Research indicates that the common anthelmintic medication fenbendazole functions as an effective anticancer agent by interfering with multiple cellular processes in malignant cells. Specifically, the drug acts as a moderate microtubule-destabilizing agent that disrupts the cellular skeleton and halts cell division, ultimately forcing cancer cells into apoptosis. Furthermore, the treatment suppresses tumor growth by blocking cellular glucose uptake and crippling key metabolic enzymes that aggressive cancer cells rely on to survive. These antitumor effects are further amplified by p53 activation and mitochondrial translocation, which work alongside the drug’s microtubule-disrupting activity. Ultimately, because the compound strongly suppresses tumors in both cell culture and live animal models without relying on traditional resistance pathways, it has significant potential for therapeutic repurposing in modern oncology.
Fenbendazole (FZ), a veterinary benzimidazole anthelmintic, demonstrates potent anticancer efficacy through a multi-targeted mechanism that combines moderate microtubule disruption, p53 pathway activation, metabolic suppression, and anti-angiogenesis.
1. Moderate Microtubule Destabilization
Mechanism & Binding: Fenbendazole binds mammalian tubulin at the colchicine-binding site.
Mild Depolymerization: Unlike colchicine or vincristine, which cause massive microtubule destruction, FZ mildly destabilizes the microtubule framework without altering acetylated α-tubulin levels.
Mitotic Arrest: FZ induces a G2/M cell cycle block, elevating Cyclin B1, CDK1, and p-histone H3 (Ser10), leading cancer cells to undergo mitotic catastrophe and apoptosis.
2. Overcoming Multidrug Resistance (MDR)
Non-P-gp Substrate: FZ is neither a substrate nor an inhibitor of P-glycoprotein (P-gp / MDR1).
Bypassing Resistance: Co-treatment with the P-gp inhibitor verapamil does not alter FZ’s cytotoxicity, allowing FZ to bypass common multidrug resistance mechanisms that impair conventional chemotherapeutics like taxanes and vinca alkaloids.
3. p53 Activation & Mitochondrial Apoptosis
p53 Dependency: Cancer cell lines expressing wild-type (WT) p53 (such as A549 and H460) display significantly higher sensitivity to FZ compared to p53-mutant or null cell lines.
Nuclear Accumulation: FZ drives nuclear accumulation of WT p53 and induces downstream target genes including p21, MDM2, TIGAR, SCO2, and GLS2.
Mitochondrial Translocation: FZ promotes direct translocation of monoubiquitinated p53 to mitochondria, depolarizing the mitochondrial membrane potential and triggering apoptosis.
4. Suppression of Glucose Metabolism (Warburg Effect Interruption)
Glucose Uptake Blockade: FZ markedly reduces cellular glucose uptake and consumption while lowering lactate secretion in cancer cells.
Hexokinase II (HKII) & GLUT-4 Inhibition: FZ down-regulates GLUT-4 transporters and directly inhibits Hexokinase II (HKII) by stably binding to its glucose/glucose-6-phosphate pocket.
Succinate Dehydrogenase (SDH) Activation: FZ enhances SDH activity, a mitochondrial tumor suppressor enzyme, helping restore normal mitochondrial oxidative dynamics.
5. Synergistic Combination Therapies
FZ displays strong synergistic cytotoxicity (Combination Index (CI)<1) when combined with metabolic inhibitors and chemotherapeutics:
Dichloroacetate (DCA) (CI≈0.04, indicating strong synergism).
2-deoxyglucose (2DG) (CI≈0.21).
Taxol / Paclitaxel (CI≈0.52).
6. In Vivo Tumor Suppression & Anti-Angiogenesis
Tumor Growth Reduction: In A549 mouse xenograft models, oral FZ (1 mg/mouse every 2 days) markedly reduced tumor volume and weight.
Anti-Angiogenesis: FZ significantly reduced tumor vascularity, as shown by lower tumor hemoglobin content and a sharp decline in CD31-positive endothelial cells in tumor tissue.
In preclinical research, the ketogenic diet (KD) facilitates drug transport and accumulation in brain tissue, though the exact molecular mechanism remains incompletely understood.
Key findings regarding how KD impacts blood-brain barrier (BBB) delivery include:
Lipid Solubilization & Bioavailability: Lipophilic small molecules like mebendazole have poor oral solubility on their own, but co-administration with a high-fat ketogenic diet improves gastrointestinal solubilization and systemic bioavailability.
Enhanced Small-Molecule Transport Across the BBB: Nutritional ketosis facilitates the delivery of structurally diverse small-molecule therapeutics across the blood-brain barrier. For example, brain tumor delivery of the glutamine antagonist DON was three-fold greater in mice fed a ketogenic diet compared to those on a standard high-carbohydrate diet.
Target Engagement & Brain Accumulation: MALDI imaging mass spectrometry confirmed mebendazole presence and accumulation directly in brain tumor tissues when delivered alongside KD. Similarly, co-administering KD with the mitochondrial inhibitor CPI-613 (devimistat) significantly reduced target enzymes like OGDH in brain tissue, whereas CPI-613 administered on a standard diet did not.
Current Mechanistic Limitation: The authors explicitly note as a study limitation that the precise physiological or cellular mechanisms by which nutritional ketosis alters blood-brain barrier transport kinetics remain unclear and require further investigation.
Peer-Reviewed Journal Articles
Dogra, N., Kumar, A., & Mukhopadhyay, T. (2018). Fenbendazole acts as a moderate microtubule-destabilizing agent and causes cancer cell death by modulating multiple cellular pathways. Scientific Reports, 8(1), Article 11926. https://doi.org/10.1038/s41598-018-30158-6
Gupta, R., Roy, D., Ghosh, A., Begum, Y., Ghosh, D., & Swarnakar, S. (2025). Mebendazole exerts anticancer activity in ovarian cancer cell lines via novel Girdin-mediated AKT/IKKα/β/NF-κB signaling axis. Cells, 14(2), Article 113.
Preprint Publication
Mukherjee, P., Maurer, J., Stopka, S. A., Greenwood, B., Aristizabal-Henao, J. J., Karmacharya, S., Chimento, A., Ta, N., Lee, D. C., Duraj, T., Bronson, R. T., Kiebish, M. A., & Seyfried, T. N. (2023). Ketogenic diet as a metabolic vehicle for enhancing the therapeutic efficacy of mebendazole and devimistat in preclinical high-grade gliomas grown in juvenile mice. bioRxiv.
Clinical Trial Registry Record
Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins. (2022). Phase I study of mebendazole therapy for recurrent/progressive pediatric brain tumors (Identifier: NCT02644291). National Library of Medicine (US). https://clinicaltrials.gov/study/NCT02644291
See the information. The patient has to meet the Eligibility Criteria-
https://www.hopkinsmedicine.org/brain-tumor/clinical-trials
Various trials have different eligibility requirements posted with the study. Let us know if you have more questions.
If someone has a brain tumor and diagnosis is terminal, can they apply to be in a trial at John Hopkins Sydney Kimmel?