RATIONALE: Interleukin-2 may stimulate a person's white blood cells to kill acute myeloid leukemia cells. Histamine dihydrochloride may prolong remission and reduce the risk of relapse in patients with acute myeloid leukemia in remission.

PURPOSE: Randomized phase III trial to determine the effectiveness of interleukin-2 plus histamine dihydrochloride in treating patients who have acute myeloid leukemia that is in remission following previous therapy.

OBJECTIVES: I. Compare the efficacy of interleukin-2 plus histamine dihydrochloride (Maxamine) vs no further therapy in prolonging the leukemia free survival in patients with acute myeloid leukemia in first or subsequent complete remission (CR) following consolidation therapy. II. Compare the relapse rate, overall survival, and quality of life in this patient population treated with interleukin-2 plus Maxamine vs no further therapy. III. Compare the remission inversion rate in patients in subsequent CR with this treatment regimen vs no further therapy.

OUTLINE: This is a randomized, open label, parallel, multicenter study. Patients are stratified according to complete remission (first vs subsequent). Patients are randomized to one of two treatment arms. Arm I: Following consolidation chemotherapy or autologous stem cell transplantation, patients receive interleukin-2 subcutaneously followed by histamine dihydrochloride subcutaneously over 5-7 minutes twice daily on days 1-21. Treatment repeats every 6 weeks for 3 courses and then every 9 weeks for 7 courses in the absence of disease relapse or unacceptable toxicity. Arm II: Patients receive no further therapy following consolidation chemotherapy or autologous stem cell transplantation. Quality of life is assessed prior to study, and at visits 6, 7, 10, 11, 16, 17, and 22. Patients are followed for relapse and survival every 3 months for 2.5 years.

PROJECTED ACCRUAL: A total of 360 patients will be accrued for this study.

DISEASE CHARACTERISTICS: Cytologically confirmed acute myeloid leukemia (AML) in first complete remission (CR) or subsequent CR Less than 5% blasts in normal bone marrow Less than 3 months since last dose of chemotherapy OR Less than 6 months since achieving CR

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: WHO 0-1 OR Karnofsky 70-100% Life expectancy: Greater than 3 months Hematopoietic: WBC at least 1,500/mm3 Platelet count at least 75,000/mm3 Hepatic: PTT normal Bilirubin no greater than 2 times upper limit of normal (ULN) SGOT and SGPT no greater than 2 times ULN Renal: Creatinine no greater than 1.5 times ULN Cardiovascular: No class III or IV heart disease No hypotension, severe hypertension, or serious or uncontrolled cardiac dysrhythmia (e.g., ventricular arrhythmias) No acute myocardial infarction within the past 12 months No active uncontrolled angina pectoris No symptomatic arteriosclerotic blood vessel disease Pulmonary: No history of asthma within the past 5 years Other: No other active malignancies except localized basal or squamous cell skin cancer or carcinoma in situ of the cervix HIV negative No prior or active peptic or esophageal ulcer disease No history of hypersensitivity to histamine or histamine products, or severe allergies Not pregnant or nursing

PRIOR CONCURRENT THERAPY: Biologic therapy: Prior autologous stem cell transplantation allowed No prior allogeneic stem cell transplantation No other concurrent immunomodulating agents Chemotherapy: See Disease Characteristics Prior induction or consolidation therapy allowed No concurrent chemotherapy Endocrine therapy: At least 24 hours since prior corticosteroids No concurrent steroids Radiotherapy: Not specified Surgery: Not specified Other: No concurrent alternative therapy (e.g., laetrile, Brudzinski's treatment, etc.)