Aptamer-modified chitosan-capped mesoporous silica nanoparticles for co-delivery of cytarabine and daunorubicin in leukemia

In this study, surface modified mesoporous silica nanoparticles (MSNs) were prepared for the targeted delivery of the anticancer agents, daunorubicin (DNR) and cytarabine (CTR), against K562 leukemia cancer cell lines. The MSNs were surface-modified with pH-sensitive chitosan (CS) to prevent the burst release of anticancer agents at the physiological pH of 7.4 and to enable a higher drug release at lower pH and higher concentration of glutathione. Finally, the MSNs were surface modified with KK1B10 aptamer (Apt) to enhance their uptake by K562 cells through ligand-receptor interactions. The MSNs were characterized using different methods and both in vitro and in vivo experiments were utilized to demonstrate their suitability as targeted anticancer agents. The resultant MSNs exhibited an average particle size of 295 nm, a surface area of 39.06 m2/g, and a cumulative pore volume of 0.09 cm3/g. Surface modification of MSNs with chitosan (CS) resulted in a more regulated and acceptable continuous release rate of DNR. The drug release rate was significantly higher at pH 5 media enriched with glutathione, compared to pH 7.4. Furthermore, MSNs coated with CS and conjugated with aptamer (MSN-DNR + CTR@CS-Apt) exhibited a lower IC50 value of 2.34 µg/ml, compared to MSNs without aptamer conjugation, which displayed an IC50 value of 12.27 µg/ml. The results of the cell cycle analysis indicated that the administration of MSN-DNR + CTR@CS-Apt led to a significant increase in the population of apoptotic cells in the sub-G1 phase. Additionally, the treatment arrested the remaining cells in various other phases of the cell cycle. Furthermore, the interactions between Apt-receptors were found to enhance the uptake of MSNs by cancer cells. The results of in vivo studies demonstrated that the administration of MSN-DNR + CTR@CS-Apt led to a significant reduction in the expression levels of CD71 and CD235a markers, as compared to MSN-DNR + CTR@CS (p < 0.001). In conclusion, the surface modified MSNs prepared in this study showed lower IC50 against cancer cell lines and higher anticancer activity in animal models.

Real-world outcomes of adult patients with acute lymphoblastic leukemia treated with a modified CALGB 10102 regimen

Acute lymphoblastic leukemia (ALL) is an aggressive bone marrow cancer with disparate outcomes. Data on patient outcomes in real world settings outside of clinical trials is limited. The current study reports on outcomes for 137 ALL patients who received an adult induction and consolidation regimen derived from the CALGB 10102 trial modified without alemtuzumab. Of the 137 patients, 32 were < 40 years old, 52 were between 40 and 59, and 53 were ≥ 60 years old. Overall, 109 (79.6%) patients achieved a complete remission (< 40: 96.1%, 40-59: 86.5%, and 62.3% ≥ 60 (p = 0.0002)). Progression free survival for the entire cohort was 13.5 months and by age was 19.8 months for less than 40, 23.4 months for 40 to 59 and 6.7 months for ≥ 60; p = 0.0002. Median survival was 22.1 months for the entire cohort (32.9 months for ages < 40, 26.6 months ages 40-59, 7.8 months ≥ 60, p < 0.001).

The Approach to Acute Lymphoblastic Leukemia in Older Patients: Conventional Treatments and Emerging Therapies

Acute lymphoblastic leukemia (ALL) among older adult patients presents significant clinical challenges. As opposed to pediatric populations, in whom long-term outcomes are markedly superior, those for adults remain grim. Nevertheless, younger adults with ALL have experienced a steady improvement in long-term survival in the last few decades. This is significantly different for older ALL patients, for whom long-term outcomes remain poor. Conventional chemotherapies are associated with sub-optimal outcomes and increased toxicity in this population. However, several emerging therapies, including antibody-drug conjugates, bi-specific engagers, and chimeric antigen receptor (CAR) T cells, have demonstrated much promise and are either incorporated into the existing therapeutic paradigms or being actively investigated to improve outcomes.

