Biology and management of relapsed acute myeloid leukaemia

Reversible switching of leukemic cells to a drug-resistant, stem-like subset via IL-4 mediated cross-talk with mesenchymal stroma

Chemoresistance of leukemic cells has largely been attributed to clonal evolution secondary to accumulating mutations. Here, we show that a subset of leukemic blasts in contact with the mesenchymal stroma undergo cellular conversion into a distinct cell type that exhibits a stem cell-like phenotype and chemoresistance. These stroma-induced changes occur in a reversible and stochastic manner driven by cross-talk, whereby stromal contact induces interleukin-4 in leukemic cells that in turn targets the mesenchymal stroma to facilitate the development of new subset. This mechanism was dependent on interleukin-4-mediated upregulation of vascular cell adhesion molecule- 1 in mesenchymal stroma, causing tight adherence of leukemic cells to mesenchymal progenitors for generation of new subsets. Together, our study reveals another class of chemoresistance in leukemic blasts via functional evolution through stromal cross-talk, and demonstrates dynamic switching of leukemic cell fates that could cause a non-homologous response to chemotherapy in concert with the patient-specific microenvironment.

Budget Impact Analysis of Gemtuzumab Ozogamicin for the Treatment of CD33-Positive Acute Myeloid Leukemia

BACKGROUND

Gemtuzumab ozogamicin (GO) was approved in 2017 in the US for the treatment of adults with newly diagnosed CD33-positive (CD33+) acute myeloid leukemia (AML), and adults and pediatric patients with CD33+ relapsed/refractory (R/R) AML.

OBJECTIVE

The aim of this study was to estimate the budgetary impact of introducing GO to a 1-million-member US health plan over a 5-year period.

METHODS

We developed models to estimate the impact of introducing GO in combination with conventional induction chemotherapy or as monotherapy for newly diagnosed AML, and as monotherapy for R/R AML. Models were built using data on drug costs and treatment-related outcomes obtained from published clinical trials and other publicly available sources. Results were reported on a per member/per year and per member/per month (PMPM) basis.

RESULTS

Base-case results of the newly diagnosed model indicated that the addition of GO in the combination setting reduced the overall budget of a 1-million-member health plan. The estimated net cost (US$) savings ranged from $72,969 ($0.006 PMPM) in year 1 to $745,426 ($0.062 PMPM) in year 5. In the monotherapy setting, GO was associated with increased net costs ranging from $4118 (0.0003 PMPM) in year 1 to $31,885 ($0.003 PMPM) in year 5. Base-case results of the R/R AML model demonstrated increased net costs that ranged from $17,326 ($0.001 PMPM) in year 1 to $46,163 ($0.004 PMPM) in year 5. Scenario analyses in all settings indicated the budget impact was not overly sensitive to the selected input assumptions, with the exception of the scenario considering only the pharmacy budget impact in the combination setting.

CONCLUSIONS

The introduction of GO for newly diagnosed and R/R AML would have a minimal impact on the budget of a US health plan and could result in cost savings in the combination therapy setting for newly diagnosed AML.

Outcome of allogeneic stem cell transplantation with active disease in acute myeloid leukemia

Introduction: Despite multiple lines of chemotherapy, some patients with acute myeloid leukemia (AML) can not achieve remission. The prognosis of these patients is quite poor and they should be evaluated for clinical trials, otherwise myeloablative conditioning regimens followed by allogeneic stem cell transplantation (Allo-SCT) should be performed to overcome the active disease which is resistant to conventional doses and as it is the only curative option. Method: In this study, we evaluated the outcome of AML patients who underwent Allo-SCT with active disease in our center retrospectively. Results: A total of 161 AML patients underwent Allo-SCT between December 2009 and November 2018 at our center. 130 of them underwent Allo-SCT in complete remission while 31 of 161 had to undergo Allo-SCT with active disease due to refractoriness to salvage therapies. The median overall survival (OS) was 7.9 ± 2.8 months. 6-month OS was 25% and 1-year OS was only 6%. Progression-free survival (PFS) was 3.53 ± 1.1 months. The transplant-related mortality rate was 12.8%. Conclusion: OS and PFS are short in patients who undergo Allo-SCT with active disease so novel treatment approaches and targeted therapies should be developed to overcome active disease that are refractory to conventional chemotherapies.

Sequential azacitidine and lenalidomide for patients with relapsed and refractory acute myeloid leukemia: Clinical results and predictive modeling using computational analysis

BACKGROUND

Patients with relapsed and refractory (R/R) acute myeloid leukemia (AML) have limited treatment options. Genomically-defined personalized therapies are only applicable for a minority of patients. Therapies without identifiable targets can be effective but patient selection is challenging. The sequential combination of azacitidine with high-dose lenalidomide has shown activity; we aimed to determine the efficacy of this genomically-agnostic regimen in patients with R/R AML, with the intention of applying sophisticated methods to predict responders.

METHODS

Thirty-seven R/R AML/myelodysplastic syndrome patients were enrolled in a phase 2 study of azacitidine with lenalidomide. The primary endpoint was complete remission (CR) and CR with incomplete blood count recovery (CRi) rate. A computational biological modeling (CBM) approach was applied retrospectively to predict outcomes based on the understood mechanisms of azacitidine and lenalidomide in the setting of each patients' disease.

FINDINGS

Four of 37 patients (11%) had a CR/CRi; the study failed to meet the alternative hypothesis. Significant toxicity was observed in some cases, with three treatment-related deaths and a 30-day mortality rate of 14%. However, the CBM method predicted responses in 83% of evaluable patients, with a positive and negative predictive value of 80% and 89%, respectively.

INTERPRETATION

Sequential azacitidine and high-dose lenalidomide is effective in a minority of R/R AML patients; it may be possible to predict responders at the time of diagnosis using a CBM approach. More efforts to predict responses in non-targeted therapies should be made, to spare toxicity in patients unlikely to respond and maximize treatments for those with limited options.

