Hematologic Recovery after Pretransplant Chemotherapy Does Not Influence Survival after Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia Patients

A retrospective comparison of salvage intensive chemotherapy versus venetoclax-combined regimen in patients with relapsed/refractory acute myeloid leukemia (AML)

Background:

Evidence that a venetoclax (VEN)-combined regimen is effective in relapsed/refractory acute myeloid leukemia (R/R AML) is emerging. However, it is unknown how VEN-combined low intensity treatment compares to intensive chemotherapy (IC) in medically fit patients with R/R AML.

Methods:

We compared AML patients who received IC (n = 89) to those who received a VEN in combination with hypomethylating agents or low dose cytarabine (VEN combination) (n = 54) as their first- or second-line salvage after failing anthracycline-containing intensive chemotherapy.

Results:

The median age was 49 years, and significantly more patients in the VEN combination group were in their second salvage and had received prior stem cell transplantation (SCT). Overall response rates including CR, CRi, and MLFS were comparable (44.0% for IC vs. 59.3% for VEN combination, p = 0.081), but VEN combination group compared to IC group tended to show lower treatment related mortality. The rate of bridging to SCT was the same (68.5%), but the percentage of SCT at blast clearance was significantly higher in the VEN-combined group (62.3% vs. 86.5%, p = 0.010). After median follow-up periods of 22.5 (IC) and 11.3 months (VEN combination), the median overall survival was 8.9 (95% CI, 5.4-12.4) and 12.4 months (95% CI, 9.5-15.2) (p = 0.724), respectively.

Conclusion:

VEN combination provides a comparable anti-leukemic response and survival to salvage IC, and provide a bridge to SCT with better disease control in medically-fit patients with R/R AML.

European LeukemiaNet-defined primary refractory acute myeloid leukemia: the value of allogeneic hematopoietic stem cell transplant and overall response

We sought to appraise the value of overall response and salvage chemotherapy, inclusive of allogeneic hematopoietic stem cell transplant (AHSCT), in primary refractory acute myeloid leukemia (prAML). For establishing consistency in clinical practice, the 2017 European LeukemiaNet (ELN) defines prAML as failure to attain CR after at least 2 courses of intensive induction chemotherapy. Among 60 consecutive patients (median age 63 years) correspondent with ELN-criteria for prAML, salvage was documented in 48 cases, 30/48 (63%) being administered intensive chemotherapy regimens and 2/48 consolidated with AHSCT as first line salvage. 13/48 (27%) attained response: CR, 7/13 (54%), CRi, 2/13 (15%), MLFS, 4/13 (31%). The CR/CRi rate was 9/48 (19%), with CR rate of 7/48 (15%). On univariate analysis, intermediate-risk karyotype was the only predictor of response (44% vs 17% in unfavorable karyotype; P = 0.04). Administration of any higher-dose (>1 g/m²) cytarabine intensive induction (P = 0.50), intensive salvage chemotherapy (P = 0.72), targeted salvage (FLT3 or IDH inhibitors) (P = 0.42), greater than 1 salvage regimen (P = 0.89), age < 60 years (P = 0.30), and de novo AML (P = 0.10) did not enhance response achievement, nor a survival advantage. AHSCT was performed in 12 patients with (n = 8) or without (n = 4) CR/CRi/MLFS. 1/2/5-year overall survival (OS) rates were 63%/38%/33% in patients who received AHSCT (n = 12) vs 27%/0%/0% in those who achieved CR/CRi/MLFS but were not transplanted (n = 5), vs 14%/0%/0% who were neither transplanted nor achieved CR/CRi/MLFS (n = 43; P < 0.001); the median OS was 18.6, 12.6 and 5.6 months, respectively. Although CR/CRi/MLFS bridged to AHSCT (n = 8), appeared to manifest a longer median OS (20 months), vs (13.4 months) for those with no response consolidated with AHSCT (n = 4), the difference was not significant P = 0.47. We conclude AHSCT as indispensable for securing long-term survival in prAML (p = 0.03 on multivariate analysis), irrespective of response achievement.

