The use of Markush structures in pharmaceutical patenting and their effect on R&D competition in drug development

• Applicant: Professor Dr. Stefan Wagner
• Subject Area: Economic Policy, Applied Economics ; Accounting and Finance
• Term: from 2021 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460047178

• Final Report Year: 2024

Final Report Abstract

The project investigates the use of Markush structures in pharmaceutical patents and their impact on research and development (R&D) competition within the drug development sector. Markush structures are a convenient chemical notation that specify a large set of related molecules in a compact form by creating a combinatorial space of different molecular specifications. The use of Markush structures allows the protection of a broad range of chemically related compounds under a single patent claim, a practice that is particularly prevalent in the pharmaceutical industry, but not restricted to this area. These structures enable companies to secure patent rights over potentially vast numbers of related chemical entities without the need to detail each molecule individually in a patent. While this approach is advantageous for the patent holders, as it creates broad protective scopes and reduces the risk of competition, it raises several concerns about its implications for innovation. This project addresses a critical gap in the existing literature by conducting the first comprehensive empirical analysis of how prevalent Markush structures are in pharmaceutical patents. Original findings show a pervasive use of Markus structures in pharmaceutical patents. Analysis of a large set of patents further reveals that "Markush patents" do not seem to induce congestion at patent offices as they exhibit no longer examination times and are also not more likely to be challenged in invalidity proceedings. Ongoing work investigates whether these structures reduce follow-on innovation by limiting competitors' ability to develop alternative compounds within the same drug class. This limitation can extend the market exclusivity of patented drugs, potentially delaying the introduction of competing therapies that could offer improved efficacy or safety profiles and thus harming R&D competition. The insights gained from this research are highly relevant for policymakers, patent offices, and other stakeholders involved in the pharmaceutical industry. By providing a deeper understanding of the strategic use of patents, particularly through Markush claims, the project contributes to ongoing debates on patent policy, competition, and public health outcomes. It highlights the need for balanced patent strategies that encourage innovation while ensuring that the public can benefit from new and effective therapies.

Publications

• Mapping Markush. Research Policy, 51(10), 104597.
  Wagner, Stefan; Sternitzke, Christian & Walter, Sascha
  
• “Mapping Markush” Annual conference of the European Policy of Intellectual Property Association EPIP, Cambridge, 2022.
  Wagner, Stefan
  
• “Available databases in the space of the pharmaceutical industry.” DRUID23, Lisbon, Portugal, 2023.
  Wagner, Stefan
  
• “Economics of AMR R&D incentives: Cost of inaction and action.” 1st Roundtable on Economics of AMR R&D incentives, AMR Action Fund, Paris, France, 2023.
  Wagner, Stefan
  
• “Exploring patterns of pharmaceutical post-marketing withdrawal” 5th AI & Strategy" Consortium, Srini Raju Centre for IT and the Networked Economy at the Indian school of Business, Hyderabad, India, 2024.
  Wagner, Stefan