Allogeneic Hemopoietic Cell Transplantation Research Articles

It's Not All in the Conditioning or the Perils of Early Trial Cessation

It's Not All in the Conditioning or the Perils of Early Trial Cessation

Enhanced labile plasma iron and outcome in acute myeloid leukaemia and myelodysplastic syndrome after allogeneic haemopoietic cell transplantation (ALLIVE): a prospective, multicentre, observational trial

The effect of systemic iron overload on outcomes after allogeneic haemopoietic cell transplantation (HCT) has been a matter of substantial debate. We aimed to investigate the predictive value of both stored (MRI-derived liver iron content) and biologically active iron (enhanced labile plasma iron; eLPI) on post-transplantation outcomes in patients with acute myeloid leukaemia or myelodysplastic syndrome undergoing allogenic HCT. The prospective, multicentre, observational, ALLogeneic Iron inVEstigators (ALLIVE) trial recruited patients at five centres in Germany. We enrolled patients with acute myeloid leukaemia or myelodysplastic syndrome undergoing allogeneic HCT. Patients underwent cytotoxic conditioning for a median of 6 days (IQR 6-7) before undergoing allogeneic HCT and were followed up for up to 1 year (±3 months) post-transplantation. eLPI was measured in serum samples with the FeROS eLPI kit (Aferrix, Tel-Aviv, Israel) and values greater than 0·4 μmol/L were considered to represent raised eLPI. Liver iron content was measured by MRI. The primary endpoints were the quantitative delineation of eLPI dynamics during allogeneic HCT and the correlation coefficient between liver iron content before HCT and dynamic eLPI (eLPIdyn; maximum eLPI minus baseline eLPI). All patients with available data were included in all analyses. This is the final analysis of this completed trial, which is registered with ClinicalTrials.gov, number NCT01746147. Between Dec 13, 2012, and Dec 23, 2014, 112 patients underwent allogeneic HCT. Liver iron content before allogeneic HCT was not significantly correlated with eLPIdyn (ρ=0·116, p=0·22). Serum eLPI concentrations rapidly increased during conditioning, and most (79 [73%] of 108) patients had raised eLPI by the day of transplantation. Patients with a pretransplant liver iron content greater than or equal to 125 μmol/g had an increased incidence of non-relapse mortality (20%, 95% CI 14-26) compared with those with lower concentrations (7%, 2-12; p=0·039) at day 100. Patients who had raised eLPI at baseline also had a significantly increased incidence of non-relapse mortality at day 100 (33%, 15-52) compared with those who had normal eLPI at baseline (7%, 2-13; p=0·00034). eLPI is a possible biological mediator of iron-related toxicity. Peritransplantation eLPI-scavenging strategies could be explored in prospective interventional clinical trials for patients with systemic iron overload. The Technical University of Dresden and Novartis.

Long-term efficacy of reduced-intensity versus myeloablative conditioning before allogeneic haemopoietic cell transplantation in patients with acute myeloid leukaemia in first complete remission: retrospective follow-up of an open-label, randomised phase 3 trial

The impact of the intensity of conditioning before allogeneic haemopoietic cell transplantation (HCT) has been studied in a randomised phase 3 trial comparing reduced-intensity conditioning with myeloablative conditioning in patients with acute myeloid leukaemia in first complete remission. Because of the short follow-up of the original trial, whether reduced-intensity conditioning increases the risk of late relapse compared with myeloablative conditioning remained unclear. To address this question, we present retrospective 10-year follow-up data of this trial and focus on late relapse. The original randomised phase 3 trial included patients aged 18-60 years, with intermediate-risk or high-risk acute myeloid leukaemia, an adequate organ function, and an available HLA-matched sibling donor or an unrelated donor with at least nine out of ten HLA alleles matched. Patients were randomly assigned (1:1) to 120 mg/m2 fludarabine combined with four 2 Gy doses of total-body irradiation (reduced-intensity conditioning) or six 2 Gy doses of total-body irradiation and 120 mg/kg cyclophosphamide (myeloablative conditioning). The primary and secondary efficacy endpoints of this trial have been published previously. In this retrospective, long-term follow-up analysis, data were collected from medical reports from individual participating study centres, and from physician and patient interviews. Endpoints included in this analysis were cumulative relapse incidence, overall survival, disease-free survival, and non-relapse mortality in the original study population and in patients alive and relapse-free at 12 months after HCT (landmark analysis). 10-year time to event rates were calculated in the intention-to-treat population and were compared with the Gray test. The trial is registered with ClinicalTrials.gov, number NCT00150878. In the original trial, 195 patients were randomly assigned to receive reduced-intensity conditioning (n=99) or myeloablative conditioning (n=96). For this retrospective analysis, data were collected with a nearly complete follow-up (completeness index 99%). Median follow-up time for surviving patients was 9·9 years (IQR 8·5-11·4), during which the cumulative incidence of relapse in the complete study population was identical in both groups (30% [95% CI 20-39] in the reduced-intensity conditioning group vs 30% [21-40] in the myeloablative conditioning group; Gray test p=0·99). Relapse occurred at a median of 5·0 months (IQR 3·0-8·8) in the reduced-intensity conditioning group versus 9·5 months (4·5-20·5) in the myeloablative conditioning group. 10-year disease-free survival was 55% (95% CI 45-66) in the reduced-intensity conditioning group and 43% (34-55) in the myeloablative conditioning group (hazard ratio [HR] 0·76 [0·51-1·14]; p=0·19). 10-year non-relapse mortality was 16% (95% CI 8-24) in the reduced-intensity conditioning group and 26% (17-36) in the myeloablative conditioning group (subdistribution HR 0·60 [95% CI 0·32-1·11]; Gray test p=0·10). The incidence of long-term toxicities associated with total-body irradiation was comparable; secondary malignancies occurred in six (6%) of 94 patients in the reduced-intensity conditioning group and five (6%) of 90 in the myeloablative conditioning group (p=1·00). There is no evidence that reduced-intensity conditioning increases the risk of late relapse compared with myeloablative conditioning. Given that the reduced-intensity conditioning group in the original trial was associated with lower early morbidity and toxicity, reduced-intensity conditioning with moderately reduced total-body irradiation doses could be the preferred conditioning strategy for patients with acute myeloid leukaemia who are younger than 60 years and transplanted in first complete remission. None.

