Drug development is often a long and costly process, yet the growing focus on drug repurposing is providing a more efficient pathway to new therapies. Repurposing existing medicines, already proven safe for other conditions, is offering a promising solution for rare diseases and infections that lack effective treatments. At the International Drug Repurposing Conference (iDR25), organised by REMEDi4ALL and Beacon for Rare Diseases and supported by the EU’s Horizon Europe programme, researchers and patient advocates presented advances in this field. The conference highlighted how collaboration between scientists, regulators, patients and funders is reshaping the development of accessible therapies while easing the financial pressures of healthcare systems.
Efficiency of Repurposing Strategies
Drug repurposing involves identifying new therapeutic uses for medicines originally designed for other conditions. Because safety and preclinical studies have already been completed, development timelines are shortened and costs are significantly reduced compared to creating entirely new drugs. Estimates suggest that developing a repurposed drug can cost around $300 million (€276 million) and take three to twelve years, whereas new drugs often require $2–3 billion (€1.84–2.76 billion) and up to seventeen years. This efficiency makes repurposing especially attractive for conditions with limited treatment options, such as rare diseases. In Europe, a disease is considered rare if it affects five in 10,000 people, yet collectively these diseases impact about 300 million people globally. With only 500 treatments available out of approximately 7,000 identified rare diseases, the potential impact of drug repurposing is considerable.
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REMEDi4ALL, coordinated by EATRIS, brings together expertise from drug discovery, patient groups, regulators and health economists to streamline the repurposing ecosystem. By addressing fragmented processes and aligning the value chain, the initiative aims to make promising therapies more accessible. Advances in biological understanding are also supporting progress, with scientists identifying shared disease pathways that allow drugs developed for one condition to be tested against others. This approach not only provides therapeutic opportunities but also deepens scientific knowledge of disease mechanisms.
Applications Across Diseases
Several cases presented at the conference demonstrated the versatility of drug repurposing. Nitisinone, originally used to treat hereditary tyrosinemia type 1, is now being trialled as an antimalarial agent. By making blood toxic to mosquitoes, the drug could help counteract rising resistance to traditional insecticides, though concerns remain due to reductions in funding for global malaria programmes.
Another example is Motor Neuron Disease (MND), a progressive neurodegenerative condition with limited treatment options. Researchers at MND-SMART are using an adaptive trial design to test multiple repurposed drugs simultaneously, including amantadine, memantine, trazodone and tacrolimus. This model, which shares a placebo arm and allows ineffective drugs to be dropped quickly, is accelerating progress. Importantly, a Patient Advisory Group has shaped the trial’s design to ensure accessibility through remote consent, digital follow-ups and patient-led outcomes.
Cyclic vomiting syndrome also illustrates the potential of unconventional solutions. A patient unresponsive to more than 25 treatments improved dramatically when AI-assisted research identified isopropyl alcohol inhalation as a viable intervention. Now recommended in emergency departments as a low-cost treatment for nausea, this case shows how computational tools can enhance drug repurposing efforts.
Patient Advocacy and New Therapies
Recurrent Respiratory Papillomatosis (RRP) exemplifies the challenges and opportunities in repurposing. Patients with this rare condition often undergo repeated surgeries to remove obstructive growths caused by HPV infection. Off-label use of bevacizumab, an angiogenesis inhibitor, has shown strong results in reducing tumour growth. However, the absence of commercial incentives for off-patent drugs has limited wider access, leaving many patients reliant on surgical interventions. Advocacy has played a central role in highlighting the need for more flexible approval pathways and patient choice in balancing treatment risks.
Recent progress offers new hope. The FDA has approved Papzimeos, an immunotherapy targeting HPV-related RRP, after trial results showed lesion resolution in more than half of participants. Although currently limited to adults, plans are underway to extend trials to paediatric patients. This development underscores the potential of combined approaches, where repurposed drugs and novel therapies complement one another to expand treatment options.
The progress demonstrates the growing recognition of drug repurposing as a vital strategy for addressing unmet medical needs, particularly in rare diseases. By cutting costs and reducing timelines, repurposing expands access to therapies that would otherwise remain out of reach. Initiatives such as REMEDi4ALL are fostering collaboration and efficiency, while patient groups are ensuring that lived experiences shape trial design and treatment priorities. With increasing interest from regulatory authorities, drug repurposing is positioned to become a central pillar of therapeutic innovation, offering both practical and scientific value in the global effort to improve healthcare outcomes.
Source: Forbes
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