Allogeneic, but not autologous, hematopoietic cell transplantation improves survival only among younger adults with acute lymphoblastic leukemia in first remission: an individual patient data meta-analysis

Hematopoietic stem cell transplant in adults with acute lymphoblastic leukemia: the present state

INTRODUCTION

Allogeneic hematopoietic stem cell transplant (allo-HSCT) has an important role in management of acute lymphoblastic leukemia (ALL). Proper patient selection is central to ensure optimal outcomes. Areas covered: This review covers various aspects of HSCT in ALL patients, including indications, donor selection, conditioning regimens, and post-transplant management. Expert commentary: Allo-HSCT is important in post-remission management of ALL but proper risk-stratification is a major challenge. Incorporation of minimal residual disease (MRD) and molecular testing will improve patient allocation. Patients receiving pediatric-inspired induction who achieve molecular remission might not need allo-HSCT in first remission. Allo-HSCT should be considered in patients who don't achieve MDR negativity, didn't receive intensive induction, or have high risk cytogenetic and molecular features. Despite improved responses with tyrosine kinase inhibitors (TKIs) in Philadelphia positive (Ph+) ALL, allo-HSCT remains standard. Matched sibling donors are the optimal graft source, but other sources are valid alternatives. There is no single optimal conditioning regimen and retrospective studies found myeloablative and reduced intensity regimens to be comparable. Following allo-HSCT, there is no role for maintenance therapy in Philadelphia-negative ALL. In Ph+ ALL, maintenance TKIs improve outcomes. The integration of targeted and immunotherapies in the peri-transplant period holds potential for improved outcomes.

CD20 expression sub-stratifies standard-risk patients with B cell precursor acute lymphoblastic leukemia

Patients with standard-risk adult acute lymphoblastic leukemia (ALL) treated with chemotherapy do not have satisfactory outcomes. To more precisely classify ALL patients and optimize treatment, we re-evaluated the risk stratification system by examining CD20 expression and other classic risk factors at diagnosis. We retrospectively analyzed response to induction chemotherapy of 217 consecutive patients with newly diagnosed Philadelphia-negative B cell precursor-ALL. Survival analyses were conducted for the 136 patients who were intended to be treated with chemotherapy alone. Among the 217 patients, 69 (31.8%) were considered standard risk based on age <35 years, white blood cell count <30 × 10⁹/L, absence of central nervous system involvement, and high-risk cytogenetic abnormalities. Seventy-four patients (34.1%) expressed CD20 on ≥20% of leukemia blasts and were considered CD20 positive. We found that fewer CD20-positive than CD20-negative patients achieved durable first complete responses (CR1 ≥3 months) (81.1% vs. 94.9%, P=0.002). Within the standard-risk group, more CD20-negative than CD20-positive patients achieved CR (100% vs. 83.3%, P=0.003) and durable CR1 (100% vs. 82.4%, P=0.014). For patients in the CD20-negative standard-risk, CD20-positive standard-risk, CD20-negative high-risk, and CD20-positive high-risk groups, the 3-year cumulative incidence of relapse was 42.6%, 70.0%, 59.3%, and 69.5%, respectively (P=0.118); the 3-year disease-free survival rates were 52.1%, 0%, 20.7%, and 13.7%, respectively (P=0.006); and the 3-year overall survival rates were 55.8%, 13.8%, 23.6%, and 16.9%, respectively (P=0.006). Our results suggest that patients with CD20-negative standard-risk B cell precursor-ALL have favorable prognosis compared with CD20-positive standard-risk or CD20-negative or -positive high-risk patients. CD20-positive standard-risk ALL patients may need other therapeutic modalities bridging to allogeneic hematopoietic stem cell transplantation.

Current challenges and opportunities in treating adult patients with Philadelphia-negative acute lymphoblastic leukaemia

Significant advances have been made in recent years in the field of Philadelphia-negative acute lymphoblastic leukaemia (ALL). New insights into the biology and genetics of ALL as well as novel clinical observations and new drugs are changing the way we diagnose, risk-stratify and treat adult patients with ALL. New genetic subtypes and alterations refine risk stratification and uncover new actionable therapeutic targets. The incorporation of more intensive, paediatric and paediatric-inspired approaches for young adults seem to have a positive impact on survival in this population. Minimal residual disease at different time points can assist in tailoring risk-adapted interventions for patients based on individual response. Finally, novel targeted approaches with monoclonal antibodies, immunotherapies and small molecules are moving through clinical development and entering the clinic. The aim of this review is to consolidate the abundance of emerging data and to review and revisit the concepts of risk-stratification, choice of induction and post-remission strategies as well as to discuss and update the approach to specific populations with ALL, such as young adult, elderly/unfit and relapsed/refractory patients with ALL.

Treatment of Young Adults with Acute Lymphoblastic Leukemia

Young adults with acute lymphoblastic leukemia are a distinctive category of patients, with substantial difference in disease biology and response to therapy; hence, they pose unique challenges and issues beyond those faced by children and older adults. Despite inferior survival compared to children, there is growing evidence to suggest that young adults have improved outcomes when treated with pediatric-based approaches. With better supportive care and toxicity management and multidisciplinary team and approach, we have made great improvement in outcomes of young adults with ALL. However, despite significant progress, patients with persistence of minimal residual disease have a poor prognosis. This review discusses current controversies in the management of young adults with ALL, outcomes following pediatric and adult protocols, and the role of allogeneic stem cell transplantation. We also explore recent advances in disease monitoring and highlight our approach to incorporation of novel therapies in the management of young adults with ALL.

[Adult B-cell acute lymphoblastic leukemias: Conclusions of the Russian prospective multicenter study ALL-2009]

AIM

To analyze the efficiency and reproducibility of the ALL-2009 protocol within the Russian prospective multicenter study based on different principles of cytostatic effects (non-intensive, but continuous cytotoxic treatment and a small number of allogeneic hematopoietic stem cells).

