Reduced intensity conditioned allograft yields favorable survival for older adults with B-cell acute lymphoblastic leukemia

Frontline treatment of adults with newly diagnosed B-cell acute lymphoblastic leukaemia

In the past decade, there has been considerable progress in the treatment of adults with newly diagnosed B-cell acute lymphoblastic leukaemia. This evolution is the product of a more profound understanding of acute lymphoblastic leukaemia biology, innovations in measurable residual disease quantification that led to precise disease-risk stratification, adoption of contemporary paediatric-inspired regimens, inclusion of tyrosine kinase inhibitors in the treatment of Philadelphia chromosome-positive acute lymphoblastic leukaemia, and the introduction of immunotherapy in the frontline setting. Nevertheless, outcomes of acute lymphoblastic leukaemia in adults are inferior compared with those of children, with excessive rates of treatment failure, and therapy-related morbidity and mortality. Simultaneously, transplant consolidation has continued to be used frequently for high-risk adults with acute lymphoblastic leukaemia in first complete remission. Considering the rapid pace of evolution in acute lymphoblastic leukaemia management, novel trial designs are warranted to accelerate advancements and streamline approaches. Here, we summarise progress in the treatment of adults with newly diagnosed acute lymphoblastic leukaemia, which adds to previously published guidelines by focusing specifically on first-line decisions for B-cell acute lymphoblastic leukaemia and how to best personalise treatment. This Viewpoint also includes experiences with regimens and testing approaches currently available not only in Europe, but also on multiple continents with different practices and resources.

Leveraging CD19CAR T cells early in the treatment of older patients with B-ALL: are we there yet?

Older adults (≥55 years old) with B-cell acute lymphoblastic leukemia (B-ALL) have dismal outcomes with standard chemotherapy as the result of low treatment efficacy and considerable risks for treatment-related morbidity and mortality. There has been a recent success with the introduction of novel therapies, such as blinatumomab and inotuzumab, in the frontline therapeutic paradigm in older adults with B-ALL. However, these agents have their own challenges including the limited durability of remission, the need for additional concurrent chemotherapy and the prolonged course of treatment, and limited efficacy in the setting of extramedullary disease. Here, we hypothesize that the incorporation of chimeric antigen receptor (CAR) T cell therapy as a consolidation treatment in older adults with B-cell ALL in their first complete remission is the ideal setting to advance treatment outcomes by reducing treatment toxicity, enhancing remission durability, and expanding the use of this effective therapy in this age population.

Total body irradiation versus busulfan based intermediate intensity conditioning for stem cell transplantation in ALL patients >45 years-a registry-based study by the Acute Leukemia Working Party of the EBMT

Allogeneic hematopoietic cell transplantation is a potentially curative treatment in high-risk acute lymphoblastic leukemia (ALL). Conditioning regimens based on ≥12 Gray total body irradiation (TBI) represent the current standard in patients ≤45 years, whereas elderly patients frequently receive intermediate intensity conditioning (IIC) to reduce toxicity. To evaluate the role of TBI as a backbone of IIC in ALL, a retrospective, registry-based study included patients >45 years transplanted from matched donors in first complete remission, who had received either fludarabine/TBI 8 Gy (FluTBI8, n = 262), or the most popular, irradiation-free alternative fludarabine/busulfan, comprising busulfan 6.4 mg/kg (FluBu6.4, n = 188) or 9.6 mg/kg (FluBu9.6, n = 51). At two years, overall survival (OS) was 68.5%, 57%, and 62.2%, leukemia-free survival (LFS) was 58%, 42.7%, and 45%, relapse incidence (RI) was 27.2%, 40%, and 30.9%, and non-relapse-mortality (NRM) was 23.1%, 20.7%, and 26.8% for patients receiving FluTBI8Gy, FluBu6.4, and FluBu9.6, respectively. In multivariate analysis, the risk of NRM, acute and chronic graft-versus-host disease was not influenced by conditioning. However, RI was higher after FluBu6.4 (hazard ratio [HR] [95% CI]: 1.85 [1.16-2.95]), and LFS was lower after both FluBu6.4 (HR: 1.56 [1.09-2.23]) and FluBu9.6 (HR: 1.63 [1.02-2.58]) as compared to FluTBI8. Although only resulting in a non-significant advantage in OS, this observation indicates a stronger anti-leukemic efficacy of TBI-based intermediate intensity conditioning.

Donor-derived CD19 CAR-T Cells versus Chemotherapy Plus Donor Lymphocyte Infusion for Treatment of Recurrent CD19-positive B-ALL After Allogeneic Hematopoietic Stem Cell Transplantation

OBJECTIVE

This study aimed to compare the efficacy of anti-CD19 chimeric antigen receptor T cells (CAR-T cells) versus chemotherapy plus donor lymphocyte infusion (chemo-DLI) for treating relapsed CD19-positive B-cell acute lymphoblastic leukemia (B-ALL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

Clinical data of 43 patients with B-ALL who relapsed after allo-HSCT were retrospectively analyzed. Twenty-two patients were treated with CAR-T cells (CAR-T group), and 21 with chemotherapy plus DLI (chemo-DLI group). The complete remission (CR) and minimal residual disease (MRD)-negative CR rates, leukemia-free survival (LFS) rate, overall survival (OS) rate, and incidence of acute graft-versus-host disease (aGVHD), cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were compared between the two groups.

