RUNX1-RUNX1T1 Transcript Levels Research Articles

Preemptive Immunotherapy for Minimal Residual Disease in Patients With t(8;21) Acute Myeloid Leukemia After Allogeneic Hematopoietic Stem Cell Transplantation.

In patients with t(8;21) acute myeloid leukemia (AML), recurrent minimal residual disease (MRD) measured by RUNX1-RUNX1T1 transcript levels can predict relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study aimed to compare the efficacy of preemptive interferon (IFN)-α therapy and donor lymphocyte infusion (DLI) in patients with t(8;21) AML following allo-HSCT. We also evaluated the appropriate method for patients with different levels of RUNX1-RUNX1T1 transcripts. In this retrospective study, consecutive patients who had high-risk t(8;21) AML and received allo-HSCT were enrolled. The inclusion criteria were as follows: (1) age ≤65 years; (2) regained MRD positive following allo-HSCT. MRD positive was defined as the loss of a ≥4.5-log reduction and/or <4.5-log reduction in the RUNX1-RUNX1T1 transcripts, and high-level, intermediate-level, and low-level MRDs were, respectively, defined as <2.5-log, 2.5−3.5-log, and 3.5−4.5-log reductions in the transcripts compared with the pretreatment baseline level. Patients with positive RUNX1-RUNX1T1 could receive preemptive IFN-α therapy or DLI, which was primarily based on donor availability and the intentions of physicians and patients. The patients received recombinant human IFN-α-2b therapy by subcutaneous injection twice a week every 4 weeks. IFN-α therapy was scheduled for six cycles or until the RUNX1-RUNX1T1 transcripts were negative for at least two consecutive tests. The rates of MRD turning negative for patients with low-level, intermediate-level, and high-level RUNX1-RUNX1T1 receiving IFN-α were 87.5%, 58.1%, and 22.2%, respectively; meanwhile, for patients with intermediate-level and high-level RUNX1-RUNX1T1 receiving DLI, the rates were 50.0% and 14.3%, respectively. For patients with low-level and intermediate-level RUNX1-RUNX1T1, the probability of overall survival at 2 years was higher in the IFN-α group than in the DLI group (87.6% vs. 55.6%; p = 0.003). For patients with high levels of RUNX1-RUNX1T1, the probability of overall survival was comparable between the IFN-α and DLI groups (53.3% vs. 83.3%; p = 0.780). Therefore, patients with low-level and intermediate-level RUNX1-RUNX1T1 could benefit more from preemptive IFN-α therapy compared with DLI. Clinical outcomes were comparable between preemptive IFN-α therapy and DLI in patients with high-level RUNX1-RUNX1T1; however, they should be further improved.

The Impact of CD19 Expression Combined with Measurable Residual Disease on Post-Remission Treatment and Outcome in Adult t(8;21) Acute Myeloid Leukemia

