L-Asparaginase Therapy for Leukemia and Other Malignant Neoplasms

Abstract

Enzyme therapy directed at depletion of an amino acid, asparagine, indispensable for tumor cell growth but not required by normal tissues, offers a new and promising approach to the problem of treatment of leukemia and disseminated cancer. Therapy with the enzyme L-asparaginase in three cases of acute lymphatic leukemia resulted in measurable improvement in two advanced cases. In the third case, there was a striking response to large dosage, with rapid necrosis of lymph node masses and clearing of leukemic infiltrates. A laboratory test to detect dependency of tumor cells on asparagine seems helpful for selection of cases for investigation of therapy. Furthermore, a variety of human malignant diseases including acute lymphatic leukemia and acute and chronic granulocytic leukemia have been shown to be asparagine-dependent by this test. Exploitation of further possible nutritional differences offers a fertile field for investigation.