A generic manufacturer who seeks to market a generic copy of the Orange Book listed patents claiming drug products or their uses (specifically methods of use) may submit an Abbreviated New Drug Application (ANDA) in which a generic manufacturer must make a certification selected from one of four alternatives: (I) no such patent information has been submitted to the Food and Drug Administration (FDA); (II) the patent has expired; (III) the patent is set to expire on a certain date; or (IV) the patent is invalid or will not be infringed by the manufacture, use, or sale of the generic drug {21 U.S.C. § 355(j)(2)(A)(vii)} and furthermore it does not infringe any patent listed in the Orange Book pertaining to its drug which is a generic copy of the originators patented drug.

For a "Use" not covered by an Orange Book listed patent, a generic drug manufacturer who files an ANDA must submit a proposed label for the unpatented use as well as a statement under 21 U.S.C. § 355(j)(2)(A)(viii) (a "Section viii" statement) that the use does not infringe any listed patent. Approval of the ANDA requires that the proposed label does not overlap with any patented method (a "carve-out").

In 2003, the 1984 Hatch-Waxman Act (also called Medicare Modernization Act of 2003) was amended to authorize a limited counterclaim for ANDA filers sued for infringement:

It states that if an owner of the patent or the holder of the approved application for the drug that is claimed by the patent or a use of which is claimed by the patent brings a patent infringement action against the [ANDA] applicant, the applicant may assert a counterclaim seeking an order requiring the holder to correct or delete the patent information submitted by the holder under subsection (b) or (c) of this section on the ground that the patent does not claim either --- (aa) the drug for which the application was approved; or (bb) an approved method of using the drug.

As part of the litigation provisions of the Hatch-Waxman Act, an ANDA filer can file a counterclaim in ANDA litigation that challenges the accuracy of the patent information submitted by the innovator, on two grounds -- either that the patent doesn't claim the approved drug or an approved method for using the drug (which is defined by the use codes and the innovator drug label). This part of the law was enacted as part of the MMA (Medicare Modernization Act) amendments and is codified as 21 U.S.C. § 355(j)(5)(c)(ii)(I).

The Hatch-Waxman Act also known as The Drug Price Competition and Patent Term Restoration Act of 1984 provides a way for the innovator companies to protect their products via patent rights as well as it gives a mechanism to the interested generics to certify suitable paragraphs in their ANDAs from composition of matter to process to method of use of the listed drugs in the Orange book.

The generic drug applicant may in certain cases not certify with respect to each Method of Use patents but may file a "counterclaim Section viii" statement. The "section viii" statement says that the generic drug manufacturer does not seek approval to market the reference listed drug in the Orange Book for one or more Method of Use or Method of Treatment associated with the listed drug products.

The counterclaim provision authorizes a generic drug maker to challenge the "patent information" submitted by an innovative pharmaceutical company if the patent does not claim an approved drug or method of using the drug product. Moreover, the counterclaim only authorizes the correction or deletion of the patent number or expiration date, and not any other information listed in the Orange Book in connection with the patent, such as a use code narrative.

In a recent case Novo Nordisk A/S v. Caraco Pharmaceutical Laboratories Ltd. and Sun Pharmaceutical Ind. the U.S. Court of Appeals for the Federal Circuit denied Caraco Pharmaceutical Laboratories, Ltd.'s ("Caraco") and Sun Pharmaceutical Laboratories, Ltd.'s ("Sun") Petition for Panel Rehearing and Rehearing en banc.

Judge Clevenger, in a short concurring opinion, stated that, in his view, "Novo did nothing that was illegal or forbidden." and that "[i]f a fix is in order under the circumstances of this case, it lies with the FDA and Congress . . . to remedy the situation," and not with Novo Nordisk. He acknowledged that FDA "may have inadvertently upset the careful balance of interests represented by the efficient dispute resolution mechanism Congress created in the Hatch-Waxman Act". But, he concluded that Congress is the appropriate entity to readjust, if necessary, the delicate balance it has struck between original drug manufacturers and their generic counterparts.

The Hatch-Waxman Act was amended earlier in order to prevent manipulative practices by innovator with respect to the Orange Book listing patents claiming drug products or their uses (specifically Methods of Use) and to provide a better scope of life for the generic manufacturer in terms of the "counterclaim" provision. These manipulative practices by innovator were designed to delay the onset of competition from generic drug manufacturers which in turn hinder the entrance of the affordable drug product to the market.

But as per the current decision made by the Federal Circuit, which fall in the goodwill of the innovator drug manufacturer, indicates that the Hatch-Waxman counterclaim for correction or deletion of patent information submitted by innovator drug manufacturers to the FDA is quite narrow. This Sua sponte decision further provides a broader protection to the patented invention of the innovator drug manufacturer which creates more hurdles for the generic manufactures and thus seems to put obstacle to the market entry of the generic manufacturer. In a nut shell it can be predicted that this ruling, which construes the statute is a contrary to its manifest purpose and allows the same manipulative practices to continue further in the context of method patents more specifically the methods of use patents, which will be an intricate situation for the generic drug manufactures.

Gautam Bakshi, a registered Patent & Trade Marks Attorney is Manager & H.O.D; Deeptymaya and Kuldeep are Research Associates in IPRD and Sukhjeet Singh is VP, R&D at Panacea Biotec Ltd.