Long-term outcomes after standard graft-versus-host disease prophylaxis with or without anti-human-T-lymphocyte immunoglobulin in haemopoietic cell transplantation from matched unrelated donors: final results of a randomised controlled trial

Previously, we demonstrated that the addition of anti-human-T-lymphocyte immunoglobulin (ATLG) to standard ciclosporin and methotrexate prophylaxis reduced graft-versus-host disease (GvHD) in adult patients treated with allogeneic haemopoietic cell transplantation from matched unrelated donors without negatively affecting relapse and survival. Since reports on long-term results from randomised trials testing anti-thymocyte globulin are scarce, we performed an extended follow-up of the trial. Between May 26, 2003, and Feb 8, 2007, 202 patients with haematological malignancies were centrally randomly assigned using computer-generated centre-stratified block randomisation to receive ciclosporin and methotrexate with or without ATLG. 201 patients who underwent transplantation with peripheral blood (n=164; 82%) or bone marrow (n=37; 18%) grafts after myeloablative conditioning were included in the full analysis set, and were analysed according to their randomly assigned treatment (ATLG n=103, non-ATLG n=98). We assessced chronic GvHD, non-relapse mortality, relapse, relapse mortality, disease-free survival, overall survival, severe GvHD-free (acute GvHD III-IV, and extensive chronic GvHD) and relapse-free survival, and time under immunosuppressive therapy after long-term follow-up. The trial is registered with the German Clinical Trials Register (DRKS00000002), ClinicalTrials.gov (NCT00655343), and EudraCT (2004-000232-91). Median follow-up was 8·6 years (IQR 8·0-9·3). Only patients at risk for chronic GvHD (ie, patients who were alive and without a second transplant at 100 days) were included in the analyses of chronic GvHD (90 patients in the ATLG group, 80 patients in the non-ATLG group). At 8 years, the incidence of extensive chronic GvHD was 14% (95% CI 8-29) in the ATLG group versus 52% (42-64) in the non-ATLG group (adjusted hazard ratio [HR] 0·18, 95% CI 0·09-0·34; p<0·0001). Non-relapse mortality was 21% (95% CI 14-30) versus 34% (26-45; adjusted HR 0·66, 95% CI 0·38-1·16; p=0·15), incidence of relapse was 35% (95% CI 27-46) versus 30% (22-41; adjusted HR 1·17, 95% CI 0·71-1·93; p=0·54), relapse mortality was 31% (95% CI 23-41) versus 29% (21-40; adjusted HR 1·03, 95% CI 0·61-1·76; p=0·90), disease-free survival was 44% (95% CI 35-54) versus 36% (27-46) (adjusted HR 0·91, 95% CI 0·63-1·31; p=0·60), overall survival was 49% (95% CI 39-59) versus 37% (27-47; adjusted HR 0·82, 95% CI 0·56-1·20; p=0·31), and severe GvHD-free and relapse-free survival was 34% (25-43) versus 13% (7-21) (adjusted HR 0·55, 95% CI 0·39-0·76; p=0·0003). The probability of being alive and free of immunosuppressive therapy was 47% (95% 37-57) in the ATLG group and 11% (5-18) in the non-ATLG group at 8 years. ATLG in addition to standard ciclosporin and methotrexate as GvHD prophylaxis improves severe GvHD-free and relapse-free survival in the long term. The use of ATLG in unrelated donor transplantation after myeloablative conditioning substantially increases the probability of surviving free of immunosuppressive therapy, and thus reduces the risk associated with long-term immunosuppression. Neovii Biotech.