Comparison of the safety and efficacy of prophylactic donor lymphocyte infusion after haploidentical versus matched-sibling PBSCT in very high-risk acute myeloid leukemia

Donor lymphocyte infusion (DLI) might be used prophylactically to reduce relapse after allogeneic hematopoietic stem cell transplantation for very high-risk leukemia/lymphoma without effective targeted therapy. To compare the safety and efficacy of prophylactic DLI for prevention of relapse after allogeneic peripheral blood stem cell transplantation from haploidentical donors (HID-SCT) and matched-sibling donors (MSD-SCT) in patients with very high-risk acute myeloid leukemia (AML), we performed a retrospective analysis in a cohort of 21 HID-SCT and 13 MSD-SCT recipients, displaying similar baseline characteristics except for donor's gender distribution. Grade 2-4 acute graft-versus-host disease (GVHD) at 100-day post-DLI was higher in HID-SCT group than that in MSD-SCT group (59.5% vs. 30.8%, p = 0.05). The grade 3-4 acute GVHD (17.5% vs. 7.7%), 1-year chronic GVHD (36.6% vs. 33.2%), and severe chronic GVHD (15.3% vs. 27.3%) were not statistically significant different between groups. One-year non-relapse mortality was higher in HID-SCT group than that in MSD-SCT group with marginal significance (27.9% vs. 0.0%, p = 0.061). One-year relapse rate was not statistically significant different between HID-SCT group and MSD-SCT group (21.6% vs. 36.5%, p = 0.543). For HID-SCT recipients, 1-year relapse rate was lower in patients receiving prophylactic DLI than that in a control cohort of eight patients with same very high-risk features but not receiving prophylactic DLI (62.5% vs. 28.3%, p = 0.037). No statistically significant difference was observed in 1-year overall survival (OS, 55.1% vs. 83.9%, p = 0.325) and relapse-free survival (RFS, 50.1% vs. 74.0%, p = 0.419) rates between HID-SCT group and MSD-SCT group. In multivariate analyses, non-remission status prior to transplant, poor-risk gene mutations, and donor's age ≥ 48 years predicted a higher risk of relapse after DLI. Non-remission status prior to transplant predicted inferior OS and RFS. Patient's age ≥ 40 years also predicted an inferior OS. In conclusion, prophylactic DLI was very safe and efficient for reducing relapse in patients with very high-risk AML receiving MSD-SCT. In the recipients of HID-SCT, the application of prophylactic DLI could reduce the risk of relapse, although with a higher incidence of DLI-associated acute GVHD than those of MSD-SCT.

DIXDC1 promotes the growth of acute myeloid leukemia cells by upregulating the Wnt/β-catenin signaling pathway

Accumulating evidence suggests that dysregulation of Dishevelled-Axin domain-containing 1 (DIXDC1) is involved in the progression and development of various cancers. However, little is known about the relevance of DIXDC1 in acute myeloid leukemia (AML). In this study, we aimed to investigate the expression status and potential biological function of DIXDC1 in AML. Our results showed that DIXDC1 expression was highly upregulated in AML cell lines and primary AML blasts compared with normal blasts. Knockdown of DIXDC1 by siRNA-mediated gene silencing significantly inhibited proliferation, induced cell cycle arrest, and promoted apoptosis of AML cells in vitro. By contrast, DIXDC1 overexpression promoted proliferation, accelerated cell cycle progression, and reduced apoptosis of AML cells. Moreover, we found that DIXDC1 knockdown decreased the expression of β-catenin and restricted the activation of Wnt signaling. In addition, DIXDC1 knockdown decreased the expression of Wnt/β-catenin target genes, including cyclin D1 and c-myc, while DIXDC1 overexpression had the opposite effect. Notably, β-catenin knockdown partially reversed the oncogenic effect of DIXDC1 in AML cells. Taken together, these results demonstrate that DIXDC1 promotes the growth of AML cells, possibly through upregulating the Wnt/β-catenin signaling pathway. Our study suggests that DIXDC1 may serve as a potential therapeutic target for the treatment of AML.

Genetic and epigenetic heterogeneity and the impact on cancer relapse

Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy with an exceedingly poor prognosis: a 5-year overall survival rate of 40%-45% in the young and a 5-year survival rate of less than 10% in the elderly (>60 years of age). Although a high percentage of patients enters complete remission after chemotherapeutic intervention, the majority of patients relapse within 3 years. Such stark prognostic outcomes highlight the need for additional clinical research, basic discovery, and molecular delineation of the etiologies and mechanisms behind responses to therapy that lead to relapse. Here, we summarize recent discoveries in tumor heterogeneity at the genetic and epigenetic levels and their independent molecular trajectories and dynamics in response to therapy. These new discoveries may have significant implications for understanding, monitoring, and treating leukemia and other cancers.

Outcomes of allogeneic stem cell transplantation among patients with acute myeloid leukemia presenting active disease: Experience of a single European Comprehensive Cancer Center

Introduction:

Allogeneic hematopoietic stem cell transplantation (ASCT) representes a potentially curative approach for patients with relapsed or refractory acute myeloid leukemia (AML). We report the outcome of relapsed/refractory AML patients treated with ASCT.

Method:

A retrospective cohort from 1994 to 2013 that included 61 patients with diagnosis of relapsed/refractory AML. Outcomes of interest were transplant-related mortality (TRM), incidence of acute and chronic graft-versus-host disease (GVHD), relapse incidence, progression-free survival (PFS) and overall survival (OS). Statistical significance was set at p<0.05.

Results:

The median age was 61 years (range 1 to 65). The cumulative incidence of 90 days, 1 year, and 3 years TRM were 60%, 26.7%, and 13.3%, respectively (p<0.001). The incidence of relapse was 21.7% at 1 year, 13% at 3 years, and 8.7% at 5 years. Median OS was estimated to be 8 months (95CI 3.266-12.734) and median PFS, 3 months (95CI 1.835-4.165).

Conclusion:

In our cohort, TRM in first years after ASCT remains considerable, but ASCT in this setting seems to be a good choice for AML patients with active disease. However, novel approaches are needed to reduce TRM and relapse in this set of patients.

Evaluation of prognostic factors in patients with relapsed AML: Clonal evolution versus residual disease

Background

It is widely known that the prognosis of acute myeloid leukemia (AML) depends on chromosomal abnormalities. The majority of AML patients relapse and experience a dismal disease course despite initial remission.

Methods

We reviewed the medical records and laboratory findings of 55 AML patients who had relapsed between 2004 and 2013 and who had been treated at the Division of Hematology of the Pusan National University Hospital.

