Scientists at Columbia University Medical Center have demonstrated in a new study that two related enzymes, phosphoinositide-3 kinase (PI3K) gamma and delta, play a key role in the development of an aggressive childhood leukemia called T-cell acute lymphoblastic leukemia (T-ALL). The study also showed that a dual P13K gamma/delta inhibitor called CAL-130, developed by Gilead Sciences, significantly prolonged survival in a mouse model of the disease. The researchers also tested the effects of CAL-130 on blood samples taken from human patients with T-ALL. The drug prevented proliferation of leukemic cells and promoted apoptosis, a self-destruct mechanism. “If this treatment strategy can safely and selectively target the activity of these enzymes in T-ALL tumors, we might be able to reduce the need for conventional chemotherapies that more broadly affect proliferating cells, including those in healthy tissues,” study leader Thomas Diacovo said.