RESULTS

The CR and MRD-negative CR rates in the CAR-T group (77.3% and 61.5%) were significantly higher than those in the chemo-DLI group (38.1% and 23.8%) (P=0.008 and P=0.003). The 1- and 2-year LFS rates in the CAR-T group were superior to those in the chemo-DLI group: 54.5% and 50.0% vs. 9.5% and 4.8% (P=0.0001 and P=0.00004). The 1- and 2-year OS rates in the CAR-T versus chemo-DLI group were 59.1% and 54.5% vs. 19% and 9.5% (P=0.011 and P=0.003). Six patients (28.6%) with grade 2-4 aGVHD were identified in the chemo-DLI group. Two patients (9.1%) in the CAR-T group developed grade 1-2 aGVHD. Nineteen patients (86.4%) developed CRS in the CAR-T group, comprising grade 1-2 CRS in 13 patients (59.1%) and grade 3 CRS in 6 patients (27.3%). Two patients (9.1%) developed grade 1-2 ICANS.

CONCLUSION

Donor-derived anti-CD19 CAR-T-cell therapy may be better, safer, and more effective than chemo-DLI for B-ALL patients who relapse after allo-HSCT.

Allogeneic stem cell transplant outcomes between TBI-containing reduced intensity and myeloablative conditioning regimens for ALL in complete remission

Total-body irradiation (TBI)-based conditioning regimen is preferred in acute lymphoblastic leukemia (ALL). We retrospectively evaluated allogeneic stem cell transplant (alloSCT) outcomes of 86 adult ALL patients in complete remission (CR) who received TBI-containing reduced intensity (RIC) (Flu/Mel/TBI = 31) and myeloablative conditioning (MAC) (VP16/TBI = 47; CY/TBI = 8) between January 2005 and December 2019. All patients received peripheral blood allografts. Patients in the RIC group were older than the MAC group (61 years old versus 36 years, p < .001). Donor was 8/8 HLA-matched in 83% and unrelated in 65% of patients. Three-year survival was 56.04% for RIC and 69.9% for MAC (HR 0.64; p = .19). Propensity score-based multivariable Cox analyses (PSCA) did not demonstrate any difference in grade III-IV acute graft versus host disease (GVHD) (SHR 1.23, p = .91), chronic GVHD (SHR 0.92, p = .88), survival (HR 0.94, p = .92), and relapse-free survival (HR 0.66, p = .47) between both groups, while relapse rate was lower (SHR 0.21, p = .02) for MAC compared to RIC. Our study did not demonstrate any difference in survival for TBI-containing RIC and MAC alloSCT for adult ALL in CR.

Expert Recommendations for the Diagnosis, Treatment, and Management of Adult B-Cell Acute Lymphoblastic Leukemia in Latin America

PURPOSE

Despite strong induction chemotherapy response rates, only 30%-40% of patients with adult B-cell acute lymphoblastic leukemia (ALL) attain long-term remission. This study analyzes ALL in Latin America (LA) and recommends diagnosis, treatment, and management protocols.

METHODS

The Americas Health Foundation organized a panel of hematologists from Argentina, Brazil, Chile, Colombia, and Mexico to examine ALL diagnosis and therapy and produce recommendations.

RESULTS

Lack of regional data, unequal access to diagnosis and therapy, inadequate treatment response, and uneven health care distribution complicate adult ALL management. The panel recommended diagnosis, first-line and refractory treatment, and post-transplantation maintenance. Targeted treatments, including rituximab, blinatumomab, and inotuzumab ozogamicin, are becoming available in LA and must be equitably accessed.

CONCLUSION

This review adapts global information on treating ALL to LA. Governments, the medical community, society, academia, industry, and patient advocates must work together to improve policies.

Real-world outcomes in elderly ALL patients with and without allogeneic hematopoietic stem cell transplantation: a single-center evaluation over 10 years

Elderly patients (EP) of 60 years and above with acute lymphoblastic leukemia (ALL) have a dismal prognosis, but pediatric-inspired chemotherapy and allogeneic stem cell transplantation (allo HCT) are used reluctantly due to limited data and historical reports of high treatment-related mortality in EP. We analyzed 130 adult ALL patients treated at our center between 2009 and 2019, of which 26 were EP (range 60-76 years). Induction with pediatric-inspired protocols was feasible in 65.2% of EP and resulted in complete remission in 86.7% compared to 88.0% in younger patients (YP) of less than 60 years. Early death occurred in 6.7% of EP. Three-year overall survival (OS) for Ph - B-ALL was significantly worse for EP (n = 16) than YP (n = 64) with 30.0% vs 78.1% (p ≤ 0.001). Forty-nine patients received allo HCT including 8 EP, for which improved 3-year OS of 87.5% was observed, whereas EP without allo HCT died after a median of 9.5 months. In Ph + B-ALL, 3-year OS did not differ between EP (60.0%, n = 7) and YP (70.8%, n = 19). Non-relapse mortality and infection rate were low in EP (14.3% and 12.5%, respectively). Our data indicate that selected EP can be treated effectively and safely with pediatric regimens and might benefit from intensified therapy including allo HCT.

Characteristics and Outcome of Elderly Patients (>55 years) with Acute Lymphoblastic Leukemia

Simple Summary

Disease-specific mortality of acute lymphoblastic leukemia (ALL) increases with age. So far, only a few analyses have investigated disease characteristics of elderly patients (>55 years) with newly diagnosed ALL. The aim of our retrospective study was to evaluate the treatment results of 93 elderly patients who received intensive chemotherapy between May 2003 and October 2020. We identify poor performance status and older age at the time of diagnosis as risk factors for inferior outcomes, while ALL immunophenotype, BCR::ABL1 status, the complexity of karyotype, and intensity of treatment did not significantly affect overall survival (OS). With 17.3% of patients dying while in complete remission (CR), an event-free survival (EFS) and OS of 32.9% and 47.3% at 3 years, our data suggest that intensive treatment of elderly ALL patients is feasible but associated with significant toxicity. These results underline the need for novel, less toxic treatment approaches for this vulnerable cohort of patients.

