Is it appropriate to offer allogeneic hematopoietic stem cell transplantation to patients with primary refractory acute myeloid leukemia?

Long-term follow-up of patients with poor-risk acute leukemia treated on a phase 2 trial undergoing intensified conditioning regimen prior to allogeneic hematopoietic cell transplantation

Patients with acute leukemia who undergo allogenic hematopoietic cell transplantation with active disease have high rates of relapse and poor overall survival (OS) post-transplant compared to patients undergoing HCT in remission. Here, we report the long-term outcomes in 32 patients who received a high-intensity conditioning regimen comprising fractionated total body irradiation (FTBI; 1200 cGy) with pharmacokinetic (PK) dosing of intravenous Busulfan (IV BU) targeted to first dose area under curve (AUC) of 700-900 µM/min and etoposide (30 mg/kg) in a prospective phase 2 clinical trial. The median age of the patients at the time of HCT was 37 years (range: 18-50) presenting with high-risk (n = 6) and relapsed/refractory(r/r) acute leukemias (n = 26). All but one patient underwent HCT using peripheral blood stem cells from matched sibling donors. At a median follow-up of 17.3 years (range 14.4-19.0), 11 patients remained alive. The disease-free survival and OS at 15 years was 34% (versus 40% at 5-years post-HCT). The 15-year cumulative incidence of relapse was 26% and non-relapse mortality (NRM) was 38% (95% CI: 21-54%) and the cumulative incidence of chronic GVHD at 15 years was 33% using a prophylactic regimen of cyclosporine A and mycophenolate mofetil. The most common life-threatening late effects were secondary malignancies, metabolic, or cardiac complications with a cumulative incidence of 6.6%, 6.6%, and 13.3%, respectively. No unusual late effects or patterns of relapse were noted on longer followed on patients treated with intensified myeloablative condition regimen. Results from this study supports continued development of intensive conditioning regimens in patients with r/r acute leukemias to improve leukemia free (LFS) and OS in this high-risk population.

Total Body Irradiation for Hematopoietic Stem Cell Transplantation: What Can We Agree on?

Total body irradiation (TBI), used as part of the conditioning regimen prior to allogeneic and autologous hematopoietic cell transplantation, is the delivery of a relatively homogeneous dose of radiation to the entire body. TBI has a dual role, being cytotoxic and immunosuppressive. This allows it to eliminate disease and create “space” in the marrow while also impairing the immune system from rejecting the foreign donor cells being transplanted. Advantages that TBI may have over chemotherapy alone are that it may achieve greater tumour cytotoxicity and better tissue penetration than chemotherapy as its delivery is independent of vascular supply and physiologic barriers such as renal and hepatic function. Therefore, the so-called “sanctuary” sites such as the central nervous system (CNS), testes, and orbits or other sites with limited blood supply are not off-limits to radiation. Nevertheless, TBI is hampered by challenging logistics of administration, coordination between hematology and radiation oncology departments, increased rates of acute treatment-related morbidity and mortality along with late toxicity to other tissues. Newer technologies and a better understanding of the biology and physics of TBI has allowed the field to develop novel delivery systems which may help to deliver radiation more safely while maintaining its efficacy. However, continued research and collaboration are needed to determine the best approaches for the use of TBI in the future.

Emerging agents and regimens for treatment of relapsed and refractory acute myeloid leukemia

Relapsed and refractory acute myeloid leukemia (R/R AML) has complicated pathogenesis. Its treatment is complicated, and the prognosis is poor. So far, there is no consensus on what is the optimal treatment strategy. With the deepening of research, new chemotherapy regimens, new small molecule inhibitors, and immunotherapy have been increasingly applied to clinical trials, providing more possibilities for the treatment of R/R AML. The most effective treatment for patients who achieve complete remission after recurrence is still sequential conditioning therapy followed by allogeneic hematopoietic cell transplantation. Finding the best combination of treatments is still an important goal for the future.

