In its present term, the United States Supreme Court is scheduled to consider a case that could significantly influence entry of some generic drugs into the United States pharmaceutical market. The case involves the same labeling requirement—a feature of our regulatory system for generic drugs that compels generic drug companies to use the same label as the innovative drug they are copying.

In Caraco Pharm. Labs. v. Novo Nordisk (Caraco), the Supreme Court is being asked to determine whether and how a generic applicant can challenge the Food and Drug Administration’s (FDA’s) application of the same labeling requirement, when actions taken by an innovator influence FDA’s administrative review. The Caraco dispute involves repaglinide—a drug marketed by Novo Nordisk as Prandin® for the treatment of Type 2 diabetes. Prandin® was first approved in 1997, and lists only one clinical indication in its current FDAapproved label:

PRANDIN® is indicated as an adjunct to diet and exercise to improve glycemic control in adults with Type 2 diabetes mellitus.  

Importantly—while the drug is approved only for one clinical indication, Novo reports two different sets of studies in its label. The first set of studies involved monotherapy trials that evaluated the effect of repaglinide on Type 2 diabetes when administered as the only active agent. The second set of studies involved combination trials that evaluated the combination of repaglinide with metformin as a treatment against Type 2 diabetes. The use of repaglinide as monotherapy against Type 2 diabetes is no longer protected by a patent; the use of repaglinide in combination with metformin is patent protected.  

While Caraco was waiting to receive final approval from FDA, Novo filed a new patent use code for its combination therapy patent that did not distinguish between monotherapy and combination therapy. Rather, the new use code for the patent more broadly recites “A method for improving glycemic control in adults with Type 2 diabetes mellitus.” When the FDA revisited Caraco’s application, it rejected Caraco’s proposed label because it still described “a method for improving glycemic control in adults with Type 2 diabetes mellitus,” as described in Novo’s use code. Because the carve-out was rejected, the FDA forced Caraco to revert to essentially the same label as Prandin®, including the description of Novo’s combination clinical trial. This left Caraco in the difficult position of admitting that its label would induce infringement of Novo’s patent, and having to invalidate Novo’s patent to bring its repaglinide generic to market.

In response, Caraco filed a lawsuit against Novo, claiming that Novo had violated FDA rules by submitting an overbroad use code. Caraco’s lawsuit remains pending on certiorari to the Supreme Court, but it is doubtful that the Supreme Court will even reach the propriety of Novo’s actions. Rather, the Supreme Court is only being asked to determine whether Caraco can bring a lawsuit in the first instance, based upon Novo’s alleged violation.  

If the Supreme Court decides that Caraco has a legitimate basis to sue, an entirely new category of generic drug litigation could be spawned in the United States. Innovators are becoming increasingly adept at listing their patents in a way that precludes generic challenges, and a Supreme Court decision in favor of Caraco would open the door for challenging those techniques in court. A decision should be rendered in the first half of 2012, which will hopefully bring some clarity to this issue.