Abstract

Prognosis of elderly ALL patients remains dismal. Here, we retrospectively analyzed the course of 93 patients > 55 years with B-precursor (n = 88) or T-ALL (n = 5), who received age-adapted, pediatric-inspired chemotherapy regimens at our center between May 2003 and October 2020. The median age at diagnosis was 65.7 years, and surviving patients had a median follow-up of 3.7 years. CR after induction therapy was documented in 76.5%, while the rate of treatment-related death within 100 days was 6.4%. The OS of the entire cohort at 1 and 3 year(s) was 75.2% (95% CI: 66.4–84.0%) and 47.3% (95% CI: 36.8–57.7%), respectively, while the EFS at 1 and 3 years(s) was 59.0% (95% CI: 48.9–69.0%) and 32.9% (95% CI: 23.0–42.8%), respectively. At 3 years, the cumulative incidence (CI) of relapse was 48.3% (95% CI: 38.9–59.9%), and the CI rate of death in CR was 17.3% (95% CI: 10.9–27.5%). Older age and an ECOG > 2 represented risk factors for inferior OS, while BCR::ABL1 status, immunophenotype, and intensity of chemotherapy did not significantly affect OS. We conclude that intensive treatment is feasible in selected elderly ALL patients, but high rates of relapse and death in CR underline the need for novel therapeutic strategies.

Conditioning Regimens for Frail Patients with Acute Leukemia Undergoing Allogeneic Stem Cell Transplant: How to Strike Gently

Despite the recent dramatic progress in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) therapy, allogeneic transplant remains a mainstay of treatment for patients with acute leukemia. The availability of novel compounds and low intensity chemotherapy regimens made it possible for a significant proportion of elderly and comorbid patients with AML or ALL to undergo curative treatment protocols. In addition, the expansion of donor availability and the recent dramatic progress in haploidentical stem cell transplant, allow the identification of an available donor for nearly every patient. Therefore, an increasing number of transplants are currently performed in elderly and frail patients with AML or ALL. However, allo-Hematopoietic stem cell transplant (HSCT) in this delicate setting represents an important challenge, especially regarding the selection of the conditioning protocol. Ideally, conditioning intensity should be reduced as much as possible; however, in patients with acute leukemia relapse remains the major cause of transplant failure. In this article we present modern tools to assess the patient health status before transplant, review the available data on the outcome of frail AML an ALL patients undergoing allo-HSCT, and discuss how preparatory regimens can be optimized in this setting.

Dasatinib and dexamethasone followed by hematopoietic cell transplantation for adults with Ph-positive ALL

Dasatinib and dexamethasone induction then allogeneic hematopoietic cell transplantation was feasible and effective for untreated Ph⁺ ALL.

Treatment failure was associated with BCR-ABL1 T315I mutation, the p210 BCR-ABL1 isoform, or isolated CNS relapse.

Post-remission strategies after dasatinib-corticosteroid induction in adult Philadelphia chromosome (Ph)–positive acute lymphoblastic leukemia (ALL) are not well studied. We evaluated dasatinib and dexamethasone induction then protocol-defined post-remission therapies, including hematopoietic cell transplantation (HCT). Adults (N = 65) with Ph-positive ALL received dasatinib-dexamethasone induction, methotrexate-based central nervous system (CNS) prophylaxis, reduced-intensity conditioning (RIC) allogeneic HCT, autologous HCT, or chemotherapy alone, and dasatinib-based maintenance. Key end points were disease-free survival (DFS) and overall survival (OS). The median age was 60 years (range, 22-87 years). The complete remission rate was 98.5%. With a median follow-up of 59 months, 5-year DFS and OS were 37% (median, 30 months) and 48% (median, 56 months), respectively. For patients receiving RIC allogeneic HCT, autologous HCT, or chemotherapy, 5-year DFS were 49%, 29%, and 34%, and 5-year OS were 62%, 57%, and 46%, respectively. Complete molecular response rate after CNS prophylaxis was 40%. Relative to the p190 isoform, p210 had shorter DFS (median 10 vs 34 months, P = .002) and OS (median 16 months vs not reached, P = .05). Relapse occurred in 25% of allogeneic HCT, 57% of autologous HCT, and 36% of chemotherapy patients. T315I mutation was detected in 6 of 8 marrow relapses. Dasatinib CNS concentrations were low. Dasatinib-dexamethasone followed by RIC allogeneic HCT, autologous HCT, or chemotherapy was feasible and efficacious, especially with RIC allogeneic HCT. Future studies should address the major causes of failure: T315I mutation, the p210 BCR-ABL1 isoform, and CNS relapse. This study was registered at www.clinicaltrials.gov as #NCT01256398.

Predictive Factors for Outcome of First Allogeneic Transplant for Elderly Patients With Acute Lymphoblastic Leukemia

INTRODUCTION/BACKGROUND

The treatment of acute lymphoblastic leukemia (ALL) in patients older than 70 is extremely challenging with dismal outcome. Allogeneic stem cell transplantation (alloHCT) has seen many advancements in the last decades showing benefits in younger ALL patients, but this treatment modality is decreasingly used with increasing age due to high treatment-related mortality.

PATIENTS AND METHODS

We identified 84 ALL patients 70 to 84 years old allografted In 2002 to 2019 from a matched related (23%), unrelated (58%), haploidentical (17%), or cord blood (2%) donor at EBMT participating centers with a median follow-up of 23 months.