Background: Acute myeloid leukemia (AML) with t(8;21) has considerable clinical heterogeneity. Only 50% of these patients receiving multiple cycles of high-dose cytarabine as post-remission treatments could achieve long term survival, and relapse occures in up to 40% of them. Therefore, further risk stratification is needed to guide appropriate post-remission treatment for t(8;21) AML patitents in first complete remission(CR1). Measurable residual disease (MRD) monitored by RUNX1-RUNX1T1 transcript levels after treatment is established as a powerful marker to predict relapse and guide treatment. Recent studies revealed cell-surface antigen CD19 negativity (CD19-) was a risk factor for relapse in t(8;21) AML. However, reports about the impact of CD19 expression combined with RUNX1-RUNX1T1 MRD on post-remission treatment remains absent to date.Methods: A total of 155 consecutive patients diagnosed with t(8;21) AML were enrolled in this study, including 69 patients who received chemotherapy (CMT) and 86 who received allogeneic stem cell transplantation (allo-SCT) as post remission treatment in CR1. MRD+ was defined as a < 3 log reduction of RUNX1/RUNX1T1 level after the second consolidation therapy.Results:With a median follow-up of 40 months (range, 4-133 months), the 3-year OS, LFS and CIR rates were 75.57% ,70.46% and 27.50% for the entire population, respectively. The 3-year CIR was dramatically decreased in allo-SCT than in CMT group (13.47% vs 49.19%, p<0.001). Allo-SCT demonstrated a significantly superior 3-year OS (85.78% vs 58.89%, p< 0.001) and LFS (85.64% vs 45.84%, p< 0.001) over CMT, respectively. The 3-year cumulative incidence of TRM was 9.27% and 7.04% in the CMT and allo-HSCT groups, respectively (p=0.890). KIT exon 17 mutation was a risk factor for OS in multivariate analysis, CD19 negativity was a risk factor for RFS in univariate analysis. Allo-SCT was a beneficial factor for LFS and OS in multivariate analysis when taking CMT as a reference. For CD19- patients (n=59), allo-HSCT demonstrated significantly lower CIR (17.20% vs 51.03%, p=0.006) , better OS (95.24% vs 51.55%, p < 0.001) and LFS (82.8% vs 39.71%, p = 0.001) than CMT. On the other hand, CMT had a comparable CIR (26.70% vs 11.40, p=0.064 ), OS (73.19% vs 86.01%, p=0.153) and LFS (71.58% vs 87.76%, p=0.067) with allo-SCT for CD19+ patients (n=80). Notably, when combined with RUNX1-RUNX1T1 transcripts after the second consolidation, allo-SCT preserved a significantly lower CIR (6.67% vs 66.67%, p=0.002), improved OS (100% vs 33.33%, p< 0.001) and LFS (93.33% vs 33.33%, p=0.001) than CMT in CD19-MRD+ group (n=22), respectively. In contranst, CMT revealed similar OS (80.0% vs 87.5%, p=0.677 ), LFS (60% vs 62.5%, p=0.663) and CIR (40.00% vs 37.50%, p=0.795 ) with allo-SCT in CD19-MRD- patients (n=13), respectively. For CD19+ patients, addition of MRD status had no impact on the outcome of allo-SCT and CMT. CMT preserved comparable OS (75% vs 84.66%, p =0.516), LFS (85.71% vs 96.30%, p =0.357 ) and CIR (12.50% vs 3.70%, p =0.367) with allo-SCT for CD19+MRD+ patients (n=36), and comparable OS (100% vs 92.31%, p =0.459), LFS (83.33% vs 85.29%, p =0.940 ) and CIR (16.67% vs 13.54%, p =0.998) with allo-SCT in CD19+MRD- patients (n=33).Conclusion: Combination of CD19 expression and RUNX1-RUNX1T1 MRD improved risk stratification and treatment guidance for t(8;21) AML in CR1. Allo-SCT might be recommended for the CD19-MRD+ patients, while CMT might be a reasnonable choice for CD19-MRD+ and CD19+ patients. Multicenter prospective studies are warranted to confirm the current results.Key words: t(8;21) AML, CD19, measurable residual disease, post-remission treatment, allo-SCT, chematherapy DisclosuresNo relevant conflicts of interest to declare.

Allogeneic hematopoietic stem cell transplantation can improve the prognosis of high-risk pediatric t(8;21) acute myeloid leukemia in first remission based on MRD-guided treatment

BackgroundPediatric acute myeloid leukemia (AML) with t(8;21) (q22;q22) is classified as a low-risk group. However, relapse is still the main factor affecting survival. We aimed to investigate the effect of allogeneic hematopoietic stem cell transplantation (allo-HSCT) on reducing recurrence and improving the survival of high-risk pediatric t(8;21) AML based on minimal residual disease (MRD)-guided treatment, and to further explore the prognostic factors to guide risk stratification treatment and identify who will benefit from allo-HSCT.MethodsOverall, 129 newly diagnosed pediatric t(8;21) AML patients were included in this study. Patients were divided into high-risk and low-risk group according to RUNX1-RUNX1T1 transcript levels after 2 cycles of consolidation chemotherapy. High-risk patients were divided into HSCT group and chemotherapy group according to their treatment choices. The characteristics and outcomes of 125 patients were analyzed.ResultsFor high-risk patients, allo-HSCT could improve 5-year relapse-free survival (RFS) rate compared to chemotherapy (87.4% vs. 61.9%; P = 0.026). Five-year overall survival (OS) rate in high-risk HSCT group had a trend for better than that in high-risk chemotherapy group (82.8% vs. 71.4%; P = 0.260). The 5-year RFS rate of patients with a c-KIT mutation in high-risk HSCT group had a trend for better than that of patients with a c-KIT mutation in high-risk chemotherapy group (82.9% vs. 75%; P = 0.400). Extramedullary infiltration (EI) at diagnosis was associated with a high cumulative incidence of relapse for high-risk patients (50% vs. 18.4%; P = 0.004); allo-HSCT can improve the RFS (P = 0.009).Conclusionsallo-HSCT can improve the prognosis of high-risk pediatric t(8;21) AML based on MRD-guided treatment. Patients with a c-KIT mutation may benefit from allo-HSCT. EI is an independent prognostic factor for high-risk patients and allo-HSCT can improve the prognosis.