SCL/TAL1: a multifaceted regulator from blood development to disease

SCL/TAL1 (stem cell leukemia/T-cell acute lymphoblastic leukemia [T-ALL] 1) is an essential transcription factor in normal and malignant hematopoiesis. It is required for specification of the blood program during development, adult hematopoietic stem cell survival and quiescence, and terminal maturation of select blood lineages. Following ectopic expression, SCL contributes to oncogenesis in T-ALL. Remarkably, SCL’s activities are all mediated through nucleation of a core quaternary protein complex (SCL:E-protein:LMO1/2 [LIM domain only 1 or 2]:LDB1 [LIM domain-binding protein 1]) and dynamic recruitment of conserved combinatorial associations of additional regulators in a lineage- and stage-specific context. The finely tuned control of SCL’s regulatory functions (lineage priming, activation, and repression of gene expression programs) provides insight into fundamental developmental and transcriptional mechanisms, and highlights mechanistic parallels between normal and oncogenic processes. Importantly, recent discoveries are paving the way to the development of innovative therapeutic opportunities in SCL+ T-ALL.

Canine acute leukaemia: 50 cases (1989-2014)

Acute leukaemia (AL) is a bone marrow malignancy of hematopoietic progenitors that historically is poorly responsive to treatment. With the widespread adoption of dose-intense chemotherapy, more human patients attain long-term survivals, but whether comparable progress has been made in canine AL is unknown. To investigate this question, medical records from three academic veterinary hospitals were reviewed. Fifty dogs met the criteria for AL, having excess circulating or marrow blasts, a major cytopenia(s), and no substantial lymphadenopathy. Thirty-six dogs received cytotoxic chemotherapy; 23 achieved a complete or partial response for a median of 56 days (range, 9-218). With failure or relapse, 14 dogs were rescued. Median survival with treatment was poor at 55 days (range, 1-300). Untreated (n = 6) and palliatively-treated (n = 8) dogs lived a median of 7.5 days. Most dogs developed chemoresistance within weeks of initiating treatment, and consequently, survival times for AL remain disappointingly short.

Prognostic significance of lymphoid enhancer-binding factor-1 expression in egyptian adult B-acute lymphocytic leukemia patients

Objective:

Lymphoid enhancer-binding factor-1 (LEF-1) is a key transcription factor of wingless-type (Wnt) signaling in various tumors and it is associated with a number of malignant diseases such as leukemia. We explored the expression profile of LEF-1 in acute lymphoblastic leukemia (ALL) and determined its specific prognostic significance in this disease.

Materials and Methods:

We studied LEF-1 expression in 56 newly diagnosed B-acute ALL adult patients using real-time quantitative polymerase chain reaction to investigate whether LEF-1 expression was associated with clinical patient characteristics and treatment outcomes.

Results:

High LEF-1 expression was associated with significantly poorer disease-free survival (p=0.03) and overall survival (p=0.005). Patients with high LEF-1 expression had a significantly higher relapse rate compared with low LEF-1 expression (p=0.01).

Conclusion:

We provide evidence that high LEF-1 expression is a prognostic marker in adult B-acute ALL patients.

Efficacy of CPX-351, (cytarabine:daunorubicin) liposome injection, against acute lymphoblastic leukemia (ALL) xenograft models of the Pediatric Preclinical Testing Program

BACKGROUND

CPX-351, a liposomal formulation of cytarabine and daunorubicin co-encapsulated at an optimized synergistic 5:1 molar ratio, has demonstrated improved clinical outcomes over conventional cytarabine/daunorubicin treatment in a randomized phase 2 trial in patients with AML as well as superior efficacy against preclinical leukemia models when compared to the free drugs in combination.

PROCEDURES

Given the promising phase 2 data, limited toxicities observed, and the known clinical activities of cytarabine/daunorubicin, we assessed the efficacy of CPX-351 against a panel of childhood ALL xenograft models. Plasma pharmacokinetics of cytarabine and daunorubicin following CPX-351 treatment were determined by HPLC in order to correlate efficacy with drug exposure.