RESULTS

The 2-year relapse incidence (RI) and non-relapse mortality were 37% and 28%, respectively, and 2-year leukemia-free survival (LFS), overall survival (OS) and GVHD-free, relapse-free survival (GRFS) were 35%, 39% and 23%, respectively. The strongest predictor of outcome was disease status at transplant whereby patients in first complete remission (CR1) had >50% 2-year OS, reflected in multivariate analysis (MVA) with significant improvement in RI, LFS, and GRFS (HR 0.23, 0.49, and 0.54, respectively). Furthermore, karnofsky score ≥90 reflective of good functional status positively influenced non-relapse mortality in both univariate and MVA (HR 0.37), and interestingly, donor CMV positivity appeared to negatively affect RI, LFS and OS in univariate analysis and RI in MVA (HR 2.87).

CONCLUSION

Our data suggest that alloHCT is an option for elderly ALL patients, particularly those carefully selected and transplanted in CR1 especially if failed or without access to novel non-chemotherapy-based approaches.

Consolidative Hematopoietic Stem Cell Transplantation After CD19 CAR-T Cell Therapy for Acute Lymphoblastic Leukemia: A Systematic Review and Meta-analysis

BACKGROUND

This study aimed to systematically evaluate and compare the efficacy and safety of consolidative hematopoietic stem cell transplantation (HSCT) after CD19 chimeric antigen receptor T (CAR-T) therapy with non-HSCT in the treatment of acute lymphoblastic leukemia (ALL).

METHODS

The PubMed, Embase, Cochrane Library and Web of Science databases were searched for clinical trials. Pooled hazard ratios (HRs) for overall survival (OS), relapse rate, and leukemia-free survival (LFS) as well as overall incidence rates for transplant-related mortality (TRM), acute graft-versus-host disease (aGVHD), chronic graft-versus-host disease (cGVHD), and infections were calculated using Stata software.

RESULTS

We screened 3,441 studies and identified 19 eligible studies with 690 patients. Among the patients who achieved complete remission (CR) after CD19 CAR-T therapy, consolidative HSCT was beneficial for OS (HR = 0.34, 95% CI, 0.170.68, P = 0.003), the relapse rate (HR = 0.16, 95% CI, 0.100.25, P < 0.001), and LFS (HR = 0.15, 95% CI, 0.080.28, P < 0.001). For patients who achieved MRD-negative (neg) CR after CD19 CAR-T therapy, consolidative HSCT was beneficial for OS (0.57, 95% CI, 0.330.99, P = 0.045), the relapse rate (0.14, 95% CI, 0.060.31, P < 0.001), and LFS (0.21, 95% CI, 0.120.35, P < 0.001). Regarding safety, we calculated pooled incidence rates for TRM (8%, 95% CI, 0.020.15), aGVHD (44%, 95% CI, 0.230.67), cGVHD (36%, 95% CI, 0.170.56), and infections (39%, 95% CI, 0.030.83).

CONCLUSIONS

Compared with non-HSCT treatment, consolidative HSCT after CD19 CAR-T therapy for R/R B-ALL patients can prolong OS and LFS and reduce the risk of relapse. The incidence rates for adverse events are acceptable. More high-quality randomized controlled trials are required to avoid bias and further determine the efficacy of HSCT.

Recent Advances in Managing Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is characterized by chromosomal translocations and somatic mutations that lead to leukemogenesis. The incorporation of pediatric-type regimens has improved survival in young adults, and the incorporation of tyrosine kinase inhibitors for patients with Philadelphia chromosome-positive disease has led to further improvements in outcomes. However, older patients often have poor-risk biology and reduced tolerance to chemotherapy, leading to lower remission rates and overall survival. Regardless of age, patients with relapsed or refractory ALL have extremely poor outcomes. The advent of next-generation sequencing has facilitated the revolution in understanding the genetics of ALL. New genetic risk stratification together with the ability to measure minimal residual disease, leukemic blasts left behind after cytotoxic chemotherapy, has led to better tools to guide postremission approaches-that is, consolidation chemotherapy or allogeneic stem cell transplantation. In this article, we discuss the evolving and complex genetic landscape of ALL and the emerging therapeutic options for patients with relapsed/refractory ALL and older patients with ALL.

New approaches to the treatment of older adults with acute lymphoblastic leukemia

Outcomes for older adults (defined here as ≥55-65 years old) with acute lymphoblastic leukemia (ALL) are poor, with long-term survival less than 20%. Pediatric chemotherapy regimens produce long-term cure rates of 80% to 90% in children and 60% to 70% in adolescents and young adults with Ph-negative ALL, however, tolerability of intensive chemotherapy becomes problematic with advanced age due to comorbidities and reduced tolerability of chemotherapy leading to high rates of treatment-related mortality. For older adults with Ph-positive ALL, BCR-ABL1-directed tyrosine kinase inhibitors in combination with corticosteroids or chemotherapy produce deep remissions with low treatment-related toxicity but optimal postremission therapy is not known. New therapeutic approaches for older adults with ALL involve integration of the novel targeted agents including monoclonal antibody-based therapy with blinatumomab and inotuzumab ozogamicin in the frontline. Ongoing studies will ideally define optimal combinations and sequencing of novel agents with or without chemotherapy, tyrosine kinase inhibitors, and/or corticosteroids to maximize efficacy while avoiding treatment-related death. Anti-CD19 chimeric antigen receptor modified T cells are a promising modality, with high rates of remission and minimal residual disease negativity achieved in early phase trials for adults with relapsed/refractory B-cell ALL but the tolerability of chimeric antigen receptor modified T cell therapies in older adults is yet to be well defined. Advances in minimal residual disease detection have helped to effectively stratify adults in complete response in terms of relapse risk and predicted relative benefit for allogeneic hematopoietic cell transplant. For older adults with ALL in complete response at high risk for relapse for whom myeloablative conditioning is predicted to result in excessive transplant-related mortality, reduced-intensity conditioning allogeneic hematopoietic cell transplant is a less toxic approach for providing a graft-versus-leukemia effect and long-term disease control.

