Phase II Trial Daily Pulse Interleukin-2 Therapy with Famotidine during Marrow and Lymphocyte Recovery in Acute Myeloid Leukemia: LJCC 0605

Background: Therapeutic advances in treating Acute Myelogenous Leukemia (AML) have been limited in the past two decades.  The outcome in patients over the age of 60 and those with high risk cytogenetics remains particularly poor with less than 10% of patients in this age group being cured. High dose Interleukin-2 (IL2) alone in relapsed AML has been shown to induce complete remissions. In this study we report the overall survival (OS), event free survival (EFS), responses and tolerability with IL2 therapy administered during marrow/lymphocyte recovery during induction, re-induction or consolidation.

Methods: Eligibility criteria included confirmed hematopathology diagnosis of AML according to WHO classification (not including acute promyelocytic leukemia) receiving marrow suppressive treatment, a total WBC count above 500 mm³, supported platelet count above 20,000, serum creatinine ≤ 2.0 mg/dl, total bilirubin and AST < 3x upper limit of normal and hemodynamic stability. Famotidine 20 mg IV push daily was administered just prior to the IL2. IL2 therapy was infused at 18 million IU/m² in 50ml 5% D5 or NS IVPB over 15-30 minutes daily for 5 days. Pre-medication prior to each pulse IL2 dose included acetaminophen 650 mg PO, odansetron 8mg IV, and meperidine 25 mg IV.

Results: 18 pts enrolled with 12 receiving IL2 infusion. The median age was 57.5 (range 32-72). 67% women, 33% men. 8 of 12 patients had AML with myelodysplasia-related changes (including complex cytogenetics), 2 AML with inv(16), 1 AML with 11q23 translocation and 1 therapy-related AML.  Median bone marrow blast percentage at diagnosis was 62% (range 32-96). 3 pts received IL2 during induction recovery, 1 during re-induction recovery, 8 during consolidation recovery. 2 pts subsequently underwent allogeneic stem cell transplantation in remission. Median follow up was 328 days (range 99-3207). Estimated 18 month overall and event free survival was 42% (CI 0.15-0.67). Of the 4 pts alive past 4 years, 3 had complex cytogenetics, 2 were greater than age 60.  IL2 infusion was well tolerated without any grade 4 toxicities or hemodynamic instability requiring ventilator or hemodynamic support.

Conclusion: IL-2 therapy administered during marrow/lymphocyte recovery after standard induction/consolidation chemotherapy in AML treatment achieved a 33% 4 year overall and event free survival.