Caraco Seeks Supreme Court Intervention In Its Prandin Patent Use Code Battle With Novo

Caraco asks the Supreme Court to decide whether it can file a counterclaim opposing Novo's revision of its patent use code for the diabetes drug.

Caraco Pharmaceutical is seeking U.S. Supreme Court review of one of the most notable patent cases of 2010: Novo Nordisk's alteration of the patent use code for its diabetes drug Prandin (repaglinide), which effectively blocked Caraco's generic version of the product.

The U.S. Court of Appeals for the Federal Circuit ruled 2-1 that Caraco could not file a counterclaim to prevent Novo from revising its original patent use code, which denotes the method of using the drug (Also see "New Tactic In ANDA Litigation: Novo Blocks Generic Prandin By Changing Its Patent Use Code" - Pink Sheet, 19 Apr, 2010.). The panel found that under the Hatch-Waxman Act, a generic manufacturer can only assert a counterclaim to correct or delete information for improperly listed patents that do not claim either the drug for which the application was approved or an approved method of using the drug.

In its December petition to the Supreme Court, Caraco asks the court to determine whether the counterclaim provision applies "where (1) there is 'an approved method of using the drug' that 'the patent does not claim,' and (2) the brand [company] submits 'patent information' to the FDA that misstates the patent's scope, requiring 'correct[ion].'"

Caraco asserts that the Federal Circuit's ruling "enables name-brand manufacturers to use their patents to block generic manufacturers from marketing drugs that concededly do not infringe."

Petition Cites FDA's Concerns With Ruling

Caraco had sought approval of its repaglinide for use as a monotherapy. It filed a section viii statement with FDA and submitted a proposed label to carve out from the label Novo's patented method of using Prandin in combination with metformin. Novo subsequently changed the patent use code for Prandin in FDA's Orange Book to make it broader. The code was changed from "use of repaglinide in combination with metformin to lower blood glucose" to claim "a method of improving glycemic control in adults with type 2 diabetes mellitus."

Caraco contends that the broader code implies Novo's patent covers use of the drug as a monotherapy when the patent for that use expired in March 2009. As a result of Novo's revision to the patent use code, FDA rescinded its approval of Caraco's carve-out label. Caraco then filed a counterclaim seeking partial summary judgment and an injunction. A district court ordered Novo to restore its original use code but the Federal Circuit reversed.

Novo's apparently unprecedented action grabbed the attention of the generic industry. Worried that brand companies could revise patent use codes to change the playing field in ANDA litigation, the Generic Pharmaceutical Association and several companies submitted amicus briefs in support of Caraco's petition for the Federal Circuit to rehear the case (Also see ""The Next Best Way To Block Generics" May Be Novo's Patent Use Code Switch" - Pink Sheet, 7 Jun, 2010.). The court denied en banc review.

FDA also has noted the significance of the case in the ANDA approval process. Elizabeth Dickinson, senior counsel in FDA's Office of the Chief Counsel, commented at a conference in October that the issue would be complicated to resolve (Also see "Patent Use Codes May Still Block Generics As FDA Looks For Alternatives" - Pink Sheet, 18 Oct, 2010.). Caraco's petition cited Dickinson's comments to bolster its argument that Supreme Court review of the case is necessary.

Patent Use Code Switch Likened To Patent De-Listing

The petition also contends that the Federal Circuit's ruling invalidates FDA regulations governing the submission of patent information and is inconsistent with the D.C. Circuit Court of Appeal's 2010 ruling in Teva v. Sebelius.

In that case, the court ruled that a brand cannot unilaterally deprive a generic of 180-day exclusivity by delisting a patent (Also see "ANDA Exclusivity Protected From Patent Delisting Under Appeals Court Ruling" - Pink Sheet, 8 Mar, 2010.). Teva had challenged FDA's finding that it had forfeited exclusivity for its generic versions of Merck's hypertension drugs Cozaar (losartan) and Hyzaar (losartan and hydrochlorothiazide).

"Like the brand in Teva, Novo seeks 'to pull the rug from under' Caraco's Section viii statement," the petition states. "The difference is that here the brand maneuver was not de-listing the patent, but changing its description. And it worked. The FDA reversed itself and rejected Caraco's carve-out label."

The petition says that without the availability of section viii statements, generics must use the same label as the brand, including the patented use which is by definition infringing. Caraco has challenged the patent on the repaglinide/metformin combination, which expires in June 2018. A bench trial was held in June and the judge has yet to issue a ruling.

- Brenda Sandburg ([email protected])