The EBMT activity survey 2007 with focus on allogeneic HSCT for AML and novel cellular therapies

Survival Advantage of Treosulfan Plus Fludarabine Before Allogeneic Hematopoietic Cell Transplantation for Older or Comorbid Patients With Myeloid Malignancies

We have previously shown an advantage of a myeloablative conditioning regimen with reduced toxicity (Fludarabine 150 mg/m², Treosulfan 42 g/m², FluTreo) compared to a reduced-intensity regimen. We aimed to determine long-term safety and efficacy of FluTreo. We prospectively studied consecutive patients who received FluTreo in our center (2014-2019) on the basis of age (≥50 years), hematopoietic cell transplantation comorbidity index (HCT-CI) ≥2, or both. FluTreo recipients were then compared to a historical control group. We studied 68 FluTreo recipients, with a median age of 58.5 years and HCT-CI of 3. We calculated cumulative incidence (CI) of acute (grade 2-4) and moderate/severe chronic graft-versus-host disease (GVHD) (29.9% and 25%, respectively). The 3-year CI of treatment-related mortality was 19.1%, associated only with acute GVHD (P < .001). With a median follow-up of 27.3 (range 5.7-84.5) months in surviving patients, the 3-year overall survival (OS) was 56.6%, and disease-free survival (DFS) was 54.9%. Median survival has not yet been reached. Among pretransplantation and transplantation factors, only HCT-CI was associated with DFS and OS (P = .022 and P = .043, respectively). FluTreo recipients aged ≥50 with HCT-CI ≤ 2 had favorable DFS and OS compared with patients aged ≥50 with HCT-CI ≤2 after myeloablative conditioning. Our real-world study confirms that HCT with FluTreo expands the transplant population with favorable outcomes compared to previously used conditions. The choice of HCT in patients of a rather older age and comorbidity index needs to be revisited.

The EBMT activity survey report 2017: a focus on allogeneic HCT for nonmalignant indications and on the use of non-HCT cell therapies

Hematopoietic cell transplantation (HCT) is widely used for acquired and congenital disorders of the hematopoietic system. Number of transplants done in Europe and associated countries continues to rise with 45,418 HCT in 41,100 patients [(17,155 allogeneic (42%) and 23,945 autologous (58%)] reported by 683 centers in 50 countries in 2017. Main indications were myeloid malignancies 10,147 (25%; 96% allogeneic), lymphoid malignancies 26,488 (64%; 19% allogeneic), solid tumors 1,607 (3.9%; 2% allogeneic), and nonmalignant disorders 2,667 (7%; 81% allogeneic). Trends in donor choice seen before continue, with growing numbers of haploidentical HCT and decreasing use of cord blood. Of interest is that after many years of continued growth, the number of patients receiving an allogeneic HCT for marrow failure is decreasing slightly (p < 0.001). Such a change may be explained by the use of thrombopoietin analogs in aplastic anemia patients. Other nonmalignant indications, however continue to grow, most importantly HCT for hemoglobinopathies by 36%, equally for thalassemias and sickle cell disease. Non-HCT cell therapies have increased by 28% since 2015 and genetically modified T cells is type of cell therapy with the fastest growth. These annual reports reflect current activity and trends and are useful for health-care planning.

Alternative donor transplants for severe aplastic anemia

Allogeneic hematopoietic stem-cell transplantation remains the only curative treatment for patients with acquired severe aplastic anemia (SAA). When a matched sibling is not available, one can search for a matched unrelated donor or a cord blood unit (CB) in the international registries or, more recently, for an HLA haploidentical (HAPLO) family member. International guidelines call for a course of antithymocyte globulin (ATG) and cyclosporine before a patient with SAA receives a transplant from a donor other than an HLA identical sibling, but whether this is necessary for patients age <20 years is less clear. Here I will examine the rapid increase in HAPLO transplantations for SAA, showing encouraging early results both in children and young adults. Graft-versus-host disease prophylaxis remains of primary importance in patients with SAA, and in vivo T-cell depletion with either ATG or alemtuzumab offers a significant survival advantage. Finally, I will discuss the strong age effect, which is particularly evident at >40 and 50 years of age for reasons not entirely clear and which should be taken into account when designing a treatment strategy for a given patient.

Is the use of unrelated donor transplantation leveling off in Europe? The 2016 European Society for Blood and Marrow Transplant activity survey report

Hematopoietic cell transplantation (HCT) is an established procedure for acquired and congenital disorders of the hematopoietic system. In 2016, there was a tendency for continued activity in this field with 43,636 HCT in 39,313 patients [16,507 allogeneic (42%), 22,806 autologous (58%)] reported by 679 centers in 49 countries in 2016. The main indications were myeloid malignancies 9547 (24%; 96% allogeneic), lymphoid malignancies 25,618 (65%; 20% allogeneic), solid tumors 1516 (4%; 2% allogeneic), and non-malignant disorders 2459 (6%; 85% allogeneic). There was a remarkable leveling off in the use of unrelated donor HCT being replaced by haploidentical HCT. Continued growth in allogeneic HCT for marrow failure, AML, and MPN was seen, whereas MDS appears stable. Allogeneic HCT for lymphoid malignancies vary in trend with increases for NHL and decreases for Hodgkin lymphoma and myeloma. Trends in CLL are not clear, with recent increases after a decrease in activity. In autologous HCT, the use in myeloma continues to expand but is stable in Hodgkin lymphoma. There is a notable increase in autologous HCT for autoimmune disease. These data reflect the most recent advances in the field, in which some trends and changes are likely to be related to development of non-transplant technologies.