RESULTS

CPX-351, at a dose of 5 units/kg (corresponding to 5 mg/kg cytarabine and 2.2 mg/kg daunorubicin), was highly efficacious against all xenografts tested, inducing complete responses in four B-lineage xenografts and partial response in one T-lineage xenograft. These therapeutic responses were achieved with CPX-351 doses that provided drug exposures (based on Cmax and AUC) comparable to those observed in patients with AML.

CONCLUSIONS

These results suggest that CPX-351 may be a promising chemotherapeutic to be utilized in the treatment of ALL and support its testing in pediatric patients with leukemia.

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.

Immunophenotypic, Cytogenetic and Clinical Features in Chinese Adult Acute Lymphoblastic Leukaemia (ALL) Patients

Introduction: This study sought to investigate the immunophenotypic subtype profiles of 110 Chinese adult patients with acute lymphoblastic leukaemia (ALL) and its association to cytogenetics and the clinical features. Materials and Methods: A total of 110 adult patients with ALL were immunophenotyped by CD45/SSC double parameters and 4 colour flow cytometry. Seventy-three cases were also subjected to karyotype analysis by R-banding technology. The clinical and laboratory data of 110 ALL patients were retrospectively analysed. Results: Of all the patients, 21.8% were identified as T-ALL, 78.2% as B-ALL. Abnormal karyotypes were detected in 37 out of 73 (50.7%) cases and the most common cytogenetic abnormality was the Philadelphia (Ph) chromosome, which was found in 23.3% (17/73) of the cases. Myeloid antigen (MyAg) expression was documented in 47.3% of the 110 adult ALL cases analysed and CD13 was the most commonly expressed MyAg in ALL patients (32.1 %). No difference was observed in the expression of MyAg between the groups of patients with T-ALL (45.8%) and B-ALL (47.7%). Our data showed that older age, higher CD34 positivity and lower proportion of patients with splenomegaly were found to be correlated with MyAg+ ALL, and that patients with Ph+ B-ALL were older, presented with higher haemoglobin level and higher CD34 expression. No statistical difference was noted in complete remission (CR) rate, relapse rate, induction mortality or total death rate among My+ and My-, Ph+ and Ph-, or B-ALL and T-ALL patients. Conclusion: Our results indicate that the distribution of ALL in Chinese adult patients was similar with the general distribution pattern in the other countries, and the expression of MyAg in patients with T-ALL and B-ALL was comparable. Both the expression of MyAg and the presence of Ph chromosome in adult ALL were significantly associated with median age and CD34 expression while not with the response to induction treatment. Key words: Biological characteristics, Cytogenetics, Immunophenotype

IGH@ translocations, CRLF2 deregulation, and microdeletions in adolescents and adults with acute lymphoblastic leukemia

PURPOSE

To determine the prevalence and prognostic impact of significant acute lymphoblastic leukemia (ALL) -related genes: CRLF2 deregulation (CRLF2-d), IGH@ translocations (IGH@-t), and deletions of CDKN2A/B, IKZF1, PAX5, ETV6, RB1, BTG1, and EBF1 in adolescents and adults.

PATIENTS AND METHODS

The cohort comprised 454 patients (age 15 to 60 years old) treated on the multicenter United Kingdom Acute Lymphoblastic Leukaemia Trial XII/Eastern Cooperative Oncology Group 2993 trial (UKALLXII/ECOG2993) with Philadelphia-negative B-cell precursor ALL. Fluorescent in situ hybridization and multiplex ligation-dependent probe amplification were used to detect these genetic alterations.

