NK Cell Infusion for Remission Consolidation in AML: A Phase II Trial

Acute Myeloid Leukemia (AML) is a complex and rapidly progressive disease with high mortality. Although significant progress has been made in recent years with the development of new drugs, resulting in better therapeutic tolerability and increased survival, disease relapse occurs in most cases. Adoptive immunotherapy has been increasingly emerging as an innovative alternative for cancer treatment. Among the immune cells tested, natural killer (NK) cells appear to exert significant antileukemic activity, particularly against AML, as demonstrated by numerous phase I/II studies published in the literature, including studies from our group. This study aims to test whether haploidentical NK cells from healthy individuals, expanded and activated in vitro, administered when the disease is nearly eradicated by chemotherapy, can eliminate residual disease, delaying or eliminating the possibility of relapse. It is a randomized, superiority, double-blind, placebo-controlled clinical trial conducted at two treatment centers in Brazil. Adult patients aged 18 to 75 years with AML, from any risk group, in complete remission after completing standard treatment, will be included. Those with a bone marrow donor and eligible for this treatment will be allowed to undergo hematopoietic stem cell transplantation (HSCT). The study's objective is to determine whether the infusion of haploidentical NK cells immediately after high-dose chemotherapy results in increased event-free survival (EFS), overall survival (OS), and lower minimal residual disease (MRD) during follow-up or immediately before HSCT compared to patients undergoing the same treatment without NK cell infusion. A total of 98 participants in complete remission (CR) will be randomized to receive 6 infusions of 1 x 10⁷ NK cells/kg or 6 placebo infusions. All participants will be evaluated for immune recovery at the cellular and molecular levels, and their immune profiles will be compared to analyze cellular response mechanisms.