Aminopterin in Treatment of Leukemia in Children

OF ALL the therapeutic agents that have been employed in recent years in the treatment of leukemia, none have attracted such widespread interest and attention as have the folic acid antagonists. Until the advent of this group of compounds, radioactive phosphorus, the nitrogen mustards and urethane had been employed with varying success. These agents, including the folic acid antagonists, came into use in the course of studies dealing with the chemotherapy of cancer. Investigation revealed that the leukotoxic effects of these drugs could probably be attributed to interference with fundamental mechanisms involved in cellular growth. The suppressive effect of nitrogen mustards and urethane on the mitosis of immature cells served to explain the clinical and hematologic improvement frequently noted after their administration. When it was subsequently discovered that the folic acid antagonists inhibited the utilization of an element essential for cellular metabolism, intensive treatment of leukemia and neoplastic diseases with