Synergistic Integration of Mesenchymal Stem Cells and Hydrostatic Pressure in the Expansion and Maintenance of Human Hematopoietic/Progenitor Cells

Ex vivo expansion of hematopoietic stem/progenitor cell (HSPC) has been investigated to improve the clinical outcome of HSPC transplantation. However, ex vivo expansion of HSPCs still faces a major obstacle in that HPSCs tend to differentiate when proliferating. Here, we cocultured HSPCs with mesenchymal stem cells (MSCs) and divided the HSPCs into two fractions according to whether they came into adherent to MSCs or not. Additionally, we used hydrostatic pressure (HP) to mimic the physical conditions in vivo. Even nonadherent cells expanded to yield a significantly larger number of total nucleated cells (TNCs), adherent cells maintained the HSPC phenotype (CD34⁺, CD34⁺CD38⁻, and CD133⁺CD38⁻) to a greater extent than nonadherent cells and had superior clonogenic potential. Moreover, applying HP significantly increased the number of TNCs, the frequency of the immature HSPC phenotype, and the clonogenic potential. Furthermore, the genetic markers for the HSPC niche were significantly increased under HP. Our data suggest that the nonadherent fraction is the predominant site of HSPC expansion, whereas the adherent fraction seems to mimic the HSPC niche for immature cells. Moreover, HP has a synergistic effect on expansion and functional maintenance. This first study utilizing HP has a potential of designing clinically applicable expansion systems.

Donor Cell-Derived Hematologic Neoplasms after Hematopoietic Stem Cell Transplantation: A Systematic Review

Development of de novo hematologic malignancies in donor cells after allogeneic stem cell transplantation (allo-SCT) provides a useful in vivo model to study the process of leukemogenesis. A systematic analysis of the cases reported in the literature was performed to identify risk factors and mechanisms involved in the pathogenesis of donor cell-derived hematologic neoplasms (DCHN) and leukemogenic transformation. Relevant data were extracted from 137 cases. Cases of DCHN show a wide heterogeneity with regard to recipient/donor age, sex mismatch, and conditioning regimen. Some characteristics, such as the type of primary disease, the type of hematologic malignancy of the DCHN, and the stem cell source used in the transplant procedure, differ from those expected. Mechanisms involved in the pathogenesis of DCHN are complex, and several hypotheses have been proposed, such as pre-existing hematologic neoplasms or premalignant clones in the donor, decreased immune surveillance, and damage to bone marrow microenvironment in the recipient. Most likely several if not all these mechanisms play a role in DCHN development. Novel approaches, such as next-generation sequencing to study consecutive samples after allo-SCT in these patients, appear to be promising to decipher the mechanisms of leukemogenesis.

Use of haploidentical stem cell transplantation continues to increase: the 2015 European Society for Blood and Marrow Transplant activity survey report

Hematopoietic stem cell transplantation (HSCT) is an established procedure for many acquired and congenital disorders of the hematopoietic system. A record number of 42 171 HSCT in 37 626 patients (16 030 allogeneic (43%), 21 596 autologous (57%)) were reported by 655 centers in 48 countries in 2015. Trends include continued growth in transplant activity over the last decade, with the highest percentage increase seen in middle-income countries but the highest absolute growth in the very-high-income countries in Europe. Main indications for HSCT were myeloid malignancies 9413 (25% 96% allogeneic), lymphoid malignancies 24 304 (67% 20% allogeneic), solid tumors 1516 (4% 3% allogeneic) and non-malignant disorders 2208 (6% 90% allogeneic). Remarkable is the decreasing use of allogeneic HSCT for CLL from 504 patients in 2011 to 255 in 2015, most likely to be due to new drugs. Use of haploidentical donors for allogeneic HSCT continues to grow: 2012 in 2015, a 291% increase since 2005. Growth is seen for all diseases. In AML, haploidentical HSCT increases similarly for patients with advanced disease and for those in CR1. Both marrow and peripheral blood are used as the stem cell source for haploidentical HSCT with higher numbers reported for the latter.

Hematopoietic stem cell transplantation in Europe 2014: more than 40 000 transplants annually

A record number of 40 829 hematopoietic stem cell transplantation (HSCT) in 36 469 patients (15 765 allogeneic (43%), 20 704 autologous (57%)) were reported by 656 centers in 47 countries to the 2014 survey. Trends include: continued growth in transplant activity, more so in Eastern European countries than in the west; a continued increase in the use of haploidentical family donors (by 25%) and slower growth for unrelated donor HSCT. The use of cord blood as a stem cell source has decreased again in 2014. Main indications for HSCT were leukemias: 11 853 (33% 96% allogeneic); lymphoid neoplasias; 20 802 (57% 11% allogeneic); solid tumors; 1458 (4% 3% allogeneic) and non-malignant disorders; 2203 (6% 88% allogeneic). Changes in transplant activity include more allogeneic HSCT for AML in CR1, myeloproliferative neoplasm (MPN) and aplastic anemia and decreasing use in CLL; and more autologous HSCT for plasma cell disorders and in particular for amyloidosis. In addition, data on numbers of teams doing alternative donor transplants, allogeneic after autologous HSCT, autologous cord blood transplants are presented.

High-resolution HLA matching in unrelated donor transplantation in Switzerland: differential impact of class I and class II mismatches may reflect selection of nonimmunogenic or weakly immunogenic DRB1/DQB1 disparities

Unrelated donor searches in Switzerland require high-resolution HLA typing for HLA-A/B/C/DRB1/DRB3,4/DQB1 loci. We evaluated this strategy accepting donors with ⩾9/10 match. Of 802 unrelated donor transplants in 2000-2013, 570 were 10/10 matched, 31 were DRB3/4 mismatched, 261 were single-allele mismatched and 13 had 2 allele mismatches. Of the 261 single-allele disparities, 60 concerned HLA-A/-B, 55 HLA-C and 73 HLA-DRB1/-DQB1 loci. Transplants were reduced intensity conditioning (289, 36%), marrow (187, 23%), EBMT risk score was low in 39, intermediate I in 331, intermediate II in 333 and high in 99 patients. Five-year survival was 48±4%. HLA affected survival in the multivariate model adjusted for risk score. HLA-A/-B and HLA-C mismatches had twice the mortality risks, whereas HLA-DRB1/-DQB1 mismatches were similar to matched transplants. HLA-DRB3/4 mismatches were associated with a nonsignificant increased mortality risk. HLA-DRB3/4 mismatches had higher graft-versus-host disease and transplant-related mortality risks and lower relapse rates compared with matched transplants. We show significant effects of HLA class I, but not HLA class II, mismatches. The lack of impact of DRB1 disparities may be related to the lower immunogenicity of the DRB1*11:01/11:04 and DRB1*14:01/14:54 mismatches, representing 46% of DRB1 incompatibilities. These results support a matching algorithm that prioritizes mismatches considered as more permissive.