Results

The event-free survival (EFS) was related to prognostic karyotype classification at the time of diagnosis and relapse (unfavorable vs. favorable or intermediate karyotypes at diagnosis, 8.2 vs. 11.9 mo, P=0.003; unfavorable vs. favorable or intermediate karyotypes at relapse, 8.2 vs. 11.9 mo, P=0.009). The overall survival (OS) was significantly correlated with karyotype classification only at diagnosis (unfavorable vs. favorable or intermediate vs. karyotypes at diagnosis, 8.5 vs. 21.8 mo, P=0.001; unfavorable vs. favorable or intermediate karyotypes at relapse, 8.5 vs. 21.2 mo, P=0.136). A change in karyotype between diagnosis and relapse, which is regarded as a factor of resistance against treatment, was not a significant prognostic factor for OS, EFS, and post-relapse survival (PRS). A Cox proportional hazards model showed that the combined use of fludarabine, cytosine arabinoside, and granulocyte colony-stimulating factor (FLAG) as a salvage regimen, was a significant prognostic factor for OS (hazard ratio=0.399, P=0.010) and the PRS (hazard ratio=0.447, P=0.031).

Conclusion

The karyotype classification at diagnosis predicts survival including PRS in relapsed AML patients as well as in treatment-naïve patients. We suggest that presently, administration of salvage FLAG could be a better treatment option.

A phase I trial of the human double minute 2 inhibitor (MK-8242) in patients with refractory/recurrent acute myelogenous leukemia (AML)

OBJECTIVE

Evaluate safety/tolerability/efficacy of MK-8242 in subjects with refractory/recurrent AML.

METHODS

MK-8242 was dosed p.o. QD (30-250mg) or BID (120-250mg) for 7on/7off in 28-day cycle. Dosing was modified to 7on/14off, in 21-day cycle (210 or 300mg BID).

RESULTS

26 subjects enrolled (24 evaluable for response); 5/26 discontinued due to AEs. There were 7 deaths; 1 (fungal pneumonia due to marrow aplasia) possibly drug-related. With the 7on/7off regimen, 2 subjects had DLTs in the 250mg BID group (both bone marrow failure and prolonged cytopenia). With the 7on/14off, no DLTs were observed in 210mg BID or 300mg BID (doses>300mg not tested). Best responses were: 1/24 PR (11 weeks;120mg QD, 7on/7off); 1/24 CRi (2 weeks;210mg BID, 7on/14off); 1/24 morphologic leukemia-free state (4 weeks; 250mg BID, 7on/7off). PK on Day7 at 210mg BID revealed AUC0-12h 8.7μM·h,Cmax 1.5μM (n=5,Tmax, 2-6h),T1/2 7.9h, CLss/F 28.8L/h, and Vss/F 317L.

CONCLUSIONS

The 7on/14off regimen showed a more favorable safety profile; no MTD was established. Efficacy was seen using both regimens providing impetus for further study of HDM2 inhibitors in subjects with AML.

Phase I trial of volasertib, a Polo-like kinase inhibitor, in Japanese patients with acute myeloid leukemia

This phase I trial conducted in Japanese patients with acute myeloid leukemia evaluated the safety, maximum tolerated dose and pharmacokinetics of volasertib (BI 6727), a selective Polo-like kinase inhibitor. The primary endpoints were the maximum tolerated dose of volasertib and the incidence of dose-limiting toxicities. Secondary endpoints were best response and remission duration. Other endpoints included safety and pharmacokinetics. Patients who were ineligible for standard induction therapy or with relapsed or refractory disease received volasertib monotherapy as a 2-h infusion on days 1 and 15 of a 28-day cycle, with dose escalation following a 3 + 3 design. A total of 19 patients were treated with three volasertib doses: 350, 400 and 450 mg. One patient receiving volasertib 450 mg reported a dose-limiting toxicity of grade 4 abnormal liver function test and 450 mg was determined as the maximum tolerated dose. The most frequently reported adverse events were febrile neutropenia (78.9%), decreased appetite (42.1%), nausea and rash (36.8% each), and sepsis, fatigue, hypokalemia, stomatitis and epistaxis (26.3% each). Best responses were complete remission (n = 3), complete remission with incomplete blood count recovery (n = 3) and partial remission (n = 1). The median remission duration of the six patients with complete remission or complete remission with incomplete blood count recovery was 85 days (range 56-358). Volasertib exhibited multi-compartmental pharmacokinetic behavior with a fast distribution after the end of infusion followed by slower elimination phases. Volasertib monotherapy was clinically manageable with acceptable adverse events and anti-leukemic activity.

Busulfan and fludarabine conditioning regimen given at hematological nadir of cytoreduction fludarabine, cytarabine, and idarubicin chemotherapy in patients with refractory acute myeloid leukemia undergoing allogeneic stem cell transplantation: a single arm pilot consort study

To improve the outcome of allogeneic stem cell transplantation in refractory acute myeloid leukemia (AML), we conducted a single-arm phase II clinical trial to evaluate the efficacy and feasibility of conditioning regimen following cytoreduction chemotherapy with 7-day interval. Adult patients with refractory AML were enrolled in the study and received fludarabine, cytarabine, and idarubicin (FLAG-IDA) as cytoreductive chemotherapy followed by busulfan and fludarabine (Flu-BU) conditioning regimen and transfusion of mobilized peripheral stem cells from human leukocyte antigen-matched sibling or unrelated donor. The primary endpoint of the study was 2-year leukemia-free survival (LFS) and secondary endpoints included complete-remission rate, 2-year overall survival (OS), nonrelapse mortality (NRM), and relapse rate. A total of 16 patients were enrolled with median age of 36 (16-60), which included 9 primary induction failure, 2 early relapse, and 5 with relapse/refractory disease. The median cycles of previous chemotherapy were 4 (3-10) with a median of 55% (1%-90%) blasts in bone marrow. Six patients received transplantation from matched sibling and 10 from matched unrelated donors. After transplantation, 15 patients achieved bone marrow remission (11 complete remissions [CRs] and 4 bone marrow remissions without platelet recovery) at day +28. A total of 8 patients remained alive in CR with median LFS of 29.5 months (9.5-40.5 months). Four patients relapsed and 3 of them died of disease and another 4 patients died because of transplantation-related toxicity. The 2-year NRM and relapse rates were 25.0% ± 10.8% and 33.4% ± 13.8%, respectively with 2-year OS at 53.5% ± 13.1% and LFS at 50.0% ± 12.5%. Based on the Simon 2-stage design, 5 out of first eligible 14 patients remained leukemia-free for more than 2 years after allogeneic hematopoietic stem cell transplantation; thus, the null hypothesis of the study will be rejected and the study protocol is accepted as being warranted for further study. Based on the above data, our phase II study demonstrated that the sequential FLAG-IDA cytoreduction chemotherapy followed by Flu-BU conditioning regimen given at the hematological nadir was feasible and has sufficient activity to warrant further investigation prospectively with a larger patient sample (clinicaltrials.gov identifier: NCT01496547).

