Strategic Patenting: Evidence from the Biopharmaceutical Industry

Biological drugs account for just two percent of prescriptions filled in the U.S. but fifty percent of prescription-drug spending. To explore the role patents play in explaining high biologics prices, we build the first comprehensive database of patents associated with all FDA-approved biologics. We first establish that much of what drives biologic patenting is the desire to block entry by competing biosimilars. For these purposes, we estimate the response to a 2010 Act that created an abbreviated pathway for biosimilars to receive FDA approval. We then document robust evidence consistent with two patenting strategies that may block biosimilar competition: thicketing and evergreening, whereby firms supplement primary patents with a dense web of later-expiring patents on secondary drug features. We conduct various exercises to suggest that these behaviors are undertaken with exclusionary purposes that go beyond the traditional justifications of the patent system. We then set forth various descriptive statistics surrounding biosimilar entry to suggest that these patenting strategies are, in fact, effective at delaying biosimilar entry. Finally, we simulate the degree to which biologics patent portfolios are impacted by policy proposals currently under consideration to address thicketing and evergreening.