RESULTS

Twenty patients (5%) had CRLF2-d (P2RY8-CRLF2, n = 7; IGH@-CRLF2, n = 13), and 36 patients (8%) harbored an IGH@-t with a different partner gene. There was little overlap between IGH@-t, CRLF2-d, and established chromosomal abnormalities. Deletions of CDKN2A/B, IKZF1, PAX5, ETV6, RB1, BTG1, or EBF1 were prevalent with 101 (33%) of 304 patients harboring one and 102 (33%) harboring two or more alterations, occurring with varying frequency in all cytogenetic subgroups. The 5-year event-free survival, relapse-free survival (RFS), and overall survival (OS) rates for the whole cohort were 40%, 55%, and 43%, respectively. Patients with CRLF2-d, IGH@-t, and IKZF1 deletions were associated with an inferior outcome in univariate but not multivariate analysis. In particular, CRLF2-d patients had a lower RFS compared with other patients (30%), whereas those with IGH@-t or IKZF1 deletions had a lower OS (27% and 35%, respectively).

CONCLUSION

CRLF2-d and IGH@-t represent distinct subtypes of adolescent and adult ALL. Deletions of key B-cell differentiation and cell cycle control genes are highly prevalent but vary in frequency by cytogenetic subgroup. CRLF2-d, IGH@-t, and IKZF1 deletions are associated with poor outcome in adolescent and adult ALL.

CD133 immunomagnetic separation: effectiveness of the method for CD133(+) isolation from umbilical cord blood

BACKGROUND AIMS

Umbilical cord blood (UCB) is a rich source of stem cells, the characterization and isolation of which requires specific stem cell markers and reliable and reproducible protocols.

METHODS

We assessed CD133 isolation in 39 UCB samples, using a commercial immunomagnetic cell-sorting protocol, and, because of its non-reproducibility, we applied optimized protocols in an effort to improve it. These included extra-labeling of the selected CD133(+) subpopulation and indirect labeling using anti-phycoerythrin (PE) microbeads, goat anti-mouse IgG microbeads or a combination of both. The CD34 isolation was used as a control.

RESULTS

The mononuclear cell fraction expressed 0.53±0.06% CD133. The corresponding value for CD34 was 1.64±0.15%. Following the manufacturer's instructions, the CD34 isolation resulted in a population expressing 93±1.25% CD34 while, after the corresponding process, CD133(+) expression ranged from 10% to 85% (median 60%). The optimized isolation protocols did not result in improved CD133(+) yield. The variation in the purity of the CD133 population cannot be attributed to the different clones of CD133 used, because they do not cross-block, while other factors such as glycosylation, which could possibly interfere, do not apply in normal hematopoietic stem cells (HSC).

CONCLUSIONS

CD34 isolation by the immunomagnetic method results in highly pure CD34(+) population, while the efficient and reproducible yield of a pure CD133(+) population is not feasible. Therefore quantification of the positive cells should follow each isolation procedure in order to confirm the number of CD133(+) cells.

Acute lymphoblastic leukemia of adulthood: progress or not?

OPINION STATEMENT

Much new information about ALL in adults has recently been learned from major clinical and laboratory studies. However, much of the recently reported improved management of this leukemia pertains only to younger patients. Elderly patients do not fair very well with modern therapy, including intensified treatment approaches. The question arises whether current treatment may be unnecessarily intensive, not only for elderly patients but for most patients. There are no prospective, randomized studies that clearly demonstrate that anthracyclines, cyclophosphamide or cytarabine are required for optimal results in this leukemia. Eliminating drugs of marginal value but with the potential for considerable toxicity may allow us to intensify treatment with drugs that are most effective at a cost of even less toxicity than usually expected.

Predictive impact of allele-matching and EBMT risk score for outcome after T-cell depleted unrelated donor transplantation in poor-risk acute leukemia and myelodysplasia