Association between anti-thymocyte globulin exposure and survival outcomes in adult unrelated haemopoietic cell transplantation: a retrospective, pharmacodynamic cohort analysis

Anti-thymocyte globulin (ATG) is used to prevent graft-versus-host disease (GvHD) after allogeneic haemopoietic cell transplantation (HCT). However, ATG can also cause delayed immune reconstitution of T cells, negatively affecting survival. We studied the relation between exposure to ATG and clinical outcomes in adult patients with acute leukaemia and myelodysplastic syndrome. We did a retrospective, pharmacokinetic-pharmacodynamic analysis of data from patients with acute lymphoid leukaemia, acute myeloid leukaemia, or myelodysplastic syndrome receiving their first T-cell repleted allogeneic peripheral blood stem cell HCT with ATG (thymoglobulin) as part of non-myeloablative conditioning from March 1, 2004, to June 1, 2015. Patients received a cumulative intravenous dose of 8 mg/kg divided over 4 days, starting on day -8 before HCT. Active ATG concentrations were measured using a validated bioassay and pharmacokinetic exposure measures (maximum concentration, concentration at time of infusion of the graft, time to reach a concentration of 1 arbitary unit [AU] per day/mL, area under the curve [AUC], and the AUC before and after HCT) were calculated with a validated population pharmacokinetic model. The main outcome of interest was 5-year overall survival, defined as days to death from any cause or last follow-up. Other outcomes were relapse-related mortality, non-relapse mortality, event-free survival, acute and chronic GvHD, and assessment of current and optimum dosing. We used Cox proportional hazard models and Fine-Gray competing risk models for the analyses. 146 patients were included. ATG exposure after HCT was shown to be the best predictor for 5-year overall survival. Optimum exposure after transplantation was determined to be 60-95 AU per day/mL. Estimated 5-year overall survival in the group who had optimum exposure (69%, 95% CI 55-86) was significantly higher than in the group who had below optimum exposure (32%, 20-51, p=0·00037; hazard ratio [HR] 2·41, 95% CI 1·15-5·06, p=0·020) and above optimum exposure (48%, 37-62, p=0·030; HR 2·11, 95% CI 1·04-4·27, p=0·038). Patients in the optimum exposure group had a greater chance of event-free survival than those in the below optimum exposure group (HR 2·54, 95% CI 1·29-5·00, p=0·007; HR for the above optimum group: 1·83, 0·97-3·47, p=0·063). Above-optimum exposure led to higher relapse-related mortality compared with optimum exposure (HR 2·66, 95% CI 1·12-6·31; p=0·027). Below optimum exposure increased non-relapse mortality compared with optimum exposure (HR 4·36, 95% CI 1·60-11·88; p=0·0040), grade 3-4 acute GvHD (3·09, 1·12-8·53; p=0·029), but not chronic GvHD (2·38, 0·93-6·08; p=0·070). Modelled dosing based on absolute lymphocyte counts led to higher optimum target attainment than did weight-based dosing. Exposure to ATG affects survival after HCT in adults, stressing the importance of optimum ATG dosing. Individualised dosing of ATG, based on lymphocyte counts rather than bodyweight, might improve survival chances after HCT. Netherlands Organization for Health Research and Development and Queen Wilhelma Fund for Cancer Research.

Association of busulfan exposure with survival and toxicity after haemopoietic cell transplantation in children and young adults: a multicentre, retrospective cohort analysis

Intravenous busulfan combined with therapeutic drug monitoring to guide dosing improves outcomes after allogeneic haemopoietic cell transplantation (HCT). The best method to estimate busulfan exposure and optimum exposure in children or young adults remains unclear. We therefore assessed three approaches to estimate intravenous busulfan exposure (expressed as cumulative area under the curve [AUC]) and associated busulfan AUC with clinical outcomes in children or young adults undergoing allogeneic HCT. In this retrospective analysis, patients from 15 centres in the Netherlands, USA, Canada, Switzerland, UK, Italy, Germany, and Australia who received a busulfan-based conditioning regimen between March 18, 2001, and Feb 12, 2015, were included. Cumulative AUC was calculated by numerical integration using non-linear mixed effect modelling (AUCNONMEM), non-compartmental analysis (AUC from 0 to infinity [AUC0-∞] and to the next dose [AUC0-τ]), and by individual centres using various approaches (AUCcentre). The main outcome of interest was event-free survival. Other outcomes of interest were graft failure or relapse, or both; transplantation-related mortality; acute toxicity (veno-occlusive disease or acute graft versus-host disease [GvHD]); chronic GvHD; overall survival; and chronic-GvHD-free event-free survival. We used propensity-score-adjusted Cox proportional hazard models, Weibull models, and Fine-Gray competing risk regressions for statistical analyses. 790 patients were enrolled, 674 of whom were included: 274 (41%) with malignant and 400 (59%) with non-malignant disease. Median age was 4·5 years (IQR 1·4-10·7). The median busulfan AUCNONMEM was 74·4 mg × h/L (95% CI 31·1-104·6), which correlated with the standardised method AUC0-∞ (r2=0·74), but the latter correlated poorly with AUCcentre (r2=0·35). Estimated 2-year event-free survival was 69·7% (95% CI 66·2-73·0). Event-free survival at 2 years was 77·0% (95% CI 72·1-82·9) in the 257 patients with an optimum intravenous busulfan AUC of 78-101 mg × h/L compared with 66·1% (60·9-71·4) in the 235 patients at the low historical target of 58-86 mg × h/L and 49·5% (29·2-66·0) in the 44 patients with a high (>101 mg × h/L) busulfan AUC (p=0·011). Compared with the low AUC group, graft failure or relapse occurred less frequently in the optimum AUC group (hazard ratio [HR] 0·57, 95% CI 0·39-0·84; p=0·0041). Acute toxicity (HR 1·69, 1·12-2·57; p=0·013) and transplantation-related mortality (2·99, 1·82-4·92; p<0·0001) were significantly higher in the high AUC group (>101 mg × h/L) than in the low AUC group (<78 mg × h/L), independent of indication; no difference was noted between AUC groups for chronic GvHD (<78 mg × h/L vs ≥78 mg × h/L, HR 1·30, 95% CI 0·73-2·33; p=0·37). Improved clinical outcomes are likely to be achieved by targeting the busulfan AUC to 78-101 mg × h/L using a new validated pharmacokinetic model for all indications. Research Allocation Program and the UCSF Helen Friller Family Comprehensive Cancer Center and the Mt Zion Health Fund of the University of California, San Francisco.

