While research in cells and mice can sometimes look promising, it’s not possible to know whether a drug will work in humans until it goes through human trials. One study has found that a dog wormer ingredient, fenbendazole, stops cancer cells from growing and may help make other drugs more effective. But there’s no evidence that the dog wormer will cure cancer, a specialist cancer information nurse has told Full Fact.
Fenbendazole, also known as mebendazole, is a popular antiparasitic medicine. It fights roundworm, hookworm and other parasites by interfering with the formation of tubulin. Tubulin is part of a protein scaffold that supports the structure and shape of cells. The structure gives cells their physical properties and allows them to change shape to fit through narrow spaces and transport organelles and cargo. It’s similar to the way in which a skeleton supports our bodies, but instead of bones it’s made from microtubules.
In a new study, Riggins and his colleagues have shown that mebendazole can stop the growth of tubulin in cancer cells. This can cut off the cell’s supply of nutrients, starving it to death. It can also block the activity of a protein called tau, which helps to keep the microtubules in place.
The team also analyzed the effects of fenbendazole on radiation-induced tumors in mice. They injected EMT6 tumor-bearing mice with three daily i.p. injections of fenbendazole or a placebo and then irradiated the tumors with 10 Gy of x-rays. The researchers then compared the tumor growth and radiation response of the two groups of mice.
They found that fenbendazole did not influence the growth of unirradiated tumors and that it did not alter the radiation response in mice receiving the drug with irradiation. However, they did find that the drug combined with irradiation reduced the number of radiation-induced lung metastases in mice.
In addition, they also tested several formulations of fenbendazole and rapamycin to determine which would be the most effective in combining them with rapamycin. They found that a formulation of the drug loaded into micelles made from polyethylene glycol was most effective in delivering both drugs to tumors. The drug-loaded micelles were stable for up to 240 hours, and the encapsulated drugs were released at similar rates throughout the irradiation experiment.
The team has now published the results of their experiments and hope to continue testing the effectiveness of fenbendazole as an immunotherapy. They plan to combine the drug with a new class of cancer drugs that are designed to be more effective in treating cancer when compared to standard chemotherapy treatments such as platinum compounds. They have also investigated the possibility of combining this treatment with other drugs that have been shown to be more effective in the same type of cancer as fenbendazole, including the hypoxia-selective nitroheterocyclic cytotoxins and radiosensitizers. They also plan to examine the combination’s potential in other types of cancer. fenbendazole for humans cancer