SUBJECTS AND METHODS

The ALL-2009 (NCT01193933) study conducted in April 2009 to December 2016 included 194 patients (95 males and 99 females) aged 15 to 55 years (median age 28 years) with Ph-negative B-cell acute lymphoblastic leukemia (ALL). There was early pre-B-cell ALL in 54 patients, common ALL in 101, pre-B ALL in 39, initial leukocytosis in 9.4·109/l (0.4-899.0), lactate dehydrogenase in 901 IU (31-13 059), an initial central nervous system lesion in 17 (8.7%), mediastinal injury in 3 (1.5%), and splenomegaly in 111 (57.2%). The results of standard cytogenetic analysis are known in 113 (60.4%) patients. Normal karyotypes were detected in 49 (54.5%) out of the patients; t(4;11) in 9 (5.4%), t(1;19) in 2 (1.2%), and other karyotypic abnormalities in 53 (46.9%). Thirteen (7.8%) patients underwent allogeneic hematopoietic stem cell transplantation in first complete remission (CR); their proportion did not differ in the federal and regional centers.

RESULTS

The frequency of CR achievement was the same in the federal and regional centers and generally amounted to 87.5%. Early (8.8%) and CR (9.6%) mortality rates remained high despite the low aggressiveness of cytotoxic action, necessitating the improvement of auxiliary treatment. The five-year overall survival (OS) rates vary considerably in the federal and regional centers (72.6 and 43.8%), the relapse-free survival (RFS) (70.2 and 53.4%) and recurrence risk (23.1 and 36.5%) are comparable. This suggests that the non-intensive, but continuous exposure principle built in the ALL-2009 protocol makes it possible to reproduce the envisaged treatment program and to achieve satisfactory results.

CONCLUSION

The ALL-2009 protocol allows both the federal and regional centers to obtain the long-term results comparable with those of current foreign studies: OS (54.2%), RFS (56.5%); and relapse risk (35.4%). Multivariate analysis has identified age (over 30 years), initial leukocytosis (30·109/l and more) and t(4;11) among the main clinical prognostic factors. Gene mutation detection evaluated in a small number of patients (8/36) is not a poor prognostic sign. There is a need for further investigations with centralized evaluation of the mutation status of leukemic cells and the clearance of minimal residual disease.

How should we treat the AYA patient with newly diagnosed ALL?

Adolescent and young adult (AYA) patients with acute lymphoblastic leukaemia (ALL) are recognized as a unique population with specific characteristics and needs. In adolescents aged 15-20 years old, the use of full paediatric protocols is supported by many comparative studies of paediatric and adult cooperative groups. In young adults, growing evidence suggests that paediatric-inspired approaches may also improve outcomes and lead to long-term survival rates of almost 70%. In the last decade, better knowledge of ALL oncogenic landscape, age distribution, and minimal residual disease prognostic impact have improved risk stratification. New targets have emerged mostly in the heterogeneous subgroup of Philadelphia-like ALL and will require both in-depth molecular investigations and specific evaluations in rare subgroups of ALL. The remaining gap with the excellent results reported in children has many other contributing factors that should not be underestimated including late or difficult access to care, or poor adherence to treatment.

Haploidentical transplantation compared with matched sibling and unrelated donor transplantation for adults with standard-risk acute lymphoblastic leukaemia in first complete remission

We retrospectively investigated outcomes of haploidentical donor (HID) transplant for adults with standard-risk acute lymphoblastic leukaemia (ALL) in first complete remission (CR1) compared with human leucocyte antigen (HLA)-matched sibling donor (MSD) and HLA-matched unrelated donor (MUD) transplants. A total of 348 adult patients were enrolled, including 127 HID, 144 MSD and 77 MUD recipients. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 39·5%, 24·0% and 40·3% for HID, MSD and MUD, respectively (P = 0·020). However, there was no difference in grade III-IV aGVHD (11·4%, 7·7%, 13·5%, respectively, P = 0·468). The 5-year cumulative transplant-related mortality was 16·4%, 11·6% and 19·6% (P = 0·162), the 5-year relapse rate post-transplantation was 14·8%, 21·1% and 16·7% (P = 0·231), the 5-year overall survival was 70·1%, 73·7% and 69·8% (P = 0·525), and the 5-year disease-free survival was 68·7%, 67·3% and 63·7%, respectively (P = 0·606). Furthermore, the 3-year GVHD-free, relapse-free survival was not different (50·8%, 54·9% and 52·2%, respectively, P = 0·847). Our results indicate that the outcomes of HID transplants are equivalent to those of MSD and MUD, and that HID transplantation is a valid alternative for standard-risk adults with ALL in CR1 who lack matched donors.

Continuing challenges and current issues in acute lymphoblastic leukemia

Conventional cytotoxic chemotherapy used to treat acute lymphoblastic leukemia (ALL) has resulted into high cure rates for pediatric patients, however outcomes for adult patients remain suboptimal. The 5-year overall survival is only 30-40% in adults and elderly patients with ALL compared to 90% in children. We have seen major advances in our understanding and management of ALL related to identification of new cytogenetic and molecular abnormalities and development of novel targeted agents for the treatment of ALL. The addition of tyrosine kinase inhibitors, monoclonal antibodies and novel immune therapies (e.g. bispecific T cell engager [BiTE] and chimeric antigen receptor [CAR] T cells) has resulted in improved outcomes. These new developments are changing the treatment paradigm of adults ALL from a 'one size fits all' approach to a more individualized treatment approach based on immunophenotypic, cytogenetic and molecular features. In this article we review recent diagnostic and therapeutic advances along with the challenges in the treatment of patients with ALL.

Unmanipulated haploidentical stem cell transplantation in adults with acute lymphoblastic leukemia: a study on behalf of the Acute Leukemia Working Party of the EBMT

Background

Allogenic hematopoietic stem cell transplantation (allo-SCT) is the most effective post-remission treatment for adults with high-risk acute lymphoblastic leukemia (ALL). The aim of the study was to analyze results of unmanipulated haploidentical allo-SCT (haplo-SCT) for adults with ALL and to identify prognostic factors.

Methods

We performed a retrospective analysis on 208 adults transplanted in EBMT centers from 2007 to 2014.