QTc prolongation during peripheral stem cell apheresis in healthy volunteers.

Today, voluntary donation of peripheral blood stem cells by healthy donors for allogeneic hemopoietic cell transplantation is common worldwide. Such donations are associated with small but measurable risks of morbidity and mortality. Most complications are associated with citrate infusion during cell collection. We studied the effects of citrate infusion on the QTc and other vital parameters during and after peripheral stem cell apheresis in volunteers. To ensure that donors were healthy, screening included taking a detailed medical history, physical examination, and laboratory measurements of plasma calcium and magnesium. Corrected QT (QTc) values were assessed using a 12-lead electrocardiographic platform that derived QTc values automatically. In all, 141 apheresis procedures were performed. The mean QTc values at baseline, at 2 and 4 h during the procedure, and at 30 min after the procedure, were 347.6 ± 59.5, 349.9 ± 52.8, 391.8 ± 54.0, and 404.8 ± 59.2 ms, respectively. The baseline and 2 h QTcs did not differ significantly, but the baseline QTc did differ significantly from the 4 h and 30 min after the procedure values. The plasma levels of calcium and magnesium did not significantly differ before and after the procedure. QTc prolongation may develop during leukopheresis, particularly if the procedure takes more than 2 h. Thus, to enhance donor safety, QTc measurement should be standard for all donors. In addition, any family history of sudden death should be noted, to prevent the development of possible fatal arrhythmia in susceptible donors.

CCR5 Δ32 homozygous cord blood allogeneic transplantation in a patient with HIV: a case report

Allogeneic donor CCR5 Δ32 homozygous haemopoietic cell transplantation (HCT) provides the only evidence to date of long-term control of HIV infection. However, availability of conventional CCR5 Δ32 homozygous donors is insufficient to develop this as a therapeutic strategy further. We present a 37-year-old patient with HIV-1 infection and aggressive lymphoma who had disease progression after five lines of radiochemotherapy including an autologous HCT, and in the absence of matched sibling donors, received an allogeneic HCT with four of six HLA-matched CCR5 Δ32 homozygous cord blood cells (StemCyte, Covina, CA), supported with purified CD34+ cells from a haploidentical sibling. Blood or tissue samples were obtained before and weekly after HCT to monitor transplant and HIV infection, including chimerism analysis, CCR5 genotyping and viral tropism, viral isolation and sequence, viral reservoir analysis, immune activation and proliferation, and ex-vivo cell infectivity assays. Combined antiretroviral therapy continued during the procedure. The patient's HIV was CCR5-tropic by genotypic and phenotypic analyses. Baseline latent reservoir tests showed HIV DNA copies in bulk and resting CD4 T cells and in gut-associated lymphoid tissue, CD4 T-cell-associated HIV RNA, replication competent viral size of 2·1 copies per 10(7) CD4 T cells, and single copy assay of 303 copies per mL. After HCT, plasma HIV DNA load was undetectable by ultrasensitive analyses. Upon cord blood full chimerism, the patient's CCR5 Δ32 homozygous CD4 T cells responded to proliferation and activation stimuli and became resistant to infection by the patient's viral isolate and by laboratory-adapted HIV-1 strains. Death related to lymphoma progression regretfully prevented long-term monitoring of the patient's viral reservoir. CCR5 Δ32 homozygous cord blood reconstitution can successfully eliminate HIV-1 and render the allogeneic graft recipient's T lymphocytes resistant to HIV infection. Thus, they build on the evidence available to strongly support the use of cord blood as a strategic platform for a broader application of non-functional CCR5 transplantation to other infected individuals. Spanish Secretariat of Research, the American Foundation for AIDS Research (amfAR).

