Impact of Minimal Residual Disease and Chimerism Monitoring at Different Timepoints after Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia

¶ Martin-Rojas RM and Oarbeascoa G contributed equally to this work. INTRODUCTION Relapse is the main cause of treatment failure after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute myeloid leukemia (AML). The evaluation of minimal residual disease (MRD) could provide a more accurate assessment of the depth of response, and therefore identify patients with higher risk of relapse. AIMS The aim of our study was to analyze the impact of pre-HSCT flow cytometry (FCM) and molecular MRD together with chimerism and MRD in the early post-HSCT period in patients with AML. METHODS We conducted a retrospective study in patients with complete remission AML who underwent a HSCT between 2008 and 2019 in our center. MRD was analyzed by flow cytometry in bone marrow aspirates and by quantitative RT-PCR (NMP1, RUNX1-RUNX1T1, CBFB-MYH11, KMT2A-MLLT3, WT1) in bone marrow aspirates and/or peripheral blood. MRD was determined within the 30 days preceding the HSCT and at day +30 and +90 post-HSCT. Bone marrow and selected CD34+ lineage chimerism was analyzed by STR (AmpFISTR SGM Plus, Thermo Fisher) at days +30 and +90 post-HSCT. This study was approved by our Institutional Ethics Committee. Data were analyzed using IBM SPSS Statistics version 24 and R version 3.5.1. RESULTS A total of 115 patients were analyzed. Pre-HSCT MRD was negative in 58 patients (50.4%) and positive in 57 patients (49.6%). We found no statistically significant differences in the characteristics between the two groups (Table 1). Median follow up was 39 months (IQR 10.4-55.8). 3-year overall survival (OS) for patients with pre-HSCT negative MRD was 72.5% versus 70.3% in patients with positive MRD (p=0.41), with an event free survival (EFS) of 66.9% versus 66.1 (p=0.48) respectively (Figure 1). Median time to the beginning of immunosuppression withdrawal was 82.5 days (IQR 59-93) for patients with negative MRD and 68 days (IQR 55.3-85.3) for patients with positive MRD (p<0.001). The cumulative incidence of grade II-IV acute graft versus host disease (aGVHD) and moderate-severe chronic GVHD did not show statistically significant differences based on the MRD status. Similarly, the cumulative incidence of relapse and the 2-year mortality was not significantly different between the two groups. Patients with negative MRD at day +30 showed a 2-year OS of 83.5% versus 58.1% in patients with positive MRD (p=0.03) and a EFS of 79.9% versus 48.6% (Figure 2). The cumulative incidence of relapse was more elevated in patients with positive MRD (29.8% versus 13.6%) at day +30. Patients with mixed chimerism (MC) at day +30 showed a significantly lower 3-year OS and EFS than patients with complete chimerism (CC). Likewise, the cumulative incidence of relapse was significantly higher in patients with MC, both if detected in bone marrow aspirate and in CD34+ cells. The multivariate analysis revealed that MRD status at day +30 post-HSCT was an independent prognostic factor for EFS (HR 3.74; 95% CI 1.38-10.1; p=0.009). CONCLUSIONS Patients with AML presenting a positive MRD in the early post-HSCT period and those who show a MC at day +30 post-HSCT have lower EFS, with positive MRD at day +30 being an independent prognostic factor for EFS. The evaluation of MRD and chimerism in the early post-HSCT period is useful to identify patients with higher risk of relapse, who may take advantage of preemptive measures. Disclosures Kwon: Gilead, Novartis, Pfizer, Jazz: Consultancy, Honoraria.

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Minimal Residual Disease After the First Cycle of Chemotherapy in Acute Myeloid Leukemia: A Comparative Study of WT1 RQ-PCR and 4-Color Flow Cytometry.

Blood ◽

10.1182/blood.v120.21.2535.2535 ◽

2012 ◽

Vol 120 (21) ◽

pp. 2535-2535

Author(s):

Carlo Marani ◽

Raffaella Grasso ◽

Nicoletta Colombo ◽

Marino Clavio ◽

Fabio Guolo ◽

...

