Pharma patent thickets allow brand manufacturers to file dozens of secondary patents on existing drugs, delaying generic and biosimilar competition by decades

Brand-name pharmaceutical manufacturers systematically file large numbers of secondary patents on already-approved drugs -- covering formulations, dosing regimens, manufacturing methods, and minor molecular variants -- to create 'patent thickets' that deter generic entry long after the original compound patent expires. Novo Nordisk has filed 320 patent applications on Ozempic, Wegovy, and Rybelsus with an estimated 49 years of monopoly protection, and AbbVie accumulated over 130 patents on Humira beyond the core patent that expired in 2016. Why it matters: manufacturers of the top 12 selling U.S. drugs have sought an average of 38 years of patent protection (nearly double the standard 20-year term), so patients and insurers continue paying inflated prices for drugs whose original innovation occurred decades ago, so generic and biosimilar companies face years of costly litigation to challenge each patent in the thicket, so fewer generics reach market which keeps drug spending artificially high (biologics are 5% of prescriptions but 51% of total U.S. drug spending as of 2024), so the entire healthcare system absorbs billions in unnecessary costs that crowd out spending on other care. The structural root cause is that the U.S. patent system allows continuation applications and does not limit the number of patents per drug product, while the FDA Orange Book listing process has lacked robust gatekeeping -- the FTC has alleged hundreds of patents were improperly listed, and in December 2025 Teva agreed to remove more than 200 patent listings under FTC pressure, revealing how the system has been exploited to delay competition.