Generic drug companies that use a low-cost alternative to court litigation to challenge brand-name drug patents are successful nearly half the time, according to a study published in Applied Health Economics & Health Policy (2018, DOI: 10.1007/s40258-018-0420-8). The U.S. Patent & Trademark Office’s inter partes review (IPR) process is quicker and less expensive than court challenges and “can help clear weak patent claims, especially those directed to formulations and methods of use,” say researchers from Harvard Medical School and Brigham & Women’s Hospital. IPR was established in 2012 as a procedure for challenging the validity of a patent before the patent office’s appeals board. The analysis of those challenges shows that generic drug manufacturers used the IPR process to challenge 198 patents covering 134 different drugs between September 2012 and April 2017. In 43% of the cases, generic drug makers succeeded in overturning all patent claims that they challenged. In addition, the proceeding has consistently been completed within 12 months. “In the pharmaceutical market, the inter partes review process can meaningfully contribute to ensuring that invalid patents do not block timely availability of generic drugs,” the researchers conclude.