INTERLEUKIN-2 BOLUS INFUSION AS LATE CONSOLIDATION THERAPY IN 2ND REMISSION OF ACUTE MYELOBLASTIC-LEUKEMIA

The activation of autologous cytotoxic cells by interleukin-2 (IL-2) m ay be a promising tool for elimination of minimal residual blast popul ations in patients with acute myelocytic leukemia (AML) to prolong dis ease-free survival. Here; we report the results of a phase II study us ing IL-2 for consolidation therapy in patients with second remission o f de novo AML. All patients in Ist relapse of AML received a uniform i nduction therapy consisting of intermediate high-dose AraC (iHDAraC) 2 x 600 mg/m(2) dl-4 and VP-16 100 mg/m(2) dl-7. Patients achieving 2nd remission were treated with 4 cycles recombinant IL-2 (rIL-2)9 x 10(6 ) IU/m(2) administered; on dl-5 and 8-12/cycle as 1h infusion every si x weeks. In 37/66 (56%) evaluable patients, complete remission (CR) wa s achieved. So far, 21/37 patients (4 after additional autologous bone marrow transplantation (ABMT)) received rIL-2 consolidation. Three pa tients are too early for evaluation, 4 received allogeneic BMT, 6 rela psed before IL-2 was scheduled and 4 refused treatment with rIL-2. The median disease-free survival (DFS) was 11 (4-49+) months. Up to now, in 5/21 (24%) patients the duration of 2nd remission exceeded that of Ist remission 7/21 (33%) are in ongoing 2nd remission (7+ to 49+ month s). The side effects of rIL-2 were generally moderate and manageable. Only in two patients, previously treated with ABMT, severe side effect s occurred; septicaemia and pneumonia in one patient and desquamative erythrodermia in the second one. In accordance with other studies rebo und lymphocytosis with a marked increase of CD56(+)-cells and release of secondary cytokines such as TNF-alpha, IFN-gamma and IL-6 was obser ved. The schedule is feasible and the data suggest a possible benefit for DFS, which, however has to be confirmed by randomized trials.