Author: Mario García
Drug repurposing benefits
The fact that this method of ‘innovation’ relies on the discovery of new indications for existing off-patent drugs means that repurposing offers significant advantages. As the safety, toxicology and pharmacokinetic profiles in humans are already established through previous use, this process allows early stages of research to be bypassed and significantly reduces the risk of clinical failure (1). Consequently, this leads to a significant reduction in R&D time (3–12 years) compared to the development of new compounds (10–15 years), and patients can gain faster access to the therapeutic benefits offered by these treatments (2). At the same time, estimates suggest that R&D costs for drug repurposing are between 40% and 90% lower, meaning the savings for the Spanish National Health Service (NHS) are very substantial (3). Furthermore, the use of affordable generic/biosimilar medicines represents an immense social and economic benefit for the Spanish NHS, facilitating the treatment of rare or neglected diseases that often lack commercial interest. Furthermore, during the COVID-19 pandemic, drug repurposing demonstrated that it was possible to accelerate drug development in emergency situations. For example, the most notable case was that of dexamethasone, which was an anti-inflammatory drug and was repurposed for the treatment of severe COVID-19 (4).
Sources for identifying opportunities for drug repurposing
The main source of opportunities for repurposing arises in everyday clinical practice, where numerous cases of off-label use are identified (5). Based on the leads generated, Real World Evidence (RWE) studies are also conducted to demonstrate efficacy, which could be used to support regulatory approval (5). In this context, artificial intelligence (AI) is also playing a role in how repurposing opportunities are identified. AI-based tools are proving particularly promising in basic research studies. For example, for screening compounds, predicting new drug combinations and therapeutic targets, and assessing adverse effects, which may ultimately accelerate the selection of existing targets and drugs for new applications (6).
Areas of highest current value for drug repurposing
At present, there are various sectors where drug repurposing is being promoted (5). Firstly, treatments for rare diseases and cancer are the areas that experts identify as having the greatest clinical and economic value for repurposing. Above all, it holds great potential for those diseases that address unmet medical needs. To this end, there are various regulatory incentives, such as Orphan Drug Status (10 years of market exclusivity for orphan drugs) in the EU and streamlined regulatory approval processes (accelerated approval schemes). Secondly, as this primarily concerns generics and biosimilars, academic researchers and non-profit organisations take on a leading role, in a context where patients could play a greater part in decision-making. In this regard, Article 48 of the draft reform of the European Pharmaceutical Strategy allows the EMA to assess scientific evidence from non-commercial entities for the approval of new indications for unmet medical needs. Thirdly, given the current active prescribing system that leads to substitution with generics in community pharmacies, the hospital is an ideal setting for repositioning. Thus, the hospital pharmacy enables the monitoring of use by indication and the generation of evidence from RWE, which could be crucial in demonstrating their effectiveness (5).
Drug repurposing in Europe and Spain
In recent years, various efforts have been underway in Europe to capitalise on the benefits of this method of ‘innovation’ for new indications. These efforts are reflected not only in regulatory support programmes (such as the EU Repurposing Pilot) and research (REPO4EU) and implementation (REMEDi4ALL) initiatives, but also in legal and regulatory incentives (5). In Spain, the Spanish Agency for Medicines and Health Products has played a key role in the European pilot through its Office for Innovation Support and the National Scientific Advisory Unit (7).
Conclusion
In conclusion, drug repurposing is thus establishing itself as a strategic tool for improving the efficiency and sustainability of the National Health Service. Its ability to speed up access to treatments, reduce costs and build on existing knowledge makes it a key pillar of the future of pharmaceutical innovation, particularly against a backdrop of growing pressure on healthcare systems.
References
1. van der Pol KH, Aljofan M, Blin O, Cornel JH, Rongen GA, Woestelandt AG, et al. Drug Repurposing of Generic Drugs: Challenges and the Potential Role for Government. Appl Health Econ Health Policy. 1 de noviembre de 2023;21(6):831-40. doi:10.1007/s40258-023-00816-6.
2. Sperry M, Ingber DE. Drug Discovery from Technology Networks [Internet]. 2024 [citado 15 de abril de 2026]. Drug Repurposing Strategies, Challenges and Successes. Disponible en: http://www.technologynetworks.com/drug-discovery/articles/drug-repurposing-strategies-challenges-and-successes-384263
3. Liddicoat J, Hamidzadeh A, Liddell K, Schito M, Simon D, Aboy M, et al. New government drug repurposing programs: Opportunities and uncertainties. Sci Transl Med. 26 de junio de 2024;16(753):eadl0998. doi:10.1126/scitranslmed.adl0998
4. Elechi KW, Adeoye AF, Olaniyi AO, Akanbi OO, Olumeko I, Udensi CG, et al. Translational Success and Pharmacoeconomic Lessons of Pandemic-Driven Drug Repurposing. Cureus. 17(5):e85033. doi:10.7759/cureus.85033 PubMed PMID: 40585709; PubMed Central PMCID: PMC12205848.
5. Garcia-Diaz M, Epstein D, Espin J. Overcoming barriers to off-patent drug repurposing: a lifecycle-based policy solutions. Front Pharmacol. 24 de octubre de 2025;16. doi:10.3389/fphar.2025.1670845
6. Anokian E, Bernett J, Freeman A, List M, Prieto Santamaría L, Tanoli Z, et al. Machine Learning and Artificial Intelligence in drug repurposing – challenges and perspectives. DrugRxiv. 12 de marzo de 2024. doi:10.58647/DRUGARXIV.PR000007.v1
7. Vidal Vademecum Spain. Vademecum.es [Internet]. 2026 [citado 15 de abril de 2026]. Vademecum: Scientia semper tecum | Conocimiento Farmacológico y Apoyo a la Decisión Clínica. Disponible en: https://www.vademecum.es/