Results

Median age at haplo-SCT was 32 years and median follow-up, 31 months. Forty-four percent of the patients were in first complete remission (CR1). Stem cell source was the bone marrow (BM) for 43% and peripheral blood (PB) for 57% of patients. Myeloablative conditioning (MAC) was used for 66% and reduced intensity regimen (RIC) for 34% of patients. GVHD prophylaxis was based on post-transplant cyclophosphamide (PT-Cy) for 118 (57%) or on anti-thymocyte-globulin (ATG) for 90 (43%) plus standard prophylaxis. One hundred eighty-four (92%) patients achieved engraftment. Cumulative incidence (CI) of grade II–IV acute-graft-versus-host-disease (GVHD) was 31%, grade III–IV 11%, and chronic GVHD 29%. Non-relapse mortality (NRM) and relapse-incidence (RI) were 32 and 37%, respectively. Overall survival (OS), leukemia-free survival (LFS), and GVHD-free, relapse-free-survival (GRFS) at 3 years were 33, 31, and 26%. For patients in CR1, OS, LFS, and GRFS were 52, 47, and 40%, respectively. Disease status was the main factor associated with transplant outcomes. Use of BM was independently associated with improvement in NRM, acute GVHD, GRFS, LFS, and OS.

Conclusions

Unmanipulated haplo-SCT may be considered a valid option for adult patients with high-risk ALL lacking HLA identical donor preferably in early disease status.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-017-0480-5) contains supplementary material, which is available to authorized users.

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.

Antibody Based Therapies in Acute Leukemia

Despite great progress in the curative treatment of acute leukemia, outcomes for those with relapsed and/or chemotherapy-refractory disease remain poor. Current intensive cytotoxic therapies can be associated with significant morbidity and novel therapies are needed to improve outcomes. Immunotherapy based approaches provide an alternative mechanism of action in the treatment of acute leukemia. Due to cell surface antigen expression, leukemia in particular is amenable to targeted therapies, such as antibody-based therapy. Based on the potential for non-overlapping toxicity, the possibility of synergistic action with standard chemotherapy, and by providing a novel method to overcome chemotherapy resistance, antibody-based therapies have shown potential for benefit. Modifications to standard monoclonal antibodies, including drug conjugation and linkage to T-cells, may further enhance efficacy of antibody-based therapies. Identifying the ideal timing for incorporation of antibody-based therapies, within standard regimens, may lead to improvement in overall outcomes. This article will provide an overview of antibody-based therapies in clinical development for the treatment of acute leukemia in children and adults, with a particular focus on the current strategies and future developments.

Hyper-CVAD Compared With BFM-like Chemotherapy for the Treatment of Adult Acute Lymphoblastic Leukemia. A Retrospective Single-Center Analysis

BACKGROUND

Several induction regimens have been developed for treatment of adult patients with acute lymphoblastic leukemia (ALL). However, only a few prospective randomized trials have directly compared these regimens.

PATIENTS AND METHODS

In this report, we retrospectively evaluated the outcome of 62 adult ALL patients treated with either hyper-CVAD (hyper fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone; n = 38) or a BFM (Berlin-Frankfurt-Munster)-like regimen (n = 24) between November 2000 and January 2016 at the American university of Beirut Medical Center in Lebanon. The feasibility of allogeneic stem cell transplantation (allo-SCT) for those patients was also evaluated.

RESULTS

The median follow-up time was 29 (range, 1-129) months. Fifteen (39%) and 10 (42%) patients underwent allo-SCT in the hyper-CVAD and BFM-like group, respectively. At the time of the last follow-up, 28 patients (74%) were in complete remission in the hyper-CVAD group versus 18 patients (75%) in the BFM-like group. Of those, 20 patients (53%) versus 11 patients (46%) were minimal residual disease-negative at the last follow-up, respectively. The 3-year overall survival rate (71.9% vs. 76.9%; P = .808) and 3-year disease-free survival (54.7% vs. 76.4%; P = .435) were similar in hyper-CVAD group compared with the BFM-like group, respectively. Both chemotherapies were relatively well tolerated.

CONCLUSION

Overall, despite the older age and a greater number of patients with high-risk category (including Philadelphia chromosome-positive) in the hyper-CVAD group, this did not translate into a difference in survival outcome between the 2 groups. The hyper-CVAD regimen appears to be feasible for adult patients with ALL in terms of tolerability and efficacy.

Haploidentical Transplantation with Post-Transplantation Cyclophosphamide for High-Risk Acute Lymphoblastic Leukemia

Haploidentical transplantation performed with post-transplantation cyclophosphamide (PTCy)-based graft-versus-host disease (GVHD) prophylaxis has been associated with favorable outcomes for patients with acute myeloid leukemia and lymphomas. However, it remains unclear if such approach is effective for patients with acute lymphoblastic leukemia (ALL). We analyzed outcomes of 109 consecutively treated ALL patients 18 years of age and older at 5 institutions. The median age was 32 years and the median follow-up for survivors was 13 months. Thirty-two patients were in first complete remission (CR1), while the rest were beyond CR1. Neutrophil engraftment occurred in 95% of the patients. The cumulative incidences of grades II to IV and III and IV acute GVHD at day 100 after transplantation were 32% and 11%, respectively, whereas chronic GVHD, nonrelapse mortality, relapse rate, and disease-free survival (DFS) at 1 year after transplantation were 32%, 21%, 27%, and 51%, respectively. Patients in CR1 had 52% DFS at 3 years. These results suggest that haploidentical transplants performed with PTCy-based GVHD prophylaxis provide a very suitable alternative to HLA-matched transplantations for patients with ALL.

Allogeneic transplantation is not superior to chemotherapy in most patients over 40 years of age with Philadelphia-negative acute lymphoblastic leukemia in first remission

Survival of patients ≥40 years of age with Philadelphia-negative acute lymphoblastic leukemia (ALL) remains poor with current therapeutic approaches. It is unknown whether allogeneic hematopoietic stem-cell transplantation (HSCT) in first remission confers a survival benefit compared to a chemotherapy-only approach. We retrospectively compared the outcome of patients >40 years treated with HSCT or chemotherapy alone in first remission (n = 40 in each cohort). Three-year overall survival (OS) and disease-free survival (DFS) were not significantly different between the chemotherapy-only and HSCT groups (OS, 46% [31-68] vs. 40% [27-59], P = 0.35; DFS, 31% [18-52] vs. 40% [27-59], P = 0.98). The 3-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were 61% [41-76] and 9% [2-21] for the chemotherapy-only group and 28% [15-43] and 32% [17-47] for the transplant group (CIR, P = 0.011; NRM, P = 0.014). Allogeneic transplantation for patients ≥40 years with Ph-negative ALL in first remission is associated with a lower CIR, but this benefit is offset by considerable NRM as compared with chemotherapy-only approach. HSCT may be beneficial in patients with high-risk disease features. Am. J. Hematol. 91:793-799, 2016. © 2016 Wiley Periodicals, Inc.

