Federal Circuit judges split on temazepam ‘sham’ case
The US Court of Appeals for the Federal Circuit has affirmed a district court’s decision that pharmaceutical company Tyco Healthcare’s patents directed to sleep aid drug temazepam were not infringed.
It comes after a long-running patent infringement case between Tyco (now Covidien) and generic drug maker Mutual Pharmaceuticals (now part of Sun Pharma).
In a split opinion handed down yesterday (August 6), the Federal Circuit also reversed the court’s finding that Tyco is liable for violating antitrust laws, and remanded that part of the case to the US District Court for the District of New Jersey.
However, dissenting judge Newman said that by reversing the district court’s summary judgment dismissing Mutual’s antitrust claims, the court “creates several new grounds of antitrust liability”.
Tyco sued Mutual for patent infringement after it filed an Abbreviated New Drug Application (ANDA) seeking approval from the US Food and Drug Administration to make and sell a generic version of Restoril.
In a counterclaim, Mutual accused Tyco of violating antitrust laws by filing a citizen petition with the FDA in which it urged the agency to change the criteria for determining how biologically similar the two drugs were. Mutual argued that Tyco’s filing of the petition delayed the FDA’s approval of its temazepam ANDA.
The case of infringement hinged on each of the drugs’ claimed surface areas (a measure of the surface area of a drug per unit of weight). Mutual claimed in its ANDA that the surface area of its generic temazepam does not fall within the range claimed in Tyco’s patent.
The district court agreed that Mutual’s generic would not infringe Tyco’s patent.
Tyco and Mutual had measured their respective drugs’ surface areas in different ways.
Despite this, it does not “convert routine patent litigation into an antitrust cause”, Newman said in her opinion.
“Although Tyco lost on the merits [of the case], its Hatch-Waxman suit was not a ‘sham’,” she said.
“Litigation is deemed a ‘sham’ when ‘no reasonable litigant could realistically expect success on the merits’”, she added.
