § 355(j)(5)(B)(iv) to allow a company to be eligible for a period of generic marketing exclusivity if it was the first ANDA applicant to file a paragraph IV certification for a particular patent, once the other statutory triggers are satisfied, even if another company had previously filed a paragraph IV certification for another patent claiming the same drug. Under this interpretation, multiple companies could be eligible for generic marketing exclusivity, and multiple periods of exclusivity are possible. This is the so-called"patentbased approach." By contrast, Apotex argues that § 355(j)(5)(B)(iv) should be interpreted to grant generic marketing exclusivity only once – i.e., only to the generic ...