Subgroup Analysis Can Optimize the Relapse-Prediction Cutoff Value for WT1 Expression After Allogeneic Hematologic Stem Cell Transplantation in Acute Myeloid Leukemia

High WT1 expression after allogeneic hematologic stem cell transplantation (allo-HSCT) can strongly predict relapse in acute myeloid leukemia (AML). However, the cutoff values obtained have been inconsistent. Precise cutoff values may be optimized through subtype analysis; the RUNX1-RUNX1T1 fusion transcript provides an ideal reference. RUNX1-RUNX1T1 and WT1 transcript levels were simultaneously measured in 1299 bone marrow samples serially collected from 176 t(8;21) AML patients after allo-HSCT. The upper limit of the normal bone marrow WT1 level was 0.6%, which we previously reported to be the cutoff value for significant relapse prediction in AML as a whole. WT1 cutoff values of 0.6%, 1.2%, and 1.8% significantly differentiated patients in relapse after allo-HSCT. Nonetheless, patients with WT1 levels of 0.6% to 1.2% and those with levels of >1.2% and 1.8% after HSCT had rates of cumulative incidence of relapse similar to those with a continuous WT1 level of ≤0.6%, and both were significantly lower than that in patients with a WT1 level of >1.8%. WT1 expression was significantly related to RUNX1-RUNX1T1 transcript levels at WT1 levels of >1.8% but not at levels of 0.6% to 1.2% or >1.2% to 1.8%. Therefore, subgroup analysis can optimize the relapse-prediction cutoff value of WT1 expression. A cutoff level of 1.8% more accurately differentiates t(8;21) AML patients in relapse after allo-HSCT than does a cutoff level of 0.6%.

Measurable Residual Disease (MRD) Monitoring in Acute Myeloid Leukemia (AML) with t(8;21)(q22;q22.1) RUNX1-RUNX1T1 Identifies Patients at High Risk of Relapse: Results of the AML Study Group (AMLSG)

Measurable Residual Disease (MRD) Monitoring in Acute Myeloid Leukemia (AML) with t(8;21)(q22;q22.1) RUNX1-RUNX1T1 Identifies Patients at High Risk of Relapse: Results of the AML Study Group (AMLSG)

Measurable residual disease monitoring in acute myeloid leukemia with t(8;21)(q22;q22.1): results from the AML Study Group

AbstractWe performed serial measurable residual disease (MRD) monitoring in bone marrow (BM) and peripheral blood (PB) samples of 155 intensively treated patients with RUNX1-RUNX1T1+ AML, using a qRT-PC–based assay with a sensitivity of up to 10−6. We assessed both reduction of RUNX1-RUNX1T1 transcript levels (TLs) and achievement of MRD negativity (MRD−) for impact on prognosis. Achievement of MR2.5 (>2.5 log reduction) after treatment cycle 1 and achievement of MR3.0 after treatment cycle 2 were significantly associated with a reduced risk of relapse (P = .034 and P = .028, respectively). After completion of therapy, achievement of MRD− in both BM and PB was an independent, favorable prognostic factor in cumulative incidence of relapse (4-year cumulative incidence relapse: BM, 17% vs 36%, P = .021; PB, 23% vs 55%, P = .001) and overall survival (4-year overall survival rate BM, 93% vs 70%, P = .007; PB, 87% vs 47%, P < .0001). Finally, during follow-up, serial qRT-PCR analyses allowed prediction of relapse in 77% of patients exceeding a cutoff value of 150 RUNX1-RUNX1T1 TLs in BM, and in 84% of patients exceeding a value of 50 RUNX1-RUNX1T1 TLs in PB. The KIT mutation was a significant factor predicting a lower CR rate and inferior outcome, but its prognostic impact was outweighed by RUNX1-RUNX1T1 TLs during treatment. Virtually all relapses occurred within 1 year after the end of treatment, with a very short latency from molecular to morphologic relapse, necessitating MRD assessment at short intervals during this time period. Based on our data, we propose a refined practical guideline for MRD assessment in RUNX1-RUNX1T1+ AML.