Hematopoietic SCT in Europe 2013: recent trends in the use of alternative donors showing more haploidentical donors but fewer cord blood transplants

A record number of 39,209 HSCT in 34,809 patients (14,950 allogeneic (43%) and 19,859 autologous (57%)) were reported by 658 centers in 48 countries to the 2013 survey. Trends include: more growth in allogeneic than in autologous HSCT, increasing use of sibling and unrelated donors and a pronounced increase in haploidentical family donors when compared with cord blood donors for those patients without a matched related or unrelated donor. Main indications were leukemias, 11,190 (32%; 96% allogeneic); lymphoid neoplasias, 19,958 (57%; 11% allogeneic); solid tumors, 1543 (4%; 4% allogeneic); and nonmalignant disorders, 1975 (6%; 91% allogeneic). In patients without a matched sibling or unrelated donor, alternative donors are used. Since 2010 there has been a marked increase of 96% in the number of transplants performed from haploidentical relatives (802 in 2010 to 1571 in 2013), whereas the number of unrelated cord blood transplants has slightly decreased (789 in 2010 to 666 in 2013). The use of donor type varies greatly throughout Europe.

Hematopoietic cell transplantation in patients with intermediate and high-risk AML: results from the randomized Study Alliance Leukemia (SAL) AML 2003 trial

The optimal timing of allogeneic hematopoietic stem cell transplantation (HCT) in acute myeloid leukemia (AML) is controversial. We report on 1179 patients with a median age of 48 years who were randomized upfront. In the control arm, sibling HCT was scheduled in the first complete remission for intermediate-risk or high-risk AML and matched unrelated HCT in complex karyotype AML. In the experimental arm, matched unrelated HCT in first remission was offered also to patients with an FLT3-ITD (FMS-like tyrosine kinase 3-internal tandem duplication) allelic ratio >0.8, poor day +15 marrow blast clearance and adverse karyotypes. Further, allogeneic HCT was recommended in high-risk AML to be performed in aplasia after induction chemotherapy. In the intent-to-treat (ITT) analysis, superiority of the experimental transplant strategy could not be shown with respect to overall survival (OS) or event-free survival. As-treated analyses suggest a profound effect of allogeneic HCT on OS (HR 0.73; P=0.002) and event-free survival (HR 0.67; P<0.001). In high-risk patients, OS was significantly improved after allogeneic HCT in aplasia (HR 0.64; P=0.046) and after HCT in remission (HR 0.74; P=0.03). Although superiority of one study arm could not be demonstrated in the ITT analysis, secondary analyses suggest that early allogeneic HCT is a promising strategy for patients with high-risk AML.

Tolerability and efficacy of busulfan and fludarabine as allogeneic pretransplant conditioning therapy in acute myeloid leukemia: comparison with busulfan and cyclophosphamide regimen

BACKGROUND

The aim of this study was to compare safety and efficacy of the association of busulfan with cyclophosphamide (BuCy2) versus busulfan and fludarabine (BuFlu) as a conditioning regimen in allogeneic hematopoietic progenitor cell transplantation (allo-HPCT) in patients with acute myeloid leukemia (AML).

PATIENTS AND METHODS

A total of 65 consecutive patients who received an allo-HPCT from Human Leucocyte Antigen-matched sibling donors were analyzed. The conditioning was BuCy2 in 48 patients and BuFlu in 17 patients.

RESULTS

There were no significant differences between the 2 cohorts in hematological engraftment, incidence of extrahematological toxicities, and acute graft versus host disease (GVHD). The incidence of chronic GVHD was 34% in the BuCy2 group versus 57% in the BuFlu group (P = .03). Transplant-related mortality was 17% (8 patients) in the BuCy2 group versus 0 in the BuFlu arm. Disease-related mortality was similar in the whole study population; in high-risk AML patients it was 11% in the BuCy2 group and 19% in the BuFlu group (P = .015). The probability of disease-free and event-free survival at 2 years was, respectively, 70% and 60% in the BuCy2 group and 59% and 58% in the BuFlu group (P = .06 and P = not significant [ns]). The probability of overall survival at 2 years was 71% in the BuCy2 group and 63% in the BuFlu group (P = ns), and in the high-risk group it was 83% and 67% in the BuCy2 and BuFlu group, respectively (P = ns).

CONCLUSION

BuFlu is well tolerated and is less toxic than BuCy2 and our results did not suggest that in high-risk AML, BuCy2 should be the favorite regimen in terms of efficacy.

Bone marrow versus peripheral blood allogeneic haematopoietic stem cell transplantation for haematological malignancies in adults

BACKGROUND

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is an established treatment option for many malignant and non-malignant disorders. In the past two decades, peripheral blood stem cells replaced bone marrow as stem cell source due to faster engraftment and practicability. Previous meta-analyses analysed patients treated from 1990 to 2002 and demonstrated no impact of the stem cell source on overall survival, but a greater risk for graft-versus-host disease (GvHD) in peripheral blood transplants. As transplant indications and conditioning regimens continue to change, whether the choice of the stem cell source has an impact on transplant outcomes remains to be determined.