Acute myeloid leukaemia: a paradigm for the clonal evolution of cancer?

Acute myeloid leukaemia (AML) is an uncontrolled clonal proliferation of abnormal myeloid progenitor cells in the bone marrow and blood. Advances in cancer genomics have revealed the spectrum of somatic mutations that give rise to human AML and drawn our attention to its molecular evolution and clonal architecture. It is now evident that most AML genomes harbour small numbers of mutations, which are acquired in a stepwise manner. This characteristic, combined with our ability to identify mutations in individual leukaemic cells and our detailed understanding of normal human and murine haematopoiesis, makes AML an excellent model for understanding the principles of cancer evolution. Furthermore, a better understanding of how AML evolves can help us devise strategies to improve the therapy and prognosis of AML patients. Here, we draw from recent advances in genomics, clinical studies and experimental models to describe the current knowledge of the clonal evolution of AML and its implications for the biology and treatment of leukaemias and other cancers.

A phase I dose escalation study of oral bexarotene in combination with intravenous decitabine in patients with AML

The response rate of non-M3 acute myeloid leukemia (AML) to all trans retinoic acid has been limited. Using Affymetrix expression arrays, we found that in diverse AML blasts RXRA was expressed at higher levels than RARA and that mouse Ctsg-PML-RARA leukemia responded to bexarotene, a ligand for RXRA. We therefore performed a phase I study of combination bexarotene and decitabine in elderly and relapsed AML patients. We found that this combination was well tolerated, although outcomes were modest (1 CRi, and 3 PR among 19 patients). Correlative studies found that patients with clinical response had increased differentiation to bexarotene both in vivo and ex vivo, suggesting that pre-treatment analysis might identify a more susceptible subgroup of patients.

Clofarabine/cyclophosphamide for debulking before stem cell transplantation

BACKGROUND

Allogeneic haematopoietic stem cell transplantation (HSCT) is the only curative rescue therapy for patients (pts) with chemotherapy-refractory acute leukaemia. Disease control prior to HSCT is essential for long-term disease-free survival after HSCT.

PATIENTS AND METHODS

We have retrospectively analysed the outcome of 20 pts aged 21-64 years with refractory leukaemia (acute myeloid leukaemia, n = 16; acute lymphatic leukaemia, n = 4) who received debulking therapy with clofarabine (10 mg/m², days 1-4) and cyclophosphamide (200 mg/m², days 1-4; ClofCy) prior to HSCT.

RESULTS

Clofarabine/cyclophosphamide (1-4 cycles) was well tolerated and resulted in a substantial reduction of leukaemic cells in all pts. HSCT was performed in 15 of 20 pts. After HSCT (myeloablative, n = 9; dose-reduced, n = 6), all pts showed engraftment and full donor chimerism (related donors, n = 4 or unrelated donors, n = 11) and all pts achieved complete haematologic remission (CR). The median survival after HSCT is 531 days (range: 48-1462 days), and six pts are still alive after a median of 1245 days. Seven pts died after they had relapsed between days +152 and +1496. One patient died from acute graft-versus-host disease (day +48) and one from systemic fungal infection (day +87).

CONCLUSION

Clofarabine/cyclophosphamide is a novel effective treatment approach for pts with chemotherapy-refractory acute leukaemia prior to HSCT. Whether this novel debulking protocol leads to improved long-term outcome in pts with refractory leukaemias remains to be determined in forthcoming clinical studies.

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.

A novel clofarabine bridge strategy facilitates allogeneic transplantation in patients with relapsed/refractory leukemia and high-risk myelodysplastic syndromes

Patients with relapsed/refractory leukemias or advanced myelodysplastic syndrome (MDS) fare poorly following allogeneic hematopoietic cell transplant (HCT). We report prospective phase II study results of 29 patients given clofarabine 30 mg/m(2)/day i.v. × 5 days followed immediately by HCT conditioning while at the cytopenic nadir. A total of 15/29 patients (52%) were cytoreduced according to pre-defined criteria (cellularity <20% and blasts <10%). Marrow cellularity (P<0.0001) and blast% (P=0.03) were reduced. Toxicities were acceptable, with transient hyperbilirubinemia (48%) and gr3-4 infections (10%). In all, 28/29 proceeded to transplant; 27 received ATG or alemtuzumab. Post HCT, 180 day non-relapse mortality (NRM) was 7% (95% confidence interval (CI): 1-21), relapse was 29% (95% CI: 13-46) and OS was 71% (95% CI: 51-85), comparing favorably to published data for high-risk patients. Two-year graft vs host disease incidence was 40% (95% CI: 21-58) and 2 year OS was 31% (95% CI: 14-48). Disease at the nadir correlated with inferior OS after HCT (HR=1.22 for each 10% marrow blasts, 95% CI: 1.02-1.46). For AML/MDS patients, there was a suggestion that successful cytoreduction increased PFS (330 vs 171 days, P=0.3) and OS (375 vs 195 days, P=0.31). Clofarabine used as a bridge to HCT reduces disease burden, is well tolerated, and permits high-risk patients to undergo HCT with acceptable NRM. Late relapses are common; thus, additional strategies should be pursued. NCT-00724009.

Salvage therapy for relapsed or refractory acute myeloid leukemia

There are a significant number of patients diagnosed with acute leukemia who either fail to achieve remission or who relapse thereafter. Challenges in treating this patient population include accurately assessing prognosis of disease and whether remission can be achieved; assessing the ability of patients to tolerate aggressive salvage therapies; choosing a salvage therapy that is most likely to succeed; and identifying suitable patients for hematopoietic stem cell transplantation. Despite the development of a variety of new investigational therapies, relapsed or refractory acute myeloid Leukemia remains a difficult clinical problem. Clinicians will need to consider all currently available approaches, including cytotoxic chemotherapy, targeted agents, and allogeneic stem cell transplantation, to optimize outcomes.

Karyotypic change between diagnosis and relapse as a predictor of salvage therapy outcome in AML patients

Background

Only a few patients who experience AML relapse derive lasting benefit from re-induction therapy. The utility of reassessing the disease karyotype at relapse is unclear. The main goals of this study were to identify prognostic factors for AML relapse and to determine the prognostic utility of karyotypic change between diagnosis and relapse as a variable for predicting response to salvage therapy for relapsed AML.

