Drug Repurposing
Exploring established medicines for potential roles in cancer through a systems oncology framework.
What Is Drug Repurposing?
Drug repurposing involves investigating an existing medicine for a new therapeutic purpose. A drug may have an established indication for one disease while researchers investigate whether it may have useful biological effects in another condition.
In oncology, repurposing is particularly interesting because many existing medicines have well-characterized pharmacology, established manufacturing pathways and known safety information from their approved uses.
However, an established drug is not automatically an established cancer treatment. Evidence for a new cancer indication must be evaluated separately.
Why Explore Existing Medicines?
Cancer involves multiple interconnected biological pathways. Some established medicines may influence pathways that are also relevant to cancer biology.
Known Pharmacology
Existing medicines often have substantially more pharmacological and safety information than a completely new compound.
Multiple Biological Targets
Some medicines influence pathways involved in metabolism, inflammation, angiogenesis, immunity or other aspects of tumor biology.
Systems Oncology
Repurposing can be considered within a broader framework rather than focusing on a single molecular target.
Potential for Combination Research
Some repurposed agents are being studied alongside established cancer therapies, although the effectiveness and safety of combinations must be demonstrated.
Drug Categories Explored in the Book
Garden of Recovery examines a range of established medicines being investigated in different areas of cancer biology.
Metabolic Modulators
Metformin, fenofibrate, statins and aspirin.
Antiparasitic Agents
Ivermectin, mebendazole, fenbendazole and niclosamide.
Antimalarial Agents
Hydroxychloroquine, chloroquine and artesunate.
Antifungal Agent
Itraconazole and its potential relevance to cancer biology.
Antibiotics
Doxycycline and clarithromycin.
Immunomodulatory & GI
Cimetidine and low-dose naltrexone.
Cardiovascular Agents
Propranolol, losartan and ACE inhibitors or ARBs.
Other Repurposed Drugs
Disulfiram, celecoxib, dipyridamole, pentoxifylline, methylene blue and high-dose intravenous vitamin C.
How Should the Evidence Be Evaluated?
The evidence for a repurposed drug can range from laboratory research to human clinical studies. These levels of evidence should not be treated as equivalent.
- Preclinical evidence: laboratory and experimental studies can identify biological mechanisms and potential therapeutic effects.
- Human clinical evidence: clinical studies provide more direct information about safety, dosing and effectiveness in people.
- Clinical relevance: evidence must be considered in relation to the specific cancer type, disease stage, treatment setting and patient.
- Benefit versus risk: a plausible mechanism does not by itself establish that a treatment will benefit a patient.
Safety Comes First
A medicine being approved for one condition does not mean that it has been proven effective for cancer. An off-label use may be legally prescribed, but effectiveness for the new indication still requires appropriate evidence.
Drug interactions, contraindications, organ function, adverse effects and interactions with conventional cancer treatment must be considered before any repurposed medicine is used.
Patients should discuss potential repurposed treatments with their oncology team rather than stopping, delaying or replacing established cancer treatment on the basis of information from this website.
Explore the Repurposed Drugs
The book provides detailed monographs covering pharmacology, molecular targets, mechanisms, interactions, safety, dosing and the available evidence for individual agents.
Explore the Book