OBJECTIVES

To assess the effect of bone marrow versus peripheral blood stem cell transplantation in adult patients with haematological malignancies with regard to overall survival, incidence of relapse and non-relapse mortality, disease-free survival, transplant-related mortality, incidence of GvHD and time to engraftment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (from 1948 to February 2014), trial registries and conference proceedings. The search was conducted in October 2011 and was last updated in February 2014. We did not apply any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing bone marrow and peripheral blood allogeneic stem cell transplantation in adults with haematological malignancies.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and extracted and analysed data independently. We contacted study authors for additional information. We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included nine RCTs that met the pre-defined selection criteria, involving a total of 1521 participants. Quality of data reporting was heterogeneous among the studies. Overall, the risk of bias in the included studies was low.For the primary outcome overall survival, our analysis demonstrated comparable results between bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT) (six studies, 1330 participants; hazard ratio (HR) 1.07; 95% CI 0.91 to 1.25; P value = 0.43; high-quality evidence).Disease-free survival (six studies, 1225 participants; HR 1.04; 95% CI 0.89 to 1.21; P value = 0.6; moderate-quality of evidence) and non-relapse or transplant-related mortality (three studies, 758 participants; HR 0.98; 95% CI 0.76 to 1.28; P = 0.91; high-quality evidence) were also comparable between transplantation arms.In the related-donor setting, data from two of eight studies with 211 participants (21%) indicated a higher relapse incidence in participants transplanted with bone marrow stem cells rather than peripheral blood stem cells (HR 2.73; 95% CI 1.47 to 5.08; P value = 0.001). There was no clear evidence of a difference in relapse incidence between transplantation groups in unrelated donors (HR 1.07; 95% CI 0.78 to 1.47; P value = 0.66). The difference between the donor-related and -unrelated subgroups (P-value = 0.008) was considered to be statistically significant.BMT was associated with lower rates of overall and extensive chronic GvHD than PBSCT (overall chronic GvHD: four studies, 1121 participants; HR 0.72; 95% CI 0.61 to 0.85; P value = 0.0001, extensive chronic GvHD: four studies, 765 participants; HR 0.69; 95% CI 0.54 to 0.9; P value = 0.006; moderate-quality evidence for both outcomes). The incidence of acute GvHD grades II to IV was not lower (six studies, 1330 participants; HR 1.03; 95% CI 0.89 to 1.21; P value = 0.67; moderate-quality evidence), but there was a trend for a lower incidence of grades III and IV acute GvHD with BMT than with PBSCT (three studies, 925 participants; HR 0.75; 95% CI 0.55 to 1.02; P value = 0.07; moderate-quality evidence).Times to neutrophil and platelet engraftment were longer with BMT than with PBSCT (neutrophil: five studies, 662 participants; HR 1.96; 95% CI 1.64 to 2.35; P value < 0.00001; platelet: four studies, 333 participants; HR 2.17; 95% CI 1.69 to 2.78; P value < 0.00001).

AUTHORS' CONCLUSIONS

This systematic review  found high-quality evidence that overall survival following allo-HSCT using the current clinical standard stem cell source - peripheral blood stem cells - was similar to that following allo-HSCT using bone marrow stem cells in adults with haematological malignancies. We found moderate-quality evidence that PBSCT was associated with faster engraftment of neutrophils and platelets, but a higher risk of GvHD (in terms of more overall and extensive chronic GvHD). There was an imprecise effect on relapse and on severe (grades III to IV) acute GvHD. Quality of life, which is severely affected by GvHD, was not evaluated.Against the background of transplantation practices that have clearly changed over the past 10 to 15 years, our aim was to provide current data on the best stem cell source for allo-HSCT, by including the results of recently conducted trials. Our review includes participants recruited up to 2009, a proportion of whom were older, had received reduced-intensity conditioning regimens or had been transplanted with stem cells from unrelated donors. However, only one, large, study included relatively recently treated participants. Nevertheless, our findings are comparable to those of previous meta-analyses suggesting that our results hold true for today's practice.

Hematopoietic SCT in Europe: data and trends in 2012 with special consideration of pediatric transplantation

In all, 661 of 680 centers in 48 countries reported 37 818 hematopoietic SCT (HSCT) in 33 678 patients (14 165 allogeneic (42%), 19 513 autologous (58%)) in the 2012 survey. Main indications were leukemias, 10 641 (32% 95% allogeneic); lymphoid neoplasias, 19 336 (57% 11% allogeneic); solid tumors, 1630 (5% 3% allogeneic); and nonmalignant disorders, 1953 (6% 90% allogeneic). There were more unrelated donors than HLA-identical sibling donors (54% versus 38% (8% being mismatched related donor HSCT)). Cord blood was almost exclusive in allogeneic transplants (5% of total). Since 2011, the highest increases in allogeneic HSCT were for AML in CR1 (12%) and for myeloproliferative neoplasm (15%). For autologous HSCT the main increases were for plasma cell disorders (7%), non-Hodgkin lymphoma (4%) and autoimmune disease (50%). There were 4097 pediatric patients <18 years of age receiving HSCT, 2902 received an allogeneic and 1195 an autologous HSCT. Overall, 69% of allogeneic and 64% of autologous HSCT were performed in dedicated pediatric centers and the remainder in combined adult and pediatric centers. Distributions of diseases, donor types and stem cell source for all patients and pediatric patients in particular are shown. A percentage of centers fulfilling the annual required criteria for patient numbers for JACIE accreditation are provided.

Hematopoietic SCT in Europe: data and trends in 2011

In all, 651 from 680 centers in 48 countries reported 35 660 hematopoietic SCT (HSCT) in 32 075 patients (13 470 allogeneic (42%), 18 605 autologous (58%)) to the 2011 survey. Main indications were: leukemias; 10 113 (32%; 94% allogeneic); lymphoid neoplasias; non-Hodgkin's lymphoma, Hodgkin's lymphoma, plasma cell disorders; 18 433 (57%; 12% allogeneic); solid tumours; 1573 (5%; 5% allogeneic); and non-malignant disorders; 1830 (6%; 92% allogeneic). There were more unrelated donors than HLA identical sibling donors (54% versus 39%); proportion of peripheral blood as stem cell source was 99% for autologous and 73% for allogeneic HSCT. Cord blood was only used in allogeneic transplants (6% of total). In the past 10 years, the overall number of transplants has increased by 53%. Allogeneic HSCT have doubled (from 7272 to 14 549) while, autologous have increased by 32% and continue to increase by about 1100 HSCT per year since 2001. In the past 2 years, an increase of >2000 HSCT per year was seen. Transplant activity is shown by team size. For allogeneic HSCT, we show use of reduced-intensity conditioning versus myeloablative conditioning across Europe and use of post-transplant donor lymphocyte infusions with considerable variation across different countries.

