Interleukin-2 in the Treatment of Acute Myelocytic Leukemias: In Vitro Data and Presentation of a Clinical Concept. In: Hiddemann W, Büchner T, Wörmann B, Plunkett W, Keating M, Andreeff M, editors. Acute Leukemias. Berlin: Springer Berlin Heidelberg; 1992. pp. 601-7. [DOI: 10.1007/978-3-642-76591-9_103]

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) may be a promising tool for elimination of minimal residual blast populations in patients with acute myelocytic leukemia (AML) to prolong disease-free survival. Here, we report the results of a phase II study using IL-2 for consolidation therapy in patients with second remission of de novo AML. All patients in 1st relapse of AML received a uniform induction therapy consisting of intermediate high-dose AraC (iHDAraC) 2 x 600 mg/m2 d1-4 and VP-16 100 mg/m2 d1-7. Patients achieving 2nd remission were treated with 4 cycles recombinant IL-2 (rIL-2) 9 x 10(6) IU/m2 administered on d1-5 and 8-12/cycle as 1h infusion every six weeks. In 37/66 (56%) evaluable patients, complete remission (CR) was achieved. So far, 21/37 patients (4 after additional autologous bone marrow transplantation (ABMT) received rIL-2 consolidation. Three patients are too early for evaluation, 4 received allogeneic BMT, 6 relapsed 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 1st remission 7/21 (33%) are in ongoing 2nd remission (7+ to 49+ months). The side effects of rIL-2 were generally moderate and manageable. Only in two patients, previously treated with ABMT, severe side effects occurred; septicaemia and pneumonia in one patient and desquamative erythrodermia in the second one. In accordance with other studies rebound lymphocytosis with a marked increase of CD56(+)-cells and release of secondary cytokines such as TNF-alpha, IFN-gamma and IL-6 was observed. The schedule is feasible and the data suggest a possible benefit for DFS, which, however has to be confirmed by randomized trials.

Long-term subcutaneous recombinant interleukin-2 as maintenance therapy: biological effects and clinical implications

Several trials have evaluated the therapeutic efficacy of rIL-2 combined with more traditional treatments such as chemotherapy and radiotherapy, but the use of IL-2 as adjuvant therapy for minimal residual disease or to maintain clinical response obtained with other standard treatments has yet to be investigated. The aim of the present trial was to study the biological effects of maintenance long-term treatment (6 months) with subcutaneous low-dose IL-2 in 16 patients with different neoplasms previously treated with chemo-immuno therapeutic regimens or with surgery (7 metastatic renal cancers, 5 locally advanced renal cancers previously subjected to radical nephrectomy, 2 metastatic breast cancers, 1 small cell lung cancer, and 1 metastatic melanoma). Clinical tolerability, feasibility and therapeutic implications are also discussed. The IL-2 schedule was as follows: 4.5 million IU/day, 3 times weekly for 6 months. A total of 14 patients completed therapy without requiring dose modifications and are free of progression after a median duration of 8+ months (range: 7+ to 34+) while two patients progressed during therapy (one inflammatory breast cancer and one renal cancer). Important and persistent hemato-immunostimulating effects in both soluble (IL-2, sIL-2R, IL-6) and cellular (lymphocyte subsets, monocytes, eosinophils) parameters were noted during the entire treatment. The IL-2 related toxicity was quite low. Moreover, this long-term IL-2 therapy could control neoplastic growth and thus prolong clinical response obtained with standard treatments. Prospective randomized studies regarding the clinical efficacy have been initiated.