Benefit of allogeneic transplantation in patients age ≥ 60 years with acute myeloid leukemia is limited to those in first complete remission at time of transplant

How to improve the outcomes of elderly acute myeloid leukemia patients through allogeneic hematopoietic stem cell transplantation

In recent years, with the gradual advancement of haploidentical transplantation technology, the availability of donors has increased significantly, along with the widespread use of reduced-intensity conditioning and the improvement of nursing techniques, giving more elderly acute myeloid leukemia (AML) patients the chance to receive allogeneic hematopoietic stem cell transplantation. We have summarized the classic and recently proposed pre-transplant assessment methods and assessed the various sources of donors, conditioning regimens, and post-transplant complication management based on the outcomes of large-scale clinical studies for elderly AML patients.

Optimizing Transplant Approaches and Post-Transplant Strategies for Patients With Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is the commonest indication for allogeneic stem cell transplantation (allo-SCT) worldwide. The increasingly important role of allo-SCT in the management of AML has been underpinned by two important advances. Firstly, improvements in disease risk stratification utilizing genetic and Measurable Residual Disease (MRD) technologies permit ever more accurate identification of allo-mandatory patients who are at high risk of relapse if treated by chemotherapy alone. Secondly, increased donor availability coupled with the advent of reduced intensity conditioning (RIC) regimens has substantially expanded transplant access for patients with high risk AML In patients allografted for AML disease relapse continues to represent the commonest cause of transplant failure and the development of novel strategies with the potential to reduce disease recurrence represents a major unmet need.

Allogeneic haemopoietic transplantation for acute myeloid leukaemia in second complete remission: a registry report by the Acute Leukaemia Working Party of the EBMT

Allogeneic haemopoietic cell transplant (allo-HCT) may be curative in acute myeloid leukaemia (AML) in second complete remission (CR2) but the impact of reduced intensity (RIC) versus myeloablative conditioning (MAC) is uncertain. The Acute Leukaemia Working Party of the European Society for Blood and Bone Marrow Transplantation Registry studied an AML CR2 cohort characterised by age ≥ 18 years, first allo-HCT 2007-2016, available cytogenetic profile at diagnosis, donors who were matched family, volunteer unrelated with HLA antigen match 10/10 or 9/10 or haplo-identical. The 1879 eligible patients included 1010 (54%) MAC allo-HCT recipients. In patients <50 years (y), two year outcomes for MAC vs RIC allo-HCT were equivalent with leukaemia-free survival (LFS) 54% for each, overall survival (OS), 61% vs 62%, non-relapse mortality (NRM) 18% vs 15% and graft versus host disease relapse-free survival (GRFS) 38% vs 42%. In patients ≥50 y, 2 y outcomes for MAC vs RIC allo-HCT were equivalent for LFS 52% vs 49%, OS 58% vs 55% and GRFS 42.4% vs 36%. However, NRM was significantly inferior after MAC allo-HCT, 27% vs 19% (P = 0.01) despite worse cGVHD after RIC-allo (32% vs 39%). These data support the need for ongoing prospective study of conditioning intensity and GVHD mitigation in AML.

Influence of FLT3-ITD and NPM1 status on allogeneic hematopoietic cell transplant outcomes in patients with cytogenetically normal AML

OBJECTIVE

In individuals with cytogenetically normal (CN) AML, disease risk is estimated using molecular features such as the status of NPM1 and FLT3-ITD genes. However, data regarding the impact of NPM1 and FLT3-ITD status on hematopoietic stem cell transplant (HCT) outcomes are limited. We examined the effect of NPM1 and FLT3-ITD status on transplant outcomes in 131 CN AML patients transplanted at Princess Margaret Hospital between 2006 and 2017.

METHODS

Overall survival (OS) was calculated using Kaplan-Meier analysis and multivariable Cox proportional hazards regression. Cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were calculated using competing risk regression.