Outcome predictors after retransplantation in relapsed acute lymphoblastic leukemia: a multicenter, retrospective study

Retransplantation is the only curative treatment option for patients with acute lymphoblastic leukemia (ALL) that has relapsed after allogeneic hematopoietic cell transplantation (allo-HCT); however, data in this setting remain scant. Hence, this multicenter, retrospective study aims to determine outcome predictors after retransplantation in relapsed ALL. We examined 55 recipients who underwent multiple allo-HCTs during 2006-2018. The 2-year overall survival (OS), progression-free survival (PFS), and non-relapse mortality rates were 35.9%, 29.1%, and 23.6%, respectively. We observed a trend of better outcome in Ph + ALL (n = 22) patients compared with non-Ph ALL (n = 33) patients; the 2-year PFS was 40.9% versus 21.2%, indicating a beneficial effect of more potent second- or third-generation tyrosine kinase inhibitors. Univariate analysis revealed that late relapse after the previous transplant was the only significant predictor of better transplant outcome among Ph + ALL patients, whereas factors related to prolonged OS/PFS in non-Ph ALL patients were late relapse after the previous transplant, longer duration from disease relapse/progression to second or more allo-HCT, disease status at the transplantation, and good performance status. Nevertheless, further investigations are warranted to determine whether novel molecular-targeted agents with higher efficacy and fewer toxicities could exceed conventional chemotherapies as a bridging strategy to next allo-HCT and improve the outcomes of non-Ph ALL patients.

Barriers to Hematopoietic Cell Transplantation for Adults in the United States: A Systematic Review with a Focus on Age

Hematopoietic cell transplantation (HCT) is an effective treatment for many hematologic malignancies, and its utilization continues to rise. However, due to the difficult logistics and high cost of HCT, there are significant barriers to accessing the procedure; these barriers are likely greater for older patients. Although numerous factors may influence HCT access, no formal analysis has detailed the cumulative barriers that have been studied thus far. We conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to better categorize the barriers to access and referral to HCT, with a focus on the subgroup of older patients. We searched for articles published in English from PubMed, Embase, Cumulative Index for Nursing and Allied Health, and Cochrane Central Register of Controlled Trials between the database inception and January 31, 2020. We selected articles that met the following inclusion criteria: (1) study design: qualitative, cross-sectional, observational cohort, or mixed-method study designs; (2) outcomes: barriers related to patient and physician access to HCT; and (3) population: adults aged ≥18 years with hematologic malignancies within the United States. Abstracts without full text were excluded. QUALSYST methodology was used to determine article quality. Data on the barriers to access and referral for HCT were extracted, along with other study characteristics. We summarized the findings using descriptive statistics. We included 26 of 3859 studies screened for inclusion criteria. Twenty studies were retrospective cohorts and 4 were cross-sectional. There was 1 prospective cohort study and 1 mixed-method study. Only 1 study was rated as high quality, and 16 were rated as fair. Seventeen studies analyzed age as a potential barrier to HCT referral and access, with 16 finding older age to be a barrier. Other consistent barriers to HCT referral and access included nonwhite race (n = 16/20 studies), insurance status (n = 13/14 studies), comorbidities (n = 10/11 studies), and lower socioeconomic status (n = 7/8 studies). High-quality studies are lacking related to HCT barriers. Older age and nonwhite race were consistently linked to reduced access to HCT. To produce a more just health care system, strategies to overcome these barriers for vulnerable populations should be prioritized. Examples include patient and physician education, as well as geriatric assessment guided care models that can be readily incorporated into clinical practice.

Evolving therapy of adult acute lymphoblastic leukemia: state-of-the-art treatment and future directions

Recent years have witnessed major advances that have improved outcome of adults with acute lymphoblastic leukemia (ALL). The emergence of the concept of measurable residual disease has fine-tuned our prognostic models and guided our treatment decisions. The treatment paradigms of ALL have been revolutionized with the advent of tyrosine kinase inhibitors targeting BCR-ABL1, monoclonal antibodies targeting CD20 (rituximab), antibody-drug conjugates targeting CD22 (inotuzumab ozogamicin), bispecific antibodies (blinatumomab), and CD19 chimeric antigen receptor T cell therapy (tisagenlecleucel). These highly effective new agents are allowing for novel approaches that reduce reliance on intensive cytotoxic chemotherapy and hematopoietic stem cell transplantation in first remission. This comprehensive review will focus on the recent advances and future directions in novel therapeutic strategies in adult ALL.

Long-Term Outcomes of Allogeneic Hematopoietic Cell Transplant with Fludarabine and Melphalan Conditioning and Tacrolimus/Sirolimus as Graft-versus-Host Disease Prophylaxis in Patients with Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is associated with poor survival in older adults, and allogeneic hematopoietic cell transplant (HCT) with reduced-intensity conditioning (RIC) has been an increasingly used strategy in this population. At City of Hope we conducted a retrospective analysis of 72 patients who underwent allogeneic HCT with fludarabine and melphalan (FluMel) as the conditioning regimen between 2005 and 2018, from either a matched sibling or fully matched unrelated donor while in complete remission. Tacrolimus and sirolimus (T/S) were used as graft-versus-host disease (GVHD) prophylaxis. Overall survival and progression-free survival at 4 years post-HCT were 58% and 44%, respectively. The cumulative incidences of relapse/progression and nonrelapse mortality at 4 years were 34% and 22%, respectively. Patients with Philadelphia chromosome-positive (Ph+) ALL had a significantly lower cumulative incidence of relapse/progression (20% versus 48% for patients with Ph-negative status, P = .007). In conclusion, RIC HCT with FluMel conditioning and T/S GVHD prophylaxis was associated with favorable outcomes in patients with Ph+ ALL and should be considered as a viable consolidative therapy for adult patients with ALL.