Efficacy and Safety of Unmanipulated Haploidentical Related Donor Allogeneic Peripheral Blood Stem Cell Transplantation in Patients with Relapsed/Refractory Acute Myeloid Leukemia

Background:

Studies of haploidentical-related donor (HRD) stem cell transplantation using a combination of peripheral blood stem cells (PBSCs) and bone marrow as the graft have reported encouraging results for patients with hematological diseases. However, few studies specifically reported transplantation of only PBSCs from HRDs among patients with relapsed or refractory acute myeloid leukemia (AML). Here, the long-term outcomes and side effects of unmanipulated HRD PBSC transplantation (HRD-PBSCT) for relapsed/refractory AML were analyzed.

Methods:

We performed a retrospective analysis of the outcomes in relapsed/refractory AML patients who underwent PBSCT from HRDs (n = 36).

Results:

Thirty-one (86.1%) patients in the HRD-PBSCT group achieved platelet recovery. The cumulative incidence of acute graft-versus-host disease (aGVHD) in the HRD-PBSCT group was 40.00%, and the cumulative incidence of grades 2–4 aGVHD in this group was 13.33%. A total of 13 patients in the HRD-PBSCT group had recurrent disease at a median of 183 days after transplantation (range: 10–1700 days), reaching cumulative incidences of relapse of 50.28% at 5 years. On multivariate analysis, donor age and patient age >40 years were independent risk factors for inferior disease-free survival or overall survival (P < 0.05). The results of the present study demonstrate rapid and complete neutrophil engraftment, a low incidence of grade 2–4 aGVHD, and promising survival rates in patients after HRD-PBSCT. Thus, granulocyte colony-stimulating factor–primed PBSCs may be a reliable graft source in unmanipulated HRD-HSCT under myeloablative conditioning when no matched sibling donor is available.

Conclusions:

Our results support the feasibility, effectiveness, and tolerability of PBSCs as a graft source in unmanipulated HRD transplantation under myeloablative conditioning in patients with leukemia.

Total Body Irradiation without Chemotherapy as Conditioning for an Allogeneic Hematopoietic Cell Transplantation for Adult Acute Myeloid Leukemia

Current therapies for acute myeloid leukemia (AML), failing induction, are rarely effective. We report our experience in 4 patients with AML who received 16 Gy TBI prior to allogeneic hematopoietic cell transplantation (alloHCT), between June 2010 and May 2011. Patients were 20 to 55 years of age, 2 with relapsed disease and 2 with AML failing induction. An HLA-matched graft from related or unrelated donor was infused on day 0. All but one, who received a CD34⁺-selected graft, received methotrexate and tacrolimus +/- antithymocyte globulin, as GVHD prophylaxis. The other patient received tacrolimus alone. Neutrophil and platelet engraftment occurred at a median of 18 and 14 days, respectively. Patients were discharged at a median of 28 days. There were no unexpected toxicities in the first 30 days. One patient had cytomegalovirus (CMV) viremia and anorexia, at two months. One patient had grade 2 acute GVHD of the skin. One patient developed chronic GVHD of the eyes, mouth, skin, joints, and lung at 4 months. Two patients died from relapse of their leukemia at days 65 and 125. Two patients remain in remission beyond day 1500. 16 Gy TBI followed by an alloHCT for AML, failing induction, is feasible and tolerable.

