Comparing regulatory pathways for drug repurposing in the EU, UK, and US

Drug repurposing may be useful in efficiently bringing important new treatments to patients. To help investigators interested in drug repurposing–particularly those in academic or non-profit settings–navigate the regulatory process, we compared available regulatory pathways for repurposed drugs at the European Medicines Agency (EMA), UK Medicines and Healthcare Products Regulatory Agency (MHRA) and the US Food and Drug Administration (FDA).We focused on 3 repurposing scenarios: a drug never approved by regulators (shelved drug), a marketed product with market exclusivity and/or active patents (new drug), and a drug no longer protected by any exclusivity (generic drug), and created flowcharts to aid academic and non-profit organizations navigate the regulatory landscape.

Repurposing shelved or new drugs must be executed either by or in collaboration with the original intellectual property holder. Shelved drugs can apply for marketing authorization by submitting complete pivotal clinical trials to demonstrate safety and effectiveness. For new drugs, repurposed indications can be added to the product’s label, making sponsors eligible for up to 3 years of market exclusivity under certain conditions. Generics are more accessible for repurposing, and repurposers may not need to collect as extensive preclinical safety data, given that generics have well established safety profiles, though regulators will still require robust clinical evidence of efficacy. Repurposers of generics may collaborate with existing marketing authorization holders to add new indications to drug labels or become marketing authorization holders themselves.

Creating streamlined regulatory pathways for prescription drug repurposing could improve the public health value of this practice. The EU has proposed a new pharmaceutical regulation that aims to facilitate drug repurposing by providing four years of data protection under certain conditions and allowing non-profit entities to submit evidence on new indications to force marketing authorization holders to add the indication to the labeling.