The activities of established and experimental antitumor drugs were te
sted against the BRO and MeWo human melanomas transplanted in the subr
enal capsule of phenotypically immunocompetent (CBA x C57BL/6)F-1 mice
. Immunosuppression was achieved with preliminary whole-body radiation
, and cytological examination showed that the tumors of untreated mice
consisted largely of viable tumor cells. Several drugs tested showed
moderate activity against one or both tumors. The system described pro
vides a basis for testing anticancer agents against a panel of human m
elanomas implanted in immunocompetent mice.