Refining the Role of Hematopoietic Cell Transplantation for Acute Lymphoblastic Leukemia as Novel Therapies Emerge

Acute lymphoblastic leukemia (ALL) is a rare adult neoplasm. The disorder consists of precursor B or T phenotypes. In the pediatric population, ALL was a success story in that 80% of children with ALL enjoy long-term survival. In adults, similar complete remission rates are achieved with current induction regimens; however, less than 50% of patients are alive at 5 years, with most deaths due to relapsed disease. Accordingly, optimizing post remission consolidation therapy might improve in outcomes. Such strategies may include chemotherapy and autologous or allogeneic transplant. Moreover, the ability to modify such therapy based on better disease risk stratification while taking into account patient characteristics such as performance status and presence of comorbidities is necessary to tailor treatment accordingly. Here, we review available medical literature on the use of hematopoietic cell transplantation as a consolidation modality in the treatment of adult ALL.

Outcomes of Adults with Acute Lymphoblastic Leukemia After Autologous Hematopoietic Stem Cell Transplantation and the Significance of Pretransplantation Minimal Residual Disease: Analysis from a Single Center of China

Background:

The postremission therapies for adult patients generally contain consolidation chemotherapy, allogeneic hematopoietic stem cell transplantation and autologous hematopoietic stem cell transplantation (auto-HSCT). Because of the various results from different centers, the optimal therapy for adult acute lymphoblastic leukemia (ALL) patients is still uncertain. This study aimed to better understand predictive factors and role of auto-HSCT in the postremission therapy for adult ALL patients.

Methods:

The outcomes of 135 adult patients with ALL, who received the first auto-HSCT in Hematopoietic Stem Cell Transplantation Center of Blood Diseases Hospital, Chinese Academy of Medical Sciences from January 1, 1994 to February 28, 2014, were retrospectively analyzed. Survival curves were estimated using the Kaplan-Meier method and simultaneous effects of multiple covariates were estimated with the Cox model.

Results:

Overall survival (OS) and disease-free survival (DFS) at 5 years for the whole cohort were 59.1 ± 4.5% and 59.0 ± 4.4%, respectively. The cumulative nonrelapse mortality and relapse rate at 5 years were 4.5 ± 0.03% and 36.6 ± 0.19%. For both OS and DFS, acute T-cell lymphoblastic leukemia, high lactate dehydrogenase (LDH) at diagnosis, blast cell proportion ≥5% on the 15^th day of induction therapy, and extramedullary infiltration before HSCT were the poor prognosis factors. In addition, age ≥35 years predicted poor DFS. Only T-ALL and high LDH were the independent undesirable factors associated with OS and DFS in Cox regression model. For 44 patients who had results of pretransplantation minimal residual disease (MRD), positive MRD (MRD ≥0.01%) indicated poor OS (P = 0.044) and DFS (P = 0.008). Furthermore, for the standard risk group, the patients with negative MRD (MRD <0.01%) had better results (OS at 18 months was 90.0 ± 9.5%, while for the patients with positive MRD OS was 50.0 ± 35.4%, P = 0.003; DFS at 18 months was 90.0 ± 9.5%, while for the positive MRD group DFS was 0%, P < 0.001).

Conclusions:

This study confirmed that auto-HSCT combined with posttransplantation maintenance chemotherapy could be an option for adult ALL patients and pretransplantation MRD may play a significant role in the direction of therapy for adult ALL patients.

Pediatric-inspired therapy compared to allografting for Philadelphia chromosome-negative adult ALL in first complete remission

For adults with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in first complete remission (CR1), allogeneic hematopoietic cell transplantation (HCT) is an established curative strategy. However, pediatric-inspired chemotherapy may also offer durable leukemia-free survival in the absence of HCT. We compared 422 HCT recipients aged 18-50 years with Ph-ALL in CR1 reported to the CIBMTR with an age-matched concurrent cohort of 108 Ph- ALL CR1 patients who received a Dana-Farber Consortium pediatric-inspired non-HCT regimen. At 4 years of follow-up, incidence of relapse after HCT was 24% (95% CI 19-28) versus 23% (95% CI 15-32) for the non-HCT (chemo) cohort (P=0.97). Treatment-related mortality (TRM) was higher in the HCT cohort [HCT 37% (95% CI 31-42) versus chemo 6% (95% CI 3-12), P<0.0001]. DFS in the HCT cohort was 40% (95% CI 35-45) versus 71% (95% CI 60-79) for chemo, P<0.0001. Similarly, OS favored chemo [HCT 45% (95% CI 40-50)] versus chemo 73% [(95% CI 63-81), P<0.0001]. In multivariable analysis, the sole factor predictive of shorter OS was the administration of HCT [hazard ratio 3.12 (1.99-4.90), P<0.0001]. For younger adults with Ph- ALL, pediatric-inspired chemotherapy had lower TRM, no increase in relapse, and superior overall survival compared to HCT. Am. J. Hematol. 91:322-329, 2016. © 2015 Wiley Periodicals, Inc.

Potential for bispecific T-cell engagers: role of blinatumomab in acute lymphoblastic leukemia

Patients with relapsed/refractory (R/R) B-precursor acute lymphoblastic leukemia (ALL) and patients whose minimal residual disease persists during treatment have a poor leukemia-free survival. Despite improvements in front-line therapy, the outcome in these patients remains poor, especially after relapse. As there are no standard chemotherapeutic regimens for the treatment of patients with R/R B-precursor ALL, T-cell-based therapeutic approaches have recently come to the forefront in ALL therapy. Recently, monoclonal antibodies have been developed to target specific antigens expressed in B-lineage blast cells. In this setting, CD19 is of great interest as this antigen is expressed in B-lineage cells. Therefore, it has been selected as the target antigen for blinatumomab, a new bi-specific T-cell engager antibody. This sophisticated antibody binds sites for both CD19 and CD3, leading to T-cell proliferation and activation and B-cell apoptosis. Owing to its short serum half-life, blinatumomab has been administrated by continuous intravenous infusion with a favorable safety profile. The most significant toxicities were central nervous system events and the cytokine release syndrome. This new therapeutic approach using blinatumomab has been shown to be effective in patients with positive minimal residual disease and in patients with R/R B-precursor ALL leading to a recent approval by the US Food and Drug Administration after an accelerated review process. This review focuses on the profile of blinatumomab and its efficacy and safety.