High aldehyde dehydrogenase activity at diagnosis predicts relapse in patients with t(8;21) acute myeloid leukemia

Acute myeloid leukemia (AML) with t(8;21) is a heterogeneous disease. Although the detection of minimal residual disease (MRD), which is indicated by RUNX1‐RUNX1T1 transcript levels, plays a key role in directing treatment, risk stratification needs to be improved, and other markers need to be assessed. A total of 66 t(8;21) AML patients were tested for aldehyde dehydrogenase (ALDH) activity by flow cytometry at diagnosis, and 52 patients were followed up for a median of 20 (1‐34) months. The median percentage of CD34+ALDH+, CD34+CD38‐ALDH+, and CD34+CD38+ALDH+ cells among nucleated cells were 0.028%, 0.012%, and 0.0070%, respectively. The CD34+ALDH+‐H, CD34+CD38‐ALDH+‐H, and CD34+CD38+ALDH+‐H statuses (the percentage of cells that were higher than the individual cutoffs) were all significantly associated with a lower 2‐year relapse‐free survival (RFS) rate in both the whole cohort and adult patients (P = .015, .016, and .049; P = .014, .018, and .032). Patients with < 3‐log reduction in the RUNX1‐RUNX1T1 transcript level after the second consolidation therapy (defined as MRD‐H) had a significantly lower 2‐year RFS rate than patients with ≥ 3‐log reduction (MRD‐L) (P = .017). The CD34+ALDH+ status at diagnosis was then combined with the MRD status. CD34+ALDH+‐L/MRD‐H patients had similar 2‐year RFS rates to both CD34+ALDH+‐L/MRD‐L and CD34+ALDH+‐H/MRD‐L patients (P = .50 and 1.0); and CD34+ALDH+‐H/MRD‐H patients had significantly lower 2‐year RFS rate compared with CD34+ALDH+‐L and/or MRD‐L patients (P < .0001). Multivariate analysis showed that CD34+ALDH+‐H/MRD‐H was an independent adverse prognostic factor for relapse. In conclusion, ALDH status at diagnosis may improve MRD‐based risk stratification in t(8;21) AML, and concurrent high levels of CD34+ALDH+ at diagnosis and MRD predict relapse.

Interferon-α Is Effective for Treatment of Minimal Residual Disease in Patients with t(8;21) Acute Myeloid Leukemia After Allogeneic Hematopoietic Stem Cell Transplantation: Results of a Prospective Registry Study.