Single-Agent High-Dose Cyclophosphamide for Graft-versus-Host Disease Prophylaxis in Human Leukocyte Antigen–Matched Reduced-Intensity Peripheral Blood Stem Cell Transplantation Results in an Unacceptably High Rate of Severe Acute Graft-versus-Host Disease

High-dose cyclophosphamide given early after allogeneic hemopoietic cell transplantation has been shown to be effective prophylaxis against graft-versus-host disease (GVHD) in the setting of HLA-matched myeloablative bone marrow grafts, allowing avoidance of long-term immunosuppression with calcineurin inhibitors in some patients. Whether this approach is feasible using granulocyte colony–stimulating factor (G-CSF)–mobilized peripheral blood stem cell grafts is unknown. We conducted an exploratory phase 2 trial of cyclophosphamide given at 50 mg/kg i.v. on days 3 and 4 after transplantation as sole GVHD prophylaxis in recipients of G-CSF–mobilized peripheral blood stem cell grafts from HLA-matched related or unrelated donors after reduced-intensity conditioning therapy with fludarabine, carmustine, and melphalan. Five patients, ages 52 to 67 years, with high-risk hematologic malignancies were enrolled. Four of the 5 developed severe acute GVHD of grades 3 to 4, requiring treatment with methylprednisolone and cyclosporine; 3 were steroid refractory and were given salvage therapy. One of these 4 patients died of hepatic GVHD, one died of sepsis, and 2 survived. We conclude that post-transplantation cyclophosphamide is inadequate as sole GVHD prophylaxis in the context of peripheral blood reduced-intensity conditioning transplantations from HLA-matched donors. This trial is registered at ACTRN12613001154796.

Outcomes of allogeneic haemopoietic stem cell transplants at a small New Zealand centre: does size matter?

Reduced intensity conditioning (RIC) protocols for allogeneic haemopoietic cell transplants (HCT) have become commonplace treatments for patients with haematological disease, extending allogeneic HCT to older and less fit patients. There is a perception that centres treating larger numbers of patients have improved outcomes. We wanted to examine whether outcomes for adult allogeneic HCT patients from our smaller centre were equivalent to those expected at larger centres internationally. Clinical and laboratory data were collected on all patients who received allogeneic HCT during 2000-2012. Outcomes, including overall survival (OS) and progression-free survival, were compared between patients receiving myeloablative conditioning (MAC) and RIC protocols. One hundred and eighteen adult patients underwent allogeneic HCT with MAC (n = 51) or RIC (n = 67). The mean age of patients receiving MAC (35.8 years, range 18-56) was lower than those receiving RIC (48.4 years, range 19-64). Two-year OS was similar for MAC and RIC patients (66% vs 62%, P = 0.17), whereas 2-year progression-free survival was superior in MAC patients (63% vs 50%, P = 0.01) due to fewer relapses. OS was reduced in older patients irrespective of conditioning. Patients with chronic graft-versus-host disease had improved survival due to fewer relapses. OS was unaffected by HCT comorbidity index, donor, cell source or patient/donor cytomegalovirus status. RIC protocols have resulted in long-term survival in many patients ineligible for MAC protocols. In our smaller centre, patient age but not conditioning intensity influenced survival, which was equivalent to reports from larger centres.

Innovations: advances in cellular therapies relating to haematological conditions

It is an exciting time for genetic and cellular therapies. Since 1989 over 1500 Phase I/II studies of direct in vivo and cell-mediated gene therapy in diverse diseases have been completed.^1,2 Substantial evidence of improved clinical outcomes has been shown in haemophilia B, immune deficiencies, haemoglobinopathies, immunotherapies and blindness. In the field of cellular therapeutics, applications have expanded beyond the foundation in autologous and allogeneic haemopoietic cell transplantation to mesenchymal and other adult cell therapy trials. Indeed, if pluripotent cells can be differentiated <i>ex vivo</i> to recreate and repair mature human tissues and organs, then regenerative medicine will become a reality. However embryonic stem cells have been mired in controversy and clinical development has been forestalled.³ Medical and, in particular, stem cell tourism has become a billion dollar industry with increasing examples of false claims. Unregulated, untested or unsafe stem cell ‘therapies' place the field at a challenging crossroad.

Alterations in Chemokine Receptor CCR5 Expression on Blood Dendritic Cells Correlate With Acute Graft-Versus-Host Disease

Dendritic cells (DC) are important in the development of acute graft-versus-host disease (GVHD) after allogeneic hemopoietic cell transplantation (alloHCT). The trafficking of immature DC from blood to GVHD target organs is likely to be regulated by chemokine receptors. We performed flow cytometry to document the expression of chemokine receptors on circulating DC and correlated the findings after alloHCT with occurrence of acute GVHD. In normal individuals, plasmacytoid DC (pDC) expressed high levels of CCR5, whereas the major CD16 myeloid DC subpopulation lacked CCR5. However, its expression on CD16 cells was induced by culture in allogeneic mixed lymphocyte reaction supernatant, an effect largely mediated by interferon-γ. CCR5 was expressed on a significant proportion of CD16 DC in 42 alloHCT patients, whereas it was down-regulated on pDC. The maximum percentage of CCR5CD16 DC, at any time after transplantation, correlated with acute GVHD, whereas the minimum CCR5 on pDC showed a similar correlation. Before developing signs of GVHD, the maximum percentage CCR5CD16 DC was higher in patients with GVHD grades II to IV than in GVHD grades 0 and I, whereas the minimum percentage CCR5 on pDC was lower in GVHD grades II to IV than in GVHD grades 0 and I. CCR5 levels more than 20.5% on CD16 myeloid DC and less than 22.6% on CD123 pDC correlated with subsequent GVHD grades II to IV with high sensitivities and specificities. These observations may reflect DC activation and altered homing during the alloimmune response and could allow early diagnosis and therapeutic intervention before the clinical diagnosis of GVHD.

