FEASIBILITY, TOXICITY, AND BIOLOGIC RESPONSE OF INTERLEUKIN-2 AFTER CONSOLIDATION CHEMOTHERAPY FOR ACUTE MYELOGENOUS LEUKEMIA - A REPORT FROM THE CHILDRENS CANCER GROUP

Purpose: Although remission can be achieved in 80% of children with ac ute myelogenous leukemia (AML), many patients experience relapse. Beca use interleukin-2 (IL-2) can induce remission in patients with overt e vidence of AML, we hypothesized that IL-2 given to patients in first r emission alter intensive consolidation chemotherapy might prevent rela pse. This study sought to determine whether such an approach was feasi ble. Patients and Methods: Twenty-one patients in complete remission r eceived IL-2 after completion of treatment on Children's Cancer Group (CCG) protocol 2941. Recombinant IL-2 9 x 10(6) IU/m(2) daily by conti nuous intravenous infusion (CIV) was given for 4 days. After 4 days re st, IL-2 1.6 x 10(6) IU/m(2) daily CIV was resumed for 10 days. We mon itored patients for toxicity and measured absolute lymphocyte count th e absolute count of cells that express CD56 and CD3 antigen, and solub le IL-2 receptor alpha-chain (sIL-2R alpha) levels before the start of IL-2 and after completion of each of the two courses of IL-2. Results : Observed toxicities included fever (57%), vascular leak (48%), hypot ension (38%), tachycardia (14%), rash (29%), septicemia (5%), thromboc ytopenia (29%), elevated transaminase (14%), electrolyte disturbance ( 29%), and hyperglycemia (10%). No patient required cardiac pressors or transfer to an intensive care unit. All patients studied developed an increase in lymphocyte count, CD56 count, CD3 count, and sIL-2R alpha levels after treatment with IL-2. Conclusion: This schedule of IL-2 w as reasonably well tolerated by children with AML in first remission. After treatment increased levels of sIL-2R alpha were observed, CCG is conducting a randomized prospective trial to assess the efficacy of I L-2 to prevent the relapse of AML (CCG-2961). (C) 1998 by American Soc iety of Clinical Oncology.