Abstract
Hydroxyurea is an antitumor agent that produces myelosuppression, anemia, and megaloblastosis. Since hydroxyurea inhibited the incorporation of p32 in the orthophos phate form into deoxyrlbonucleic acid (DNA) of an ascites tumor, it is apparent that this agent is a specific inhibitor of DNA synthesis. Hydroxyurea effectively controlled chronic myelogenous leukemia in 9 patients including 4 patients not responsive to busulfan. This provides a further means of control of this disease.