Fenbendazole
(FBZ) is a low-cost veterinary antiparasitic drug that has gained
global attention as a potential anticancer therapy. Like
ivermectin—another antiparasitic widely repurposed in research and
clinical practice for its potent anti-tumor effects—fenbendazole appears to work far beyond its original veterinary use.
Preclinical
studies show fenbendazole disrupts cancer cell survival through
multiple pathways, but until now, human evidence has been scarce.
A newly published case series by Dr. William Makis et al in Case Reports in Oncology
presents three remarkable patients with advanced, stage IV cancers
(breast, prostate, and melanoma) who self-administered Fenbendazole
outside conventional oncology protocols. All three achieved either complete or near-complete remission — sustained for up to three years — without chemotherapy:
Case 1 – Stage IV Breast Cancer
Patient: 83-year-old woman with widely metastatic ER/PR-positive, HER2-negative breast cancer involving the liver, lungs, and spine.
Treatment: Daily FBZ (222 mg), fulvestrant (estrogen blocker), brief targeted radiation for spinal lesions, vitamin D and multivitamins.
Outcome:
Within 8 months, tumor markers normalized and PET scans confirmed no
evidence of disease. She has remained recurrence-free for nearly 3 years on continued FBZ with no adverse effects.
Case 2 – Stage IV Prostate Cancer
Patient: 75-year-old man with recurrent metastatic prostate cancer (spine, pelvis, humerus, and lymph nodes).
Outcome: Regression of bone and lymph node metastases. PSA remained undetectable for over 2 years. He is in a near-complete remission at 26 months follow-up, continuing FBZ with ADT.
Case 3 – Stage IV Melanoma (BRAFV600+)
Patient: 63-year-old man with recurrent metastatic melanoma, also diagnosed with a ureteral carcinoma.
Treatment:
Began FBZ (222–444 mg/day) during a treatment gap, later received two
doses of nivolumab. Also took routine supplements (vitamin C, D, CoQ10,
B12, glutathione).
Outcome: Circulating tumor DNA dropped from 123 → 0 in under 2 months. Imaging confirmed complete remission with no evidence of disease. Patient remains recurrence-free 11 months later.
MECHANISMS OF ACTION
As
outlined in this case series, preclinical studies on fenbendazole
reveal multiple anticancer mechanisms that may explain the dramatic
outcomes seen in these cases:
Microtubule destabilization
→ FBZ binds tubulin, blocking polymerization, leading to mitotic arrest
and apoptosis (similar to chemotherapy agents like vinca alkaloids).
p53 activation → triggers mitochondrial apoptosis and DNA damage response, selectively killing cancer cells.
Proteasome inhibition → interferes with protein degradation, suppressing tumor cell proliferation.
Metabolic disruption → inhibits glucose uptake and likely glutamine utilization, starving cancer cells of essential fuel.
Cancer stem cell effects → FBZ and other benzimidazoles appear capable of suppressing resistant tumor-initiating cells.
This
is only the second published case series documenting human cancer
remissions linked to fenbendazole use. Strikingly, two of the three
patients achieved “no evidence of disease” — a rare outcome in advanced stage IV cancers.
However:
Patients self-medicated without controlled oversight.
All used FBZ alongside other treatments, making causality unclear.
Spontaneous remission, though rare, cannot be excluded.
Still,
the consistency across cases — different cancers, different regimens,
same outcome: regression or remission — signals a phenomenon too
important to dismiss.
FBZ is cheap, accessible, and already proven
safe in veterinary medicine. What’s lacking is rigorous human clinical
research. Clinical trials should be immediately inititated to assess
fenbendazole’s true potential.
By Independent News Roundup
.svg){kind=logo}