A multicenter trial of myeloablative clofarabine and busulfan conditioning for relapsed or primary induction failure AML not in remission at the time of allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) may produce long-term survival in AML after relapse or primary induction failure (PIF). However, outcomes of HCT performed for AML not in remission are historically poor given high relapse rates and transplant-related mortality. Preliminary studies suggest conditioning with clofarabine and myeloablative busulfan (CloBu4) may exert significant anti-leukemic effects without excessive toxicity in refractory hematologic malignancies. A prospective multicenter phase II trial was conducted to determine the efficacy of CloBu4 for patients proceeding directly to HCT with AML not in remission. Seventy-one patients (median age: 56 years) received CloBu4. At day 30 after HCT, 90% achieved morphologic remission. The incidence of non-relapse mortality and relapse at 2 years was 25% and 55%, respectively. The 2-year overall survival (OS) and event-free survival (EFS) were 26% and 20%, respectively. Patients entering HCT in PIF had significantly greater EFS than those in relapse (34% vs 8%; P<0.01). Multivariate analysis comparing CloBu4 with a contemporaneous cohort (Center for International Blood and Marrow Transplantation Research) of AML not in remission receiving other myeloablative conditioning (n=105) demonstrated similar OS (HR: 1.33, 95% confidence interval: 0.92-1.92; P=0.12). HCT with myeloablative CloBu4 is associated with high early response rates and may produce durable remissions in select patients with AML not in remission.

CD25 expression on residual leukemic blasts at the time of allogeneic hematopoietic stem cell transplant predicts relapse in patients with acute myeloid leukemia without complete remission

Recent studies have shown that CD25 expression at the time of diagnosis of acute myeloid leukemia (AML) may be associated with an unfavorable outcome. We focus on patients with AML without complete remission (CR) and examine the clinical correlation between surface CD25 expression at the time of transplant and subsequent transplant outcomes. We observed a significant difference in overall survival (OS), disease-free survival (DFS) and cumulative incidence of relapse (CIR) between CD25 positive (+) (n = 22) and negative (-) groups (n = 44) (2-year OS; CD25 (+) group: 5% vs. CD25 (-) group: 40%, p < 0.0001, 2-year DFS; 5% vs. 29%, p < 0.0001, 2-year CIR; 77% vs. 52%, p = 0.03). Multivariate analysis showed that CD25 expression was an independent adverse factor for OS (p = 0.002) and relapse (p = 0.001). Patients with AML with residual CD25 positive blasts at the time of transplant may require additional therapy before or after transplant to improve survival.

Multicentre survey to explore current survival of patients with acute myeloid leukaemia who failed induction chemotherapy

BACKGROUND

Acute myeloid leukaemia not responsive to first induction chemotherapy (PIF-AML) still remains a challenge, and there are only few recent epidemiological data regarding the outcome of these patients. In this multicentre survey, we evaluate the prognosis and outcome of patients with PIF-AML, who were diagnosed and treated in the last 5 yrs in four Italian institutions.

RESULTS

One hundred PIF-AML were recorded, 57 males and 43 females, with a median age of 63 yrs (19-79), 42% were younger than 60 yrs; 42% had a secondary AML and 40% had an adverse karyotype. According to cytogenetic/molecular risk stratification at diagnosis, 33% of patients were classified as favourable/intermediate-1 risk and 56% as intermediate-2/adverse risk. After a median follow-up of 11 months (1-49), 77% of patients died, while 23% were alive (with 12/23 in cCR). Thirty-six patients underwent allogeneic SCT, and of these, 11 of 36 (31%) were alive at last follow-up. The 12- and 24-month OS probability of the whole population was 45% and 21%, respectively. In multivariate analysis, the probability of OS of the whole population was significantly improved by Allo-SCT procedure (12-month OS probability 60% vs. 35%; P < 0.0001) and was better in patients with favourable/intermediate-1 risk at diagnosis (12-month OS probability 58% vs. 40%; P = 0.028). In transplanted cases, a pretransplant responsive disease was the only significant factor to predict a favourable outcome after Allo-SCT (P = 0.006).

CONCLUSION

Treatment options of PIF-AML still are limited and the prognosis, even recently, remains extremely poor. This survey shows that PIF-AML is still rarely cured without Allo-SCT and confirms the importance of initiating an urgent unrelated donor search in cases without a matched sibling donor. Moreover, the outcome of Allo-SCT is better in patients who achieve a good AML debulking before transplant. To reach this goal, new predictive scores and new protocols of salvage therapy (with target drugs or combinations) need to be explored urgently in PIF-AML.

