Histamine dihydrochloride and low-dose interleukin-2 in an emerging landscape of relapse prevention in acute myeloid leukemia.

Effective strategies to maintain complete remission in adults with acute myeloid leukemia (AML) are critically needed. Early clinical trials aimed at preventing relapse in the postconsolidation phase explored prolonged chemotherapy, single-agent immunotherapy, and hybrid chemo-immunotherapy, but none of these approaches produced practice-changing results. More recent trials have identified efficacious remission maintenance strategies, including (1) midostaurin or quizartinib for patients with FLT3-mutated AML, (2) oral azacitidine for older AML patients, and (3) immunotherapy with histamine dihydrochloride and low-dose interleukin-2 (HDC/IL-2) for younger patients. In this review, we examine key phase III trial and follow-up study results for approved remission maintenance therapies, with a particular focus on HDC/IL-2. We discuss clinical efficacy in relation to patient age and anti-leukemic immunity as well as leukemic cell chemosensitivity, chromosomal integrity, and mutational profiles. Finally, we propose a role for HDC/IL-2 within an evolving landscape of strategies to achieve durable remission in a broader population of AML patients.