Many parameters predict for outcome after unrelated donor (URD) allogeneic hematopoietic stem cell transplantation (alloSCT). High-resolution HLA-matching significantly impacts outcome and also the European Group of Blood and Marrow Transplantation (EBMT) risk score, based on patient age, disease stage, donor type, time from diagnosis to SCT and gender combination, may predict for non-relapse mortality and overall survival (OS). We evaluated the individual and combined effects of allele-matching and the EBMT risk score in 327 patients with poor-risk acute leukemia or myelodysplasia, who received a T-cell depleted URD alloSCT. Matching for HLA-A, -B, -C and -DRB1 alleles (8/8 match) was associated with a 5-year OS of 40% compared with 30% for mismatched (≤7/8) pairs (P=0.02). Patients with EBMT risk scores of 1-2, 3, 4 and 5-7 had 5-year OS estimates of 53, 43, 30 and 20%, respectively (P<0.001). The favorable prognostic impact of an 8/8 donor was most pronounced if the EBMT risk score was low (1-2). Five-year OS was 74±8% vs 39±11% for fully matched patients with a low-risk EBMT score as compared with EBMT low-risk patients with ≤7/8 donors. These data underscore the importance of incorporating both the EBMT risk score and the degree of high-resolution HLA-matching in the risk assessment prior to URD alloSCT.

Delayed platelet recovery after allogeneic transplantation: a predictor of increased treatment-related mortality and poorer survival

Delayed platelet recovery (DPR) is common after allo-SCT. Insufficient data on risk factors and association with OS and TRM are available. We conducted a retrospective analysis of all allografts at the University of Minnesota between 2000 and 2005 to characterize the frequency of DPR (platelets <50 000/μL by day 60), risk factors and related complications. A total of 850 patients with hematological malignancies and benign disorders were included. Myeloablative (MA) conditioning was used in 65% of the patients and 45% received umbilical cord blood (UCB) grafts. The 60-day cumulative incidence of platelet recovery was 40% in UCB, 57% in unrelated donor (URD) and 74% in sibling donor. Multivariate analysis confirmed that the variables associated with DPR were MA (versus reduced intensity) conditioning, graft source other than sibling donor, ABO major mismatch, recipient CMV-positive serostatus, the presence of grade II-IV acute GVHD and slower neutrophil recovery. These data demonstrate that DPR is frequent after allogeneic hematopoietic cell transplantation, especially after UCB. DPR is a significant independent risk factor for increased TRM and poorer OS along with HLA-mismatched URD, but not UCB, grade II-IV acute GVHD, old age and advanced disease stage.

High BAALC expression predicts chemoresistance in adult B-precursor acute lymphoblastic leukemia

Overexpression of BAALC is an adverse prognostic factor in adults with cytogenetically normal acute myeloid leukemia and T-cell acute lymphoblastic leukemia (ALL). Here, we analyzed the prognostic significance of BAALC in B-precursor ALL. BAALC MRNA expression was determined in 368 primary adult B-precursor ALL patients enrolled on the 06/99 and 07/03 GMALL trials. Patients were grouped into tertiles according to BAALC expression (T1-T3). Higher BAALC expression (T3 vs T2 vs T1) was associated with higher age (P < .001), a higher white blood cell count (P = .008), CD34 (P = .001), BCR-ABL (P < .001), and MLL-AF4 (P < .001). Higher BAALC expression predicted primary therapy resistance in the overall cohort (P = .002) and in the BCR-ABL− and MLL-AF4− subgroup (P = .01). In BCR-ABL− and MLL-AF4− patients, higher BAALC expression was associated with a shorter overall survival (OS; 5-year OS: T3, 38%; T2, 52%; T1, 70%; P = .004) and independently predicted OS in multivariate models (P = .03). Gene-expression profiling revealed an up-regulation of stem cell markers and genes involved in chemoresistance (TSPAN7 and LYN) in the high BAALC group. Thus, high BAALC expression is associated with an immature, chemoresistant leukemic phenotype and identifies patients with inferior OS. Determination of BAALC might contribute to risk assessment of molecularly undefined adult B-precursor ALL.

