CEBPA ‐bZIP Mutations in AML Patients Treated With Non‐Intensive Therapy: A Study by the Spanish PETHEMA Registry

The aim of our study was to analyze the incidence, co-mutation pattern, and prognostic impact of CEBPA gene mutations in a large multicenter consecutive series of 1367 adult patients AML patients treated with non-IT modalities. A total of 83 patients (6.1%) had mutations in CEBPA gene. Among these, 34 (2.5%) harbored mutations located in bZIP domain (bZIP in-frame N = 6) and 49 (3.6%) in other regions of the gene (other CEBPAmut). Genes most frequently co-mutated in these CEBPAmut patients were TET2 (45.8%, N = 38), SRSF2 (42.2%, N = 35), and ASXL1 (40.9%, N = 34). Using the Bradley-Terry model we identified that mutations in MDS-related genes, in TP53, and in epigenetic regulators appear to occur earlier. In contrast, genes involved in activating cell signaling appeared to occur later than CEBPAmut. Overall Survival (OS) of non-IT AML patients was analyzed according to the type of CEBPAmut. Median OS was 11.6 months in CEBPA-bZIP patients compared to 9.0 and 6.9 for patients with other CEBPAmut or CEBPAwt, respectively. When selecting 1129 AML patients treated with HMA or HMA-based combinations, CEBPA-bZIP patients had a median survival time of 11.6 months (range 9.6-NR) and 2.5 years survival probability of 20.1% which were outcomes comparable to remaining ELN2024 favorable patients. We concluded that our series of non-IT AML patients within the PETHEMA registry confirm a low percentage of CEBPA mutated cases which are frequently co-mutated with MDS related genes. Those CEBPA-bZIP cases harbor a similar median OS than those belonging to favorable ELN2024 risk category.