Mebendazole Repurposing Exposes Cracks in Oncology's High-Cost Paradigm for Glioblastoma

A systematic review in the British Journal of Clinical Pharmacology synthesizes 22 preclinical studies showing mebendazole (MBZ), a decades-old anthelmintic costing pennies per dose, consistently impairs glioblastoma growth via microtubule disruption, Hedgehog pathway blockade, anti-angiogenesis, and radiosensitization. Yet the review itself is observational in nature, aggregating cell-line and rodent data without new randomized controlled trials (RCTs); mouse studies report doubled survival and occasional long-term tumor-free outcomes when combined with radiation, but human evidence remains limited to small, non-randomized safety cohorts with inconsistent tumor responses. This pattern echoes earlier repurposing attempts like metformin in pancreatic cancer or aspirin in colorectal prevention, where inexpensive agents stall at phase II due to absent commercial incentives. What original coverage overlooks is the pharmacokinetic barrier: MBZ polymorph C suffers P-glycoprotein efflux at the blood-brain barrier, a limitation partially mitigated by elacridar co-administration in cited animal work, suggesting any future trial must incorporate efflux inhibitors rather than relying on oral monotherapy. The low-cost model challenges the $100,000+ annual pricing typical for glioblastoma agents like temozolomide combinations or bevacizumab, yet regulatory pathways still demand expensive phase III RCTs that few nonprofits can fund. No conflicts of interest are declared in the Bond University-led review, but sample sizes in the underlying animal experiments rarely exceed 20-30 subjects per arm, limiting generalizability. Larger, adaptive platform trials integrating MBZ with standard care could test this hypothesis efficiently, but without public funding shifts, the opportunity risks remaining preclinical.