Leukemia-selective uptake and cytotoxicity of CPX-351, a synergistic fixed-ratio cytarabine:daunorubicin formulation, in bone marrow xenografts

The objective of this study was to examine the pharmacodynamic basis for the potent preclinical and clinical anti-leukemic activity of CPX-351, a nano-scale liposome formulation of cytarabine and daunorubicin co-encapsulated at a synergistic 5:1 molar ratio. A bone marrow-engrafting CCRF-CEM leukemia model in Rag2-M mice was utilized to correlate the therapeutic and myelosuppressive properties of CPX-351 with bone marrow delivery and drug uptake in leukemia cells relative to normal bone marrow cell populations. When administered to mice bearing CCRF-CEM human leukemia xenografts, CPX-351 ablated bone marrow (BM) leukemic cells to below detectable levels for multiple weeks, whereas the free-drug cocktail only transiently suppressed leukemia growth. In contrast to the activity against leukemia cells, CPX-351 and free-drug cocktail induced similar myelosuppression in non-tumor-bearing BM. In leukemia-laden BM, drug concentrations were markedly elevated for CPX-351 over free-drug cocktail and the first dose of CPX-351, but not free-drug cocktail, potentiated BM drug accumulation for subsequent doses. Confocal fluorescence microscopy revealed that CPX-351 liposomes are taken up by CCRF-CEM cells and subsequently release drugs intracellularly. The improved in vivo efficacy of CPX-351 appears related to increased and prolonged exposure of synergistic cytarabine:daunorubicin ratios in BM, and the selective killing of leukemia may arise from direct liposome-leukemia cell interactions. These features may also have broader applicability in the treatment of other haematological malignancies.

A population-based cytogenetic study of adults with acute lymphoblastic leukemia

Chromosomal abnormalities are increasingly used to risk stratify adults with acute lymphoblastic leukemia. Published data describing the age-specific incidence of chromosomal abnormalities and their prognostic relevance are largely derived from clinical trials. Trials frequently have age restrictions and low recruitment rates. Thus we investigated these factors in a population-based cohort of 349 patients diagnosed during the course of 19 years in the northern part of England. The incidence of most chromosomal abnormalities varied significantly with age. The incidence of t(9;22)(q34;q11) increased in each successive decade, up to 24% among 40- to 49-year-old subjects. Thereafter the incidence reached a plateau. t(4;11)(q21;q23) and t(1;19)(q23;p13) were a rare occurrence among patients older than 60 years of age. In contrast, the frequency of t(8;14)(q24;q32) and t(14;18)(q32;q21) increased with age. High hyperdiploidy occurred in 13% of patients younger than 20 years of age but in only 5% of older patients. The incidence of low hypodiploidy/near-triploidy and complex karyotype increased with age from 4% (15-29 years) to 16% (≥ 60 years). Overall survival varied significantly by age and cytogenetics. Older patients and those with t(9;22), t(4;11), low hypodiploidy/near-triploidy, or complex karyotype had a significantly inferior outcome. These population-based results demonstrate the cytogenetic heterogeneity of adult acute lymphoblastic leukemia. These data will inform the delivery of routine clinical services and the design of new age-focused clinical trials.

Reduced-intensity conditioning hematopoietic stem cell transplantation in patients over 60 years: hematologic malignancy outcomes are not impaired in advanced age

Reduced-intensity-conditioning (RIC) hematopoietic stem cell transplantation (HSCT) is markedly underutilized in the elderly, in part because the impact of advanced age on outcomes is poorly understood. We retrospectively analyzed outcomes in 158 consecutive hematologic malignancy patients aged > or =60 years (median, 63 years; range: 60-71 years) undergoing fludarabine/busulfan-based RIC, with a median-follow-up of 34 months (range: 12.0-85.7). Multivariate analysis was undertaken for factors having an impact on outcome. For the patients aged > or =60 years, 2-year nonrelapse mortality (NRM) and relapse was 10% and 54.6%, respectively. Two-year overall and progression-free survival (OS, PFS) was 46% and 35%, respectively. Grade II-IV acute and chronic graft-versus-host disease (aGVHD, cGVHD) incidence was 19.6% and 45.9%, respectively. Comparing 110 patients aged 60-64 years versus 48 patients aged > or =65 years, 2-year NRM and relapse was 10.5% versus 8.3% (P = .84) and 53.5% versus 56.3% (P = .31), respectively. Grade II-IV aGVHD and cGVHD incidence was 19.1% versus 22.9% (P = .52) and 51.8% versus 32.5% (P = .01), respectively. Two-year OS and PFS was 49% versus 41% (P = .11) and 36% versus 35% (P = .24), respectively. In a multivariate Cox-model, high-risk disease associated with poorer PFS (hazard ratio [HR] = 2.1, P = .01) and OS (HR = 1.84, P = .03); acute myelogenous leukemia/myelodysplastic syndrome diagnosis (HR = 1.66, P = .03) and matched-related donor (HR = 1.62, P = .03) associated with poorer PFS. RIC HSCT is well tolerated, with reasonable survival in elderly patients. Age is not associated with impaired outcomes. HSCT should not be excluded solely based on advanced patient age.

