Despite the resurgence of the Joe Tippens Protocol, there is currently insufficient evidence to support the use of fenbendazole for human cancer. While studies in cell cultures and animals suggest that fenbendazole may have anticancer effects, the drug is not FDA approved for use in humans and has no known clinically proven anticancer activity in humans.
A patient with advanced nonsmall-cell lung cancer (NSCLC) was self-administering fenbendazole, a benzimidazole carbamate medication, because she believed it was effective against her disease. She had obtained this information via social media, where she had seen anecdotal reports of patients who self-administered fenbendazole and experienced remission of their disease.
The woman was also receiving pembrolizumab, an immunotherapy agent, to treat her cancer. Her CEA level had increased and she was worried about cancer progression. Her physician suggested reducing the dose of her pembrolizumab therapy to half, and she also began taking oral fenbendazole. This was an unapproved use of the drug for humans and constituted extra-label use.
Fenbendazole is a benzimidazole carbamate and acts by inhibiting the polymerization of tubulin, which is part of a protein scaffolding called the cytoskeleton that gives cells their shape and structure. This mechanism of action is similar to the way cytotoxic anticancer agents work.
In a study of colorectal cancer cells, fenbendazole caused G2/M arrest and cell death in 5-FU sensitive SNU-C5 and SNU-C5/5-FUR CRC cells by activating p53 and p21 pathways . Its cytotoxic effect was partially due to mitochondrial injury, and caspase-3-mediated apoptosis was also enhanced by decreased GPX4 expression.
It is likely that fenbendazole may also interfere with the formation of microtubules, which are essential for cellular movement and vesicle transport. The cytoskeleton also provides a stable platform for the binding of other proteins to the cell membrane and enables the cell to change its shape to move through narrow spaces or to transport organelles and cargo.
A patient who is taking fenbendazole should not take any other prescription or over-the-counter medicines, including supplements and herbs, without first talking to her doctor. There is a potential for serious adverse reactions, including liver damage, from these interactions. fenbendazole for humans