Ranbaxy and Teva won a victory in the U.S. Court of Appeals for the D.C. Circuit that preserved their 180-day exclusivity when patents are delisted from the FDA Orange Book. Ranbaxy et al. v. Michael O. Leavitt, Secretary of Health and Human Services et al. (06-5154). Ranbaxy and Teva had challenged the decision on the basis that it was inconsistent with the Hatch-Waxman Act.

Before marketing a new branded drug, the manufacturer must file with the FDA a New Drug Application (NDA), including evidence the drug is safe and effective, and the identifying number and expiration date of any patent or patents covering the drug. When it approves the NDA, the FDA must publish the patent information, which it does in Approved Drug Products with Therapeutic Equivalence Evaluations (a/k/a the Orange Book).

Before marketing a generic drug, the manufacturer may submit an Abbreviated New Drug Application (ANDA). Unlike an NDA, an ANDA need not contain evidence of the drug’s safety or efficacy. However, each ANDA, however, must contain “a certification … with respect to each patent which claims [a drug or a method of using a drug listed in the Orange Book] for which the applicant is seeking approval under this subsection and for which information is required to be filed under subsection (b) or (c) of this section – (I) that such patent information has not been filed, (II) that such patent has expired, (III) [that] such patent will expire [on a specified date], or (IV) 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[.]”

The Act rewards the first manufacturer to file an approved ANDA containing the certification in paragraph IV by giving it a 180-day period of marketing exclusivity, which begins with the earlier of the applicant’s first commercial marketing of the generic drug or when the applicant prevails in a suit over infringement or the validity of the patents covering the branded drug.

When a patent is removed from the Orange Book (or delisted), the FDA by regulation requires the sponsor of the corresponding ANDA to delete its paragraph IV certification with respect to the delisted patent. If no patent covering the branded drug remains listed, then the generic applicant must file a paragraph I certification, and the FDA treats the ANDA as though it had never contained a paragraph IV certification. As a result, the generic applicant that was first to file an approved application does not get the 180-day period of exclusivity.

Merck submitted to the FDA information with respect to three patents covering the drug Zocor®: U.S. Patent Nos. 4,444,784, RE 36,481, and RE 36,520. Teva and Ranbaxy each filed an ANDA to market generic simvastatin. The two ANDAs – both of which were eligible for a 180-day period of marketing exclusivity because they involved different dosages – each contained a paragraph IV certification with respect to the ‘481 and ‘520 Patents. With respect to the ‘784 Patent, Ranbaxy and Teva each filed a paragraph III certification that it would expire in December 2005.

Merck, however, did not sue Ranbaxy or Teva for patent infringement based upon their paragraph IV certifications. Instead, before their ANDAs were approved, Merck asked the FDA to delist the ‘481 and ‘520 Patents from the Orange Book, which the agency did in 2004. Consequently, Ranbaxy and Teva were required to delete the paragraph IV certifications from their ANDAs and thereby lost their eligibility for a period of marketing exclusivity.

Ranbaxy and Teva each filed a citizen petition asking the FDA to relist the two patents. The FDA denied the petitions because Merck had not sued Ranbaxy or Teva for patent infringement. Ranbaxy and Teva then repaired to the district court, which entered a summary judgment for the plaintiffs, and the FDA appealed.

The D.C. Circuit held that the FDA’s requirement that a generic manufacturer’s patent challenge give rise to litigation as a condition of retaining exclusivity when a patent is delisted is inconsistent with the Act, which provides that the first generic manufacturer to file an approved application is entitled to exclusivity when it either begins commercially to market its generic drug or is successful in patent litigation.

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