RUNX1-RUNX1T1 transcript levels were established as a powerful marker for predicting relapse in patients with t(8;21) acute myeloid leukemia (AML). We aimed to identify the efficacy of minimal residual disease (MRD)-directed interferon-alpha (IFN-α) treatment in patients with t(8;21) AML who were positive for MRD after allogeneic hematopoietic stem cell transplantation (allo-HSCT; n=42). MRD-positive status was defined as a <4.5-log reduction from diagnosis in RUNX1-RUNX1T1 transcripts and/or the loss of a ≥4.5-log reduction after 3 months after HSCT. Patients with positive MRD received six cycles of IFN-α treatment (twice or thrice weekly of every 4 weeks cycle). The 1-year cumulative incidence of severe acute and chronic graft-versus-host disease after MRD-directed IFN-α treatment was 7.1% and 4.8%, respectively. After the treatment, 15 (35.7%), 5 (11.9%), 3 (7.1%), and 9 (21.5%) patients achieved MRD negativity at 1, 2, 3, and >3 months, respectively. Three patients relapsed after the IFN-α treatment, in which the 1-year cumulative incidence of relapse was 7.2%. One patient died of severe infection at 460 days after treatment. The 1-year probabilities of event-free survival, disease-free survival, and overall survival after treatment were 76.0%, 92.4%, and 92.5%, respectively. The clinical outcomes in patients who received MRD-directed IFN-α treatment were significantly better than those of the MRD-positive patients without any interventions in the historical cohort. MRD-directed IFN-α treatment is effective for patients with t(8;21) AML who were MRD-positive after allo-HSCT. The study was registered at http://clinicaltrials.gov as NCT02027064. In patients with t(8;21) acute myeloid leukemia (AML), the presence of post-allogeneic hematopoietic stem cell transplantation (allo-HSCT) minimal residual disease (MRD), measured by RUNX1-RUNX1T1 transcript levels, has been established as a powerful marker for predicting relapse. Interferon-alpha (IFN-α) could exert a relatively strong graft-versus-leukemia effect, and MRD-directed IFN-α treatment is effective for patients with t(8;21) AML who were MRD-positive after allo-HSCT.

Application value of quantitative monitoring of RUNX1-RUNX1T1 fusion gene in pediatric acute myeloid leukemia

Objective To explore the prognostic value of quantitative monitoring of RUNX1-RUNX1T1 fusion gene in pediatric t(8; 21)/RUNX1-RUNX1T1 positive acute myeloid leukemia (AML). Methods A total of 81 newly diagnosed AML children with t (8; 21)/RUNX1-RUNX1T1 positive were enrolled in the People′s Hospital, Peking University, between August 2005 and January 2016.RUNX1- RUNX1T1 gene copy number of all the patients was analyzed by real-time quantitative PCR (qPCR) technology at diagnosis and after therapy in all patients.Cumulative incidence of relapse rate (CIR), event-free survival (EFS) rate and overall survival (OS) rate were estimated by Kaplan-Meier method and prognostic factors were evaluated by COX regression. Results The level of RUNX1-RUNX1T1 gene on diagnosis was used as the baseline to determine whether the level of gene after treatment had a more than 3 logarithmic (3 log) reduction.After 2 courses of induction therapy, the patients with a more than 3 log reduction of RUNX1-RUNX1T1 transcript levels(≥3 log)had better EFS rate (82.4% vs.57.6%, χ2=7.454, P<0.01), and better OS (93.6% vs.59.3%, χ2=9.703, P<0.01), compared to the patients with a less than 3 log reduction(<3 log). Multivariate analysis showed that 3 log reduction in RUNX1- RUNX1T1 transcript levels after 2 courses of induction therapy was an independent prognostic factor for EFS rate [hazard ratio(HR)=4.223, 95% confidence interval(CI): 1.507-11.836, P<0.01]and OS rate (HR=5.002, 95%CI: 1.282-19.516, P<0.05). When periodically monitoring the RUNX1-RUNX1T1 gene, 63 out of the 81 children patients were monitored for more than 6 times.The patients who had a more than 3 log reduction of gene before, but then those whose gene transcript level rose more than 1 log level were divided into group A, and the remaining patients were divided group B, and the difference of CIR was statistically significant between group A and group B (46.7% vs.4.7%, P<0.01). Conclusions RUNX1-RUNX1T1 gene copy number was detected with qPCR method in pediatric t(8; 21)/RUNX1-RUNX1T1 positive AML, which can determine the treatment effect, predict the recurrence of patients and assess long-term prognosis.Thus it has great clinical application value. Key words: Leukemia, myeloid, acute; Gene fusion, RUNX1-RUNX1T1 fusion gene; Neoplasm, residual; Survival analysis; Child

Prognostic value of dynamic monitoring of RUNX1-RUNX1T1 transcript in pediatric acute myeloid leukemia