[Current indications of allogeneic stem cell transplant in adults with acute myeloid leukemia]

Allogeneic stem cell transplantation (SCT) is an increasingly important therapeutic option for the treatment of adult patients with acute myeloid leukemia. Here we review the current indications of SCT in this disease. While patients with favorable cytogenetics should receive consolidation chemotherapy, patients with unfavorable karyotype are prime candidates for SCT or new approaches to SCT (which should be done in first complete remission). Patients with intermediate prognoses should also receive SCT in first complete remission. In the absence of a suitable matched related donor, most patients will be able to find an alternative donor to proceed to a potentially curative allogeneic transplantation. The use of reduced-intensity conditioning regimens before SCT has allowed patients in the sixth or seventh decades of life to be routinely transplanted. Despite major differences among transplant centers in the intensity and composition of the conditioning regimen and immunosuppression, choice of graft source, postgraft immune-modulation, and supportive care, there has been a dramatic improvement in terms of tolerance. Although it is presumed to be a curative strategy, major complications of SCT remain graft-versus-host disease, delayed immune recovery, multiple comorbidities, and relapse after transplant.

Allogeneic hematopoietic cell transplant for acute myeloid leukemia: Current state in 2013 and future directions

Acute myeloid leukemia (AML) represents a heterogeneous group of high-grade myeloid neoplasms of the elderly with variable outcomes. Though remission-induction is an important first step in the management of AML, additional treatment strategies are essential to ensure long-term disease-free survival. Recent pivotal advances in understanding the genetics and molecular biology of AML have allowed for a risk-adapted approach in its management based on relapse-risk. Allogeneic hematopoietic cell transplantation (allo-HCT) represents an effective therapeutic strategy in AML providing the possibility of cure with potent graft-versus-leukemia reactions, with a demonstrable survival advantage in younger patients with intermediate- or poor-risk cytogenetics. Herein we review the published data regarding the role of allo-HCT in adults with AML. We searched MEDLINE/PubMed and EMBASE/Ovid. In addition, we searched reference lists of relevant articles, conference proceedings and ongoing trial databases. We discuss the role of allo-HCT in AML patients stratified by cytogenetic- and molecular-risk in first complete remission, as well as allo-HCT as an option in relapsed/refractory AML. Besides the conventional sibling and unrelated donor allografts, we review the available data and recent advances for alternative donor sources such as haploidentical grafts and umbilical cord blood. We also discuss conditioning regimens, including reduced intensity conditioning which has broadened the applicability of allo-HCT. Finally we explore recent advances and future possibilities and directions of allo-HCT in AML. Practical therapeutic recommendations have been made where possible based on available data and expert opinion.

A critical review of which children with acute myeloid leukaemia need stem cell procedures

The last decades have seen parallel improvements in chemotherapy-based and haematopoietic stem cell transplantation (HSCT) regimens for acute myeloid leukaemia (AML) in children. There has been no consensus on indication for HSCT. Reserving HSCT for high-risk and relapsed patients spare many patients from the long-term toxicity of this treatment. The results of matched unrelated donor HSCT equal family donor transplantation and the presence of a matched sibling should no longer be a transplant indication. Minimal residual disease measured by flow cytometry may identify poor responders benefitting from HSCT in first complete remission (CR1) and those with a favourable response to induction therapy who do not need HSCT even with adverse cytogenetic aberrations. FLT3-internal tandem duplication without NPM1 mutation has a very high relapse rate despite favourable response and HSCT is indicated in CR1 in these cases. Finding the optimal indications for HSCT is a delicate balance between risk of relapse and late effects.