What have we learned from transplanting older patients?

Aggressive curative therapies have now been extended to patients older than 65 years, a fast-growing segment of the population. As the number of allogeneic transplants in patients older than age 65 is increasing, attention is now focused on improving outcomes in this group. This paper discusses important aspects of allogeneic transplant in the older patient, focusing on donor and patient selection, choice of conditioning regimen and graft source, and the importance of timely access to a transplant center.

Safety of allogeneic hematopoietic cell transplant in adults after CD19-targeted CAR T-cell therapy

Allogeneic hematopoietic cell transplantation (allo-HCT) is offered to selected patients after chimeric antigen receptor-modified T-cell (CAR-T) therapy. Lymphodepleting chemotherapy and CAR-T therapy have immunosuppressive and immunomodulatory effects that could alter the safety profile of subsequent allo-HCT. We reviewed our experience with 32 adults (acute lymphoblastic leukemia [ALL], n = 19; B-cell non-Hodgkin lymphoma [NHL]/chronic lymphocytic leukemia [CLL], n = 13) who received an allo-HCT after CAR-T therapy, with a focus on posttransplant toxicities. Myeloablative conditioning (MAC) was used in 74% of ALL patients and 39% of NHL/CLL patients. The median time from CAR-T therapy to allo-HCT was 72 days in ALL patients and 122 days in NHL/CLL patients. Cumulative incidences of grade 3-4 acute graft-versus-host disease (GVHD) and chronic GVHD were 25% and 10%, respectively. All patients had neutrophil recovery (median, 18.5 days) and all but 3 had platelet recovery (median, 12 days). Twenty-two percent had viral or systemic fungal infection within 100 days after allo-HCT. The 100-day and 1-year cumulative incidences of NRM were 16% and 21%, respectively, for ALL patients and 15% and 33%, respectively, for NHL/CLL patients. In ALL patients, later utilization of allo-HCT after CAR-T therapy was associated with higher mortality. In NHL/CLL patients, MAC was associated with higher mortality. Toxicities did not exceed the expected incidences in this high-risk population.

Hematopoietic Cell Transplantation in the Treatment of Adult Acute Lymphoblastic Leukemia: Updated 2019 Evidence-Based Review from the American Society for Transplantation and Cellular Therapy

The role of hematopoietic cell transplantation (HCT) in adults with acute lymphoblastic leukemia (ALL) is reviewed and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the recommendations. A panel of ALL experts developed consensus on the treatment recommendations based on the evidence. Allogeneic HCT offers a survival benefit in selected patients with ALL, and this review summarizes the standard indications as well as the areas of controversy. There is now greater experience with pediatric-inspired chemotherapy regimens that has transformed upfront therapy for adult ALL, resulting in higher remission rates and overall survival. This in turn has increased the equipoise around decision making for ALL in first complete remission (CR1) when there is no measurable residual disease (MRD) at the end of induction and/or consolidation. Randomized studies are needed for adults with ALL to compare allogeneic HCT in CR1 with pediatric-inspired chemotherapy alone. Indications for transplantation in the evolving landscape of MRD assessments and novel targeted and immune therapeutics remain important areas of investigation.

Survival in adult acute lymphoblastic leukaemia (ALL): A report from the Swedish ALL Registry

OBJECTIVES

As new, effective therapies emerge for acute lymphoblastic leukaemia (ALL), the results of clinical trials need to relate to standard of care.

METHODS

We used the population-based Swedish ALL Registry to evaluate characteristics, treatment and long-term outcome in 933 patients with diagnosis between 1997 and 2015.

RESULTS

The median age was 53 years. The frequency of Philadelphia (Ph)-positive leukaemia was 34% of examined B-ALL with a peak incidence at 50-59 years. Five-year overall survival (OS) improved between 1997-2006 and 2007-2015; in patients 18-45 years from 50% (95% CI 43-57) to 65% (95% CI 58-72), 46-65 years from 25% (95% CI 18-32) to 46% (95% CI 37-55) and >65 years from 7% (95% CI 2.6-11) to 11% (95% CI 5.9-16) (P < 0.05). Men with Ph-neg B-ALL 46-65 years had inferior OS compared with women (P < 0.01). Standardised mortality ratio was 5.7 (95% CI 5.0-6.3) for patients who survived 5 years from diagnosis. In multivariable analysis, Ph-positive disease was not associated with impaired prognosis but with lower risk of death in 2007-2015.

CONCLUSIONS

In a population-based cohort, OS has improved in adult ALL, especially for Ph-positive disease but for middle-aged men with Ph-negative B-ALL outcome was poor. Cure without late toxicity or relapse is still desired.

Hematopoietic stem cell transplantation for adults with Philadelphia chromosome-negative acute lymphoblastic leukemia in first remission: a position statement of the European Working Group for Adult Acute Lymphoblastic Leukemia (EWALL) and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT)

Allogeneic hematopoietic stem cell transplantation (HSCT) in first complete remission is a standard of care for adult patients with Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) and high risk of relapse. However, the stratification systems vary among study groups. Inadequate response at the level of minimal residual disease is the most commonly accepted factor indicating the need for alloHSCT. In this consensus paper on behalf of the European Working Group for Adult Acute Lymphoblastic Leukemia and the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we summarize available evidence and reflect current clinical practice in major European study groups regarding both indications for HSCT and particular aspects of the procedure including the choice of donor, source of stem cells and conditioning. Finally, we propose recommendations for daily clinical practice as well as for planning of prospective trials.

