Mutiple myeloma resistant to melphalan (NSC-8806) treated with cyclophosphamide (NSC-26271), prednisone (NSC-10023), and chloroquine (NSC-187208).

A prospective randomized study of the effects of two different therapeutic regimens was conducted in 41 patients with multiple myeloma resistant to therapy with melphalan. The results of treatment with cyclophosphamide plus prednisone were compared with those of cyclophosphamide, prednisone, and chloroquine. Chloroquine, which inhibits the repair process of DNA in animals, has reportedly produced responses to alkylating agents to which the animal had been resistant. No significant differences in response to the doses used with either regimen could be found. Toxocity consisted mainly of leukopenia and thrombocytopenia.