A common drug used to treat parasitic worms has shown promise in humans with pancreatic cancer, according to a new study. The research may point to a novel combination therapy that could improve the survival of patients with this deadly cancer.
The drug, called fenbendazole (also known as mebendazole), was originally developed to eradicate roundworms and hookworms by starving the parasitic infections of their energy source. But it appears to have a similar effect on cancer cells as well, stopping their growth by interfering with tubulin production, the protein that forms part of the inner cell skeleton and is involved in transport within the cell.
Researchers discovered that the drug inhibits the aggregation of a molecule called guanosine triphosphate, or GTP, which controls the assembly and movement of a structure called the mitotic spindle. This is critical to the even separation of chromosomes during cell division, which occurs during anaphase in the cell cycle. In a test in the laboratory, fenbendazole and other drugs that interfere with microtubule activity killed paraganglioma cells. When the same team of scientists added a tumor-targeting antibody, called nivolumab, to fenbendazole in mice with pancreatic cancer, the mice lived longer after the combination treatment than when chemotherapy alone was used.
The researchers are now planning to test a similar approach in human cancer patients with a type of pancreatic cancer known as pancreatic ductal adenocarcinoma, or PDAC. They will combine nivolumab with two types of chemotherapy, paclitaxel and gemcitabine, which are already approved to treat PDAC. The randomized trial will identify whether patients with specific biomarkers can benefit from the combination, and how to best select those patients for treatment.
Pancreatic cancer is notoriously difficult to treat effectively, with only 10 percent of patients diagnosed with metastatic disease living more than five years after a diagnosis. Standard chemotherapy regimens are ineffective, and newer immune-targeting therapies—such as the checkpoint blockade antibodies PD-1 inhibitors and TIGIT inhibitors—have been largely ineffective against pancreatic cancer.
However, a few patients with pancreatic cancer have reported remission after taking fenbendazole on their own or in combination with other treatments. Anecdotal reports have fueled the belief that this drug, which has been studied in petri dishes and mouse models of cancer, might also work against PDAC in people. But this is based on little more than anecdotal evidence and requires confirmation by other experts. As a result, many doctors continue to recommend conventional cancer treatments, including fenbendazole, to patients with pancreatic cancer. fenbendazole for pancreatic cancer