An Empirical Analysis of Primary and Secondary Pharmaceutical Patents in Chile
We analyze the patent filing strategies of foreign pharmaceutical companies in Chile distinguishing between “primary” (active ingredient) and “secondary” patents (patents on modified compounds, formulations, dosages, particular medical uses etc.). There is prior evidence that secondary patents are used by pharmaceutical originator companies in the U.S. and Europe to extend patent protection on drugs in length and breadth. Using a novel dataset that comprises all drugs registered in Chile between 1991 and 2010 as well as the corresponding patents and trademarks, we find evidence that foreign originator companies pursue similar strategies in Chile. We find a primary to secondary patents ratio of 1:4 at the drug-level which is comparable to the available evidence for Europe; most secondary patents are filed over several years following the original primary patent and after the protected active ingredient has obtained market approval in Chile. This points toward effective patent term extensions through secondary patents. Secondary patents dominate “older” therapeutic classes like anti-ulcer and anti-depressants. In contrast, newer areas like anti-virals and anti-neoplastics (anti-cancer) have a much larger share of primary patents.
The authors thank INAPI (in particular the pharmaceutical patents team), as well as Aisen Etcheverry, Catalina Olivos Besserer, Maria Lorena Chacon, and Alhena Fuentes for their generous support in constructing the data. We also thank representatives of ASILFA and Camara de la Innovacion Farmaceutica for insightful discussions. We also benefitted from the comments of two anonymous referees, Carsten Fink, Catalina Martinez, Keith Maskus, and participants of the 2014 Meide conference in Santiago and seminars at INAPI, UC Berkeley, and UC Davis.
The data construction effort for this paper was partially funded by the World Intellectual Property Association, with additional support from the United Nations University-MERIT and Santa Clara University. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.