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Residual Disease ◽

Leukemic Cells ◽

Color Flow ◽

Minimal Residual ◽

Acute Myeloid ◽

Intermediate Dose

Abstract Abstract 2535 Background and aims. Detection of minimal residual disease (MRD) has a relevant prognostic value in Acute Myeloid Leukemia (AML). MRD, when used as early treatment response assessment, allows identification of true low-risk and high-risk patients, who may profit alternative chemotherapy approach. In the present retrospective study, we evaluated the impact of MRD assessed by 4-color flow cytometry and WT1 RQ-PCR gene expression in a cohort of AML patients treated at our institution. Methods. Bone marrow samples of 50 adult AML patients (45 de novo and 5 secondary) with available karyotype (K), FLT3-ITD and NPM-A genes mutational status were assessed for MRD after induction. All included patients had a baseline WT1 expression greater than 1000 copies/Ablx104 (range 1060–346060; lab references for normal values 0–500). Fludarabine-based regimen was used as induction; one course of intermediate dose Ara-C 2g/sqm plus idarubicin, followed by 3 courses of intermediate dose Ara-C (2g/sqm) as further consolidation therapy. WT1 log reduction (DWT1) was used to assess the WT1 clearance (DWT1 = logWT1diagnosis – logWT1 post induction). A positive flow MRD was defined by the presence of no less than 25 clustered leukemic cells/105 total events - threshold of 2.5 × 10−4 residual leukemic cells. In patients submitted to bone marrow transplantation (BMT) only the first consolidation course was administered and disease free survival (DFS) was censored at the date of BMT. Results. Two (4%) patients had favorable, 40 (80%) intermediate, and 5 (10%) poor risk K (3 had no metaphases); 14 (28/%) carried FLT3-ITD mutation: among them 8 carried NPM-A mutation too, while 6 were wild type. After the first induction regimen 42 of 50 (84%) patients achieved a complete remission (CR). Patients with a negative flow MRD (32%) had 3 years DFS of 69.5%, whereas those with a positive flow MRD (68%) had a DFS of 27.3% (p = 0.032). Patients with a DWT1 > 1.5 log (65%) had a 3-years DFS of 58.3%, whereas those with a DWT1 ≤ 1.5 log (35%) had a DFS at 1 and 2-years of 13,5% and 0%, respectively (p < 0.001). All patients with a negative flow MRD had also a DWT1 > 1.5 log, whereas 12 (52%) of those who achieved a DWT1 > 1.5 log were still positive by flow MRD. Fourteen (28%) patients with a high risk (HR) profile at diagnosis (poor risk K, intermediate K with FLT3-ITDpos/NPM-Aneg, AML secondary to therapy or previous haematological disorder), 6 were no responder to induction, whereas no one of 8 patients in CR reached a negative MRD status in both test with a very poor outcome (projected DFS 4.8 months). MRD assessment using both flow and DWT1 allow to discriminate no-HR profile patients in three prognostic group: good (flow MRD neg) intermediate (flow MRD pos and DWT1 > 1.5 log) and adverse prognosis (flow MRD pos and DWT1 ≤ 1.5 log) with a projected DFS of 70.5 months, 38.2 months and 4.2 months, respectively (p < 0.001). Conclusions. DWT1 identified patients who would relapse better than flow, whereas a negative flow MRD was the best predictor of long DFS. Using both test in combination with baseline biologic parameters enabled the definition of discrete prognostic categories (Fig 1). Outcome of patients with DWT1 ≤ 1.5 log was very poor and comparable with that of patients with HR profile at diagnosis. In these patients forecast a cure is very difficult with the current treatment option and clinical trials with new drugs should be used already in up-front setting. Disclosures: No relevant conflicts of interest to declare.

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Persistence of Minimal Residual Disease Assessed By Multi-Parameter Flow Cytometry (MFC) at 30 and 90 Days after Achieving Complete Remission Predicts Outcome in Patients with Acute Myeloid Leukemia

Blood ◽

10.1182/blood.v124.21.1015.1015 ◽

2014 ◽

Vol 124 (21) ◽

pp. 1015-1015

Author(s):

Pramod Pinnamaneni ◽

Jeffrey L. Jorgensen ◽

Hagop M. Kantarjian ◽

Elias Jabbour ◽

Sherry R. Pierce ◽

...

Keyword(s):