Reduced-intensity conditioning versus standard conditioning before allogeneic haemopoietic cell transplantation in patients with acute myeloid leukaemia in first complete remission: a prospective, open-label randomised phase 3 trial

Reduced-intensity conditioning regimens have been developed to minimise early toxic effects and deaths after allogeneic haemopoietic cell transplantation. However, the efficacy of these regimens before this procedure has not been investigated in a randomised trial. In this prospective, open-label randomised phase 3 trial we compared a reduced-intensity fludarabine-based conditioning regimen with a standard regimen in patients with acute myeloid leukaemia in first complete remission. Patients were aged 18-60 years and had intermediate-risk or high-risk acute myeloid leukaemia (defined by cytogenetics) in first complete remission; an available HLA-matched sibling donor or an unrelated donor with at least nine of ten HLA alleles; and adequate renal, cardiac, pulmonary, and neurological function. Between Nov 15, 2004, and Dec 31, 2009, patients were randomly assigned (1:1, by a computer-based minimisation procedure that balanced patients for age, cytogenetic risk, induction therapy, and donor type) to receive either reduced-intensity conditioning of four doses of 2 Gy of total-body irradiation and 150 mg/m(2) fludarabine or standard conditioning of six doses of 2 Gy of total-body irradiation and 120 mg/kg cyclophosphamide. All patients were given ciclosporin and methotrexate as prophylaxis against graft-versus-host disease. Neither investigators nor patients were blinded to study treatment. Our primary endpoint was the incidence of non-relapse mortality, analysed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00150878. The trial was stopped early on Dec 31, 2009, because of slow accrual of patients. 99 patients were randomly assigned to receive reduced-intensity conditioning and 96 to receive standard conditioning. The incidence of non-relapse mortality did not differ between the reduced-intensity and standard conditioning groups (cumulative incidence at 3 years 13% [95% CI 6-21] vs 18% [10-26]; HR 0·62 [95% CI 0·30-1·31]). Relapse incidence (cumulative incidence 3 years 28% [95% CI 19-38] vs 26% [17-36]; HR 1·10 [95% CI 0·63-1·90]), disease-free survival (3 year disease-free survival 58% [95% CI 49-70] vs 56% [46-67]; HR 0·85 [95% CI 0·55-1·32]), and overall survival (3 year overall survival 61% [95% CI 50-74] vs 58% [47-70]; HR 0·77 [95% CI 0·48-1·25]) did not differ significantly between groups. Grade 3-4 of oral mucositis was less common in the reduced-intensity group than in the standard conditioning group (50 patients in the reduced-intensity conditioning group vs 73 patients in the standard conditioning group); the frequency of other side-effects such as graft-versus-host disease and increased concentrations of bilirubin and creatinine did not differ significantly between groups. Reduced-intensity conditioning results in a similar incidence of non-relapse mortality and reduced toxic effects compared with standard conditioning without affecting survival outcomes, and thus could be preferentially used in patients younger than 60 years with acute myeloid leukaemia transplanted in first complete remission.

New developments in cell and gene therapy

It is an exciting time for cellular and genetic therapies. Since 1989 over 1500 Phase I/II studies of direct in vivo and cell-mediated gene therapy in diverse diseases have been completed. 1 Substantial evidence of improved clinical outcomes has been shown in haemophilia B, immune deficiencies, haemoglobinopathies, immunotherapies and blindness. In the field of cellular therapeutics, applications have expanded beyond the foundation in autologous and allogeneic haemopoietic cell transplantation to mesenchymal and other adult cell therapy trials. Indeed, if plur-ipotent cells can be differentiated ex vivo to recreate and repair mature human tissues and organs, then regenerative medicine will become a reality. However, embryonic stem cells have been mired in controversy and clinical development has been forestalled. 2 Almost every country in the Asia-Pacific region offers at least some cellular therapy options, from ‘highly regulated’ countries like Singapore, Japan, Korea and Australia, through to countries where the oversight is less formal. Medical and, in particular, stem cell tourism has become a billion dollar industry with increasing examples of false claims. 3 Unregulated, untested or unsafe stem cell ‘therapies’ place the field at a challenging crossroad.