RESULTS

There was no difference in 3-year OS among NPM1⁺ /FLT3-ITD^- , NPM1^- /FLT3-ITD^- , NPM1⁺ /FLT3-ITD⁺ and NPM1^- /FLT3-ITD⁺ patients: 56% (95% CI, 29%-76%), 61% (95% CI, 46%-73%), 53% (95% CI, 34%-70%) and 52% (95% CI, 17%-78%), respectively. CIR at 3-years was similar among NPM1^- /FLT3-ITD^- , NPM1⁺ /FLT3-ITD⁺ and NPM1^- /FLT3-ITD⁺ patients-14% (95% CI, 6%-26%), 13% (95% CI, 4%-28%) and 19% (95% CI, 4%-41%), respectively-while there were no relapses in the NPM1⁺ /FLT3-ITD^- group. NRM at 3 years for NPM1⁺ /FLT3-ITD^- , NPM1^- /FLT3-ITD^- , NPM1⁺ /FLT3-ITD⁺ and NPM1^- /FLT3-ITD⁺ patients was similar at 44% (95% CI, 19%-67%), 38% (95% CI, 25%-50%), 43% (95% CI, 25%-59%) and 44% (95% CI, 14%-71%), respectively.

CONCLUSION

NPM1 and FLT3-ITD status may provide limited prognostic information about transplant outcomes in CN AML patients.

Allogeneic stem cell transplantation benefits for patients ≥ 60 years with acute myeloid leukemia and FLT3 internal tandem duplication: a study from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Intermediate-risk cytogenetic acute myeloid leukemia with an internal tandem duplication of FLT3 (FLT3-ITD) is associated with a high risk of relapse, and is now a standard indication for allogeneic stem cell transplantation. Nevertheless, most studies supporting this strategy have been performed in young patients. To address the benefit of allogeneic transplantation in the elderly, we made a selection from the European Society for Blood and Marrow Transplantation registry of de novo intermediate-risk cytogenetic acute myeloid leukemia harboring FLT3-ITD in patients aged 60 or over and transplanted from a related or unrelated donor between January 2000 and December 2015. Two hundred and ninety-one patients were identified. Most patients received a reduced-intensity conditioning (82%), while donors consisted of an unrelated donor in 161 (55%) patients. Two hundred and twelve patients received their transplantation in first remission, 37 in second remission and 42 in a more advanced stage of the disease. The 2-year leukemia-free survival rate was 56% in patients in first remission, 22% in those in second remission and 10% in patients with active disease, respectively (P<0.005). Non-relapse mortality for the entire cohort was 20%. In multivariate analysis, disease status at transplantation was the most powerful predictor of worse leukemia-free survival, graft-versus-host disease and relapse-free survival, and overall survival. In this elderly population, age was not associated with outcome. Based on the current results, allogeneic transplantation translates into a favorable outcome in fit patients ≥ 60 with FLT3-ITD acute myeloid leukemia in first remission, similarly to current treatment recommendations for younger patients.

Age does not adversely influence outcomes among patients older than 60 years who undergo allogeneic hematopoietic stem cell transplant for AML and myelodysplastic syndrome

Allogeneic hematopoietic stem cell transplant (AHSCT) outcomes data of older AML/myelodysplastic syndrome (MDS) patients are limited. We retrospectively evaluated consecutive patients ⩾60 years old with AML/MDS who underwent AHSCT between January 2005 and December 2014. The primary objectives were to determine nonrelapse mortality (NRM), relapse, relapse-free survival (RFS) and overall survival (OS) at 1 year post AHSCT. A total of 159 patients underwent AHSCT with a median age of 64 (range, 60-75) years. Of these, 103 patients (65%) had AML and 56 patients (35%) had MDS. At 1 year post AHSCT, grade III-IV acute GvHD and chronic GvHD occurred in 20.8% (95% confidence interval (CI), 14.9-27.5%) and 54.1% (95% CI, 46.0-61.5%) of patients, respectively. NRM, RFS, relapse rate and OS at 1 year post AHSCT were 25.3% (95% CI, 18.8-32.3%), 53.3% (95% CI, 46.1-61.7%), 21.4% (95% CI, 15.4-28.1%) and 56.4% (95% CI, 49.2-54.7%), respectively. High disease risk index was associated with poor RFS, OS and higher relapse rate (P<0.03), whereas non-thymoglobulin-based GvHD prophylaxis, higher comorbidity index (⩾3) and MDS were associated with higher NRM (P<0.03). Importantly, age did not have an adverse effect on NRM, relapse, RFS and OS. AHSCT was well tolerated. Hence, older age alone should not be considered a contraindication to AHSCT.

