Drug repurposing and treatment optimisation in oncology: regulatory challenges and policy priorities
- 1Transforming Cancer Outcomes Through Research (TOUR), School of Cancer & Pharmaceutical Sciences, King’s College London
- 2Medical Oncology, Guy’s and St Thomas NHS Foundation Trust
- 3Advanced Therapies, Guy’s and St Thomas NHS Foundation Trust
Abstract
Drug repurposing and treatment optimisation are increasingly important strategies to improve cancer outcomes by making better use of existing therapies. Drug repurposing involves identifying new clinical indications for approved or abandoned medicines, while treatment optimisation focuses on refining how established therapies are used within their licensed indications, for example, through dose, duration, or sequencing modifications. Although both approaches aim to maximise patient benefit and are supported by extensive clinical experience, they face distinct and shared regulatory challenges. We examine why current regulatory and legislative frameworks remain poorly aligned with the objectives, risk profiles, and evidentiary needs of drug repurposing and treatment optimisation studies. Drawing on illustrative case studies in oncology, including aspirin and metformin repurposing, immunotherapy optimisation, and regulatory initiatives such as Project Optimus, we demonstrate how regulatory systems designed primarily for de novo drug development create disproportionate burdens, delay evidence generation, and impede translation into routine clinical practice. The heterogeneity of evidence across prevention and treatment settings, the absence of clear licensing pathways for off-patent medicines, and the limited integration of optimisation into post-authorisation management are recurring themes. This review highlights how regulatory bottlenecks arise across the trial life cycle and how diverse treatment optimisation study designs could better address patient-centred outcomes. We propose that proportionate regulatory frameworks encompassing marketing authorisation, post-authorisation evidence generation, and reimbursement mechanisms are necessary to enable the efficient evaluation, regulatory approval, and sustainable implementation of repurposed and treatment-optimised therapies. Aligning regulation with real-world cancer care requires coordinated action from regulators, policymakers, academia, industry and clinicians to ensure that established medicines are not only approved, but used optimally to deliver meaningful, evidence-based benefit.
Related
- Cardiometabolic medicine in China: Burden, challenges, and strategic priorities
- Advances in the management of pneumonia caused by drug-resistant bacteria: from antimicrobial optimisation to integrated treatment adaptation
- Repurposing nystatin and taurocholate to target intracellular spore persistence during antibiotic treatment to prevent recurrent Clostridioides difficile infection.
- Legal challenges and regulatory responses in online medical consultation
- Sub-national estimates of visceral leishmaniasis and optimisation of geographical accessibility to treatment centres in Kenya
BibTeX
@article{george2026drug,
title = {{Drug repurposing and treatment optimisation in oncology: regulatory challenges and policy priorities}},
author = {Gincy George and Harriet Wylie and Danielle Crawley and Deborah Enting and Anne Rigg and Sarah Rudman and Nisha Shaunak and Mieke Van Hemelrijck},
journal = {Frontiers in Pharmacology},
year = {2026},
month = nov,
doi = {10.3389/fphar.2026.2008061},
url = {https://www.frontiersin.org/articles/10.3389/fphar.2026.2008061/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Drug repurposing and treatment optimisation in oncology: regulatory challenges and policy priorities
AU - Gincy George
AU - Harriet Wylie
AU - Danielle Crawley
AU - Deborah Enting
AU - Anne Rigg
AU - Sarah Rudman
AU - Nisha Shaunak
AU - Mieke Van Hemelrijck
PY - 2026
DA - 2026/11/03
JO - Frontiers in Pharmacology
DO - 10.3389/fphar.2026.2008061
UR - https://www.frontiersin.org/articles/10.3389/fphar.2026.2008061/full
AB - Drug repurposing and treatment optimisation are increasingly important strategies to improve cancer outcomes by making better use of existing therapies. Drug repurposing involves identifying new clinical indications for approved or abandoned medicines, while treatment optimisation focuses on refining how established therapies are used within their licensed indications, for example, through dose, duration, or sequencing modifications. Although both approaches aim to maximise patient benefit and are supported by extensive clinical experience, they face distinct and shared regulatory challenges. We examine why current regulatory and legislative frameworks remain poorly aligned with the objectives, risk profiles, and evidentiary needs of drug repurposing and treatment optimisation studies. Drawing on illustrative case studies in oncology, including aspirin and metformin repurposing, immunotherapy optimisation, and regulatory initiatives such as Project Optimus, we demonstrate how regulatory systems designed primarily for de novo drug development create disproportionate burdens, delay evidence generation, and impede translation into routine clinical practice. The heterogeneity of evidence across prevention and treatment settings, the absence of clear licensing pathways for off-patent medicines, and the limited integration of optimisation into post-authorisation management are recurring themes. This review highlights how regulatory bottlenecks arise across the trial life cycle and how diverse treatment optimisation study designs could better address patient-centred outcomes. We propose that proportionate regulatory frameworks encompassing marketing authorisation, post-authorisation evidence generation, and reimbursement mechanisms are necessary to enable the efficient evaluation, regulatory approval, and sustainable implementation of repurposed and treatment-optimised therapies. Aligning regulation with real-world cancer care requires coordinated action from regulators, policymakers, academia, industry and clinicians to ensure that established medicines are not only approved, but used optimally to deliver meaningful, evidence-based benefit.
SN - 1663-9812
ER -