Upregulation of the Chemokine Receptor CCR5 on CD16+ Myeloid Blood Dendritic Cells in Allogeneic Hemopoietic Cell Transplant Patients Predicts for Acute Graft Versus Host Disease

Abstract 1982 Introduction:Dendritic cells (DC) are centrally involved in the development of acute graft-versus-host disease (GvHD) following allogeneic hemopoietic cell transplantation (alloHCT). We previously showed that the activation status, as assessed by CMRF-44 antigen expression, of CD11c+ myeloid blood DC is highly associated with the onset and severity of acute GvHD (Transplantation. 2007;83:839–846). We also reported a positive correlation between acute GvHD and the expression of the chemokine receptor CCR5 on CD11c+ myeloid DC (Blood. 2009;114 Suppl.:2251). Given the phenotypic and functional heterogeneity of the CD11c+ DC population, we investigated CCR5 expression on the CD11c+ DC subsets and then monitored the informative CD11c+ CD16+ DC subset expression of CCR5 in the peripheral blood of 42 patients post alloHCT, and correlated the findings with GvHD. Methods:Peripheral blood was collected twice weekly up to Day 100 post transplant from 42 alloHCT patients. The expression of CCR5 receptor on CD11c+ and CD11c- DC subsets was evaluated using multiparameter flow cytometry. Results:Only the CD11c+ CD16+ DC subset lacked CCR5 and induced it upon alloactivation. Seventeen of 42 patients developed acute GvHD (5 grade I, 12 grades II-IV). The percentage of CD11c+ CD16+ DC expressing CCR5 correlated with the development of acute GvHD grades II-IV. The maximum CCR5 expression detected on CD11c+ CD16+ DC in patients prior to developing grades II-IV GvHD (mean 22.7 ± 4.3%, n=12) was higher than in those with grades 0-I GvHD (11.4 ± 1.7%, n=30) (p=0.0285). CCR5 levels >20% on CD16+ myeloid DC predicted grades II-IV GvHD with a sensitivity of 66.7% and specificity of 86.7%. Levels of expression of CCR5 on the CD11c+ CD16- DC and CD123+ plasmacytoid DC were not predictive of GvHD. Conclusion:Expression of CCR5 on circulating CD11c+ CD16+ myeloid DC post alloHCT correlated with the development of moderate to severe GvHD. This observation may reflect DC activation or altered DC homing during the alloimmune response. Detection of increased CCR5+ CD11c+ CD16+ DC may allow pre-emptive therapeutic intervention prior to the clinical diagnosis of GvHD. Disclosures:No relevant conflicts of interest to declare.

Increased Production of the Inflammatory Cytokine IL12p70 by Activated Human Blood Dendritic Cells Is Associated with Increased Severity of Acute Graft Vs Host Disease Post Allogeneic Hemopoietic Cell Transplantation

Abstract 4539 Introduction:Dendritic cells (DC) are centrally involved in the initiation of acute graft versus host disease (GVHD) after allogeneic hemopoietic cell transplantation (alloHCT). We have shown that the activation status of peripheral blood CD11c+ myeloid DC, as assessed by CMRF-44 antigen expression, is highly associated with the occurrence and severity of acute GvHD (Transplantation 2007;83: 839–846). However, very little is known about the function of DC after human alloHCT. We examined the relationship between DC functional properties and the severity of acute GvHD. Methods:Peripheral blood CD11c+ myeloid DC from 12 patients were studied weekly up to 8 weeks post transplant for production of IL2, IL4, INFg, IL10 and IL12 using an intracellular cytokine flow assay. Mixed lymphocyte reactions using flow sorted patient DC and third party T cells were used to assess allogeneic immune responses induced by recipient DC in 5 patients. Results:IL12 was the only cytokine detected in post transplant DC. Five of 12 patients developed grade II-IV GvHD, the remaining 7 patients developed either no aGvHD or only grade I. In comparison with pre-transplant levels of expression of IL12, patients with grade II-IV GVHD had a significantly higher percentage of CD11c+ DC expressing IL12 (median 15.1%, range 11.2–20.9%) as compared to patients with grade 0-I GvHD in whom there was no change from baseline values (median 6.6% range 2.8–8.9%) p=0.0025. Increased expression of IL12 was observed in CD11c+ DC commencing at day 25 post transplant. Interestingly, analysis of 5 paired samples comparing sorted DC from normal donors with sorted DC from peripheral blood at day +30 post-transplant showed a marked reduction (measured by thymidine uptake from 60% to 90%) in the capacity of post-transplant donor DCs to stimulate 3rd party lymphocyte proliferation. None of these patients developed clinically significant aGvHD. Conclusion:Production of IL-12p70 by CD11c+ myeloid DC correlates with severity of GvHD despite impaired capacity of these cells to elicit third party proliferative responses. Disclosures:No relevant conflicts of interest to declare.

Role of HCT-comorbidity index, age and disease status at transplantation in predicting survival and non-relapse mortality in patients with myelodysplasia and leukemia undergoing reduced-intensity-conditioning hemopoeitic progenitor cell transplantation