Minimal Residual Disease Monitoring in Adult ALL to Determine Therapy

Almost 90 % of children and 50 % of adults with acute lymphoblastic leukemia (ALL) are cured by modern treatment regimens, with significant variations due to several disease- and host-related characteristics. The attainment of an early remission and the avoidance of relapse and treatment-related mortality are the fundamental therapeutic steps. In remission patients, the assessment of the disease response to early intensive therapy through the detection and monitoring of minimal residual disease (MRD) can accurately refine the individual prognosis and is increasingly used to support a risk-oriented treatment strategy. In this way, only the patients with an unfavorable MRD response are preferably selected for allogeneic stem cell transplantation, irrespective of their clinical risk class. This choice spares transplant-related toxicities to MRD responsive cases. Further advancement is expected by integrating the MRD analysis with improved pediatric-type regimens and novel targeting agents for ALL subsets at higher risk of relapse.

Autologous stem cell transplantation versus alternative allogeneic donor transplants in adult acute leukemias

The availability of alternative sources of stem cells including most recently T-replete haploidentical marrow or peripheral blood, and the increasing use of reduced-intensity conditioning (RIC), renders feasible an allogeneic transplant to almost all patients with acute leukemia up to 70 years of age. Autologous stem cell transplantation (ASCT) for consolidation of complete remission (CR), however, offers in some circumstances an alternative option. Although associated with a higher relapse rate, autologous transplant benefits from a lower non-relapse mortality, the absence of graft-versus-host disease (GVHD), and a better quality of life for long-term survivors. The recent use of intravenous busulfan (IVBU) with high-dose melphalan, better monitoring of minimal residual disease (MRD), and maintenance therapy post autografting bring new interest. Few retrospective studies compared the outcome following alternative donor versus autologous transplants for remission consolidation. Genoidentical and phenoidentical allogeneic stem cell transplantations are undisputed gold standards, but there are no data showing the superiority of alternative allogeneic donor over autologous transplantation, at the time of undetectable MRD, in patients with good- and intermediate-1 risk acute myelocytic leukemia (AML) in first complete remission (CR1), acute promyelocytic leukemia in second complete remission (CR2), and Philadelphia chromosome-positive (Ph(+)) acute lymphocytic leukemia (ALL).

Improved survival in adult patients with acute lymphoblastic leukemia in the Netherlands: a population-based study on treatment, trial participation and survival

This nationwide population-based study assessed trends in treatment, trial participation and survival among 1833 adult patients diagnosed with acute lymphoblastic leukemia (ALL) in the Netherlands between 1989 and 2012 reported to the Netherlands Cancer Registry. Patients were categorized into four periods and five age groups (18-24, 25-39, 40-59, 60-69 and ⩾70 years). The application of allogeneic stem cell transplantation (alloSCT), particularly reduced-intensity conditioning (RIC) alloSCT, increased over time up to age 70 years. The inclusion rate in the trials was 67, 66, 55, 58 and 0% for the five age groups. Survival improved over time for patients below 70 years. Five-year relative survival in the period 2007-2012 was 75, 57, 37, 22 and 5% for the five age groups. In that same period, 5-year overall survival among patients aged 18-39 years was 68% for the chemotherapy-alone group and 66% for the alloSCT group. For patients aged 40-69 years, the corresponding estimates were 24 and 41%. Pronounced survival improvement observed among patients aged 18-39 years might mainly be explained by implementation of pediatric-based regimens since 2005, whereas among patients aged 40-69 years, increased application of RIC-alloSCT has contributed significantly to the observed improvement. Outcome of patients aged ⩾70 remains unsatisfactory, indicating a need for specific trials for the elderly.

Autologous stem cell transplantation for adult acute leukemia in 2015: time to rethink? Present status and future prospects

The use of autologous stem cell transplantation (ASCT) as consolidation therapy for adult patients with acute leukemia has declined over time. However, multiple randomized studies in the past have reported lower relapse rates after autologous transplantation compared with chemotherapy and lower non-relapse mortality rates compared with allogeneic transplantation. In addition, quality of life of long-term survivors is better after autologous transplantation than after allogeneic transplantation. Further, recent developments may improve outcomes of autograft recipients. These include the use of IV busulfan and the busulfan+melphalan combination, better detection of minimal residual disease (MRD) with molecular biology techniques, the introduction of targeted therapies and post-transplant maintenance therapy. Therefore, ASCT may nowadays be reconsidered for consolidation in the following patients if and when they reach a MRD-negative status: good- and at least intermediate-1 risk acute myelocytic leukemia in first CR, acute promyelocytic leukemia in second CR, Ph-positive acute lymphocytic leukemia. Conversely, patients with MRD-positive status or high-risk leukemia should not be considered for consolidation with ASCT.

Risk factors for outcomes after unrelated cord blood transplantation for adults with acute lymphoblastic leukemia: a report on behalf of Eurocord and the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

We performed a retrospective analysis on 421 adult patients who underwent unrelated cord blood transplantation (UCBT) for ALL. Median age was 32 years; 46% were in first CR (CR1), 32% in CR2 and 22% had advanced disease. Double UCBT was performed in 173 patients (41%). Myeloablative conditioning (MAC) was given to 314 patients (75%). Cumulative incidence (CI) of 60-day neutrophil recovery was 78%. CI of acute and chronic GVHD was 33 and 26%, respectively. Non-relapse mortality (NRM) at 2 years was 42%. Age⩾35 years (P<0.0001), advanced disease at UCBT (P<0.0001) and use of MAC (P<0.0001) were associated with increased NRM. Relapse incidence (RI) at 2 years was 28%; use of reduced intensity conditioning (RIC) (P=0.0002) was associated with increased RI. Two-year leukemia-free survival (LFS) was 39% for patients in CR1, 31% for CR2 and 8% for advanced disease. In multivariate analysis, factors associated with decreased LFS rate were: age ⩾35 years (P=0.034), use of MAC (P=0.032) and advanced disease (P<0.0001). These results show that UCBT is a valuable option to treat high-risk adult ALL when in remission. Strategies to decrease toxicity and relapse are needed to improve final outcomes.

