[by Amy Kapczynski] Chan Park, Bhaven Sampat and I recently published in PLoS, perhaps of interest to folks here. We provide data about the ubiquity and significance of so-called “secondary” patents in pharma (e.g. salt patents, polymorph patents, dosage and method of treatment patents, etc). The full paper is here:
We coded all of the patents in the Orange Book, and provide evidence find that secondary claims are common, and add substantial additional patent life. Particularly relevant for this blog, we note:
“Our data also reveal the stakes of the decision that developing countries must make about the permissible scope of patents. Although the World Trade Organization’s Trade-Related Aspects of Intellectual Property Agreement does require member countries to adopt patent protection for medicines, its requirements are general, and do not clearly require countries to permit secondary patents. We can quantify the stakes of such decisions: If the future looks like the past (and the patent landscape in other countries like that in the U.S.) a conservative estimate is that eliminating secondary patents could free up 36% of new medicines for generic production, since only 64% of drugs in our sample had patents with chemical compound claims. Additionally, for those drugs that still come under patent because a chemical compound claim exists, exclusions on secondary patents could limit the duration of patent protection by 4–5 years. The converse is that this study reveals the very substantial implications of new trade agreements. Negotiations are now underway for a new “Trans-Pacific Partnership” treaty, and the U.S. has apparently proposed barring exactly the kind of limits on secondary patents adopted by India, and under consideration by other countries.”