Reduced-intensity-conditioning (RIC) regimens have allowed older patients to have allogeneic hemopoietic progenitor cell transplantation (HCT). This retrospective study was done to assess the impact of the HCT-comorbidity index (HCT-CI) in addition to other pre-transplant factors on the outcome of RIC transplants. In all 121 such patients were transplanted between 2002 and 2008 at two centers using fludarabine, melphalan and alumtuzumab conditioning. The OS and non-relapse mortality (NRM) were 56% and 30% at 2 years, respectively. The NRM of patients with HCT-CI ≥ 3 was not significantly different from the NRM of those with HCT-CI 0-2 (P value 0.24). Age and disease status at transplantation were significant factors affecting OS (P value 0.07 and 0.008, respectively), with no impact on NRM (P value 0.14 and 0.24, respectively). Although HCT-CI on its own did not independently predict NRM or survival, taken together with age and disease status at transplantation, it can be utilized to further delineate RIC allograft recipients into groups with different outcomes. Patients with none or one of these three adverse factors (age ≥ 60 years, leukemia in second CR or PR/high-risk myelodysplasia (MDS) and HCT-CI ≥ 3) had a 2-year NRM and survival of 18% and 80%, respectively, which was significantly better than those of patients with two or more of these adverse factors with 2-year NRM and survival of 46% (P value 0.03) and 40% (P value 0.02), respectively. None of the patients with all three adverse factors (age ≥ 60 years, leukemia in second CR or PR/high-risk MDS and HCT-CI ≥ 3) had survived for 2 years (median survival 12 months). This information can be used to guide patient selection for RIC transplants and to appropriately counsel patients of the risks and benefits of this treatment.

Cytokine Induced Killer Cells as Promising Immunotherapy for Solid Tumors

Cytokine-induced killer (CIK) cells are a heterogeneous subset of ex-vivo expanded T lymphocytes which present a mixed T-NK phenotype and are endowed with a MHC-unrestricted antitumor activity. The main functional properties of CIK cells may address some of the main limitations that are currently preventing the successful clinical translation of adoptive immunotherapy strategies. Clinically adequate quantities of immune effectors, sufficient for multiple adoptive infusions, may be obtained based on their relatively easy and inexpensive ex-vivo expansion starting from peripheral blood mononuclear cells. The MHC-unrestricted tumor-killing is mainly based on the interaction between NKG2D molecules on CIK cells and MIC A/B or ULBPs molecules on tumor cells; it has been proved effective against several solid and hematological malignancies and does not require any HLA-restriction increasing the number of patients that might potentially benefit from such approach. Finally, CIK cells present a reduced alloreactivity across HLA-barriers with important clinical implications for their potential use as alternative to conventional Donor Lymphocyte Infusions after allogeneic hemopoietic cell transplant with a reduced risk of GVHD. In the present report we review the main functional characteristics of CIK cells discussing recent findings and future perspectives to improve their antitumor activity and potential clinical applications.

Increased activity and improved outcome in unrelated donor haemopoietic cell transplants for acute myeloid leukaemia in Australia, 1992–2005

Numbers of unrelated donor allogeneic haemopoietic cell transplants (HCT) for acute myeloid leukaemia have increased in Australia in recent years. The aims of this study were to investigate the components of this change and find contributing factors to changes in outcome. The study method was a retrospective analysis of 213 consecutive first unrelated donor HCT for acute myeloid leukaemia performed within Australia for adult patients during the years of 1992-1997 (n= 43) and 1998-2005 (n= 170). The proportion of patients transplanted in first or second complete remission (CR) increased markedly from 21% in 1992-1997 to 52% in 1998-2005. The cumulative incidence of relapse at 1 year post HCT was significantly lower for the later cohort (22% vs 30%, P= 0.04) and for patients transplanted in CR compared with those not in CR (16% vs 31%, P= 0.01). The overall survival probability was significantly better at 5 years post HCT for patients transplanted in 1998-2005 compared with 1992-1997 (40% vs 21%, P= 0.04). Multivariate analysis identified five independent significant favourable factors for survival among the whole patient group: age under 40 years, transplant in CR1, CR2 or first relapse, patient CMV seronegativity, good performance status and year of transplant within 1998-2005. The later cohort of patients had improved survival even after allowing for the effects of age, remission status and other factors, which suggests a general improvement in the safety of the procedure over time, particularly for patients in early disease stages at transplant.

Re: Does Having a Personal Physician Improve Quality of Care in Diabetes?

Graft-vs-host disease (GVHD) is the major cause of morbidity and mortality after allogeneic hemopoietic cell transplantation. From a genetic perspective, GVHD is a complex phenotypic trait. Although it is understood that susceptibility results from interacting polymorphisms of genes encoding histocompatibility Ags and immune regulatory molecules, a detailed and integrative understanding of the genetic background underlying GVHD remains lacking. To gain insight regarding these issues, we performed a forward genetic study. A MHC-matched mouse model was used in which irradiated recipient BALB.K and B10.BR mice demonstrate differential susceptibility to lethal GHVD when transplanted using AKR/J donors. Assessment of GVHD in (B10.BR × BALB.K)F₁ mice revealed that susceptibility is a dominant trait and conferred by deleterious alleles from the BALB.K strain. To identify the alleles responsible for GVHD susceptibility, a genome-scanning approach was taken using (B10.BR × BALB.K)F₁ × B10.BR backcross mice as recipients. A major susceptibility locus, termed the <i>Gvh1</i> locus, was identified on chromosome 16 using linkage analysis (logarithm of the odds, 9.1). A second locus was found on chromosome 13, named <i>Gvh2</i>, which had additive but protective effects. Further identification of <i>Gvh</i> genes by positional cloning may yield new insight into genetic control mechanisms regulating GVHD and potentially reveal novel approaches for effective GVHD therapy.