Bone Marrow ◽

Flow Cytometry ◽

Acute Myeloid Leukemia ◽

Complete Remission ◽

Minimal Residual Disease ◽

Myeloid Leukemia ◽

Residual Disease ◽

Response To Therapy ◽

Minimal Residual ◽

Acute Myeloid

Abstract Purpose – To determine the value of Minimal Residual Disease (MRD) assessed by Multi-parameter Flow Cytometry (MFC) after achieving initial response to therapy, in predicting outcome in patients with acute myeloid leukemia (AML) Methods – We investigated the predictive value of MRD assessment by MFC in 191 patients with newly diagnosed AML treated between February 2010 and April 2014 at our institution who had available MRD assessment. MRD by MFC was assessed using an 8-color panel containing 19 distinct markers, on bone marrow specimens obtained at the time of achievement of CR and at approximately 30 days and 90 days after achieving CR. Residual leukemic blasts were identified based on phenotypic differences from normal myelomonocytic precursors. Sensitivity was estimated at 0.1% in most cases, with maximum achievable sensitivity of 0.01%, depending on the leukemic phenotype. Results – Of the 191 patients, 167 (87%) achieved complete remission (CR) or CR without platelet recovery (CRp). Their median age was 58 years (Range, 17-85). 84 (44%) were older than 60 years. Median WBC at presentation was 3.2 x 109/L(Range, 0.5-100.2 x 109/L) and median bone marrow blast percentage was 43% (Range, 11-96%). Cytogenetics was favorable risk in 4 (2%), intermediate risk in130 (68%) and adverse risk in 57 (30%). Treatment included cytarabine plus anthracycline in 170 (89%) and hypomethylating agents-based strategies in 21 (11%). 48 patients had available samples at 30 days post CR and 32 (67%) became MRD negative. Achieving MRD negative status was associated with a statistically significant improvement in CR duration (p=0.02) and overall survival (OS) (p=0.0005). 56 patients were evaluated for MRD status at 90 days and 45 (80%) were negative. Again, achieving MRD negative status was associated with a significant improvement in CR duration (p=0.002) and OS (p=0.0009). Conclusion – Achieving MRD negative status by MFC at 30 and 90 days post CR is associated with an improved outcome in patients with AML Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

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Optimal Post-Remission Therapy for Flow-Cytometry Minimal Residual Disease Positive Patients with Acute Myeloid Leukemia.

Blood ◽

10.1182/blood.v108.11.610.610 ◽

2006 ◽

Vol 108 (11) ◽

pp. 610-610

Author(s):

Francesco Buccisano ◽

Luca Maurillo ◽

Valter Gattei ◽

Giovanni Del Poeta ◽

Maria Ilaria Del Principe ◽

...

Keyword(s):

Flow Cytometry ◽

Acute Myeloid Leukemia ◽

Stem Cell ◽

Stem Cell Transplantation ◽

Minimal Residual Disease ◽

Myeloid Leukemia ◽

Residual Disease ◽

Consolidation Therapy ◽

Minimal Residual ◽

Acute Myeloid

Abstract Autologous (AuSCT) and allogeneic stem cell transplantation (SCT) are well established post-remissional strategies for patients with Acute Myeloid Leukemia (AML). However, there is still a debate ongoing about the relative merit of each of these options in first CR. Minimal residual disease (MRD) may be a useful tool to stratify AML patients into categories of risk which can benefit from differentiated post-remissional approaches. To address this issue, we analysed retrospectively, a series of 123 patients affected with AML in whom flow-cytometry serial determinations of MRD were available, at established time-points (post-induction, post-consolidation, post-stem cell transplantation). All were entered into the EORTC/GIMEMA protocols AML10/AML12 (age <61 yrs) or AML13 (age>61 yrs), all consisting in intensive induction and consolidation cycles, and, for patients aged <61 years, AuSCT or SCT. Median age was 52 years (range 18–78), no APL cases were included in the study. The “Maximally Selected Rank Statistic” analysis was used to select the MRD level and the time-point of analysis achieving the best prognostic significance in terms of overall survival (OS) and relapse free survival (RFS). This test was specifically developed to find out the optimal cut-off for a given biological variable correlating with clinical parameters of interest. This approach confirmed the threshold of 3.5x10−4 residual leukemic cells after consolidation therapy, as a discriminator between MRD− and MRD+ cases with different 5-years OS (64% vs. 14%, P<.001) and RFS (68% vs. 13%, P<.001). Therefore, among these 123 patients, we enucleated 2 groups of patients which underwent stem cell transplant procedure, 53 AuSCT and 11 SCT. The two subgroups were balanced in terms of FAB categories, WBC count, karyotype and expression of MDR-1 phenotype; 34/64 (53%) were MRD+ (9 SCT, 25 AuSCT) and 30/64 (47%) were MRD− (1 SCT, 28 AuSCT). Among the 53 patients submitted to AuSCT, MRD− had a significant better outcome than those MRD+, both in terms of 5-years OS (68% vs. 24%, P=0.003) and RFS (68% vs. 11%, P<.001). In the SCT group the low numbers hampered any firm conclusion; however, when the category of post-consolidation MRD+ patients was separately analysed, the use of SCT was associated with a better RFS (49% vs. 11%, P=NS); we assume that the lack of statistical significance was merely due to the few cases in the SCT group. In conclusion, the threshold of 3.5x10−4 at post-consolidation check-point is critical to predict disease outcome; MRD− patients have an excellent outcome regardless of the post-consolidation therapy; in the MRD+ group, AuSCT seems not to improve the prognosis whereas the use of SCT is associated with a superior outcome, although a larger number of patients is required to confirm this assumption. Figure Figure

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