{"entity":{"id":"paper-mansoori-mebendazole-gi-cancer-phase-2a-sci-rep-2021","kind":"paper","name":"A phase 2a clinical study on the safety and efficacy of individualized dosed mebendazole in patients with advanced gastrointestinal cancer","aka":[],"tldr":"A Swedish trial gave mebendazole to ten people with advanced bowel and stomach cancers that had stopped responding to treatment; it was safe, but every patient's cancer kept growing, four of them unusually fast.","summary":"Patients with treatment-refractory gastrointestinal cancer received mebendazole at individually adjusted doses up to 4 g a day aiming at a serum level of 300 ng/mL; 11 were included and 10 started treatment (Mebendazole phase 2a 2021). Two stopped before and the remaining eight after the eight-week CT scan, all for progressive disease, four met suggested criteria for hyperprogression, only five reached the target level, and no severe adverse effects were observed; the authors conclude that new approaches such as prodrugs or combinations would be needed for further exploration (Mebendazole phase 2a 2021).","asOf":"2026-09-24","links":[{"label":"Mebendazole phase 2a 2021","url":"https://doi.org/10.1038/s41598-021-88433-y"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/33903692/"}],"tags":[],"related":[],"cancers":["colorectal","gastric"],"sections":[],"technologies":["drug-repurposing"],"targets":[],"drugs":["mebendazole"],"companies":[],"institutions":[],"pathways":[],"terms":["single-arm"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"provenance":{"editedBy":"OnCo agent (Claude Fable 5.1)","editedOn":"2026-09-24","note":"Written from cached ClinicalTrials.gov v2, Europe PMC, DailyMed, Drugs@FDA and WHO eEML responses; no figure appears without its source link."},"journal":"Scientific Reports","year":2021,"doi":"10.1038/s41598-021-88433-y","pmid":"33903692","authors":"Mansoori S, Fryknäs M, Alvfors C, Loskog A, Larsson R, Nygren P.","paperType":"translational","findings":["10 treated; all 10 stopped for progressive disease by the eight-week scan; four met hyperprogression criteria.","No severe adverse effects; only five reached the target serum concentration."],"whatItMeans":"The only completed efficacy study of an internet-famous dewormer in cancer patients found no benefit in anyone. It is the clearest human result in this whole story.","caveats":["Small single-arm study in heavily pretreated patients; drug exposure was below target in half of them."],"changedPractice":false,"participants":11},"route":"/key-papers/paper-mansoori-mebendazole-gi-cancer-phase-2a-sci-rep-2021/","neighbours":{"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"}],"technology":[{"id":"drug-repurposing","kind":"technology","name":"Systematic drug repurposing","route":"/technologies/drug-repurposing/"}],"drug":[{"id":"mebendazole","kind":"drug","name":"Mebendazole","route":"/drugs/mebendazole/"}],"term":[{"id":"single-arm","kind":"term","name":"Single-arm trial","route":"/terms/single-arm/"}]}}