Stanford researchers didn’t set out to fight cancer, but the lessons they’ve learned in their work fighting viruses like hepatitis and the common cold have led them to a novel drug that appears to be effective in mice. It’s fenbendazole, a broad-spectrum anthelmintic that’s used to treat parasites in animals and humans.

The article published in the journal Science Advances reports that a single injection of the drug slashed the number of tumor cells in seven different cancer cell types by at least 40%. The results support the notion that drugs that target parasites may be able to boost the effectiveness of anticancer chemotherapy.

In the experiments, cultured EMT6 human tumor cells were treated in hypoxic conditions — a sealed glass bottle with gaskets and needles for inflow and outflow of gases, plus a continuous supply of oxygen at less than 2 ppm — for two hours before receiving graded doses of the taxane docetaxel. The clonogenicity of the cultures was assessed after the treatment to quantify their ability to form colonies, and survival curves for the untreated control cultures and those treated in combination with 10 mM fenbendazole (shown in Figure 2) were calculated using relative surviving fractions from the EMT6 cell numbers in each group, or by counting the number of viable colonies formed in cultures exposed to docetaxel alone.

The fenbendazole molecule (methyl [5-(phenylsulfanyl)-1H-benzimidazol-2-yl] carbamate) binds to beta-tubulin, inhibiting its formation and thus disrupting the assembly of microtubules that form the cellular skeleton. It promotes apoptosis and cell cycle arrest in 5-FU-sensitive CRC cells and enhances p53-mediated apoptosis and ferroptosis in resistant CRC cells. fenbendazole for cancer