Self-administered ivermectin and fenbendazole in a patient with metastatic melanoma showed mixed radiographic and ctDNA responsesOne man with melanoma tries antiparasitic drugs for his cancer

This case report describes the experience of a 74-year-old man with nodular melanoma of the right lateral neck and associated nodal and hepatic metastases who self-administered ivermectin and fenbendazole. The report focuses on the patient's clinical course and the observation of mixed responses to these interventions.

Initial results showed a reduction in metabolic activity and tumor size without new sites of involvement. Concurrently, ctDNA levels decreased from 2.04 to 0.18 MTM/mL. However, these findings were followed by a worsening of the dominant axillary nodal mass and an increase in ctDNA to 0.93 MTM/mL.

The authors emphasize that there is a lack of clinical evidence supporting the efficacy of repurposing antiparasitic drugs for cancer treatment. They suggest that spontaneous immune-mediated regression is at least as plausible as any potential effect from the patient's self-administered medications.

Clinical practice relevance is limited by the lack of evidence. The report highlights the necessity of providing safety counseling regarding the known toxicities of antiparasitic drugs and notes the absence of evidence for their use in oncology. The results are not sufficient to establish any treatment effect for ivermectin or fenbendazole.