Acute Lymphoblastic Leukemia in the Older Adult

Acute lymphoblastic leukemia (ALL) in older adults presents a real challenge as a result of adverse disease biology and comorbidities that preclude delivering curative regimens. Conventional chemotherapy approaches have generally yielded unsatisfactory results in older patients with ALL as a result of excessive induction mortality, chemotherapy resistance of the leukemia, and the need to omit or dose reduce key drugs during the course of therapy because of adverse effects. Philadelphia chromosome–positive ALL represents about a quarter of newly diagnosed older adults, and the striking single-agent activity and excellent safety profile of tyrosine kinase inhibitors has allowed incorporation of these agents into therapy, significantly improving the outcome of older adults with Philadelphia chromosome–positive ALL. Allogeneic hematopoietic cell transplantation using reduced-intensity conditioning is a potentially curative approach in the older adult with ALL, and ironically, it may be better tolerated than intensive combination chemotherapy in a subset of older patients with ALL. Immunotherapies such as chimeric antigen receptor–modified T-cells, the bispecific T-cell–engaging antibody targeting CD19 (blinatumomab), and the antibody-drug conjugate targeting CD22 (inotuzumab) have shown safety and exceptional activity even in advanced ALL, and the efficacy of these agents has been observed irrespective of patient age. Several promising studies tailored specifically toward older adults with ALL are ongoing, with the majority of them incorporating novel immunotherapies, targeted therapies, or third-generation tyrosine kinase inhibitors into the front-line treatment regimen.

Adults with Philadelphia Chromosome-Like Acute Lymphoblastic Leukemia: Considerations for Allogeneic Hematopoietic Cell Transplantation in First Complete Remission

Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a subset of high-risk B cell ALLs. A large proportion of Ph-like ALL cases carry activating kinase mutations that could potentially allow them to be targeted by tyrosine kinase inhibitors. Ph-like ALL is not an uncommon entity, especially among adults, with a frequency exceeding 20%, including in older patients (>60 years old) with ALL. Ph-like ALL is associated with inferior outcomes across all ages, and studies have consistently shown a higher incidence of persistent postinduction minimal residual disease in patients carrying Ph-like ALL compared with other subgroups of ALL, and this translates into inferior leukemia-related outcomes. The inferior outcome of conventional chemotherapy for Ph-like ALL in adults raises the fundamental question of whether all adults with Ph-like ALL require an allogeneic hematopoietic cell transplantation (HCT) in first complete remission (CR1) regardless of other presenting features and treatment response parameters. Here we present and discuss several scenarios in which adults with Ph-like ALL underwent or were considered for HCT in CR1 for various reasons. Although the decision to proceed with HCT was clear and indisputable in some of these situations, in others we struggled with the decision to transplant in CR1 because of the lack of published data regarding the efficacy of allogeneic HCT as consolidation for Ph-like ALL. We emphasize the urgent need for developing well-designed studies to address this important question.

Elderly acute lymphoblastic leukemia: a Mayo Clinic study of 124 patients

Poor outcomes in elderly acute lymphoblastic leukemia (ALL) are well recognized, but the contributors are ill-defined. We characterized 124 patients ≥60 years old at our institution. The majority (n = 102, 82%) were treated with intensive chemotherapy. Of these, 8/102 (8%) died within the first 100 days; 92/102 (90%) achieved complete remission (CR/CRi). Only 31/124 (25%) patients underwent allogeneic hematopoietic stem cell transplantation. The median overall survival (OS) for the entire cohort was 19.8 months. In a multivariate analysis, ECOG performance status ≥2, high white blood cell count, and high lactate dehydrogenase (at time of diagnosis) negatively influenced OS (p<.01). In a subgroup analysis of the intensive treatment group, BCR-ABL1+ patients had markedly better OS (hazard ratio 0.3, 95% CI 0.1-0.7; p<.01). In summary, despite few early deaths and a high CR/CRi rate, elderly ALL continues to have a poor prognosis, underscoring the need for more effective therapies.

Reduced Intensity Conditioning Allogeneic Hematopoietic Stem Cell Transplantation for Acute Lymphoblastic Leukemia; Current Evidence, and Improving Outcomes Going Forward

PURPOSE OF REVIEW

Outcomes for older adults with acute lymphoblastic leukemia (ALL) remain poor, and allogeneic hematopoietic stem cell transplant (HSCT) remains a potentially curative modality. However, benefits are offset by high rates of non-relapse mortality (NRM) in patients undergoing myeloablative conditioning (MAC) regimens. Reduced intensity conditioning (RIC) regimens can extend this therapy to adults who are unfit for MAC, although at the cost of higher relapse rates. In this review, we discuss evidence to support the usage of RIC regimens, controversies, and potential strategies to improve transplant outcomes going forward.

RECENT FINDINGS

Several novel therapies have recently been approved for the treatment of relapsed ALL and may play an important role in bridging adults with residual disease to RIC transplant. Assessing response to initial therapy via minimal residual disease (MRD) monitoring may determine which patients will derive the most benefit from allogeneic HSCT. Reduced intensity allogeneic HSCT remains a potentially curative therapy that can be offered to older adults however challenges remain. Going forward, MRD testing and novel therapies may help better select which patients should proceed to transplant and assist in getting those patients to transplant with optimally controlled disease.

Novel Therapies for Older Adults With Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Older adults with acute lymphoblastic leukemia (ALL) have worse survival compared to their younger counterparts. Here, we review the reasons for the poorer outcomes of older patients with ALL and also summarize the current and future therapeutic approaches to ALL in the elderly population.

