CPX-351 Induces Deep Response and Suppress the Impact of Poor Prognosis Mutations (TP53, ASXL1, RUNX1 and EVI1) Defined By ELN-2017 in t-AML and MRC AML: A Report from a Multicentric French Cohort

Description

IntroductionCPX-351 is a liposomal formulation of cytarabine and daunorubicin packaged at a 5:1 molar ratio. This drug has recently been approved by FDA and EMEA for patients with therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (MRC-AML).The primary objective of this study was to analyze the efficacy of CPX-351 in a real-life setting, evaluating the impact of mutations on response and minimal residual disease (MRD) in responding patients.MethodsWe retrospectively collected data from patients treated by CPX-351 in eleven centers in France. Clinical, biological and treatment information were available for all patients. NGS (19 genes or more) was performed in 67 patients (84%) at diagnosis.Overall response rate (ORR) was defined by complete remission (CR) and CR with incomplete haematological recovery (CRi). Among the patients in CR or CRi, 25 (56%) had MRD evaluation assessed by NGS or flow cytometry. Overall survival (OS) was calculated from the date of AML diagnosis to the date of death or last follow-up. All statistical analyses were performed using SPSS v.22 software (IBM SPSS Statistics).ResultsBetween April 2018 and July 2019, 80 patients treated with CPX-351 were included in this study. Sex ratio M/F was 43/37 and median age was 66 years old (range 20-83). AML subtypes were MRC-AML (61%) including AML with prior myelodysplastic syndrome (MDS-AML) (33%), prior chronic myelomonocytic leukemia (CMML-AML) (7%), or t-AML (29%). Sixteen patients (20%) had received prior treatment by hypomethylating agents (HMA), at the time of MDS diagnosis, before AML evolution. According to ELN 2017 classification, genetic risk was favorable, intermediate and adverse in 1 (1%), 31 (38%) and 47 (58%), respectively. 36% and 28% patients had complex and monosomal karyotypes, respectively. Assessed by NGS the most frequent mutated gene were : RUNX1 (n=17, 25%), TP53 (n=15, 22%), ASXL1 (n=14, 21%), TET2 (n=13, 19%), DNMT3A (n=11, 16%), srsf2 (n=9, 13%), FLT3-ITD (n=8, 12%), CBL (n=7, 10%), WT1 (n=7, 10%), and EZH2 (n=7, 10%). According to a genetic ontogeny-based classifier (Lindsley et al., Blood 2015), 23 patients (34%), 29 (43%), 15 (22%) had de novo/pan-AML, secondary type mutations AML, and TP53 mutated AML, respectively.Only 4 patients discontinuing treatment due to prolonged haematological toxicity. Early death rate was 5% and 8.75% through day 30 and day 60, respectively.Median time to neutrophil recovery (>0,5 G/L) and platelet recovery (>20G/L) after induction was 29 days (range 19-78) and 28 days (range 12-77), respectively. Seventy-five patients (95%) had at least one grade 3 or more AEs, including 69 (86%) febrile neutropenia. We observed gastrointestinal toxicity 32 patients (40%) (nausea/vomiting (30%/11%), mucositis (15%)) including 4% with grade 3 or more and alopecia in only 12%.ORR was 45/80 (56%) after induction 1 including 53% CR and 3% CRi. ORR increased to 58% after induction 2. Among the 45 CR/CRi patients, 25 were evaluable for MRD at the time of the 1st consolidation. 72% had MRD below 10-3 (64% below 10-4). Prior treatment by HMA and presence of monosomal karyotype were identified as factors predicting a lower rate of CR/CRi (P=0.001 and P=0.002, respectively). Lindsley's classifier predicted significantly a better chemosensitivity in de novo/pan-AML mutations (P= 0.037). Poor molecular prognosis subgroups defined by 2017 ELN risk stratification (n = 53) as TP53, ASXL1, RUNX1 and EVI1 mutations were not associated with a lower response rate with CPX-351 (Table 1).Twenty-one (26%) patients underwent an allogeneic haematopoietic stem cell transplant (HSCT) with an improved median OS compared to non-transplanted patients (non reached vs 8 months, P= 0.004). With a median follow up of 8.5 months, median OS was not reached. Survival analysis in subgroups will be available for the ASH meeting.ConclusionThese data confirmed the efficacy and safety of CPX-351 in poor risk AML (t-AML and MRC-AML). The high rate of CR with low MRD compares favorably with previous report using 7+3 in elderly unfavorable AML (Sylvie D. Freeman et al., JCO 2013) and may explain the favorable outcome observed in patients after HSCT. Moreover, CPX-351 erases the poor prognosis associated with unfavorable mutations defined in 2017 ELN risk stratification. Lindsley's classifier was the best prognostic scoring system in patients treated by CPX-351.

Abstract

61st Annual Meeting and Exposition of the American-Society-of-Hematology (ASH), Orlando, FL, DEC 07-10, 2019

Abstract

International audience

Additional details