Purpose

RATIONALE: Drugs used in chemotherapy work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as gemtuzumab, can block cancer growth in different ways. Some find cancer cells and help kill them or carry cancer-killing substances to them. Others interfere with the ability of cancer cells to grow and spread. Gemtuzumab may also stop the growth of promyelocytic leukemia by blocking blood flow to the cancer. Giving gemtuzumab together with combination chemotherapy may be more effective in treating promyelocytic leukemia. PURPOSE: This phase II trial is studying how well giving gemtuzumab together with combination chemotherapy works in treating patients with previously untreated promyelocytic leukemia.