Impact of depth of clinical response on outcomes of acute myeloid leukemia patients in first complete remission who undergo allogeneic hematopoietic cell transplantation

Acute myeloid leukemia (AML) patients often undergo allogeneic hematopoietic cell transplantation (alloHCT) in first complete remission (CR). We examined the effect of depth of clinical response, including incomplete count recovery (CRi) and/or measurable residual disease (MRD), in patients from the Center for International Blood and Marrow Transplantation Research (CIBMTR) registry. We identified 2492 adult patients (1799 CR and 693 CRi) who underwent alloHCT between January 1, 2007 and December 31, 2015. The primary outcome was overall survival (OS). Multivariable analysis was performed to adjust for patient-, disease-, and transplant-related factors. Baseline characteristics were similar. Patients in CRi compared to those in CR had an increased likelihood of death (HR: 1.27; 95% confidence interval: 1.13-1.43). Compared to CR, CRi was significantly associated with increased non-relapse mortality (NRM), shorter disease-free survival (DFS), and a trend toward increased relapse. Detectable MRD was associated with shorter OS, shorter DFS, higher NRM, and increased relapse compared to absence of MRD. The deleterious effects of CRi and MRD were independent. In this large CIBMTR cohort, survival outcomes differ among AML patients based on depth of CR and presence of MRD at the time of alloHCT. Further studies should focus on optimizing post-alloHCT outcomes for patients with responses less than CR.

Pretransplant bone marrow cellularity and blood count recovery are not associated with relapse or survival risk following allogeneic stem cell transplant for AML in CR

INTRODUCTION

Allogeneic hematopoietic cell transplantation (HCT) can be curative for acute myeloid leukemia (AML). Novel therapies may render patients' bone marrow hypocellularity and lead to prolonged post-therapy pancytopenia. Patients' bone marrow cellularity (BMC) at pretransplant assessment and post-treatment pancytopenia (classification CR-incomplete [CRi]) may manifest AML persistence.

METHODOLOGY

We retrospectively examined the impact of BMC and ELN response (ELNr) on a single-center cohort of 337 patients who underwent allogeneic HCT for AML in CR1.

RESULTS

Median follow-up was 33 months. Overall survival (OS) for the whole cohort was 55.8% at 2 years, while cumulative incidence of relapse (CIR) was 20.8%, and non-relapse mortality was 27.5%. OS and CIR were not significantly different between BMC groups; and neither was ELNr. ELNr CRi was associated with BMC aplastic and hypocellular marrow states (P < 2.6e-8). Multivariate analysis confirmed neither BMC nor attainment of ELNr CR vs CRi affected OS or relapse. Significant factors for survival included age at transplant, cytogenetic risk, development of acute Gr II-IV GvHD, and moderate-severe chronic GvHD, while cytogenetic risk and chronic GvHD affected relapse.

CONCLUSION

Neither ELNr status nor pretransplant BMC influenced relapse post-HCT or OS. Hypocellularity and CRi are not negative prognostic factors for post-HCT outcomes of AML.

Complete Remission with Incomplete Blood Count Recovery Is a Strong Predictor of Nonrelapse Mortality in Acute Myeloid Leukemia Patients Undergoing Allogeneic Stem Cell Transplantation

INTRODUCTION

Achievement of an initial complete remission (CR) following induction chemotherapy is tightly correlated with survival in acute myeloid leukemia (AML) patients, yet patients in CR with incomplete hematologic recovery (CRi) still experience improved outcomes compared with nonresponding patients. Whether CRi predicts prognosis in patients referred to an allogeneic stem cell transplantation (allo-SCT) is incompletely defined. In this analysis, we evaluated whether clinical outcomes of transplanted AML patients in CR and CRi were significantly different.

METHODS

A retrospective single-center analysis of all de novo AML patients who underwent an allo-SCT between 2001 and 2015. The cohort included all adult patients with AML who underwent a first allo-SCT either in first or second CR or CRi at the time of transplantation.

RESULTS

The study cohort included 186 CR patients and 44 CRi patients. In univariate analysis, CRi was associated with inferior 3-year survival and 3-year nonrelapse mortality (NRM) compared to CR (41 vs. 62%; p = 0.022 and 27 vs. 10%; p = 0.006, respectively). In multivariate analysis, CRi was associated with decreased rates of survival (hazard ratio [HR] 2.01; 95% CI, 1.24-3.25; p = 0.005) and NRM (HR, 3.5; 95% CI, 1.6-7.8; p = 0.002).

CONCLUSION

CRi in transplanted AML patients is potentially a potent predictor of increased NRM and survival.