RECENT FINDINGS

The poor outcomes of older adults with ALL are driven largely by lack of tolerance to standard-dose chemotherapy, which leads to unacceptably high rates of myelosuppression-related deaths. Recent studies have shown promising results with the use of low-intensity or chemotherapy-free regimens in older patients with ALL, which are able to retain efficacy without excess toxicity. Novel antibody constructs such as inotuzumab ozogamicin and blinatumomab as well as potent later-generation tyrosine kinase inhibitors such as ponatinib hold significant promise in the management of ALL in the older adult. Innovative combination strategies may further improve the outcomes of these patients.

Comparison of intensive, pediatric-inspired therapy with non-intensive therapy in older adults aged 55-65 years with Philadelphia chromosome-negative acute lymphoblastic leukemia

BACKGROUND AND OBJECTIVE

The standardization of treatment of older adults with Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL) is challenging, especially in the age range of 55-65 years. This study aimed to compare intensive, pediatric-inspired therapy with non-intensive therapy in this population of patients.

PATIENTS AND METHODS

The outcomes of 67 patients prospectively included in two consecutive pediatric-inspired intensive protocols (ALL-HR03 and ALL-HR11) from the Spanish PETHEMA Group were compared with those from 44 patients included in a contemporary semi-intensive protocol (ALL-OLD07).

RESULTS

Baseline patient and ALL characteristics were similar in both groups, except for a younger median age in the intensive group (medians: 58 vs. 62 years). Patients treated intensively had a higher complete remission rate (85% vs. 64%, p = 0.005), a lower cumulative incidence of relapse (39% [95%CI, 25% to 52%] vs. 60% [95%CI, 38% to 77%], p = .003), a similar cumulative incidence of treatment-related mortality (28% [95% CI, 18%, 40%] vs. 21% [95% CI, 10%, 34%]) and superior event-free survival at 2 years (37% [95%CI, 25%-49%) vs. 21% [8%-34%], p = 0.002). On multivariable analysis the type of protocol was the only variable with independent significance for event-free survival (HR [95% CI]: 2 [1.3, 3], p = .002).

CONCLUSIONS

Compared with less intensive chemotherapy, pediatric-inspired intensive chemotherapy significantly improves the outcome of older adults with Ph-negative ALL in the age range of 55-65 years.

Allogeneic stem cell transplantation in acute lymphoblastic leukemia patients older than 60 years: a survey from the acute leukemia working party of EBMT

Hematopoietic stem cell transplantation (HSCT) is being increasingly explored as a treatment modality for older patients with acute lymphoblastic leukemia (ALL). Yet, concerns regarding the long term outcome of transplantation in older patients limit the wide spread applicability of this approach. In this analysis we set out to determine the outcome of ALL patients over the age of 60 who underwent reduced intensity HSCT. Herein, we present the experience of the acute leukemia working party (ALWP) of the EBMT in this age group. We analyzed a cohort of 142 patients transplanted in first remission with a median age of 62 (range 60–76 years) and a median follow-up period of 36 months post-transplant. At 3 years, overall survival (OS) and leukemia-free survival were 42% and 35%, respectively. Multivariate analyses identified cytomegalovirus (CMV) donor-recipient matching (CMV D+/R+) to be significantly associated with inferior OS. Patients transplanted from unrelated donors experienced increased grade II-IV acute graft versus host disease compared to those receiving grafts from matched related donors [Hazard ratio (HR) of 3.7, 95% confidence interval (CI), 1.75–7.8; p = 0.0005). Outcome was not impacted by Philadelphia chromosome status. A select subset of older ALL patients will benefit from extended survival and a disease free state following HSCT.

Impact of Toxicity on Survival for Older Adult Patients after CD34+ Selected Allogeneic Hematopoietic Stem Cell Transplantation

Ex vivo CD34⁺ selection before allogeneic hematopoietic stem cell transplantation (allo-HCT) reduces graft-versus-host disease without increasing relapse but usually requires myeloablative conditioning. We aimed to identify toxicity patterns in older patients and the association with overall survival (OS) and nonrelapse mortality (NRM). We conducted a retrospective analysis of 200 patients who underwent CD34⁺ selection allo-HCT using the ClinicMACS® system between 2006 and 2012. All grade 3 to 5 toxicities by CTCAE v4.0 were collected. Eighty patients aged ≥ 60 years with a median age of 64 (range, 60 to 73) were compared with 120 patients aged < 60 years. Median follow-up in survivors was 48.2 months. OS and NRM were similar between ages ≥ 60 and <60, with 1-year OS 70% versus 78% (P = .07) and 1-year NRM 23% versus 13% (P = .38), respectively. In patients aged ≥ 60 the most common toxicities by day 100 were metabolic, with a cumulative incidence of 88% (95% CI, 78% to 93%), infectious 84% (95% CI, 73% to 90%), hematologic 80% (95% CI, 69% to 87%), oral/gastrointestinal (GI) 48% (95% CI, 36% to 58%), cardiovascular (CV) 35% (95% CI, 25% to 46%), and hepatic 25% (95% CI, 16% to 35%). Patients aged ≥ 60 had a higher risk of neurologic (HR, 2.63 [95% CI, 1.45 to 4.78]; P = .001) and CV (HR, 1.65 [95% CI, 1.04 to 2.63]; P = .03) toxicities but a lower risk of oral/GI (HR, .58 [95% CI, .41 to .83]; P = .003) compared with those aged < 60. CV, hepatic, neurologic, pulmonary, and renal toxicities remained independent risk factors for the risk of death and NRM in separate multivariate models adjusting for age and hematopoietic cell transplantation-specific comorbidity index. Overall, the toxicity of a more intense regimen is potentially balanced by the absence of toxicity related to methotrexate and calcineurin inhibitors in older patients. Prospective study of toxicities after allo-HCT in older patients is essential.