Indications for allo- and auto-SCT for haematological diseases, solid tumours and immune disorders: current practice in Europe, 2015

This is the sixth special report that the European Society for Blood and Marrow Transplantation regularly publishes on the current practice and indications for haematopoietic SCT for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred in the field of haematopoietic SCT over the last years. Cord blood units as well as haploidentical donors have been increasingly used as stem cell sources for allo-SCT, thus, augmenting the possibility of finding a suitable donor for a patient. Continuous refinement of conditioning strategies has also expanded not only the number of potential indications but also has permitted consideration of older patients or those with co-morbidity for a transplant. There is accumulating evidence of the role of haematopoietic SCT in non-haematological disorders such as autoimmune diseases. On the other hand, the advent of new drugs and very effective targeted therapy has challenged the role of SCT in some instances or at least, modified its position in the treatment armamentarium of a given patient. An updated report with revised tables and operating definitions is presented.

Role of allogeneic stem cell transplantation in adult patients with Ph-negative acute lymphoblastic leukemia

Because a pediatric-inspired Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL) protocol yielded a markedly improved outcome in adults with Philadelphia chromosome-negative ALL, we aimed to reassess the role of allogeneic stem cell transplantation (SCT) in patients treated in the GRAALL-2003 and GRAALL-2005 trials. In all, 522 patients age 15 to 55 years old and presenting with at least 1 conventional high-risk factor were candidates for SCT in first complete remission. Among these, 282 (54%) received a transplant in first complete remission. At 3 years, posttransplant cumulative incidences of relapse, nonrelapse mortality, and relapse-free survival (RFS) were estimated at 19.5%, 15.5%, and 64.7%, respectively. Time-dependent analysis did not reveal a significant difference in RFS between SCT and no-SCT cohorts. However, SCT was associated with longer RFS in patients with postinduction minimal residual disease (MRD) ≥10(-3) (hazard ratio, 0.40) but not in good MRD responders. In B-cell precursor ALL, SCT also benefitted patients with focal IKZF1 gene deletion (hazard ratio, 0.42). This article shows that poor early MRD response, in contrast to conventional ALL risk factors, is an excellent tool to identify patients who may benefit from allogeneic SCT in the context of intensified adult ALL therapy. Trial GRAALL-2003 was registered at www.clinicaltrials.gov as #NCT00222027; GRAALL-2005 was registered as #NCT00327678.

Role of allogeneic hematopoietic stem cell transplantation in adult patients with acute lymphoblastic leukemia

Adult acute lymphoblastic leukemia (ALL) is a heterogeneous disease, due to the expression of different biological and clinical risk factors, for which allogeneic stem cell transplantation (alloHSCT) is an effective consolidation therapy. The non-relapse mortality of alloHSCT remains significantly higher compared with that of conventional chemotherapy. Therefore, one of the main challenges in the care of ALL is to establish a more precise prognostic definition to select patients who could take advantage from an alloHSCT. Currently, the use of minimal residual disease following induction and early consolidation therapy has improved the prognostic accuracy in defining ALL risk class. In Philadelphia-positive ALL, the introduction of tyrosine kinase inhibitors pre and post alloHSCT appears to improve outcomes significantly and, in the absence of specially designed clinical trials, alloHSCT remains the most effective post-remission therapy. Nowadays, alloHSCT can be performed according to various modalities encompassing the use of different conditioning regimens, as well as distinct donors and stem cell source, with a significant accessibility to transplant.

Should all adults with acute lymphocytic leukemia receive allogeneic stem cell transplantation in first remission?

SUMMARY 

The role of allogeneic hematopoietic stem cell transplantation (AHCT) in patients with Philadelphia-chromosome negative acute lymphocytic leukemia (Ph- ALL) in first remission is controversial. Some studies suggest that AHCT in first remission yields a statistically significant small improvement in overall survival. However, novel therapies and monitoring strategies may tip the balance away from immediate consolidation with AHCT for a majority of adults with Ph- ALL. Here we compare data for AHCT with recent therapeutic and diagnostic advances for patients with newly diagnosed and with relapsed and refractory Ph- ALL. We conclude that AHCT remains appropriate for a specific group of these patients, but that a majority will do as well if not better with an initial nontransplant-based consolidation strategy.

Haploidentical hematopoietic SCT may be superior to conventional consolidation/maintenance chemotherapy as post-remission therapy for high-risk adult ALL

Only 30% of high-risk adult ALL patients in their first complete remission (CR1) are able to receive an HLA-matched sibling stem cell transplant. The role of haploidentical hematopoietic SCT (haplo-HSCT) in post-remission therapy is not well established. Recently, we developed a novel protocol for unmanipulated haploidentical transplantation. In this study, we compared haplo-HSCT with conventional consolidation and maintenance chemotherapy in adult high-risk ALL patients. Between January 2000 and December 2012, 104 patients received conventional chemotherapy and 79 patients received haplo-HSCT. Patients who underwent haplo-HSCT had significantly improved 3-year OS (72.5% vs 26.6%; P<0.001), 3-year disease-free survival (DFS) (63.9% vs 21.1%; P<0.001) and 3-year relapse (18.7% vs 60.5%; P<0.001) rates. The non-relapse mortality (NRM) rate was not different between patients treated with haplo-HSCT vs chemotherapy (19.2% vs 14.4%; P=0.80). In multivariate analysis, the only factor associated with improved OS, better DFS and low risk of relapse was haplo-HSCT. The only factor associated with high NRM was enrollment before 2006. In conclusion, haplo-HSCT may be an option for adults with high-risk ALL in CR1 who do not have an HLA-matched donor.