The complete story of less than complete responses: The evolution and application of acute myeloid leukemia clinical responses

Complete remission (CR) has long been the critical therapeutic response in acute myeloid leukemia (AML). However, "less than CR" responses have been and continue to be proposed to define clinically meaningful post-therapy outcomes. These responses include CR with incomplete recovery (CRi), CR with incomplete platelet recovery (CRp) and, most recently, CR with partial hematologic recovery (CRh), which has been introduced and subsequently used for regulatory approval. However, the clinical benefits associated with "less than CR" responses have primarily been evaluated in the context of intensive therapies. In an era with sophisticated measurable residual disease (MRD) assessments, including flow-based, cytogenetic and molecular techniques, and an increase in "targeted", non-intensive therapies, the clinical value of responses that are "less than CR" must be reevaluated. Improvements in the rate of CR has not always led to improvements in OS among older patients. As such, MRD techniques might help define a more stringent response criterion (MRD-negative CR) that might better correlate with OS and should be incorporated in future clinical trials. Here we discuss the evolution of CR and "less than CR" responses, data regarding their clinical benefits, and considerations relevant to response assessments with newer therapies.

[The comparison of predicting clinical outcomes between immunolophenotype and hematological complete remission before human leukocyte antigen-matched sibling donor transplantation in acute myeloid leukemia]

目的

比较移植前免疫表型缓解（ICR）和血液形态学缓解对急性髓系白血病（AML）患者同胞HLA相合造血干细胞移植（MSDT）疗效的预测价值。

方法

回顾性分析182例接受MSDT的AML患者（除外急性早幼粒细胞白血病），将移植前血液形态学缓解分为血细胞恢复的完全缓解（CR）、血小板未恢复的CR（CRp）、血小板和中性粒细胞均未恢复的CR（CRi），将多参数流式细胞术检测微小残留病阴性定义为ICR。

结果

①全部182例AML患者中，男97例，女85例，中位年龄41（4~62）岁。②移植前CR、CRp+CRi率分别为80.8%（147/182）、19.2%（35/182）；移植前CRp+CRi组、CR组的预期4年累积复发率（CIR）[（11.0±4.3）%对（16.0±7.1）%，χ²=0.274，P=0.600]、非复发死亡率（NRM）[（14.0±4.3）%对（9.0±6.3）%，χ²=0.913，P=0.339]、无白血病生存（LFS）率[（75.0±5.1）%对（75.0±8.3）%，χ²=0.256，P=0.613]、总生存（OS）率[（77.0±5.2）%对（80.0±8.1）%，χ²=0.140，P=0.708]差异均无统计学意义。③移植前ICR组（147例）与非ICR组（35例）比较，4年CIR较低[（11.3±3.4）%对（55.2±8.8）%，χ²=32.687，P<0.001]，LFS率[（76.2±4.7）%对（32.8±8.7）%，χ²=26.234，P<0.001]和OS率[（79.0±4.7）%对（39.0±9.1）%，χ²=25.253，P<0.001]较高，NRM差异无统计学意义[（12.5±4.1）%对（12.0±7.1）%，χ²=1.002，P=0.656]。④多因素分析显示，移植前非ICR是影响AML患者MSDT后复发[HR=11.026（95% CI 4.685~25.949），P<0.001]、LFS[HR=5.785（95% CI 2.974~11.254），P< 0.001]和OS[HR=5.578（95%CI 2.575~27.565），P<0.001]的独立危险因素。

结论

移植前ICR对AML患者MSDT的疗效预测价值优于HCR。

The impact of minimal residual disease prior to unmanipulated haploidentical hematopoietic stem cell transplantation in patients with acute myeloid leukemia in complete remission

The minimal residual disease (MRD) before and after a haploidentical hematopoietic stem cell transplantation (HSCT) of 86 patients with acute myeloid leukemia (AML) in complete remission (CR) was measured using flow cytometry (FCM) and Wilms tumor 1 (WT1). In all, 18 patients met the criteria of pre-MRD + before HSCT. The FCM + (p = .028) and the combinative criteria for positive MRD (MRDco+) (p = .022) post-transplantation were significantly correlated to relapse in univariate analysis. A multivariate analysis showed that only MRDco + post-transplantation was an independent risk factor of leukemia relapse (p = .022, HR = 4.653, 95% CI: 1.249-17.334). A significant difference in the cumulative incidence of relapse between patients with or without post-transplant MRDco + was observed (p < .001). However, the results suggested that the MRD status before transplantation might not affect leukemia relapse of patients with AML in CR after haploidentical HSCT. These types of patients might not need to receive further intensive chemotherapy or active intervention concerning HSCT.