The antiparasitic drug fenbendazole may be able to shrink tumors in mice, according to a study published on Jan. 22 in Science Translational Medicine. The research, which was conducted at Stanford ChEM-H’s Medicinal Chemistry Knowledge Center and supported by the National Institutes of Health’s ViRx@Stanford initiative, shows that drugs that disrupt “normal” cellular processes that viruses and cancer cells rely on to grow and spread can cause those cells to die.

The researchers administered fenbendazole, which is available as oral granules or a liquid suspension, to colorectal cancer (CRC) cells and observed time-dependent inhibition of cell proliferation. The cells were then treated with ferrostatin-1 or deferoxamine mesylate (DFOM), which can block SLC7A11-dependent ferroptosis, to see if this was the primary mechanism by which fenbendazole induced apoptosis. The results showed that fenbendazole caused the cells to enter apoptosis independently of p53, and that the apoptosis was enhanced by ferroptosis-augmented GPX4-dependent oxidative stress.

In addition, the researchers found that fenbendazole inhibited glucose uptake in CRC cells, which is a common indicator of increased glucose usage by tumors for energy. These findings suggest that fenbendazole, which has been approved by the FDA as an antiparasitic for humans and dogs, could be used to treat human cancers.

However, the non-profit organization Cancer Research UK told PolitiFact that there is insufficient evidence to support Joe Tippens’ claim that fenbendazole cures lung cancer, and that it hasn’t been proven to be safe or effective in clinical trials. The Food and Drug Administration told PolitiFact that fenbendazole isn’t authorized or approved for treating cancer, though it’s widely available in pharmacies in South Korea where it was promoted by Tippens. fenbendazole for cancer