Pharmacokinetics, pharmacodynamics and physiologically-based pharmacokinetic modelling of monoclonal antibodies

Development of monoclonal antibodies (mAbs) and their functional derivatives represents a growing segment of the development pipeline in the pharmaceutical industry. More than 25 mAbs and derivatives have been approved for a variety of therapeutic applications. In addition, around 500 mAbs and derivatives are currently in different stages of development. mAbs are considered to be large molecule therapeutics (in general, they are 2-3 orders of magnitude larger than small chemical molecule therapeutics), but they are not just big chemicals. These compounds demonstrate much more complex pharmacokinetic and pharmacodynamic behaviour than small molecules. Because of their large size and relatively poor membrane permeability and instability in the conditions of the gastrointestinal tract, parenteral administration is the most usual route of administration. The rate and extent of mAb distribution is very slow and depends on extravasation in tissue, distribution within the particular tissue, and degradation. Elimination primarily happens via catabolism to peptides and amino acids. Although not definitive, work has been published to define the human tissues mainly involved in the elimination of mAbs, and it seems that many cells throughout the body are involved. mAbs can be targeted against many soluble or membrane-bound targets, thus these compounds may act by a variety of mechanisms to achieve their pharmacological effect. mAbs targeting soluble antigen generally exhibit linear elimination, whereas those targeting membrane-bound antigen often exhibit non-linear elimination, mainly due to target-mediated drug disposition (TMDD). The high-affinity interaction of mAbs and their derivatives with the pharmacological target can often result in non-linear pharmacokinetics. Because of species differences (particularly due to differences in target affinity and abundance) in the pharmacokinetics and pharmacodynamics of mAbs, pharmacokinetic/pharmacodynamic modelling of mAbs has been used routinely to expedite the development of mAbs and their derivatives and has been utilized to help in the selection of appropriate dose regimens. Although modelling approaches have helped to explain variability in both pharmacokinetic and pharmacodynamic properties of these drugs, there is a clear need for more complex models to improve understanding of pharmacokinetic processes and pharmacodynamic interactions of mAbs with the immune system. There are different approaches applied to physiologically based pharmacokinetic (PBPK) modelling of mAbs and important differences between the models developed. Some key additional features that need to be accounted for in PBPK models of mAbs are neonatal Fc receptor (FcRn; an important salvage mechanism for antibodies) binding, TMDD and lymph flow. Several models have been described incorporating some or all of these features and the use of PBPK models are expected to expand over the next few years.

Survival and cure of acute myeloid leukaemia in England, 1971-2006: a population-based study

The 5-year relative survival of adults diagnosed with acute myeloid leukaemia (AML) was less than 10% during the 1970s and 1980s in England. This population-based study estimated the 5-year relative survival and 'cure' for 48 380 adult patients diagnosed with AML in England during 1971-2006. Relative survival and cure mixture models were used to produce estimates of 5-year relative survival and the percentage 'cured'. 'Cure' was defined as the proportion of a group of survivors for whom there is no excess mortality compared with the general population. The 5-year relative survival and the percentage 'cured' increased for patients aged under 70 years at diagnosis during 1971-2006, but advancing age was associated with poorer outcome. During the study period a dramatic increase in 5-year relative survival occurred in those aged 15-24 years, from 7% to 53%. The percentage 'cured' was less than 10% for all ages in 1975, but increased to 45% for those aged 15-24 years in 2000. Cure could not be estimated for patients over 70 years, because survival was consistently low (<5%). The long-term outcome of patients with AML has improved substantially, particularly in younger patients. The potential exists for further increasing levels of 'cure'.

Environmental prevention of infection in stem cell transplant recipients: a survey of the Infectious Diseases Working Party of the European Group for Blood and Marrow Transplantation

BACKGROUND

The developments of peripheral blood stem cells in autologous hematopoietic stem cell transplantation (auto-HCT), and of reduced-intensity conditioning (RIC) regimens in allogeneic HCT (allo-HCT), have considerably changed the transplant approach. Prolonged neutropenia combined with severe mucosal damage and organ dysfunction is no longer the rule in the early post-HCT pancytopenic phase. Although strict isolation during pancytopenia was followed by most HCT units in the past, this may not be the current practice.

METHODS

In 2008, a questionnaire was sent out to the 463 European Group for Blood and Marrow Transplantation centers, enquiring about their current environmental protection procedures; 89 (20%) returned the questionnaire.

RESULTS

Most centers housed auto-HCT recipients in high-efficiency particulate air (HEPA)-filtered rooms without (52%) or with laminar air flow (LAF) (29%) after total body irradiation (TBI), whereas HEPA-filtered rooms were used in 53% of auto-HCT conditioned without TBI. During the initial pancytopenic phase after allo-HCT, patients were housed in HEPA/LAF rooms in 50% and 42% of the centers, if a high-dose myeloablative conditioning regimen or a RIC regimen was used, respectively. Surprisingly, 8-24% of the centers reported that no isolation procedures were used in patients colonized or infected with highly transmissible pathogens (i.e., Clostridium difficile, respiratory viruses, and varicella zoster virus).

CONCLUSION

In conclusion, universal recommendations for infected or colonized patients may be poorly known or applied in many HCT units.

The impact of center experience on results of reduced intensity: allogeneic hematopoietic SCT for AML. An analysis from the Acute Leukemia Working Party of the EBMT

Allogeneic hematopoietic SCT with reduced-intensity conditioning (RIC-HSCT) is increasingly adopted for the treatment of older adults with AML. Our goal was to verify for the first time, if center experience influences outcome of RIC-HSCT. Results of 1413 transplantations from HLA-matched related or unrelated donors for adult patients with AML in first CR were analyzed according to the level of center activity. Transplants were performed in 203 European centers between 2001 and 2007. The 2-year probability of leukemia-free survival (LFS) after RIC-HSCT performed in centers with the lowest activity (< or =15 procedures/7 years) was 43±3% compared with 55±2% in the remainder (P<0.001). The incidence of non-relapse mortality (NRM) was 24±3% and 15±1% (P=0.004), whilst relapse rate was 33±3% and 31±1% (P=0.33), respectively. In a multivariate model, adjusted for other prognostic factors, low RIC-HSCT activity was associated with decreased chance of LFS (hazard ratio (HR)=0.64; P<0.001) and increased risk of NRM (HR=1.47, P=0.04) and relapse (HR=1.41, P=0.01). Center experience is a very important predictor of outcome and should be considered in future analyses evaluating the results of RIC-HSCT. The reasons why centers with low RIC-HSCT activity have worse outcomes should be further investigated.

