SENSITIVITY OF HUMAN-MELANOMA XENOGRAFTS TO ANTITUMOR DRUGS OF THE NITROSOALKYLUREA CLASS

We studied the sensitivity of human melanoma (Bro strain) xenografts t o drugs of the nitrosoalkylurea (NAU) class: nitrosomethylurea (NMM), karmustin (BCNU), nimustin (ACNU), nitrulin, and ADEKO. High antitumor activity of NAM was shown when the drugs were applied not only at the early, but also at the late stages of tumor progression (tumor mass 4 00 and 1200 mg, respectively). The therapeutic effect of the drugs was estimated with the use of criteria characterizing the kinetics of tum or regression, increased life span, and survival of treated animals. A fter early administration of the drugs (Day 4 after tumor transplantat ion), 67% and 50% of animals survive under the influence of nitrulin a nd ACNU, respectively, while the rate of tumor regression increased in the sequence nitrulin < karmustin < NMM < ACNU. After late administra tion (11 days after tumor transplantation), NMM was most effective at increasing survival (35% of survived animals by 35 days of observation ), while the rate of tumor regression increased in the sequence ADEKO < NMM < karmustin < nitrulin < ACNU.