Providing personalized prognostic information for adult leukemia survivors

Prediction of subsequent leukemia-free survival (LFS) and chronic graft-versus-host disease (GVHD) in adults with acute leukemia who survived at least 1 year after allogeneic hematopoietic cell transplantation is difficult. We analyzed 3339 patients with acute myeloid leukemia and 1434 patients with acute lymphoblastic leukemia who received myeloablative conditioning and related or unrelated stem cells from 1990 to 2005. Most clinical factors predictive of LFS in 1-year survivors were no longer significant after 2 or more years. For acute myeloid leukemia, only disease status (beyond first complete remission) remained a significant adverse risk factor for LFS 2 or more years after transplantation. For lymphoblastic leukemia, only extensive chronic GVHD remained a significant adverse predictor of LFS in the second and subsequent years. For patients surviving for 1 year without disease relapse or extensive chronic GVHD, the risk of developing extensive chronic GVHD in the next year was 4% if no risk factors were present and higher if noncyclosporine-based GVHD prophylaxis, an HLA-mismatched donor, or peripheral blood stem cells were used. Estimates for subsequent LFS and extensive chronic GVHD can be derived for individual patients or populations using an online calculator (http://www.cibmtr.org/LeukemiaCalculators). This prognostic information is more relevant for survivors than estimates provided before transplantation.

The development and validation of a decision-analytic model representing the full disease course of acute myeloid leukemia

BACKGROUND

The treatment of acute myeloid leukemia (AML) is moving towards personalized medicine. However, due to the low incidence of AML, it is not always feasible to evaluate the cost-effectiveness of personalized medicine using clinical trials. Decision analytic models provide an alternative data source.

OBJECTIVE

The aim of this study was to develop and validate a decision analytic model that represents the full disease course of AML.

METHODS

We used a micro simulation with discrete event components to incorporate both patient and disease heterogeneity. Input parameters were calculated from patient-level data. Two hematologists critically evaluated the model to ensure face validity. Internal and external validity was tested by comparing complete remission (CR) rates and survival outcomes of the model with original data, other clinical trials and a population-based study.

RESULTS

No significant differences in patient and treatment characteristics, CR rate, 5-year overall and disease-free survival were found between the simulated and original data. External validation showed no significant differences in survival between simulated data and other clinical trials. However, differences existed between the simulated data and a population-based study.

CONCLUSIONS

The model developed in this study is proved to be valid for analysis of an AML population participating in a clinical trial. The generalizability of the model to a broader patient population has not been proven yet. Further research is needed to identify differences between the clinical trial population and other AML patients and to incorporate these differences in the model.

Clofarabine and busulfan conditioning facilitates engraftment and provides significant antitumor activity in nonremission hematologic malignancies

Patients with hematologic malignancies not in remission before allogeneic hematopoietic stem cell transplantation (HSCT) have a poor prognosis. To improve the antitumor activity of conditioning, we combined clofarabine with myeloablative doses of busulfan in a phase 1/2 study in nonremission hematologic malignancies. Forty-six patients were enrolled, including 31 patients with nonremission acute myelogenous leukemia (AML). Patients had a median age of 53 years, with a median comorbidity index of 3. Donors were unrelated, HLA mismatched, or both in 59% of patients. Common grade III to IV nonhematologic toxicities included transient transaminitis (50%), mucositis (24%), hand-foot syndrome (13%), transient hypoxia (13%), nausea/vomiting (9%), and diarrhea (9%). All patients engrafted. Complete remission was achieved in 80% of all patients by day +30 and in 100% of AML patients without prior hematopoietic stem cell transplantation. Two-year nonrelapse mortality for all patients was 31%, and overall survival was 28%. In AML, the overall survival was 48% at 1 year and 35% at 2 years. These data suggest that clofarabine combined with myeloablative doses of busulfan is well tolerated, secures engraftment, and possesses significant antitumor activity, particularly in nonremission AML. This study is registered at www.ClinicalTrials.gov under identifier NCT00556452.