Hematopoietic stem cell transplantation for adults with acute lymphoblastic leukemia

PURPOSE OF REVIEW

The long-term survival for patients with adult acute lymphoblastic leukemia (ALL) has not significantly changed over the past two decades and, as opposed to pediatric ALL, it is less than 40% despite high initial complete remission rate. These observations raise several important issues regarding the pathobiology of adult leukemic stem cells, the ability of adults to tolerate intensive treatment and the best postremission approach.

RECENT FINDINGS

Progress has been made in understanding the biology of adult ALL and its prognostic significance. The follow-up of minimal residual disease status, adopting protocols from childhood ALL to young adults and use of targeted therapy may improve long-term survival. Transplantation for standard-risk ALL in first remission proved to be beneficial in a large cooperative group study. Limited data on the use of alternative donor transplantation as well as reduced intensity protocols are now available for consideration in specific groups of patients.

SUMMARY

Data suggest that the best antileukemic treatment should be applied in first remission and type of treatment should be based on individualized risk stratification, while incorporating recent information on alternative donors and reduced intensity approaches to transplantation.

Transplantation in adult ALL

The value of the allogeneic graft-versus-leukemia effect in adult acute lymphoblastic leukemia (ALL) has now been conclusively demonstrated and confirmed. While this is true for adults in all age groups, it may not be the best clinical option for young adults for whom increasingly intensive pediatric protocols are clearly of benefit. On the other hand, there is potentially wider applicability of allogeneic donor transplantation for adults 25 to 45 years old, for whom matched unrelated donors may be as safe and effective as sibling donors, and for the patient older than 45 years for whom reduced-intensity conditioning may be a promising way forward. Since the treatment-related mortality of allogeneic transplantation remains significant, careful selection of patients is mandatory. Patients with the Philadelphia chromosome, those with t(4;11) and those with a complex karyotype remain transplant candidates, and allogeneic transplantation remains the best option for salvage, where achievable, in a remission beyond first. As in childhood ALL minimal residual disease studies may be extremely useful in predicting outcome and, therefore, strategy, but at present there are less definite data in adults. Clinical indications to harness the allogeneic effect will mature as the true value of pediatric protocols in adult patients and the safety and efficacy of a sibling, unrelated and reduced intensity transplant emerge in this disease.

Evolving paradigms in the therapy of Philadelphia chromosome–negative acute lymphoblastic leukemia in adults

Important studies challenging previous approaches to the treatment of adults with Philadelphia chromosome–negative acute lymphoblastic leukemia (ALL) have emerged in the past decade. Donor versus no donor comparisons of allogeneic transplant highlight a potent graft-versus-leukemia effect in ALL, and the application of reduced-intensity conditioning transplants may exploit this effect while reducing non-relapse mortality. The adoption of the use of pediatric intensity-type regimens in adolescents and young adults shows promise to improve outcomes in this population. New therapeutic targets such as mutations in NOTCH1 in T-cell ALL and CD22 in pre-B ALL are being exploited in clinical trials. The application of molecular techniques and flow cytometry to quantitate minimal residual disease will allow further stratification of patients by risk. Although the outcomes of adults with ALL lag behind the stunningly successful results seen in children, new paradigms and new discoveries bring hope that this disparity will steadily lessen.