The EBMT activity survey: 1990-2010

A total of 654 centers from 48 countries were contacted for the 2010 survey. In all, 634 centers reported a total of 33 362 hematopoietic SCT (HSCT) with 30 012 patients receiving their first transplant (12 276 allogeneic (41%) and 17 736 autologous (59%)). Main indications were leukemias: 9355 (31%; 93% allogeneic), lymphoid neoplasias specifically Non Hodgkin's lymphoma, Hodgkin's lymphoma and plasma cell disorders: 17 362 (58%; 12% allogeneic), solid tumors: 1585 (5%; 6% allogeneic) and non-malignant disorders: 1609 (6%; 88% allogeneic). There were more unrelated donors than HLA-identical sibling donors (53% versus 41%); the proportion of peripheral blood as stem cell source was 99% for autologous and 71% for allogeneic HSCT. Cord blood was primarily used in allogeneic transplants (6% of total) with three autologous cord blood HSCT being reported. The number of transplants has increased by 19% since 2005 (allogeneic 37% and autologous 9%) and continued to increase by about 1100 HSCT per year since 2000. Patterns of increase were distinct and different. The data show the development of transplantation in Europe since 1990, with the number of patients receiving a HSCT increasing from 4200 to over 30 000 annually. The most impressive trend seen is the steady increase of unrelated donor transplantation, in parallel to the availability of unrelated donors through donor registries.

Targeting natural killer cells and natural killer T cells in cancer

Natural killer (NK) cells and natural killer T (NKT) cells are subsets of lymphocytes that share some phenotypical and functional similarities. Both cell types can rapidly respond to the presence of tumour cells and participate in antitumour immune responses. This has prompted interest in the development of innovative cancer therapies that are based on the manipulation of NK and NKT cells. Recent studies have highlighted how the immune reactivity of NK and NKT cells is shaped by the environment in which they develop. The rational use of these cells in cancer immunotherapies awaits a better understanding of their effector functions, migratory patterns and survival properties in humans.

The survey on cellular and engineered tissue therapies in Europe in 2009

Thanks to the coordinated efforts of four major scientific organizations, this report describes the "novel cellular therapy" activity in Europe for the year 2009. Fifty teams from 22 countries reported data on 814 patients using a dedicated survey, which were combined to additional 328 records reported by 55 teams to the standard European Blood and Marrow Transplantation (EBMT) database. Indications were cardiovascular (37%; 64% autologous), graft-vs.-host disease (27%; 7% autologous), musculoskeletal (17%; 98% autologous), epithelial/parenchymal (8%; 73% autologous), autoimmune (9%; 84% autologous), or neurological diseases (3%; 50% autologous). Autologous cells were used predominantly for cardiovascular (42%) and musculoskeletal (30%) disorders, whereas allogeneic cells were used mainly for graft-vs.-host disease (58%) and cardiovascular (30%) indications. Reported cell types were mesenchymal stem/stromal cells (MSC) (46%), hematopoietic stem cells (27%), chondrocytes (7%), keratinocytes (5%), dermal fibroblast (13%), and others (2%). In 59% of the grafts, cells were delivered after expansion; in 2% of the cases, cells were transduced. Cells were delivered intraorgan (46%), on a membrane or gel (29%), intravenously (16%) or using 3D scaffolds (8%). As compared to last year, the number of teams adopting the dedicated survey was 1.7-fold higher, and, with few exceptions, the collected data confirmed the captured trends. This year's edition specifically describes and discusses the use of MSC for the treatment of autoimmune diseases, due to the scientific, clinical, and economical implications of this topic.

Impact of HLA-DPB1 haplotypes on outcome of 10/10 matched unrelated hematopoietic stem cell donor transplants depends on MHC-linked microsatellite polymorphisms

Hematopoietic stem cell transplantation (HSCT) with HLA-A, -B, -C, -DRB1, -DQB1 allele matched (10 of 10) unrelated donors is still associated with a significant rate of posttransplantation complications. In order to disclose additional immunogenetic factors, we analyzed the impact of HLA-DPB1 disparities and major histocompatibility complex (MHC)-resident microsatellite polymorphisms in 246 HLA 10 of 10 matched HSCT patients. First we showed that patients with more frequent/conserved HLA haplotypes had a higher 5-year survival (55% ± 18% versus 39% ± 18%, P = .021). In addition, DPB1 incompatibilities and 3 microsatellite alleles were associated with outcome. In a Cox regression model adjusting for European Blood and Marrow Transplant (EBMT) risk score, T cell depletion, and year of treatment, HSCT with a tumor necrosis factor d (TNFd) 4/d5-positive donor was associated with increased mortality (hazard ratio [HR] = 2.03; confidence interval [CI] 1.25-3.31; P = .004), whereas the D6S510-184 allele was protective (HR = 0.44; CI 0.22-0.87; P = .018). The 2 MHC-linked genetic donor factors, DPB1 mismatch (MM), and TNFd4/d5-positivity, acted in synergy with the EBMT risk score with an always lower survival (HR = 2.97; CI 1.27-6.92; P = .012). These data show that multiple MHC-linked genetic donor factors impact on outcome after unrelated donor HSCT. Their additive and potentially divergent effects could explain previous discrepant results, particularly with respect to the role of HLA-DPB1 disparities. We conclude that HLA-DPB1 typing combined with a simple TNFd microsatellite genotyping assay may significantly help in pretransplantation risk assessment for graft-versus-host disease and mortality, particularly for patients with several potential 10 of 10 matched donors.

Effects of peripheral blood stem cell apheresis on systemic cytokine levels in patients with multiple myeloma

BACKGROUND AIMS. Pro-angiogenic cytokines can affect myeloma cell proliferation directly and indirectly through stimulation of cancer-associated angiogenesis. METHODS. We investigated how peripheral blood stem cell (PBSC) collection affected plasma angioregulatory cytokine levels in 15 consecutive myeloma patients. RESULTS. Plasma levels of hepatocyte growth factor (HGF) were significantly increased prior to apheresis in patients compared with donors, and a further increase was detected immediately after PBSC apheresis. HGF levels decreased within 24 h, but were still higher than the levels in healthy donors, whose HGF levels were not altered by platelet apheresis. Pre-apheresis levels of other angioregulatory cytokines, angiopoietin-2 and vascular endothelial growth factor (VEGF), were also increased in patients, whereas angiopoietin-1, angiogenin and basic fibroblast growth factor levels did not differ from healthy controls. PBSC harvesting decreased angiopoietin-1 and VEGF levels, increased the microvascular endothelial cell marker endocan levels but did not affect the other mediators. CONCLUSIONS. Our results show that PBSC apheresis alters systemic angioregulatory profiles in myeloma patients. This cytokine modulation is not a general characteristic of all apheresis procedures and was not seen in healthy platelet donors.