Allogeneic Hematopoietic Cell Transplantation for Older Patients: Prognosis Determined by Disease Risk Index

The treatment of elderly patients with advanced hematological malignancies has expanded to include reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT) as a potentially curative option. We studied the association between Disease Risk Index (DRI) and clinical outcomes of 196 elderly patients (median age, 64.8; range, 60 to 75 years) with hematological malignancies receiving RIC alloHCT (2000 to 2014). Donors were related and unrelated adults (n = 100, 51.1%) or umbilical cord blood (n = 96, 48.9%). DRI classified 12 patients (6.1%) as low risk (LR), 146 patients (74.5%) as intermediate risk (IR), and 38 patients (19.4%) as high risk (HR). Two-year overall survival (OS) was 47% (52% for LR/IR versus 29% for HR, P < .01) and 2-year disease-free survival was 39% (44% for LR/IR versus 21% for HR, P < .01). Relapse incidence was 30% (26% for LR/IR versus 44% for HR, P < .01). Treatment-related mortality was 29% at 2 years; this was similar for all DRI groups. In multiple regression analysis, HR DRI was associated with increased risk of relapse (hazard ratio, 2.07; 95% confidence interval [CI], 1.34 to 3.33; P = .02) and treatment failure (hazard ratio, 2.07; 95% CI, 1.35 to 3.18; P < .01) and decreased OS (hazard ratio, 2.11; 95% CI, 1.34 to 3.33; P < .01). In elderly patients, DRI is a significant prognostic factor for post-transplantation relapse, treatment failure, and mortality. Because of increased risk of relapse leading to poor survival in HR DRI, participation in clinical trials offering relapse prevention strategies after RIC alloHCT should be encouraged when available.

Cytogenetic risk determines outcomes after allogeneic transplantation in older patients with acute myeloid leukemia in their second complete remission: A Center for International Blood and Marrow Transplant Research cohort analysis

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT) offers curative potential to a number of older patients with acute myeloid leukemia (AML) in their first complete remission. However, there are limited data in the literature concerning post-HCT outcomes for older patients in their second complete remission (CR2).

METHODS

The purpose of the current study was to retrospectively investigate within the Center for International Blood and Marrow Transplant Research database parameters influencing posttransplant outcomes for patients 60 years of age or older undergoing HCT for AML in CR2.

RESULTS

In total, 196 patients from 78 centers were identified; the median age was 64 years (range, 60-78 years). Seventy-one percent had a Karnofsky performance status ≥ 90 at the time of HCT. Reduced-intensity conditioning regimens were used in 159 patients (81%). A univariate analysis demonstrated a 3-year overall survival (OS) rate of 42% (95% confidence interval [CI], 35%-49%), a leukemia-free survival rate of 37% (95% CI, 30%-44%), a cumulative incidence of nonrelapse mortality of 25% (95% CI, 19%-32%), and a cumulative incidence of relapse (CIR) of 38% (95% CI, 31%-45%). A multivariate analysis demonstrated that cytogenetic risk was the only independent risk factor for OS (P = .023) with a hazard ratio (HR) of 1.14 (95% CI, 0.59-2.19) for intermediate-risk cytogenetics and an HR of 2.32 (95% CI, 1.05-5.14) for unfavorable-risk cytogenetics. For CIR, cytogenetic risk was also the only independent prognostic factor (P = .01) with an HR of 1.10 (95% CI, 0.47-2.56) for intermediate-risk cytogenetics and an HR of 2.98 (95% CI, 1.11-8.00) for unfavorable-risk cytogenetics.

CONCLUSIONS

Allogeneic HCT is a curative treatment option for older patients with AML in CR2, particularly for those with favorable or intermediate cytogenetic risk. Cancer 2017;123:2035-2042. © 2017 American Cancer Society.

