The issues around financial and regulatory obstacles to the repurposing of off-patent/generic medicines are well characterized in the academic literature and are familiar to policymakers and funders. However, the repurposing of on-patent medicines is less well-characterized, including funding and regulatory obstacles that may occur in these cases. The Rising Tide Foundation for Clinical Cancer Research and the Anticancer Fund have, in recent years, been faced with clinical trial proposals involving on-patent medicines. In this report we have explored the commercial, regulatory, and social factors involved in on-patent drug repurposing, with particular emphasis on issues most relevant to research funders.
We begin by defining terms given that 'off-label', 'off-patent' and 'generic' are often used interchangeably - we define these terms and outline the regulatory paths available for adding approvals for new medical indications to drugs. In particular, the tension between market exclusivity and the arrival of competitor products is shown to be a major factor in the decision-making process of commercial drug developers. The prevalence of on-patent drug repurposing in oncology is also touched upon, using both data derived from a repurposing clinical trial database and case studies.
The label extension pathways are outlined, showing both the central role of data generation via clinical trials and the role of the marketing authorization holder, particularly when the data is generated by academic or not-for-profit sponsors. The importance of label extension is also emphasized, contrasting this with the use of drugs 'off-label', which is possible but is not an optimal solution to the problem of access to repurposed medicines for patients. In contrast to generic medicines repurposing, on-patent repurposing may include the possibility that not-for-profit organizations can contract with the commercial owners of a drug to get a return on their philanthropic investment. This 'revenue sharing' approach is discussed in the report.
Finally, the report includes the philanthropic approach that has been adopted by RTFCCR as a policy when dealing with future on-patent drug repurposing proposals.