Fenbendazole is a broad spectrum benzimidazole anthelmintic used for giardia, roundworms, hookworms, whipworms, lungworms, and tapeworms of the genus Taenia (but not the common dog tapeworm Dipylidium caninum). It also has been demonstrated to be effective against flukes and intestinal parasites in cats. In addition to these gastrointestinal parasites, fenbendazole is known to have significant antitumor effects in several animal models and human patients.
In vitro, fenbendazole inhibits tubulin polymerization and blocks cell-cycle progression at mitosis. This results in mitotic catastrophe and the cytoplasmic shrinkage of cancer cells. In vivo, fenbendazole significantly reduces tumor growth in mice with metastatic NSCLC. This effect correlates with a decrease in tumor vascularity and glycometabolism.
Recently, a female with advanced NSCLC received the PD-1 inhibitor pembrolizumab monotherapy. However, her CEA level increased, and she began self-administering fenbendazole, an anthelmintic commonly prescribed for gastrointestinal parasites, based on information from social media sites that suggested it was effective against cancer.
This article describes the case of this patient who experienced tumor regression after receiving fenbendazole. We discuss the possible mechanisms of fenbendazole action and its antitumor activity in NSCLC, including its interaction with hypoxia. fenbendazole capsules