Angiopoietin-2 predicts disease-free survival after allogeneic stem cell transplantation in patients with high-risk myeloid malignancies

Emerging data suggest a critical role for bone marrow angiogenesis in hematologic malignancies. The angiopoietin/Tie ligand-receptor system is an essential regulator of this process. We evaluated whether circulating angiopoietin-2 (Ang-2) is a predictor for the probability of disease-free survival (DFS) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) for high-risk acute myeloid leukemia or myelodysplastic syndrome. Ang-2 was measured by enzyme-linked immunosorbent assay in serum from 20 healthy controls and 90 patients with acute myeloid leukemia or myelodysplastic syndrome before conditioning for HSCT. Circulating Ang-2 was elevated in patients (median, 2.21 ng/mL; range, 0.18-48.84 ng/mL) compared with controls (median, 0.87 ng/mL; range, 0.27-4.51 ng/mL; P < .001). Multivariate analyses confirmed the independent prognostic impact of Ang-2 (hazard ratio [HR] = 2.46; 95% confidence interval [CI], 1.27-4.76, P = .005), percentage of bone marrow infiltration (HR = 1.14; 95% CI, 1.01-1.29, P = .033), and chemotherapy cycles before HSCT (HR = 1.38; 95% CI, 1.01-1.08, P = .048). Regression tree analysis detected optimal cutoff values for Ang-2 and recursively identified bone marrow blasts and Ang-2 as the best predictors for DFS. Because few predictors for DFS exist in the setting of allo-HSCT, Ang-2 may be used as a readily available powerful biomarker to pre-estimate DFS and may open new perspectives for risk-adapted treatment of high-risk myeloid malignancies.

Plasma elevations of tumor necrosis factor-receptor-1 at day 7 postallogeneic transplant correlate with graft-versus-host disease severity and overall survival in pediatric patients

Tumor necrosis factor-alpha (TNF-alpha) is known to play a role in the pathogenesis of graft-versus-host disease (GVHD), a cause of significant morbidity and treatment-related mortality (TRM) after allogeneic hematopoietic stem cell transplantation (HCT). We measured the concentration of TNF-Receptor-1 (TNFR1) in the plasma of HCT recipients as a surrogate marker for TNF-alpha both prior to transplant and at day 7 in 82 children who underwent a myeloablative allogeneic HCT at the University of Michigan between 2000 and 2005. GVHD grade II-IV developed in 39% of patients at a median of 20 days after HCT. Increases in TNFR1 level at day 7 post-HCT, expressed as ratios compared to pretransplant baseline, correlated with the severity of GVHD (P = .02). In addition, day 7 TNFR1 ratios >2.5 baseline were associated with inferior 1-year overall survival (OS 51% versus 74%, P = .04). As an individual biomarker, TNFR1 lacks sufficient precision to be used as a predictor for the development of GVHD. However, increases in the concentration of TNFR1, which are detectable up to 2 weeks in advance of clinical manifestations of GVHD, correlate with survival in pediatric HCT patients.

Hematopoietic stem cell transplantation in adults with acute myeloid leukemia

Hematopoietic stem cell transplantation (HSCT) is an integral part of the treatment of many patients with acute myeloid leukemia (AML). Despite extensive study, the appropriate role and timing of allogeneic and autologous transplantation in AML are poorly defined. This review critically analyzes the extensive literature, focusing on the recent advances, and provides practical recommendations for the use of HSCT in AML.

Risk assessment in haemotopoietic stem cell transplantation: disease and disease stage

This chapter addresses the impact of the disease and disease status on the outcome of stem-cell transplantation. In consideration of the other topics addressed within this volume we have elected to focus on allogeneic rather than autologous transplantation. Furthermore we have not tried to be comprehensive and discuss the role of disease status in all conditions amenable to allografting, but rather to review the evidence that exists for selected haematological malignancies. Where possible we have made some clear recommendations, but where evidence is less clear we have indicated the ongoing controversies.

