Treatment of advanced and refractory breast cancer with doxorubicin, vincristine and continuous infusion of verapamil. A phase I-II clinical trial.
Cancer cell resistance to several cytotoxic drugs, including doxorubicin and vincristine can be reduced in vitro by verapamil; this drug works at least in part by inhibitive competition for the multiple-drug resistance efflux-pump P-glycoprotein-170. To evaluate the clinical potential of this experimental concept we combined verapamil in continuous infusion with adriamycin and vincristine in the treatment of patients with advanced and anthracycline-refractory breast cancer. Sixteen patients were included and 55 treatment courses were given at different dose levels of chemotherapy; verapamil was given by continuous infusion of 0.003 mg kg-1 min-1 for 48 h. Overall, cardiac toxicity was low but a potentiation of neurotoxicity and hematotoxicity was observed. The objective response rate was 21% (3 partial responses in 16 patients) and the median survival was 6 months; these results are comparable to those of other second line treatment studies, using drugs not supposed to be cross-resistant.
Ries
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F
Department of Hematology-Oncology, Centre Hospitalier, Luxembourg.
Dicato
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M
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use* / Q000633:toxicity; D001943:Breast Neoplasms / Q000188:drug therapy*; D004317:Doxorubicin / Q000008:administration & dosage; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008875:Middle Aged; D009362:Neoplasm Metastasis; D014700:Verapamil / Q000008:administration & dosage; D014750:Vincristine / Q000008:administration & dosage
D014750:Vincristine; D004317:Doxorubicin; D014700:Verapamil