How Can Health Technology Assessment Help in Addressing Challenges in Drug Repurposing? A Conceptual Framework

Objective: Drug repurposing is the process of investigating already-existing drugs for their potential to treat other indications. While drug repurposing can be more time and cost-effective than de novo drug development, it faces various challenges that hinder its full potential ^1,2. Our aim was to develop a comprehensive framework of all key challenges in drug repurposing and explore how health technology assessment (HTA) can help in addressing them.

Methods: We reviewed the literature on drug repurposing challenges up until April 20, 2023. Using a thematic analysis approach, we developed a framework for drug repurposing challenges by creating categories and subcategories among the identified challenges. We assessed the completeness of the framework through a focus group and semi-structured interviews with experts from the REPO4EU consortium. We then matched drug repurposing challenges within our framework with HTA methods that could potentially address them, using two recent reviews ^3,4 that categorised HTA methods according to their objectives.

Results: The final framework of drug repurposing challenges was developed based on 73 articles, a focus group with five experts, and seven interviews with 14 experts from the REPO4EU consortium. The framework identified 20 interconnected challenges grouped into six categories: data access, research and development, collaboration, business case, regulatory, and legal challenges. HTA methods that can address data access challenges are stakeholder analysis, Bayesian statistics, clinical trial simulation and structured expert elicitation. Various HTA methods, including health economic analysis, expert elicitation, patient preferences, and clinical research methods can tackle challenges in research and development and the business case. Stakeholder consultation methods address collaboration challenges by collecting different perspectives, eliciting preferences, and building consensus on the expected repurposed drug’s value. Patient forums, discussion groups and Delphi panels facilitate the early engagement with regulatory bodies to understand the regulatory requirements and legal options for registering the repurposed drug.

Conclusion: We have developed a framework for linking HTA methods to challenges in drug repurposing. This framework is intended to help researchers in anticipating challenges they may encounter during drug repurposing projects and identifying HTA methods that can help address these challenges. Incorporating HTA methods early in drug repurposing research can provide evidence for decision-making, assess the value proposition of the repurposed drug and inform further research.