Methods

This retrospective study included 58 patients with relapsed AML treated at the Yonsei University College of Medicine between 2005 and 2010. Karyotypes at both diagnosis and relapse were available for 45 patients (77%). A change in karyotype at relapse was observed in 17 of 45 cases (37%), and no change was noted in 28 of 45 cases (62%).

Results

Karyotypic changes between diagnosis and relapse were associated with the response rate (RR) to salvage therapy (P=0.016). Overall survival (OS) and event-free survival (EFS) in the group with karyotypic changes between diagnosis and relapse were significantly different from those with no karyotypic changes (P=0.004 and P=0.010, respectively). We applied multiple multivariate Cox regression analyses to identify independent prognostic factors for overall response (OR), OS, and EFS. A change in karyotype between diagnosis and relapse was significantly associated with OS (P=0.023; RR=2.655) and EFS (P=0.033; RR=2.831).

Conclusion

Karyotypic changes between the diagnosis and relapse of AML could be used to predict outcomes and tailor clinical and biological therapeutic strategies for relapsed AML patients.

The mortality and response rate after FLANG regimen in patients with refractory/relapsed acute leukemia

Background:

Oncologists today are greatly concerned about the treatment of relapsed/refractory acute leukemia. FLANG regimen, combination of novantron, cytarabine, fludarabine, and granulocyte-colony stimulating factor, has been used in treatment of refractory/relapsed acute leukemia since 1990s. The present study has evaluated mortality and response rate of this regimen.

Materials and Methods:

In this study, 25 patients with refractory/relapsed acute leukemia aged 15-55 years underwent FLANG regimen at Seyed-Al-Shohada Hospital, Isfahan, Iran during 2008-2009. One month later, bone marrow samples were taken to evaluate the responsiveness to treatment. Participants were followed for a year. The data was analyzed by student-t and chi-square tests, logistic, and Cox regression analysis, and Kaplan-Meier curves in SPSS₁₉.

Results:

Out of the 25 patients, 8 patients (32%) had acute lymphoblastic leukemia (5 refractory and 3 relapsed cases) and 17 subjects had acute myeloid leukemia (7 refractory and 10 relapsed cases). According to the bone marrow biopsies taken one month after FLANG regimen, 10 patients (40%) had responded to treatment. Five patients of the 10 responders underwent successful bone marrow transplantation (BMT). On the other hand, 13 patients (52%), who had not entered the CR period, died during the follow-up. Logistic regression analysis did not reveal any significant associations between disease type and responsiveness to treatment.

Conclusion:

This study indicated higher rates of unresponsiveness to treatment while its mortality rate was comparable with other studies. Overall, according to limitations for BMT (as the only chance for cure) in Iran, it seems that FLANG therapy is an acceptable choice for these patients.

Outcome of treatment after first relapse in younger adults with acute myeloid leukemia initially treated by the ALFA-9802 trial

Forty-seven percent of adults with acute myeloid leukemia (AML) who entered the ALFA-9802 trial and achieved a first complete remission (CR) experienced a first relapse. We examined the outcome of these 190 adult patients. Eighty-four patients (44%) achieved a second CR. The median overall survival (OS) after relapse was 8.9 months with a 2-year OS at 25%. Factors predicting a better outcome after relapse were stem cell transplant (SCT) performed in second CR and a first CR duration >1 year. Risk groups defined at the time of diagnosis and treatment received in first CR also influenced the outcome after relapse. The best results were obtained in patients with core binding factor (CBF)-AML, while patients initially defined as favorable intermediate risk showed a similar outcome after relapse than those initially entering the poor risk group. We conclude that most adult patients with recurring AML could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option at this stage of the disease.

A phase I dose-escalation study of clofarabine in combination with fractionated gemtuzumab ozogamicin in patients with refractory or relapsed acute myeloid leukemia

Clofarabine and gemtuzumab ozogamicin (GO) are active agents against acute myeloid leukemia (AML), but have not previously been tested in combination. We conducted a phase I study to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLTs) of clofarabine when combined with GO in adult patients with relapsed or refractory AML. Twenty patients received clofarabine (10, 20 or 30 mg/m(2)) on days 1-5, with GO 3 mg/m(2)/day on days 1, 4 and 7. Common dose-limiting toxicities were prolonged myelosuppression and hepatotoxicity. Clofarabine 20 mg/m(2) was the MTD, but with a DLT rate of 0.38 (5/13) - a rate that is prohibitively high to recommend for phase II study. The overall response rate (complete response [CR] + complete response with incomplete hematologic recovery [CRi]) was 42% among all patients. Thus, this combination demonstrated activity in relapsed and refractory patients, but further testing of the combination using lower doses of GO may identify more favorable rates of toxicity while maintaining efficacy.

Clofarabine and high-dose cytosine arabinoside in the treatment of refractory or relapsed acute myeloid leukaemia

Clofarabine (40 mg/m²/day × 5) and high-dose cytosine arabinoside (Ara-C, 1–2 g/m²/day × 5) were used in 10 men and 11 women, at a median age of 45 (22–62) years, with refractory (N = 4) and relapsed (N = 17) acute myeloid leukaemia, after a median of 3 (2–5) prior regimens. Grade 4 myelosuppression was observed in all cases, with two patients dying of bacterial sepsis. Nine patients achieved a complete remission. Disease status, number of prior therapies, and cytogenetic aberrations were not associated with the outcome. However, remission was only achieved with Ara-C at 2 g/m²/day and not 1 g/m²/day (9/15 versus 0/4, P = 0.03).

A new Leukemia Prognostic Scoring System for refractory/relapsed adult acute myelogeneous leukaemia patients: a GOELAMS study

A simplified prognostic score is presented based on the multivariate analysis of 138 refractory/relapsed acute myeloid leukaemia (AML) patients (median age 55 years, range: 19-70) receiving a combination of intensive chemotherapy+Gemtuzumab as salvage regimen. Overall, 2-year event-free survival (EFS) and overall survival (OS) were 29±4% and 36±4%, respectively. Disease status (relapse <12 months, including refractory patients), FLT3-ITD-positive status and high-risk cytogenetics were the three strongest independent adverse prognostic factors for OS and EFS in this series. We then defined three subgroups with striking different outcomes at 2 years: no adverse factor (favourable, N=36): OS 58%, EFS 45%; one adverse factor (intermediate, N=54): OS 37%, EFS 31%; two or three adverse factors (poor, N=43): OS 12%, EFS 12% (P<10(-4), P=0.001). This new simplified Leukemia Prognostic Scoring System was then validated on an independent cohort of 111 refractory/relapsed AML patients. This new simplified prognostic score, using three clinical and biological parameters routinely applied, allow to discriminate around two third of the patients who should benefit from a salvage intensive regimen in the setting of refractory/relapsed AML patients. The other one third of the patients should receive investigational therapy.