目的探讨动态监测RUNX1-RUNX1T1转录本水平在儿童t（8;21）急性髓系白血病（AML）预后评估中的价值。方法以2010年1月至2016年4月就诊于郑州大学人民医院的55例儿童t（8;21）AML患者为研究对象，应用实时荧光定量PCR（RQ-PCR）动态监测患者的RUNX1-RUNX1T1转录本水平，分析其变化与疾病预后的关系。结果初诊时患者骨髓细胞中的RUNX1-RUNX1T1转录本水平与复发及预后无关。1个疗程诱导缓解治疗后，骨髓细胞中RUNX1-RUNX1T1转录本水平比诊断时下降大于2个对数级（a>2 Log）者与a≤2 Log者相比：5年累积复发率（CIR）分别为（24.3±8.4）%及（52.6±9.7）%（χ2=9.046，P=0.003），5年无复发生存（RFS）率分别为（71.6±12.7）%及（48.1±13.2）%（χ2=5.814，P=0.016），5年总生存（OS）率分别为（76.9±12.5）%及（48.9±14.7）%（χ2=6.346，P=0.012），差异均有统计学意义。多因素Cox回归模型结果显示，1个疗程诱导缓解后RUNX1-RUNX1T1转录本下降是否大于2 Log是影响RFS（HR=0.263，95% CI 0.081~0.851，P=0.026）与OS（HR=0.214，95% CI 0.057~0.808，P=0.023）的独立预后因素。巩固治疗及治疗结束随访期间动态监测RUNX1-RUNX1T1转录本水平变化，共有16例患者发生分子学复发，其中13例患者发生了血液学复发，分子学复发至血液学复发的中位时间为4.0（1.5~5.8）个月。对2例分子学复发后的患者及时采取异基因造血干细胞移植治疗后，患者未发生血液学复发。结论通过RQ-PCR动态监测儿童t（8;21）AML患者的RUNX1-RUNX1T1转录本水平，可以将儿童t（8;21）AML细分为相对低危组和相对高危组并提前预测血液学复发，为实现儿童t（8;21）AML的精准分层和风险-适应治疗提供科学依据。

The dynamics of RUNX1-RUNX1T1 transcript levels after allogeneic hematopoietic stem cell transplantation predict relapse in patients with t(8;21) acute myeloid leukemia

BackgroundThe optimal monitoring schedules and cutoff minimal residual disease (MRD) levels for the accurate prediction of relapse at all time points after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain unclear in patients with t(8;21) acute myeloid leukemia (AML).MethodsRUNX1-RUNX1T1 transcript levels were measured in bone marrow samples collected from 208 patients at scheduled time points after transplantation (1530 samples in total).ResultsA total of 92.3% of the requested samples were collected, and 74.0% of patients had complete sample collection. The 1-, 3-, and 6-month RUNX1-RUNX1T1 transcript levels could significantly discriminate between continuous complete remission and a hematologic relapse at 1.5–3, 4–6, and 7–12 months but not at >3, >6, and >12 months, respectively. Over 90% of the 175 patients who were in continuous complete remission had a ≥3-log reduction in RUNX1-RUNX1T1 transcript levels from the time of diagnosis at each time point after transplantation and a ≥4-log reduction at ≥12 months. A <3-log reduction within 12 months and/or a <4-log reduction at ≥12 months was significantly related to a higher 3-year cumulative incidence of relapse (CIR) rate in both the entire cohort and the patients with no intervention after HSCT (58.4 vs. 2.2%, 76.5 vs. 2.0%; all P < 0.0001). Patients who had received a preemptive donor lymphocyte infusion when the increase in RUNX1-RUNX1T1 transcripts was ≤1-log according to the above dual cutoff values had significantly lower 1-year CIR rate after intervention than the patients who had received an infusion when the increase was >1-log (0 vs. 55.0%, P = 0.015).ConclusionsRUNX1-RUNX1T1 transcripts with a <3-log reduction from diagnosis within 12 months and/or a <4-log reduction at ≥12 months after allo-HSCT could accurately predict relapse and may prompt a timely intervention in patients with t(8;21) AML.

