Teva's skirmish with FDA has paid off. The company launched generic versions of Merck's top-selling hypertension drugs Cozaar (losartan) and Hyzaar (losartan/hydrochlorothiazide) on April 6 with 180 days of marketing exclusivity.

The only generic competition Teva faces is from Sandoz, which launched authorized generics of the two drugs the same day. Both companies are selling three dosage strengths of the drugs: losartan in 25 mg, 50 mg and 100 mg tablets and the combination drug in 50 mg/12.5 mg, 100 mg/12.5 mg and 100 mg/25 mg tablets.

Roxane, Mylan and Torrent also received FDA approval of their ANDAs for the 12.5/100 mg dosage of Hyzaar, which was not covered by Merck's patent.

At one point Teva's chances of getting exclusivity appeared slim. But in a series of dramatic courtroom clashes, the battle over generic losartan has taken surprising twists and turns.

FDA denied the company exclusivity on the grounds that Merck had delisted its patent from FDA's Orange Book. A district court upheld the agency's decision but the U.S. Court of Appeals for the District of Columbia Circuit reversed, finding that a brand company cannot trigger forfeiture of exclusivity.

FDA Requests Court Rehearing

Apotex then informed FDA that the patent at issue had expired and argued that Teva was thus not eligible for exclusivity. Under the Medicare Modernization Act of 2003, six events can cause a first ANDA applicant to forfeit exclusivity, including delisting and expiration of a patent.

FDA agreed that under the statute Teva should not get exclusivity. But the agency said it had no choice but to follow the Circuit's reasoning on the question of delisting and apply it to patent expiration, so it awarded Teva marketing exclusivity.

FDA is seeking to have the Circuit's decision on delisting reversed. On April 5 the agency filed a petition for a panel rehearing and rehearing by the full court.

The circuit panel's interpretation of the statute "is not only contrary to the unambiguous text and Congress's deliberate rebalancing of competing goals, it squarely conflicts with this circuit's message in other FDA decisions concerning the importance of fidelity to Congress's enactments," FDA stated in its filing.

"As a result, FDA finds itself whipsawed, with a 'damned-if-you-do, damned-if-you-don't' dilemma in administering this very complex statute," the agency said.

FDA asserted that the statute says nothing about unilateral action by the brand manufacturer. "And, the very existence of the six separate forfeiture events is compelling evidence that Congress intended to alter the previous incentive structure by enhancing full generic competition and limiting exclusivity," the agency said.

Teva May Run Out Clock on Challenges

Apotex also unsuccessfully sought to block Teva's exclusivity. On April 5 it filed a motion with the circuit court for a stay and summary reversal of the district court's decision denying its request for a preliminary injunction. The district court had ruled that FDA was correct in awarding Teva exclusivity by applying the reasoning of the circuit's decision on delisting to the issue of patent expiration (¹ Also see "Teva's Generic Exclusivity For Cozaar/Hyzaar Is Upheld By District Court; Apotex Appeals" - Pink Sheet, 5 April, 2010.). The circuit denied Apotex's motion for emergency relief the following day and is to consider the merits of the motion at a later date.

Chad Landmon, a partner at Axinn Veltrop & Harkrider, said Teva may get the entire benefit of its exclusivity period by the time the court reaches a final decision. He said briefing could take a few months at least and noted that the D.C. Circuit does not regularly sit over the summer and panels will only hear oral argument for emergency matters.

"Unless Apotex or Roxane files another emergency motion for expedited consideration (or FDA files for expedited relief on its motion for a rehearing en banc), we are looking at September as the earliest date for oral argument," Landmon said.

- Brenda Sandburg ( ² b.sandburg@elsevier.com )

Teva Launches Generic Cozaar/Hyzaar With Market Exclusivity As FDA Seeks Court Action To Permit Other Entrants

More from Archive

More from Pink Sheet