Acute myeloid leukemia with KMT2Ar and association with risk of bleeding and early mortality.

Abstract

7026 Background: Acute myeloid leukemia (AML) with rearrangement of KMT2A is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. Methods: In a retrospective analysis, we compared causes and rates of early mortality following induction treatment between a cohort of adults with KMT2Ar AML (N=172) and an age-matched cohort of patients (pts) with normal karyotype (NK) AML (N=522). Results: The 30 and 60-day (60d) mortality in pts with KMT2Ar AML were significantly higher compared to those with NK AML, with rates of 10% (17/172 pts) and 15% (26/172 pts) in KMT2Ar AML vs 4% (20/522 pts) and 7% (38/522 pts) in NK AML, respectively ( P=0.004). Among those who died within 60d, the most common contributing cause in KMT2Ar was respiratory failure without a clear infectious etiology in 38% (10/26 pts) vs 11% (4/38 pts) in NK AML ( P=0.01). We found 42% (11/26 pts) with KMT2Ar AML who died within 60d were either diagnosed with or had high clinical suspicion for diffuse alveolar hemorrhage (DAH) that warranted empiric therapy vs 18% (7/38 pts) with NK AML ( P=0.05). Given the high occurrence of DAH in KMT2Ar AML, we set out to quantify bleeding events and recorded major and minor bleeds as defined by the International Society of Thrombosis and Haemostasis. We found 65% (17/26 pts) with KMT2Ar AML had at least one bleeding event vs 32% (12/38 pts) with NK AML ( P=0.01). There was a significantly higher frequent occurrence of major bleeds (rate ratio=6.22; P=0.005) and total bleeding events (rate ratio=4.5; P=0.001) in KMT2Ar AML vs NK AML. KMT2Ar was associated with disseminated intravascular coagulopathy (DIC), as 93% of evaluable pts (14/15 pts) vs 54% (7/13 pts) in NK AML had overt DIC before death. Longitudinal trajectories of DIC parameters of pts who died within 60d showed significantly higher prothrombin time levels ( P=0.008) in KMT2Ar. In a multivariate analysis, KMT2Ar and a monocytic phenotypic were the only independent predictors of any bleeding event in pts who died within 60d (OR 3.5, 95% CI 1.4-10.4, P=0.03; OR 3.2, 95% CI 1.1-9.4, P=0.04). Conclusions: KMT2Ar AML is associated with higher early mortality and an increased risk of bleeding and coagulopathy compared with NK AML. Early recognition and aggressive management of DIC and coagulopathy are important considerations that could mitigate the risk of death during induction treatment.[Table: see text]