Improved outcome of patients with low- and intermediate-risk cytogenetics acute myeloid leukemia (AML) in first relapse with gemtuzumab and cytarabine versus cytarabine: results of a retrospective comparative study

BACKGROUND

Acute myeloid leukemia (AML) in first relapse is associated with a poor outcome even when treated with intermediate- to high-dose cytarabine (IHDAraC). Gemtuzumab ozogamycin (GO) used as a single agent has clinical activity in relapsed and refractory AML. Various combination regimens of GO have been developed, but few data are available regarding their efficacy compared with IHDAraC-based regimens.

METHODS

The authors performed a retrospective analysis of response and survival in 90 AML patients in first relapse treated with either IHDAraC (n = 56) or IHDAraC + GO (n = 34). Patient characteristics of the two groups were comparable.

RESULTS

Median follow-up was 37 months. Compared with IHDAraC, IHDAraC + GO induction was associated with a better response rate (68% vs 45%, P = .04), a better overall survival (median, 35 months vs 6 months, P = .001), and a better event-free survival (24 months vs 6 months, P = .002). This effect was limited to patients with low-risk and intermediate-risk cytogenetics. In multivariate analysis, age, cytogenetic risk, first complete remission duration, and the use of IHDAraC + GO were independently associated with better results.

CONCLUSIONS

This study showed that the addition of GO to IHDAraC is associated with a better efficacy for patients in first relapse of AML with low- or intermediate-risk cytogenetics. Prospective controlled studies of GO in this population are warranted. Patients with high-risk cytogenetics should be offered investigational new drugs.

Late relapses in acute myeloid leukemia: analysis of characteristics and outcome

Relapse after 5 years of complete remission (CR) is uncommon in acute myeloid leukemia (AML). Among 2347 patients seen between 1980 and 2008, 1366 achieved CR; 942 relapsed. Eleven (1.16% of all relapses) relapsed after a CR of >5 years. The median age was 66 years (range, 37-79). Initial therapy was cytarabine plus anthracycline in six, amsacrine-based in three, and other in two. The median CR1 duration was 81 months (range, 60-137). At relapse, the karyotype was different from the initial finding in five of eight (63%) patients with available data. Treatment for relapse included cytarabine with anthracycline in eight, and other in three patients, with a second CR (CR2) achieved in four (36%). The median CR2 duration was 1 month (range, 0-37), and median survival after relapse was 6.4 months (range, 1-39). Late relapses in AML are infrequent, with poor response to therapy. Karyotype at relapse is frequently different, raising the question of second AML versus relapse with the original clone.

Feasibility of clofarabine cytoreduction before allogeneic transplant conditioning for refractory AML

To control disease before allogeneic hematopoietic cell transplantation (HCT) for relapsed/refractory AML, we used clofarabine cytoreduction. Seventeen patients received clofarabine 30-40  mg/m(2) i.v. daily for 5 days with plans to initiate conditioning during the nadir, 14 days later. Bone marrow biopsy 12 days after clofarabine showed effective cytoreduction (that is,<20% cellularity with <10% blasts) in 10 of 17 patients (59%). Ineffective cytoreduction correlated with lower PFS (3.8 vs 6.4 months; HR=2.7, 95% CI=1.10-14.29, P=0.035) and OS (5.1 vs 16.6 months; HR=2.5, 95% CI=0.98-12.17, P=0.053). Significant toxicities before HCT, attributable to clofarabine, were grade 1-2 hyperbilirubinemia (18%); grade 1-2 (59%) or grade 3-4 (18%) transaminitis; and grade 1-2 (18%) creatinine elevation. Sixteen patients proceeded to HCT infusion 22 days (median) after initiation of clofarabine. Day 100 and 2-year transplant-related mortality were 6 and 36%. Nine patients relapsed. One year PFS and OS were 25 and 38%, respectively. Two patients are alive in remission at 18 and 52 months. Clofarabine cytoreduction followed by immediate HCT is feasible with acceptable toxicity and TRM. Outcomes for this cohort of patients with refractory AML remain poor and we are studying this approach in a prospective manner.

Diagnosis and management of acute myeloid leukemia in adults: recommendations from an international expert panel, on behalf of the European LeukemiaNet

In 2003, an international working group last reported on recommendations for diagnosis, response assessment, and treatment outcomes in acute myeloid leukemia (AML). Since that time, considerable progress has been made in elucidating the molecular pathogenesis of the disease that has resulted in the identification of new diagnostic and prognostic markers. Furthermore, therapies are now being developed that target disease-associated molecular defects. Recent developments prompted an international expert panel to provide updated evidence- and expert opinion–based recommendations for the diagnosis and management of AML, that contain both minimal requirements for general practice as well as standards for clinical trials. A new standardized reporting system for correlation of cytogenetic and molecular genetic data with clinical data is proposed.

Salvage therapy for acute myeloid leukemia with fludarabine, cytarabine, and idarubicin with or without gemtuzumab ozogamicin and with concurrent or sequential G-CSF

The current salvage therapies for relapsed/refractory acute myeloid leukemia (AML) are unsatisfactory. Over the past 7 years, we have used two salvage regimens: fludarabine, cytarabine, and idarubicin with (FLAG-IM) or without gemtuzumab ozogamicin (GO) (9 mg/m(2) on Day 8) (FLAG-I) in relapsed/refractory AML. Three-quarters of patients also received concurrent G-CSF. Seventy-one patients were treated, 23 with FLAG-I and 48 with FLAG-IM. The median duration of follow-up was 30.6 months. The treatment groups were well balanced with median ages of 48 years (range 18-70) and 47 years (range 20-68), unfavorable cytogenetics in 57% and 35%, prior allogeneic stem cell transplant in 43% and 42%, and CR1 duration <1 year in 60% and 67%, respectively, for FLAG-I and FLAG-IM. The complete remission (CR) rate in the FLAG-I group was 39% with an additional 13% achieving a CRp [overall response rate (ORR) 52%]; the CR rate in the FLAG-IM group was 29% with an additional 27% achieving a CRp (ORR 56%). The median duration of response (DOR; 16.8 vs. 8.3 months), event-free survival (EFS; 7.4 vs. 4.1 months), and overall survival (OS; 8.8 vs. 5.0 months) trended to favor FLAG-I over FLAG-IM. The patients who received G-CSF concurrent with chemotherapy had superior overall response rate (ORR; 62% vs. 29%, P = 0.026), median EFS (6.2 vs. 3.4 months, P = 0.010), and OS (8.8 vs. 3.9 months, P = 0.004) when compared with those who sequentially received G-CSF and chemotherapy, regardless of chemotherapy regimen. The addition of GO, at this dose and schedule, to FLAG-I failed to improve the outcomes in patients with relapsed/refractory AML. The patients who received G-CSF concurrently with chemotherapy had improved outcomes. Am. J. Hematol., 2009. (c) 2009 Wiley-Liss, Inc.

