Mebendazole is a decades-old antiparasitic drug now being studied in cancer. Dr. Johnston looks at a 40-patient randomized, placebo-controlled trial that added it to chemotherapy for metastatic colorectal cancer. The trial was small, and larger studies are needed.
Mebendazole is an old anti-parasitic drug that's been used for a long time, but researchers are now investigating something completely different. Could this old drug have activity against cancer?
Mebendazole disrupts microtubules, structures the cancer cells need to divide. It's a scaffolding on which cancer is built, and that's very interesting because microtubules are well-established target for FDA-approved chemotherapy agents. Drugs like vincristine and paclitaxel are known to attack microtubules. That's how they work.
Laboratory and animal studies have consistently demonstrated that mebendazole has anti-cancer activity against glioblastoma, colorectal cancer, breast cancer, melanoma, and several other kinds of cancers. Let's start with the preclinical data, and then we will move on to the human trials.
In two mice models of glioblastoma, John Hopkins researchers found that mebendazole increased average survival as much as 63%.
In a randomized, double-blinded, placebo-controlled trial, 40 patients with metastatic colorectal cancer received standard chemotherapy, and half also received mebendazole 500 mg twice daily. After 12 weeks, the objective response rate was only 10% with standard chemotherapy and placebo compared with 65% when mebendazole was added. That's a 55 percentage point difference.
And there's another remarkable human report. A 74-year-old man with metastatic colon cancer had already experienced progression after conventional chemotherapy. He was given mebendazole alone, 100 mg twice daily. After just 6 weeks, CAT scans showed near-complete remission of his lung and lymph node metastases and a substantial partial remission of his liver metastases. Now, that was only one patient, and a case report cannot prove a treatment's valid and works for everybody.
And here's another unusual part of the story. John Hopkins was granted a United States patent in 2021 involving a particular polymorph of mebendazole called form C. It's a crystallized form, but once it reaches the bloodstream, it's the same medicine. The polymorph allows them to get a patent off an old drug, and the patent was for glioblastoma.
Here's the research. You decide.
Educational research summary, not medical advice. Talk with your oncologist and pharmacist before starting, stopping or changing any treatment or supplement.