Treatment of adolescent and young adults with acute lymphoblastic leukemia

The primary objective of this review was to update and discuss the current concepts and the results of the treatment of acute lymphoblastic leukemia (ALL) in adolescents and young adults (AYA). After a brief consideration of the epidemiologic and clinicobiologic characteristics of ALL in the AYA population, the main retrospective comparative studies stating the superiority of pediatric over adult-based protocols were reviewed. The most important prospective studies in young adults using pediatric inspired or pediatric unmodified protocols were also reviewed emphasizing their feasibility at least up to the age of 40 yr and their promising results, with event-free survival rates of 60–65% or greater. Results of trials from pediatric groups have shown that the unfavourable prognosis of adolescents is no more adequate. The majority of the older adolescents with ALL can be cured with risk-adjusted and minimal residual disease-guided intensive chemotherapy, without stem cell transplantation. However, some specific subgroups, which are more frequent in adolescents than in children (e.g., early pre-T, iAMP21, and BCR-ABL-like), deserve particular attention. In summary, the advances in treatment of ALL in adolescents have been translated to young adults, and that explains the significant improvement in survival of these patients in recent years.

Autologous Hematopoietic Stem Cell Transplantation for High-risk Acute Lymphoblastic Leukemia: non-Randomized Study with a maximum Follow-up of more than 22 Years

OBJECTIVE

To evaluate the efficacy and toxicity of autologous hematopoietic stem cell transplantation (AHSCT) for high-risk acute lymphoblastic leukemia (ALL).

MATERIAL AND METHODS

Overall, 128 high-risk ALL patients at a median age of 26 years (range 18-56 years) at diagnosis received AHSCT between 1991-2008. Induction treatment was anthracycline-based in all patients. Conditioning regimen consisted of CAV (cyclophosphamide, cytarabine, etoposide) in 125 patients whereas 3 subjects received cyclophosphamide and TBI (total body irradiation). Bone marrow was stored for 72 hours in 4°C and re-infused 24 hours after conditioning completion. Bone marrow was a source of stem cells in 119 patients, peripheral blood in 2 and 7 subjects received both bone marrow and peripheral blood.

RESULTS

With a median follow-up after AHSCT of 1.6 years (range 0.1-22.3 years), the probability of leukemia-free survival (LFS) for the whole group at 10 years was 27% and 23% at 20 years. Transplant-related mortality at 100 days after AHSCT was 3.2%. There was a strong tendency for better LFS for MRD-negative patients if compared with patients who had positive or unknown MRD status at AHSCT (32% vs 23% and 25%, respectively; p=0.06). There was no difference in LFS between B- and T-lineage ALL as well as between patients transplanted in first complete remission (CR1) and CR2. LFS at 10 years for patients with Philadelphia-positive (Ph+) ALL at transplant was 20% and this was comparable with subjects with negative and missing Ph status (26% and 28%; p=0.97).

CONCLUSIONS

The results of AHSCT for high-risk ALL remains unsatisfactory with low probability of long-term LFS.

Survival improvements in adolescents and young adults after myeloablative allogeneic transplantation for acute lymphoblastic leukemia

Adolescents and young adults (AYAs, ages 15 to 40 years) with cancer have not experienced survival improvements to the same extent as younger and older patients. We compared changes in survival after myeloablative allogeneic hematopoietic cell transplantation (HCT) for acute lymphoblastic leukemia (ALL) among children (n = 981), AYAs (n = 1218), and older adults (n = 469) who underwent transplantation over 3 time periods: 1990 to 1995, 1996 to 2001, and 2002 to 2007. Five-year survival varied inversely with age group. Survival improved over time in AYAs and paralleled that seen in children; however, overall survival did not change over time for older adults. Survival improvements were primarily related to lower rates of early treatment-related mortality in the most recent era. For all cohorts, relapse rates did not change over time. A subset of 222 AYAs between the ages of 15 and 25 at 46 pediatric or 49 adult centers were also analyzed to describe differences by center type. In this subgroup, there were differences in transplantation practices among pediatric and adult centers, although HCT outcomes did not differ by center type. Survival for AYAs undergoing myeloablative allogeneic HCT for ALL improved at a similar rate as survival for children.

Treatment of High-Risk Philadelphia Chromosome–Negative Acute Lymphoblastic Leukemia in Adolescents and Adults According to Early Cytologic Response and Minimal Residual Disease After Consolidation Assessed by Flow Cytometry: Final Results of the PETHEMA ALL-AR-03 Trial

Purpose

Minimal residual disease (MRD) is an important prognostic factor in adults with acute lymphoblastic leukemia (ALL) and may be used for treatment decisions. The Programa Español de Tratamientos en Hematología (PETHEMA) ALL-AR-03 trial (Treatment of High Risk Adult Acute Lymphoblastic Leukemia [LAL-AR/2003]) assigned adolescent and adult patients (age 15 to 60 years) with high-risk ALL (HR-ALL) without the Philadelphia (Ph) chromosome to chemotherapy or to allogeneic hematopoietic stem-cell transplantation (allo-HSCT) according to early cytologic response (day 14) and flow-MRD level after consolidation.

Patients and Methods

Patients with good early cytologic response (< 10% blasts in bone marrow at day 14 of induction) and a flow-MRD level less than 5 × 10−4 at the end of consolidation were assigned to delayed consolidation and maintenance therapy, and allo-HSCT was scheduled in patients with poor early cytologic response or flow-MRD level ≥ 5 × 10−4.

Results

Complete remission was attained in 282 (87%) of 326 patients, and 179 (76%) of 236 patients who completed early consolidation were assigned by intention-to treat to receive allo-HSCT (71) or chemotherapy (108). Five-year disease-free survival (DFS) and overall survival (OS) probabilities were 37% and 35% for the whole series, 32% and 37% for patients assigned to allo-HSCT, and 55% and 59% for those assigned to chemotherapy. Multivariable analysis showed poor MRD clearance (≥ 1 × 10−3 after induction and ≥ 5 × 10−4 after early consolidation) as the only prognostic factor for DFS and OS.

Conclusion

Prognosis for Ph-negative HR-ALL in adolescents and adults with good early response to induction and low flow-MRD levels after consolidation is quite favorable when allo-HSCT is avoided. In this study, the pattern of MRD clearance was the only prognostic factor for DFS and OS.

