Legal framework and challenges for drug repurposing in Europe

Drug repurposing—identifying new therapeutic uses for existing medicines—holds considerable scientific promise and societal value. Yet it faces persistent legal and regulatory barriers. In Europe and beyond, a fragmented system of protections—including purpose-limited patents, the EU's 8+2(+1) data and market exclusivity scheme, Supplementary Protection Certificates (SPCs), and in the United States, Hatch-Waxman provisions such as Orange Book use codes, 505(b)(2) applications, and orphan exclusivity—seeks to balance public health needs with commercial incentives. However, these frameworks, largely designed for traditional drug development, have proven ill-suited for today's rapidly evolving innovation landscape. Globally, divergent intellectual property regimes, heterogeneous health technology assessment (HTA) processes, and inconsistent payer policies further complicate repurposing and often delay clinical uptake. Challenges differ by context: <!-- named anchor --> Off-patent drugs:scientifically promising but commercially unattractive, as generic competition undermines incentives without additional exclusivity mechanisms. On-patent but neglected drugs:access may be blocked by existing rights despite limited originator interest; since compulsory licensing is rarely applied, progress depends on voluntary agreements or litigation. On-patent drugs targeted for new formulations or treatment algorithms:third parties can seek protection for innovations such as fixed-dose combinations or treatment protocols, yet enforcement remains uncertain due to regulatory carve-outs (e.g., "skinny labels" in the EU) or litigation risks (e.g., induced infringement in the US). Taken together, these obstacles create a "catch-22": repurposing offers a cost-effective, high-value solution for patients and health systems, but current frameworks provide insufficient incentives and little political momentum for reform at either the national or European level.