Thanks to Congress’ administrative alternative to court litigation of patents, generic drug manufacturers have embraced a new process, known as inter partes review (IPR), and successfully challenged patents about 50% of the time, according to a new study published in Applied Health Economics and Health Policy
The study, written by researchers at the Program On Regulation, Therapeutics, And Law (PORTAL) at Harvard Medical School and Brigham & Women’s Hospital, reveals that the IPR process “can help clear weak patent claims, especially those directed to formulations and methods of use,” the authors write.
First author Jonathan Darrow told Focus
that in general, generic drug companies “are most interested in going after large markets, where profit margins are high, and where the original patent on the active ingredient has expired. Follow-on patents, like those directed to formulations or methods of use, tend to be weaker and more likely to be invalidated.
“Generic firms can also use IPR as a strategy device: Many IPRs are filed after generic firms have already been sued in court. The IPR filing can create a ‘second front’ that puts additional pressure on the brand name drug company to come to the settlement table,” he said. “The legal standards in the patent office are also more challenger-favorable compared to the standards applied by a court.”
And the IPR process has meant generic drugs coming to market sooner than they would have if the process did not exist.
The US Food and Drug Administration (FDA) approved at least one generic drug application for 35 (26%) of 134 new drugs studied. These 35 generic applications were approved a median of 8.4 years after new drug approval, indicating, according to the authors, an effective market exclusivity period substantially shorter than both the 20-year patent term and the 12.5-year median market exclusivity previously calculated for top-selling drugs.
“The enthusiasm with which generic firms have pursued inter partes review, combined with the lobbying efforts of the branded pharmaceutical industry to exclude Orange Book-listed patents from eligibility for it, suggests that both segments of the drug industry view inter partes review as a mechanism that meaningfully alters the balance between patent holders and patent challengers,” the authors write.