SET-NUP214 is a recurrent γδ lineage-specific fusion transcript associated with corticosteroid/chemotherapy resistance in adult T-ALL

The SET-NUP214 (TAF1/CAN) fusion gene is a rare genetic event in T-cell acute lymphoblastic leukemia (T-ALL). Eleven (6%) of 196 T-ALL patients enrolled in the French Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL) 2003 and 2005 trials harbored a SET-NUP214 transcript. SET-NUP214-positive patients were predominantly (10 [91%] of 11) T-cell receptor (TCR)-negative and strikingly associated with TCRγδ lineage T-ALLs, as defined by expression of TCRγδ, TCRδ and/or TCRγ rearrangements but no complete TCRβ variable diversity joining rearrangement in surface CD3/TCR-negative cases. When compared with SET-NUP214-negative patients, SET-NUP214-positive patients showed a significantly higher rate of corticosteroid resistance (91% vs 44%; P = .003) and chemotherapy resistance (100% vs 44%; P = .0001). All SET-NUP214-positive patients but one achieved complete remission, and 9 were allografted. Despite the poor early-treatment sensitivity, the outcome of SET-NUP214-positive patients was similar to that of SET-NUP214-negative patients.

Predictors of outcome in adults with BCR-ABL negative acute lymphoblastic leukemia treated with a pediatric-based regimen

We retrospectively evaluated the outcome of 156 adults age 17-60 with BCR-ABL negative acute lymphoblastic leukemia treated with a pediatric-inspired protocol. The CR rate was 93%; 5-year overall survival (OS) and disease-free survival were 66% and 70%, respectively. Age <34 years and low presenting WBC were independent predictors of favorable OS (p<0.0001). The 5 year OS of patients age <34 and 34-60 presenting with a low WBC were 85% and 57%, respectively; the 5 year OS for those presenting with a high WBC were 57% and 30%, respectively. Cytogenetics and phenotype were not independent predictors of OS.

The role of hematopoietic cell transplantation in adult ALL: clinical equipoise persists

Adults with acute lymphoblastic leukemia (ALL) in first complete remission (CR1) may be treated either with ongoing systemic chemotherapy or with allogeneic hematopoietic cell transplantation (alloHCT). Despite the presence of phase III trials to support clinical decision-making, we hypothesized that physicians who treat adult ALL would demonstrate wide practice variation. Canadian hematologists who treat ALL were surveyed electronically. Overall, 69 of 173 physicians responded (40%). There was high agreement with offering alloHCT for ALL with high-risk cytogenetics or induction failure after a single chemotherapy cycle. However, only a minority of respondents felt that age >35 years was an indication for alloHCT in CR1. Almost all respondents (96%) felt that a well-matched unrelated donor was an acceptable alternative to a sibling donor. There was uncertainty about the role of cord blood (53% agree) and the utility of reduced intensity conditioning HCT (41% agree). In contrast to the results of the MRC/ECOG study, respondents considered alloHCT to be particularly helpful in high-risk patients. Consensus was lacking on the use of cord blood, RIC alloHCT, and the application of MRD. Equipoise exists on the role of alloHCT in CR1 in ALL, suggesting that further trials in this area are required.

Management of adult and paediatric acute lymphoblastic leukaemia in Asia: resource-stratified guidelines from the Asian Oncology Summit 2013

Survival for adults and children with acute lymphoblastic leukaemia has risen substantially in recent years because use of improved risk-directed treatments and supportive care has widened. In nearly all developed countries, multidisciplinary panels of leukaemia experts have formulated clinical practice guidelines in which standard treatment approaches are recommended on the basis of current evidence. However, those guidelines do not take into account resource limitations in low-income countries, including financial and technical challenges. In Asia, huge disparities in economy and infrastructure exist between countries, and even among different regions in some large countries. At a consensus session held as part of the 2013 Asian Oncology Summit in Bangkok, Thailand, a panel of experts summarised recommendations for management of adult and paediatric acute lymphoblastic leukaemia. Strategies were developed for Asian countries on the basis of available financial, skill, and logistical resources and were stratified in a four-tier system according to the resources available in a particular country or region (basic, limited, enhanced, and maximum).

Cellular immunotherapy for refractory hematological malignancies

Background

Acute myeloid leukemia (AML) and other aggressive refractory hematological malignancies unresponsive to upfront therapy remain difficult conditions to treat. Often, the focus of therapy is centered on achieving complete remission of disease in order to proceed with a consolidative stem cell transplant. At issue with this paradigm is the multitude of patients who are unable to achieve complete remission with standard chemotherapeutic options. A major benefit of transplantation is the graft versus tumor effect that follows successful engraftment. However, with this graft versus tumor effect comes the risk of graft versus host disease. Therefore, alternative treatment options that utilize immunotherapy while minimizing toxicity are warranted. Herein, we propose a novel treatment protocol in which haploidentical peripheral blood stem cells are infused into patients with refractory hematological malignancies. The end goal of cellular therapy is not engraftment but instead is the purposeful rejection of donor cells so as to elicit a potent immune reaction that appears to break host tumor tolerance.

Methods/design

The trial is a FDA and institutional Rhode Island Hospital/The Miriam Hospital IRB approved Phase I/II study to determine the efficacy and safety of haploidentical peripheral blood cell infusions into patients with refractory hematological malignancies. The primary objective is the overall response rate while secondary objectives will assess the degree and duration of response as well as safety considerations. Patients with refractory acute leukemias and aggressive lymphomas over the age of 18 are eligible. Donors will be selected amongst family members. Full HLA typing of patients and donors will occur as will chimerism assessments. 1-2x10⁸ CD3+ cells/kilogram will be infused on Day 0 without preconditioning. Patients will be monitored for their response to therapy, in particular for the development of a cytokine release syndrome (CRS) that has been previously described. Blood samples will be taken at the onset, during, and following the cessation of CRS so as to study effector cells, cytokine/chemokine release patterns, and extracellular vesicle populations. Initially, six patients will be enrolled on study to determine safety. Provided the treatment is deemed safe, a total of 25 patients will be enrolled to determine efficacy.

Discussion

Cellular Immunotherapy for Refractory Hematological Malignancies provides a novel treatment for patients with relapsed/refractory acute leukemia or aggressive lymphoma. We believe this therapy offers the immunological benefit of bone marrow transplantation without the deleterious effects of myeloablative conditioning regimens and minus the risk of GVHD. Laboratory correlative studies will be performed in conjunction with the clinical trial to determine the underlying mechanism of action. This provides a true bench to bedside approach that should serve to further enrich knowledge of host tumor tolerance and mechanisms by which this may be overcome.

Trial registration

NCT01685606.