Trends of hematopoietic stem cell transplantation in the Eastern Mediterranean region, 1984-2007

Hematopoietic stem cell transplantation (HSCT) activity was surveyed in the 9 countries in the World Health Organization Eastern Mediterranean region that reported transplantation activity. Between the years of 1984 and 2007, 7933 transplantations were performed. The number of HSCTs per year has continued to increase, with a plateau in allogeneic HSCT (allo-HSCT) between 2005 and 2007. Overall, a greater proportion of transplantations were allo-HSCT (n = 5761, 77%) compared with autologous HSCT (ASCT) (n = 2172, 23%). Of 5761 allo-HSCT, acute leukemia constituted the main indication (n = 2124, 37%). There was a significant proportion of allo-HSCT for bone marrow failures (n = 1001, 17%) and hemoglobinopathies (n = 885, 15%). The rate of unrelated donor transplantations remained low, with only 2 matched unrelated donor allo-HSCTs reported. One hundred umbilical cord blood transplantations were reported (0.017% of allo-HSCT). Peripheral blood stem cells were the main source of graft in allo-HSCT, and peripheral blood stem cells increasingly constitute the main source of hematopoietic stem cells overall. Reduced-intensity conditioning was utilized in 5.7% of allografts over the surveyed period. ASCT numbers continue to increase. There has been a shift in the indication for ASCT from acute leukemia to lymphoproliferative disorders (45%), followed by myeloma (26%). The survey reflects transplantation activity according to the unique health settings of this region. Notable differences in transplantation practices as reported to the European Group for Blood and Marrow Transplantation over recent years are highlighted.

Insufficient recovery of thymopoiesis predicts for opportunistic infections in allogeneic hematopoietic stem cell transplant recipients

BACKGROUND

Recovery of thymopoiesis after allogeneic hematopoietic stem cell transplantation is considered pivotal for full immune competence. However, it is still unclear to what extent insufficient recovery of thymopoiesis predicts for subsequent opportunistic infections and non-relapse mortality.

DESIGN AND METHODS

A detailed survey of all post-engraftment infectious complications, non-relapse mortality and overall survival during long-term follow-up was performed in 83 recipients of allogeneic stem cell grafts after myeloablative conditioning. Recovery of thymopoiesis was assessed using analysis of signal joint T-cell receptor rearrangement excision circles. The impact of recovery of thymopoiesis at 2, 6, 9 and 12 months post-transplantation on clinical outcome beyond those time points was evaluated by univariate and multivariate Cox regression analyses.

RESULTS

The cumulative incidence of severe infections at 12 months after transplantation was 66% with a median number of 1.64 severe infectious episodes per patient. Patients in whom thymopoiesis did not recover were at significantly higher risk of severe infections according to multivariable analysis. Hazard ratios indicated 3- and 9-fold increases in severe infections at 6 and 12 months, respectively. Impaired recovery of thymopoiesis also translated into a higher risk of non-relapse mortality and outweighed pre-transplant risk factors including age, donor type, and disease risk-status.

CONCLUSIONS

These results indicate that patients who fail to recover thymopoiesis after allogeneic hematopoietic stem cell transplantation are at very high risk of severe infections and adverse clinical outcome.

Serum after autologous transplantation stimulates proliferation and expansion of human hematopoietic progenitor cells

Regeneration after hematopoietic stem cell transplantation (HSCT) depends on enormous activation of the stem cell pool. So far, it is hardly understood how these cells are recruited into proliferation and self-renewal. In this study, we have addressed the question if systemically released factors are involved in activation of hematopoietic stem and progenitor cells (HPC) after autologous HSCT. Serum was taken from patients before chemotherapy, during neutropenia and after hematopoietic recovery. Subsequently, it was used as supplement for in vitro culture of CD34⁺ cord blood HPC. Serum taken under hematopoietic stress (4 to 11 days after HSCT) significantly enhanced proliferation, maintained primitive immunophenotype (CD34⁺, CD133⁺, CD45⁻) for more cell divisions and increased colony forming units (CFU) as well as the number of cobblestone area-forming cells (CAFC). The stimulatory effect decays to normal levels after hematopoietic recovery (more than 2 weeks after HSCT). Chemokine profiling revealed a decline of several growth-factors during neutropenia, including platelet-derived growth factors PDGF-AA, PDGF-AB and PDGF-BB, whereas expression of monocyte chemotactic protein-1 (MCP-1) increased. These results demonstrate that systemically released factors play an important role for stimulation of hematopoietic regeneration after autologous HSCT. This feedback mechanism opens new perspectives for in vivo stimulation of the stem cell pool.

[The methods used to collect hematopoietic stem cells]

The methods used to collect hematopoietic stem cells in their natural environment (bone marrow or cord blood) or in the peripheral blood after stimulation are well-defined and ruled both to ensure the donor security and perform a quality hematopoietic transplantation. Safety of the familial or non-familial donor must be ensured not only during the collection but also on a medium- or a long-term basis. The stem cells amount in a graft and its characterisation depend on the collection site of hematopoietic stem cells and on the technique used. The knowledge of conditions influencing these amounts allows optimising the hematopoietic stem cells collection while preventing conditions in which the donor safety could be decreased. The collection site also influences the collection of significant amounts of other blood cells. This knowledge conditions the preparation procedures of the graft in cell therapy units or the management of per- or post-transplantations complications in haematology units. Thus, hematopoietic transplantations concern not only hematological units but also the teams involved in various stages of donor selection, hematopoietic stem cells collection and graft preparation. In order to allow an appropriate care of both donor and recipient, a concomitant knowledge of all the stages involved in hematopoietic collection conditions, characterisation of collected cells, hematological diseases and conditioning must be brought to hematological, collection and cell therapy teams.