Decitabine combined with fractionated gemtuzumab ozogamicin therapy in patients with relapsed or refractory acute myeloid leukemia

Salvage chemotherapy for patients with relapsed or refractory acute myeloid leukemia (AML) is generally associated with a low-response rate and significant nonhematologic toxicity. Both decitabine and gemtuzumab ozogamicin have activity in AML as single agents and can be administered sequentially with potential synergy due to their toxicity profiles. Twelve patients with AML, who had received a median of three prior regimens (range 1-6), were treated with decitabine 20 mg/m(2) on days 1 through 5 followed by gemtuzumab ozogamicin 3 mg/m(2) on days 6, 9, and 12. Five patients achieved a complete response (42%) and subsequently underwent hematopoietic stem cell transplantation. Three patients are in complete remission and four are still alive 7 to 16 months after treatment. The regimen was well tolerated with the primary nonhematologic toxicity of Grade 1 or 2 transaminitis observed in four patients. These results indicate that decitabine in combination with gemtuzumab is a regimen of promising efficacy worthy of further investigation in controlled trials.

Acute myelogenous leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with outcomes dependent upon several factors, including patient age, karyotype, mutational status, and comorbid conditions. For younger patients, approximately 60% to 80% achieve complete remission with standard therapy involving cytarabine and an anthracycline. However, only 20% to 30% have long-term disease-free survival. For adults older than 60 years of age, only 40% to 55% achieve a complete remission, with dismal long-term survival rates. Unfortunately, the median age at diagnosis for AML is 70 years. Significant advances in our understanding of the molecular biology of AML have led to newer therapies that specifically target molecular abnormalities. Examples of such therapies include the immunoconjugate gemtuzumab ozogamicin, FMS-like tyrosine kinase 3 inhibitors, farnesyl transferase inhibitors, histone deacetylase inhibitors, DNA hypomethylating agents, multidrug-resistance inhibitors, BCL-2 inhibitors, antiangiogenesis agents, and various nucleoside analogs. This review summarizes the standard treatments for AML and discusses the role of novel therapies.

Characteristics and outcomes of acute myelogenous leukemia patients with very late relapse (>5 years)

The clinical characteristics and outcome of 15 patients with acute myelogenous leukemia (AML) who experienced relapse at least 5 years after induction of complete remission (very late-relapse AML) are described. This subgroup represented 3% of all relapsed patients seen at this institution over the same time period. There were eight males in this cohort and the median age at diagnosis was 48 years (range 13 - 77 years). Nine patients had M4/M5 French - American - British (FAB) classification subtype and most had intermediate risk cytogenetics. The median duration of first complete remission (CR-1) was 9 years (range 5.2 - 11.5 years). Thirteen patients (86%) achieved CR-2 with reinduction therapy. The 5-year relapse-free survival and overall survival rates of this cohort were 59% and 51%, respectively. We conclude that very late-relapse AML is a rare event, and that reinduction in these patients is associated with very high CR rates and a potential cure fraction.

Twice daily fludarabine/Ara-C associated to idarubicin, G-CSF and ATRA is an effective salvage regimen in non-promyelocytic acute myeloid leukemia

Preclinical data suggest that all-trans retinoic acid (ATRA) synergizing with granulocyte colony stimulating factor (G-CSF), can improve the effectiveness of chemotherapy in acute myeloid leukemia (AML). Fludarabine 15 mg/m(2) is the minimum dose able to optimize intensification with fludarabine-arabinosylcytosine regimen. In this study 52 patients with relapsed/refractory AML obtained a complete remission (CR) rate of 69.2% after FLAIRG regimen (Fludarabine and arabinosylcytosine twice daily, idarubicin, G-CSF, ATRA). This schedule resulted effective and tolerable enabling 53% of the responding patients to receive transplant procedure. FLAIRG regimen could be proposed as a "bridge" to transplant treatment in this poor risk setting.

Phase I clinical study of diphtheria toxin-interleukin 3 fusion protein in patients with acute myeloid leukemia and myelodysplasia

DT(388)IL3 fusion protein containing the catalytic and translocation domains of diphtheria toxin fused to human interleukin 3 was administered in an inter-patient dose escalation trial by 15 min i.v. infusions every other day for up to 6 doses to patients with chemo-refractory acute myeloid leukemia (AML) and myelodysplasia (MDS). The maximal tolerated dose was >12.5 microg/kg/dose. Transient grade 3 transaminasemia and grade 2 fevers, chills, hypoalbuminemia, and hypotension occurred. Peak DT(388)IL3 levels correlated with dose and day of administration but not antibody titer. Anti-DT(388)IL3 antibodies developed in most patients between day 15 and 30. Of 40 evaluable AML patients, 1 had a CR (8 months) and 1 had PR (3 months). Of 5 MDS patients, 1 had a PR (4 months). Because of the prolonged infusion schedule, many patients failed to receive six doses. DT(388)IL3 produces remissions in patients with relapsed/refractory AML and MDS with minimal toxicities, and alternate schedules of administration are needed to enhance the response rate.

Potential cure of acute myeloid leukemia : analysis of 1069 consecutive patients in first complete remission

BACKGROUND

Potential cure of acute myeloid leukemia (AML) is now a widely accepted idea, but it is uncertain whether there is heterogeneity in the failure rate in patients once they have been in complete remission (CR) for various periods of time.