Minimal Residual Disease Monitoring in Acute Myeloid Leukemia (AML) with Translocation t(8;21)(q22;q22): Results of the AML Study Group (AMLSG)

Background: Acute myeloid leukemia (AML) with t(8;21)(q22;q22) results in the formation of the RUNX1-RUNX1T1 fusion transcript which can be used to monitor minimal residual disease (MRD) by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Early identification of patients (pts) with a high risk of relapse will allow pre-emptive therapy including allogeneic hematopoietic cell transplantation (alloHCT). Recent studies in AML with NPM1 mutation or the CBFB-MYH11 gene fusion revealed that MRD persistence is significantly associated with a high risk of relapse. However, the prognostic impact of MRD assessment in RUNX1-RUNX1T1-positive AML is not well established.Aims: To assess the prognostic impact of qRT-PCR-based MRD monitoring in bone marrow (BM) of pts with t(8;21)/RUNX1-RUNX1T1-positive AML obtained at defined time-points (diagnosis, first and second cycle of chemotherapy, end of treatment).Methods: In total, 120 pts were included based on the availability of a diagnostic BM sample and at least two subsequent BM samples obtained during therapy and at the end of treatment; 106 pts were enrolled in one of six AMLSG treatment trials: AML HD93 (n=1), AML HD98A (NCT00146120; n=13), AMLSG 06-04 (NCT00151255; n=4), AMLSG 07-04 (NCT00151242; n=43), AMLSG 11-08 (NCT00850382; n=31), AMLSG 21-13 (NCT02013648; n=14); 14 pts were treated outside clinical trials. All pts received anthracycline- and cytarabine-based intensive induction followed by subsequent high-dose cytarabine consolidation cycles. For MRD assessment, qRT-PCR from BM specimens was performed using TaqMan technology; RUNX1-RUNX1T1 transcript levels (TL) were reported as the normalized value of RUNX1-RUNX1T1 per 106 transcripts of the housekeeping gene beta2-microglobulin. The maximum sensitivity of the assay was 10-6.Results: The median age of the pts was 47 years (yrs; range, 18-73 yrs); at the time of diagnosis there was a broad range of RUNX1-RUNX1T1 TL (18490 to 14440000) with a median of 227800. RUNX1-RUNX1T1 TL did not correlate with clinical features (age, WBC, platelets, LDH, BM blasts) or associated gene mutations such as KIT, FLT3-ITD/TKD, NRAS or ASXL2. However, pts with additional FLT3 mutation showed higher TL compared to wild-type pts (median, 412955 vs 219052). Cox regression analysis using RUNX1-RUNX1T1 TL as a log10 transformed continuous variable showed that higher RUNX1-RUNX1T1 TL were significantly associated with a higher cumulative incidence of relapse (CIR), inferior event-free survival (EFS) and shorter overall survival (OS) for the two time points "after first treatment cycle" and "at end of treatment" (CIR: HR, 1.84, p=0.001; HR, 1.60, p=0.03; EFS: HR, 1.59, p=0.01, HR, 1.74, p=0.01; OS: HR, 1.63, p=0.02, HR 2.13, p=0.009, respectively). In univariate analyses achievement of MRD negativity (n=35) at the end of treatment was significantly associated with a superior 4-yr OS (93% vs 67%; p=0.007) and 4-yr EFS (81% vs 61%; p=0.04) whereas achievement of MRD negativity after the first (1/85) and second (20/89) treatment cycle was low not reaching significance for any of the clinical endpoints. Separation of the RUNX1-RUNX1T1 TL according to quartiles of distribution showed significant differences in OS (p=0.04), and remission duration (p=0.006) "after first cycle" whereas "at end of treatment" significant differences were only found for OS (p=0.009). Finally, we evaluated the impact of concurrent KIT mutations on the kinetics of RUNX1-RUNX1T1 TL. Following the first treatment cycle, the median RUNX1-RUNX1T1 TL were significantly lower in the KIT wildtype group compared with the KIT mutated group (p=0.02); the same was true "at the end of treatment" (p=0.02).Conclusions: In our study, achievement of MRD negativity at the end of treatment was significantly associated with a better outcome in t(8;21)-positive AML. The fact that earlier time points did not allow the identification of pts with a high relapse risk is probably due to the high sensitivity of the qRT-PCR assay which is also reflected by the low number of pts achieving qRT-PCR negativity after first and second treatment cycle, respectively. Further analyses are ongoing including multivariable as well as molecular subgroup analyses.*These authors contributed equally to the work: MA, ACMA was supported by the Else-Kröner-Fresenius-Stiftung (EKFS). DisclosuresPaschka:Celgene: Honoraria; Pfizer Pharma GmbH: Honoraria; Bristol-Myers Squibb: Honoraria; Medupdate GmbH: Honoraria; Novartis: Consultancy; ASTEX Pharmaceuticals: Consultancy. Lübbert:Ratiopharm: Other: Study drug valproic acid; Janssen-Cilag: Other: Travel Funding, Research Funding; Celgene: Other: Travel Funding. Fiedler:Amgen: Consultancy, Other: Travel, Patents & Royalties, Research Funding; Teva: Other: Travel; Kolltan: Research Funding; Ariad/Incyte: Consultancy; Novartis: Consultancy; Gilead: Other: Travel; GSO: Other: Travel; Pfizer: Research Funding. Heuser:Karyopharm Therapeutics Inc: Research Funding; Pfizer: Research Funding; Bayer Pharma AG: Research Funding; Celgene: Honoraria; Tetralogic: Research Funding; BerGenBio: Research Funding; Novartis: Consultancy, Research Funding. Schlenk:Pfizer: Honoraria, Research Funding; Amgen: Research Funding.

