C-MOP: A Narrative Review and Clinical Framework for Adjunctive Repurposed-Drug Therapy in Active Cancer

Cancer metabolic adaptability and treatment resistance provide a rationale for evaluating coordinated interventions across complementary tumor and host processes. This narrative review examines five medications used within the Cancer Metabolic Optimization Protocol (C-MOP) - metformin, atorvastatin, doxycycline, mebendazole, and ivermectin - and describes a physician-directed framework for adjunctive use in adults with active cancer. The central hypothesis is that complementary effects on energy regulation, mevalonate signaling, mitochondrial function, microtubule dynamics, and adaptive stress responses may constrain compensatory pathways and enhance sensitivity to conventional treatment. Selected experimental combinations and early clinical experience with other multi-agent repurposing regimens support investigation of this strategy. Evidence for the individual agents is heterogeneous: metformin and statins have the largest human evidence base, with mixed or negative randomized findings in several settings; doxycycline and mebendazole have predominantly preclinical, translational, and early-phase support. Ivermectin remains the most experimental component, with predominantly preclinical evidence and evolving dosing and long-term safety questions in oncology. The framework links agent selection to patient-specific goals, conventional oncology treatment, organ function, interactions, sequential initiation, monitoring, and reassessment of treatment burden. The clinical benefit of the complete five-agent regimen remains to be established. By defining the combination rationale, patient selection, individualized implementation, and safety procedures, C-MOP provides a foundation for consistent clinical reporting and prospective evaluation.