Blood and marrow transplantation in elderly acute myeloid leukaemia patients - older certainly is not better

Acute myeloid leukaemia in the elderly is a disease with distinct biological properties, commonly associated with leukaemic cell treatment resistance and with an increased number of high-risk features, including concomitant myelodysplasia and poor-risk cytogenetic abnormalities such as monosomy 5 and 7. Complete remission rates after standard induction chemotherapy in patients above age 60 years are less than 50%, with long-term survival rates below 10%. Post-remission stem cell transplant therapies have not been studied extensively. Autologous transplants can result in an acceptable 3-year leukaemia-free survival rate of up to 47%, yet this procedure is applicable only to a small minority of patients. Myeloablative allogeneic transplants similarly show feasibility in selected few patients and in general are very toxic. Non-myeloablative allogeneic transplants are associated with reduced toxicity, but are plagued by an increased relapse rate. The latter strategy appears promising, but must be validated in larger, multi-centre prospective trials, in which outcomes are compared to non-transplant approaches.

Late relapse of acute myelogenous leukemia followed by epstein-barr virus-associated lymphoproliferative disease 11 years after allogeneic bone marrow transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) following myeloablative conditioning represents the treatment of choice for patients with chemotherapy-resistant leukemia. We describe a 49-year-old man with advanced, refractory acute myelogenous leukemia (AML) that was treated successfully by allogeneic bone marrow transplantation from a sibling donor with HLA mismatched at 1 locus. However, the patient developed a quiescent form of chronic graft-versus-host disease (GVHD) 7 years after transplantation, requiring long-term immunosuppressive therapy. AML relapse was documented 11 years after transplantation. Subsequently, Epstein-Barr virus (EBV)-associated posttransplantation lymphoproliferative disorder (PTLD) was also diagnosed. Immune reconstitution after allo-HSCT might have been impaired by the persistent chronic GVHD and the prolonged administration of immunosuppressive agents. As a result, immune surveillance against remaining quiescent leukemic cells as well as viral infection may have been defective, leading to the relapse of leukemia and EBV-associated PTLD.

Outcome of 609 adults after relapse of acute lymphoblastic leukemia (ALL); an MRC UKALL12/ECOG 2993 study

Most adults with acute lymphoblastic leukemia (ALL) who achieve complete remission (CR) will relapse. We examined the outcome of 609 adults with recurring ALL, all of whom were previously treated on the Medical Research Council (MRC) UKALL12/ECOG2993 study, where the overall survival (OS) of newly diagnosed patients is 38% (95% confidence interval [CI]=36%-41%) at 5 years. By contrast, OS at 5 years after relapse was 7% (95% CI=4%-9%). Factors predicting a good outcome after salvage therapy were young age (OS of 12% in patients younger than 20 years vs OS of 3% in patients older than 50 years; 2P<.001) and short duration of first remission (CR1) (OS of 11% in those with a CR1 of more than 2 years versus OS of 5% in those with a CR1 of less than 2 years; 2P<.001). Treatment received in CR1 did not influence outcome after relapse. In a very highly selected subgroup of patients who were able to receive HSCT after relapse, some were long-term survivors. We conclude from a large, unselected series with mature follow-up that most adults with recurring ALL, whatever their prior treatment, cannot be rescued using currently available therapies. Prevention of recurrence is the best strategy for long-term survival in this disease.

Induction of complete remission in a patient with acute myeloid leukemia refractory to high-dose chemotherapy through treatment with 5-azacytidine

For patients with acute myeloid leukemia refractory to intensive chemotherapy prognosis is very poor and treatment options are limited. 5-Azacytidine, a demethylating drug, is effective in the treatment of myelodysplastic syndromes when administered at a low-dose, subcutaneously. We report a case of a patient with AML refractory to induction chemotherapy as well as to two high-dose salvage regimens. The patient achieved CR through monotherapy with low-dose azacytidine.