In a November 2025 edition of the CPI Antitrust Chronicle devoted to the intersection of competition law and intellectual property, CRA’s Erin McDermott and Daniel Shack’s article, “Anticompetitive Conduct and Patents Listed in the Orange Book,” examine recent efforts to challenge “improper” Orange Book patent listing.
Branded pharmaceutical manufacturers are required by law to list all patents in the Orange Book that cover an approved drug product. However, over-inclusiveness of such listings can give rise to allegations of anticompetitive conduct. A review of recent rulings shows that courts have taken a statutory interpretation in ex-post decisions regarding inappropriate patent listings. Additionally, to avoid determinations that such inappropriate listings constitute anticompetitive conduct, the burden appears to be on the manufacturer to demonstrate such listings were reasonable and in good faith.
These decisions imply branded manufacturers may exclude certain patents in Orange Book listings going forward. Not listing patents in the Orange Book removes the assurance of exclusivity that is inherent in the current regulatory framework. Consequently, returns on research and development may decrease, leading to uncertainty regarding the impact on branded manufacturers’ future investment decisions.
