ALBERT

Description: The majority of relapses in acute myeloid leukemia (AML) patients occur in the first or second year following complete remission. In routine, AML patients are followed during five years because few relapses can occur after three or five years. These late or very late relapses remain poorly described, particularly at the molecular level, with only few consistent series in the literature. (Medeiros B et al., Leuk Lymphoma 2007; Verma D et al., Leuk Lymphoma 2010; Watts J et al., Leuk Res 2014). We retrospectively studied all AML relapses occurring after complete remission (CR) obtained with one or two induction cycles between 2000 and 2012 in Toulouse University Hospital, France. Our analyses focused on late relapses (LR, 〉3 years from CR) and very late relapses (VLR, 〉5 years from CR) in comparison to early relapses (ER, ≤3 years from CR). Between 2000 and 2012, out of 636 CR patients, 346 had morphological relapses (54.4%). The median time to relapse was 0.9 years (range, 0.1-11.9 years; interquartile range [IQR], 0.5-1.5 years). There were 198 relapses during the first year (57.2%), 82 during the second year (23.7%), 24 during the third year (6.9%) whereas 42 relapses occurred after 3 years (12.1%) and 16 after 5 years (4.6%). Characteristics at diagnosis, i.e., age, AML status, WBC count, karyotype, FLT3-ITD mutation, CEBPA mutation and induction regimen did not differ between ER and LR or VLR. However, NPM1 mutations were more frequent in LR (NPM1m at diagnosis in relapses 〉3 years: 46% vs. 28% in relapses 5 years: 67% vs. 27% % in relapses 5 years: 2.5%; 〉8 years: 0.6%; P=.0317, .0037 and .0783 respectively). NPM1m relapses represented one half of LR (48%) and two thirds of VLR (67%). Among them, genotype was NPM1m/FLT3-wild type in most patients (75% in LR and 88% in VLR patients). In LR and VLR, NPM1 mutational status had no impact on CR2 and OS2: CR2LR/NPM1m: 42% vs. CR2LR/NPM1-WT: 38% (P=.8702); CR2VLR/NPM1m: 50%vs. CR2LR/NPM1-WT: 50% (P=1.0000); OS2LR/NPM1m: 7.4 months vs. OS2LR/NPM1-WT: 19.4 months (P=.2019); OS2VLR/NPM1m: 7.8 months vs. OS2VLR/NPM1-WT: 29.8 months (P=.0917). Our data show that LR and VLR are not infrequent in AML patients with NPM1 mutations. Although this finding needs to be validated in updated multicentric cohorts with a very long follow-up, it strongly suggests that AML patients with NPM1 mutations should benefit from a prolonged follow-up beyond 5 years from CR. Table Table. Disclosures No relevant conflicts of interest to declare.

Description: Intermediate dose cytarabine (IDAC) defined by daily intravenous bolus of 1g/m² during 5 days has been recently defined as the standard control arm in phase 3 placebo-controlled randomized trials for patients with relapsed or refractory acute myeloid leukemia (R/R AML). In these trials assessing clofarabine/IDAC (CLASSIC-1 study, Faderl S et al., JCO 2012) or vosaroxin/IDAC (VALOR study, Ravandi F. et al., Lancet Oncol 2015) vs placebo/IDAC, complete remission rates and median overall survival with placebo/IDAC were 17.8%/18.9% and 6.3/6.1 months in the CLASSIC-1 and VALOR studies, respectively. However, the dose-intensity of this IDAC regimen remains questioned in routine practice since many centers still use higher doses of cytarabine often in combination with an anthracycline and a third drug including fludarabine, etoposide or gemtuzumab ozogamycin (FLAG-ida, MEC or MIDAM regimen for example) although these regimen have proved little efficacy and higher toxicity. We assessed the outcome of R/R AML patients that fulfilled main VALOR inclusion criteria consecutively treated in our center with intensive salvage regimen. All patients with a diagnosis of AML in first relapse or with refractory disease were eligible for this study. Acute promyelocytic leukemia were excluded. Relapse was defined as re-emergence of at least 5% leukemia blasts in bone marrow or at least 1% blasts in peripheral blood 90 days to 24 months after first complete remission or complete remission with incomplete platelet recovery. Refractory AML was defined as persistent disease at least 28 days after initiation of induction therapy, or relapse less than 90 days after first complete remission (CR) or CR with incomplete platelet recovery (CRi). All patients have received previous induction therapy with an anthracycline. Salvage regimen used were mainly cytarabine 3 g/m²/12h, d1-4 plus idarubicine 12 mg/m²/d, d1-3 or dauno 60 mg/m²/d, d1-2 or amsacrine 200 mg/m²/d, d1-3; less frequently MiDAM (mitoxantrone 12mg/m² d1-3, cytarabine1 g/m²/12h d1-5, GO 4-6mg/m², d4) or FLAG-Ida. Cytarabine dose for patients 〉60 was reduced to 1g/m²/12h, d1-5. We found, in our database, 151 R/R AML according to VALOR criteria treated between 2000 and 2013: 72 patients (48%) had refractory diseases (primary refractory: n=60, 40% and relapse less than 90 days after CR: n=12, 8.0%) and 79 (52%) had relapsed (early relapse more than 90 days after CR and less than one year: n=52, 66%; late relapse between one and two years: n=27, 34%). Patients characteristics were as follows: 85 (56%) were male, median age was 48 years (interquartile range [IQR], 36-60.5; 38 (27%) were 60 years or older). Cytogenetics at diagnosis was favorable in 18 (12%); intermediate in 93 (62%); adverse in 38 (25%) or unknown in 2 (1%) patients, respectively. They were treated as first line therapy with one (42%) or two cycles (58%). Early death rates at day 30 and day 60 were 7% and 17% in the whole cohort; 6% and 12% in younger patients and 12% and 29% in patients 60 years or older. Combined CR rate (defined as CR and CRi) was 53% for the whole cohort, and 57%/42%/56%/52%/63%/50% for