Drug Repurposing: The New Frontier in Fighting Cancer

Drug repurposing presents a promising pathway in contemporary cancer drug discovery by revealing new mechanistic insights into existing drugs and adapting them for different cancer types. Drug repurposing has emerged as a crucial strategy in discovering new cancer treatments, offering numerous advantages. This method significantly decreases the time, cost, and effort associated with drug development and enhances safety, as essential factors like target validation, toxicological profiles, and pharmacokinetics are already well established. Cancer remains an extraordinarily challenging and heterogeneous disease, with various drug classes struggling to deliver effective and durable treatments. Traditional drug development is a protracted and expensive endeavour, often taking 15 to 18 years and costing billions of dollars, with a high failure rate in late-stage clinical trials due to efficacy, toxicity, and safety concerns. In contrast, drug repurposing can significantly shorten this timeline to 3 to 5 years and cut costs from billions to millions of dollars, making it a far more efficient and pragmatic strategy. Given that cancer continues to claim millions of lives globally each year, drug repurposing stands as one of the most effective and viable alternatives in advancing cancer drug discovery.
Despite significant advances, cancer treatments remain limited by several drawbacks. Currently available drugs are highly cytotoxic, expensive, and frequently associated with severe off-target effects. Moreover, although innovative, targeted therapies and biological interventions such as gene therapy or CAR-T therapy are prohibitively expensive and remain inaccessible to large patient populations. Given the continued global burden of cancer and the unmet need for curative options, repurposing already marketed and affordable drugs offers a practical and cost-effective alternative. Repurposed drugs can be evaluated for cancer regression rates in both preclinical and clinical models. At the same time, their therapeutic potential may be enhanced through advanced drug delivery systems, such as liposomal formulations, or rational combination therapies. These combinations may include pairing repurposed drugs with standard chemotherapeutics, antibody-drug conjugates, radiotherapy, or other modalities to achieve synergistic effects. Such integrated approaches improve treatment efficacy and promise to make cancer therapy more accessible and sustainable.
This Research Topic focuses on drug repurposing as a promising strategy in cancer therapy, aiming to highlight novel mechanistic insights, translational potential, and innovative applications of existing drugs in oncology. We invite contributions that explore diverse aspects of repurposed agents, including their roles in overcoming resistance, enhancing therapeutic efficacy, reducing toxicity, and improving accessibility and affordability of cancer treatments. Themes of interest include mechanistic studies, preclinical and clinical evaluations, combination therapies, novel drug delivery systems, biomarker-guided repurposing, and computational approaches for drug repositioning.
We welcome Original Research Articles, Reviews, Mini-Reviews, Perspectives, and Case Reports that provide critical advances or novel insights into drug repurposing for cancer. Submissions addressing multidisciplinary approaches, including pharmacology, immunology, nanotechnology, and systems biology, are strongly encouraged.

Please note: Manuscripts consisting solely of bioinformatics, computational analysis, or predictions of public databases, which are not accompanied by validation (independent clinical or patient cohort, or biological validation in vitro or in vivo, which are not based on public databases), are not suitable for publication in this journal.