The United States Supreme Court reversed the Federal Circuit in Caraco Pharmaceutical Laboratories v. Novo Nordisk, No. 10-844 (April 17, 2012). The Court held that "[a] generic manufacturer may employ the counterclaim provision [of the Medicare Modernization Act, 21 U.S.C. § 355(j)(5)C(ii)(l)] to force correction of a use code that inaccurately describes the brand's patent as covering a particular method of using a drug." The case involved a Hatch-Waxman challenge and Novo's maneuverings to prevent Caraco's efforts to market its drug for an approved use, a use that was not covered by any patents held by Novo. The Court's decision clarifies the language of the Act and closes an unintentional loophole in the statue by stopping the practice of overly broad "use codes" to prevent generic drug manufacturers from entering the market.

The underlying case involved the diabetes drug Prandin® which had been approved by the FDA for three separate uses. The compound patent itself had expired in 2009, but Novo's method of use patent, valid until 2018, covered only one of the three approved uses. Despite this, Novo had submitted to the FDA a summary of the scope of the patent claiming that it covered the other two uses, effectively preventing the generic from marketing its drug for the unpatented uses because of the Orange book listing.

Caraco filed suit under 21 U.S.C. § 355, seeking to "correct" Novo's summary of the scope of its patents so that it could market its generic version. The Federal Circuit held that such a remedy was not available. By doing so, the Federal Circuit, effectively allowed Novo's unregulated description to extend the scope of its method-of-use patents, while leaving no room for administrative or judicial correction. In a unanimous opinion authored by Justice Kagan, the U.S. Supreme Court reversed the Federal Circuit.

The decision turned on the distinction between the words "an" and "any" in the statute and whether or not the use codes were "correctable patent information". Section 355 of the Act states that a challenger can only prevail if it can prove that the branded manufacturer's patent does not extend to "an" approved method of use. The Federal Circuit took that to mean that there must be no approved methods claimed in the patents listed in the Orange book. Caraco in contrast, argued that "an" meant "not a particular one" and that counterclaims are available to a challenger whenever a listed patent does not claim a specific method of use. Relying on legislative history, the Court agreed with Caraco and found that Section viii of the Act allows generic manufacturers to carve out the patented uses from their labeling and therefore one patented use must not foreclose other non-patented uses. The Court also found that the scope of correctable information included the correction of the "use codes" and not just patent numbers and expiration dates.

While the Court's holding is based on statutory interpretation, it may nevertheless send a message to the Federal Circuit that it should take a more realistic and balanced approach when interpreting complex statutes in the battle between innovators and generics.