Low WT1 transcript levels at diagnosis predicted poor outcomes of acute myeloid leukemia patients with t(8;21) who received chemotherapy or allogeneic hematopoietic stem cell transplantation.

BackgroundAcute myeloid leukemia (AML) with t(8;21) is a heterogeneous disease. Identifying AML patients with t(8;21) who have a poor prognosis despite achieving remission is important for determining the best subsequent therapy. This study aimed to evaluate the impact of Wilm tumor gene-1 (WT1) transcript levels and cellular homolog of the viral oncogene v-KIT receptor tyrosine kinase (C-KIT) mutations at diagnosis, and RUNX1-RUNX1T1 transcript levels after the second consolidation chemotherapy cycle on outcomes.MethodsEighty-eight AML patients with t(8;21) who received chemotherapy only or allogeneic hematopoietic stem cell transplantation (allo-HSCT) were included. Patients who achieved remission, received two or more cycles of consolidation chemotherapy, and had a positive measureable residual disease (MRD) test result (defined as <3-log reduction in RUNX1-RUNX1T1 transcript levels compared to baseline) after 2–8 cycles of consolidation chemotherapy were recommended to receive allo-HSCT. Patients who had a negative MRD test result were recommended to receive further chemotherapy up to only 8 cycles. WT1 transcript levels and C-KIT mutations at diagnosis, and RUNX1-RUNX1T1 transcript levels after the second consolidation chemotherapy cycle were tested.ResultsPatients who had a C-KIT mutation had significantly lower WT1 transcript levels than patients who did not have a C-KIT mutation (6.7% ± 10.6% vs. 19.5% ± 19.9%, P < 0.001). Low WT1 transcript levels (≤5.0%) but not C-KIT mutation at diagnosis, a positive MRD test result after the second cycle of consolidation chemotherapy, and receiving only chemotherapy were independently associated with high cumulative incidence of relapse in all patients (hazard ratio [HR] = 3.53, 2.30, and 11.49; 95% confidence interval [CI] 1.64–7.62, 1.82–7.56, and 4.43–29.82; P = 0.002, 0.034, and <0.001, respectively); these conditions were also independently associated with low leukemia-free survival (HR = 3.71, 2.33, and 5.85; 95% CI 1.82–7.56, 1.17–4.64, and 2.75–12.44; P < 0.001, 0.016, and <0.001, respectively) and overall survival (HR = 3.50, 2.32, and 4.34; 95% CI 1.56–7.82, 1.09–4.97, and 1.98–9.53; P = 0.002, 0.030, and <0.001, respectively) in all patients.ConclusionsTesting for WT1 transcript levels at diagnosis in patients with AML and t(8;21) may predict outcomes in those who achieve remission. A randomized study is warranted to determine whether allo-HSCT can improve prognosis in these patients.