The EBMT activity survey 2009: trends over the past 5 years

Six hundred and twenty-four centers from 43 countries reported a total of 31,322 hematopoietic SCT (HSCT) to this 2009 European Group for Blood and Marrow Transplantation (EBMT) survey with 28,033 first transplants (41% allogeneic, 59% autologous). The main indications were leukemias (31%; 92% allogeneic), lymphomas (58%; 12% allogeneic), solid tumors (5%; 6% allogeneic) and non-malignant disorders (6%; 88% allogeneic). There were more unrelated than HLA-identical sibling donors (51 vs 43%) for allogeneic HSCT; the proportion of peripheral blood as stem cell source was 99% for autologous and 71% for allogeneic HSCT. Allogeneic and autologous HSCT continued to increase by about 1000 HSCT per year since 2004. Patterns of increase were distinct and different. In a trend analysis, allogeneic HSCT increased in all World Bank Categories (P=0.01, two sided; all categories), autologous HSCT increased in middle- (P=0.01, two sided) and low-income (P=0.01, two sided) countries. EBMT practice guidelines appeared to have an impact on trend, with a clear increase in absolute numbers within the categories 'standard' and 'clinical option' for both allogeneic and autologous HSCT (P=0.01, two sided; for both allogeneic and autologous HSCT) and a clear decrease in autologous HSCT for the 'developmental' and 'generally not recommended' indications (P=0.01, two sided). These data illustrate the status and trends of HST in Europe.

Synergistic effects of growth factors and mesenchymal stromal cells for expansion of hematopoietic stem and progenitor cells

OBJECTIVE

The number of hematopoietic stem and progenitor cells (HPCs) per cord blood unit is limited, and this can result in delayed engraftment or graft failure. In vitro expansion of HPCs provides a perspective to overcome these limitations. Cytokines as well as mesenchymal stromal cells (MSCs) have been shown to support HPCs ex vivo expansion, but a systematic analysis of their interplay remains elusive.

MATERIALS AND METHODS

Twenty different combinations of growth factors (stem cell factor [SCF], thrombopoietin [TPO], fibroblast growth factor-1 [FGF-1], angiopoietin-like 5, and insulin-like growth factor-binding protein 2), either with or without MSC coculture were systematically compared for their ability to support HPC expansion. CD34(+) cells were stained with carboxyfluorescein diacetate N-succinimidyl ester to monitor cell division history in conjunction with immunophenotype. Colony-forming unit frequencies and hematopoietic reconstitution of nonobese diabetic severe combined immunodeficient mice were also assessed.

RESULTS

Proliferation of HPCs was stimulated by coculture with MSCs. This was further enhanced in combination with SCF, TPO, and FGF-1. Moreover, these conditions maintained expression of primitive surface markers for more than four cell divisions. Colony-forming unit-initiating cells were not expanded without stromal support, whereas an eightfold increase was reached by simultaneous cytokine-treatment and MSC coculture. Importantly, in comparison to expansion without stromal support, coculture with MSCs significantly enhanced hematopoietic chimerism in a murine transplantation model.

CONCLUSIONS

The supportive effect of MSCs on hematopoiesis can be significantly increased by addition of specific recombinant growth factors; especially in combination with SCF, TPO, and FGF-1.

Limited transplantation of antigen-expressing hematopoietic stem cells induces long-lasting cytotoxic T cell responses

Harnessing the ability of cytotoxic T lymphocytes (CTLs) to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs) following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and prolonged maintenance of fully functional effector T cell responses in a mouse model. Recipient animals display high levels of antigen-specific CTLs four months following transplantation in contrast to dendritic cell-immunized animals in which the response typically declines at 4–6 weeks post-immunization. Majority of HSC-induced antigen-specific CD8⁺ T cells display central memory phenotype, efficiently kill target cells in vivo, and protect recipients against tumor growth in a preventive setting. Furthermore, we confirm previously published observation that high level engraftment of antigen-expressing HSCs following myeloablative conditioning results in tolerance and an absence of specific cytotoxic activity in vivo. In conclusion, the data presented here supports potential application of immunization by limited transplantation of antigen-expressing HSCs for the prevention and treatment of cancer and therapeutic immunization of chronic infectious diseases such as HIV-1/AIDS.

Oral care in Brazilian bone marrow transplant centers

Background

Oral care is a fundamental procedure for the success of the hematopoietic stem cell transplantation, particularly regarding the control of oral infectious diseases. Information about oral care protocols and the inclusion of dental professionals in transplantation medical staff is poorly known.

Objective

The aim of this study was to carry out a survey about the protocols of Brazilian dental professionals with regard to oral care of HSCT patients.

Methods

A questionnaire was mailed to 36 Brazilian transplant centers with questions about basic oral care protocols, the indication of specific mouthwashes, antibiotic therapy regimens, laser therapy, and treatment of oral mucositis and graft-versus-host disease. All the respondent centers (n = 12) have dentists as members of the HSCT medical staff.

Results

The majority indicate non-alcoholic chlorhexidine (n = 9; 75.0%) and sodium bicarbonate (n = 5; 41.7%) as routine mouthwashes. Laser therapy was frequently indicated (n= 9; 75.0%), mainly in the prevention of oral mucositis and in oral pain control. In the post-transplant period, antibiotic therapy was only indicated for invasive dental treatments (n= 8; 66.7%). Several treatments for graft-versus-host disease were mentioned without a trend towards establishing a standard protocol.

Conclusion

Basic oral care constitutes regular assessment in the routine treatment of hematopoietic stem cell transplantation patients in Brazilian centers.

Challenges for allogeneic hematopoietic stem cell transplantation in chronic myeloid leukemia in the era of tyrosine kinase inhibitors

Following the introduction of the tyrosine kinase inhibitor (TKI) imatinib in the treatment of chronic myeloid leukemia (CML) patients, the allogeneic hematopoietic stem cell transplantation (HSCT) scene in CML has changed dramatically. The number of patients receiving HSCT in first chronic phase (CP) has declined rapidly, as allogeneic HSCT in CP is now performed in these patients only in case of failure or intolerance of TKIs. Second, those CML patients who undergo allogeneic HSCT represent a selection of high-risk patients due to more advanced disease with high rates of accelerated or blast phase (being associated with an increased relapse risk), advanced age and relevant co-morbidities. Efforts at meeting these special challenges are being developed: treatment with TKIs aims to improve the pre-transplant remission status before HSCT. Dose-reduced conditioning protocols were introduced to decrease transplant-related mortality in patients with co-morbidities or older age. In the post-transplant period, TKIs may be administered for prophylaxis and for treatment of post-transplant relapse. Still, the outcome of patients in advanced CML phases remains guarded, and requires an improvement in current transplant strategies.