Outcomes of Allogeneic Stem Cell Transplantation in Elderly Patients with Acute Myeloid Leukemia: A Systematic Review and Meta-analysis

A large number of elderly patients with acute myeloid leukemia (AML) are not offered treatments with curative intent, such as allogeneic stem cell transplantation (SCT), because of fears of toxicity and perceived futility of intensive treatment. Therefore, the outcomes of SCT in elderly AML patients remain poorly defined. We performed a meta-analysis of all previous articles up until September 22, 2015 of SCT in AML patients >60 years. The primary endpoints were relapse-free survival (RFS) and overall survival (OS) at 6 months and at 1, 2, and 3 years. A total of 13 studies (749 patients) were included. The pooled estimates and 95% confidence intervals (CI) for RFS at 6 months, 1 year, 2 years, and 3 years were 62% (95% CI, 54% to 69%), 47% (95% CI, 42% to 53%), 44% (95% CI, 33% to 55%), and 35% (95% CI, 26% to 45%), respectively. The corresponding numbers for OS were 73% (95% CI, 66% to 79%), 58% (95% CI, 50% to 65%), 45% (95% CI, 35% to 54%), and 38% (95% CI, 29% to 48%), respectively. We found no evidence of publication bias in our primary endpoints, with the exception of relapse, where there appeared to be a relative lack of small studies with high relapse rates. Sensitivity analysis did not identify an overtly influential study for our primary endpoints, with 1 exception in 2-year RFS analysis. The present analysis argues against significant publication bias and demonstrates consistency among reports despite differences in patient-, disease-, center-, and transplantation-related characteristics. Our results suggest that reduced-intensity SCT is a viable treatment option for elderly AML patients with a 3-year RFS of 35% for those over the age of 60. These results argue against using age per se as the sole criterion against SCT and would help remove some of the barriers that often preclude curative intent treatment. Correct identification of patients who would benefit from SCT can improve outcomes in this frequently undertreated population.

Are we curing more older adults with acute myeloid leukemia with allogeneic transplantation in CR1?

PURPOSE OF REVIEW

Despite the fact that acute myeloid leukemia (AML) is most common in older adults aged at least 60 years, curative therapy remains elusive in this population. Here we examine the data for predicting which patients are candidates for 'curative therapy', available therapeutic options, and the utilization of reduced intensity allogeneic stem cell transplantation in first remission.

RECENT FINDINGS

Incorporation of geriatric assessment tools to assess patient frailty, in addition to evaluation of comorbid conditions, improves patient selection for intense therapy. The majority of patients eligible for and treated with induction chemotherapy achieve complete remission, and overall survival in the older AML population is superior after allogeneic stem cell transplant. However, population-based studies continue to demonstrate the undertreatment or lack of treatment of older AML patients.

SUMMARY

New patient assessment tools, ability to offer more successful outcomes after induction chemotherapy, and improved survival after allogeneic transplantation has not yet translated to increased 'curative' treatment on a population level of older AML patients. It is critical that the tools and therapies available be put into practice while older patient enrollment in well designed therapeutic clinical trials which include the option of allogeneic transplantation is increased.

Patient age, remission status and HCT-CI in a combined score are prognostic for patients with AML undergoing allogeneic hematopoietic cell transplantation in CR1 and CR2

For AML, older age, advanced disease and increased hematopoietic cell transplant comorbidity index (HCT-CI) are associated with worse prognosis following allogeneic hematopoietic cell transplantation (HCT). This single-center retrospective study investigated the influence of pre-transplant characteristics on outcomes of 387 patients undergoing allogeneic HCT for AML in CR1 and CR2. The multivariable analysis model for overall survival (OS) included age (hazard ratio (HR)=2.24 for ages 31-64 years and HR=3.23 for age ⩾65 years compared with age ⩽30 years, P=0.003), remission status (HR=1.49 for CR2 compared with CR1, P=0.005) and HCT-CI score (HR=1.47 for ⩾3 compared with <3, P=0.005). Transplant year was significantly associated with OS (P=0.001) but this did not influence the model. A weighted score was developed with age ⩽30, CR1 and HCT-CI score <3 receiving 0 points each, and CR2 and HCT-CI score ⩾3 receiving 1 point each. Ages 31-64 received 2 points, age ⩾65 received 3 points. Scores were grouped as follows: scores 0-1 (low risk, n=36), score 2 (intermediate-low risk, n=147), score 3 (intermediate-high risk, n=141) and scores 4-5 (high risk, n=63) with 3-year OS of 71%, 55%, 42% and 29% for scores 0-1, 2, 3 and 4-5, respectively (P<0.0001). The score predicted nonrelapse mortality (P=0.03) but not cumulative incidence of relapse (P=0.18). This model should be validated for the pre-HCT assessment of AML patients in CR1 and CR2.