METHODS

The long-term outcomes were analyzed in 1069 consecutive AML patients in first CR who were diagnosed and treated at the University of Texas M. D. Anderson Cancer Center between 1991 and 2003. RESULTS.: The failure rates as yearly risk of treatment failure were 69.1 in the first year, 37.7 in the second year, 17.0 in the third year, 7.6 in the fourth year, and 6.6 in the fifth year, suggesting that 3 years from the CR date is a convenient time to consider patients potentially cured. The effect of cytogenetics on relapse-free survival (RFS) remained constant throughout the first 3 years, whereas the effect of age increased with time. The probability of RFS for patients alive without disease recurrence at 3 years was 84.0% at 6 years. When the interaction between age and cytogenetics was examined for these patients, the outcomes of those with favorable cytogenetics were found to be excellent regardless of age. However, in the intermediate cytogenetic group, although patients aged <60 years had excellent outcomes, those aged > or =60 years were found to be at a substantial risk of disease recurrence even after 3 years of CR, with a 6-year RFS rate of 56.5%. There were only 6 patients with adverse cytogenetics in this cohort.

CONCLUSIONS

The results of the current study demonstrate that the risk of treatment failure differs over time according to a combination of cytogenetics and age.

Reduced intensity compared with high dose conditioning for allotransplantation in acute myeloid leukemia and myelodysplastic syndrome: a comparative clinical analysis

We evaluated the efficacy of hematopoietic stem cell transplantation (HSCT) using reduced intensity (RI) vs. myeloablative (MA) conditioning for patients with acute myeloid leukemia (AML) and myelodysplastic syndrome. Thirty two patients (median age 54) who underwent a RI HSCT (2000-2003) were compared with 187 patients (median age 39) who received a MA transplant (1990-2003). Neutrophil engraftment was more rapid in the RI group (median 11.5 vs. 21 days). Platelet recovery was similar and graft failure was infrequent. The incidence of graft-versus-host disease (GVHD) and treatment-related mortality was similar though relapse was more frequent after RI conditioning (RR 2.2 [95% CI = 1.1-4.6] P = 0.03). At 2 years, disease-free survival (DFS) (31% vs. 30%, P > 0.1) and overall survival (33% vs. 35%, P > 0.1) were comparable between RI and MA groups, respectively. We suggest that RI allografts can yield satisfactory DFS both for older as well as younger patients with pre-existing comorbidities, who are ineligible for MA allografts. Advances in GVHD management and new approaches for relapsed or refractory disease are necessary to improve these outcomes.

Improved outcome after relapse in children with acute myeloid leukaemia

In the Nordic Society for Paediatric Haematology and Oncology paediatric study acute myeloid leukaemia (AML) 93, event-free survival was 50% and overall survival was 66%, indicating that many patients were cured following relapse. Factors influencing outcome in children with relapsed AML were investigated. The study included all 146 children in the Nordic countries diagnosed with AML between 1988 and 2003, who relapsed. Data on disease characteristics and relapse treatment were related to outcome. Sixty-six percentage achieved remission with survival after relapse (5 years) 34 +/- 4%. Of 122 patients who received re-induction therapy, 77% entered remission with 40 +/- 5% survival. Remission rates were similar for different re-induction regimens but fludarabine, cytarabine, granulocyte colony-stimulating factor-based therapy had low treatment-related mortality. Prognostic factors for survival were duration of first complete remission (CR1) and stem cell transplantation (SCT) in CR1. In early relapse (<1 year in CR1), survival was 21 +/- 5% compared with 48 +/- 6% in late relapse. For children receiving re-induction therapy, survival in early relapse was 29 +/- 6% and 51 +/- 6% in late. Patients treated in CR1 with SCT, autologous SCT or chemotherapy had a survival of 18 +/- 9, 5 +/- 5 and 41 +/- 5%, respectively. Survival was 62 +/- 6% in 64 children given SCT as part of their relapse therapy. A significant proportion of children with relapsed AML can be cured, even those with early relapse. Children who receive re-induction therapy, enter remission and proceed to SCT can achieve a cure rate of 60%.

Long-Term Outcomes of Myeloablation and Autologous Transplantation of Relapsed Acute Myeloid Leukemia in Second Remission: A British Society of Blood and Marrow Transplantation Registry Study

Relapsed acute myeloid leukemia (AML) in adults has a poor prognosis if treated with chemotherapy alone. Case series have previously supported the role of myeloablation and autologous transplantation as a potentially curative treatment. This study aimed to use the large numbers and extended follow-up data in the British Society of Blood and Marrow Transplantation (BSBMT) registry database to establish long-term outcomes and relate these to biological and procedural factors. The BSBMT registry database was used to retrospectively identify 152 adult patients (age, 16-69 years) with AML in second remission treated with autologous transplantation in 1982-2003. Cytogenetic data were available for 68% of the patients; of these, at diagnosis, 42% had good risk features, 57% had standard risk features, and 1% had poor risk features. Conditioning regimens varied; autologous rescue was provided with bone marrow (BM) (71%), peripheral blood stem cells (PBSCs) (18%), or both (11%), which were harvested during first complete remission (CR1) and/or second CR (CR2). Median follow-up was 84 months (range, 2-200 months). At 10 years, actuarial overall survival (OS) was 32%, progression-free survival (PFS) was 28%, and relapse rate (RR) was 57%. The 100-day nonrelapse mortality (NRM) was 7%, rising to 11% at 1 year and to 14% at 10 years. OS was significantly related to M3 subtype (5-year OS, 66%; P = .005), patient age at diagnosis (P = .005) and transplantation (P = .026), and length of CR1, with greatest significance if the patient was dichotomized at CR1 duration of < 8 months or > or = 8 months (P = .0001). There was no difference in OS between regimens containing total body irradiation (TBI) and chemotherapy alone (P = .7). In relation to the nature of autologous graft material, there was improved OS (P = .025) and PFS (P = .009) with the use of cells harvested entirely in CR1 compared with cells harvested in CR2 or in both CR1 and CR2. Engraftment times were significantly shortened with the use of PBSCs alone or in combination with BM compared with BM alone (P = .0001), but there was no significant long-term impact on OS, PFS, RR, or NRM. This study provides long-term follow-up data in one of the largest series of patients with standard-risk and good-risk AML in CR2 treated with autologous transplantation and supports earlier observations that long-term survival is achievable in about 1/3 of patients overall and in about 2/3 of patients with M3 with a relatively low NRM. Outcomes are better in patients with CR1 > or = 8 months by use of grafts obtained entirely in CR1 and use of PBSCs. TBI conditioning did not confer an advantage. Randomized studies against unrelated donor transplantation are warranted.

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.