Interleukin-2 before and/or after autologous bone marrow transplantation for pediatric acute leukemia patients

The role of ABMT in the treatment of acute leukemia patients with poor prognosis is controversial because of the high risk of relapse. We attempted to obtain an anti-tumor effect by administering rIL-2 pre- and/or post-ABMT. We report our experience in 10 consecutive pediatric patients: two AML late responders and eight ALL in 2nd or subsequent CR who received ABMT and rIL-2. Five patients (group A) received rIL-2 only post-ABMT. A 120 h/week rIL-2 'induction' cycle at 6 x 10(6) IU/m2/24 h was administered by continuous intravenous infusion for 2 weeks. A further six maintenance rIL-2 cycles at 18 x 10(6) IU/m2/24 h were given 72 h/week on a monthly basis. Five patients (group B) received a single 120 h cycle of rIL-2 at 6 x 10(6)/m2/24 h before BM harvesting. Three of the five group B patients entered the same protocol described above after ABMT. Increased NK and LAK activity were documented. The cycles were well tolerated; no delayed engraftment in group B was observed. One patient in group A and two patients in group B are still in CCR, respectively 47, 42 and 15 months after ABMT. Our rIL-2 regimen; pre- and/or post-ABMT, was safely tolerated and induced significant immunomodulatory effects in pediatric patients