1,‐(2‐chloroethyl)‐3‐cyclohexyl‐1‐nitrosourea (methyl CCNU) and adriamycin combination therapy

Methyl CCNU and Adriamycin have dissimilar patterns of myelosuppression and different mechanisms of antitumor activity. A clinical trial of the combination was undertaken on this basis. Methyl CCNU (150–200 mg/m2) and Adriamycin (40–90 mg/m2) were administered at 5–6-week intervals. Thirty-one patients (26 with breast cancer) were treated. Toxicity patterns were comparable to previous reports for the two agents. Myelosuppression was common (leukopenia 13/16; thrombocytopenia 10/16) but unassociated with complications. The leukopenic and thrombocytopenic nadirs occurred at 2 weeks and were consistent with that observed for Adriamycin, with a delayed recovery (5–6 weeks) related to the nitrosourea. Cumulative marrow suppression was suggested by the earlier nadirs with successive courses of therapy. Five objective responses occurred (CR 2, PR 3) and stabilization of disease was achieved in an additional 5 patients. The low level of activity of nitrosoureas in breast cancer and the extensive prior treatment may account for the low response rate to this combination.