A murine IgG2b monoclonal antibody directed to the constant part of the human alpha/beta T cell receptor (BMA031) was investigated in a pilot study as an initial treatment for acute graft-versus-host ...disease (aGvHD) after allogeneic bone marrow transplantation. The treatment protocol consisted of 5 mg BMA031 on 5 consecutive days with continuation of the prophylactic baseline immuno suppression using cyclosporin. Seven patients with grades II-III acute graft-versus-host disease were entered on the protocol and six patients completed the full treatment course. Mild to moderate acute adverse reactions to the first BMA031 infusion occurred in three patients. A nearly complete decline of circulating T lymphocytes was observed during BMA031 therapy, but the T cells returned to pretreatment values within 1 week after the last infusion. Serum pharmacokinetics of free antibody best fitted to a two-compartment open model with a mean initial half-life of 6 h and an estimated mean terminal half-life of 40 h. One patient developed antimurine antibodies of the IgM subclass. In five patients a complete and sustained resolution of all disease manifestations was attained, while in one patient a temporary response of skin involvement with aGvHD was noted. These results indicate that BMA031 can be safely administered as initial treatment of aGvHD. The therapeutic responses observed warrant its further clinical evaluation in this setting.
Patients with chronic lymphocytic leukemia with del(17p) or del(11q) have poor long-term prognosis with targeted therapies. Conversely, this retrospective European Society for Blood and Marrow ...Transplantation registry study shows that young high cytogenetic risk responsive patients with human leukocyte antigen-matched donors have a high 8-year progression-free survival and low 2-year non-relapse mortality after allogeneic stem cell transplantation. This treatment then may compare favorably with targeted therapies for younger high cytogenetic risk patients.
Patients with genetically high-risk relapsed/refractory chronic lymphocytic leukemia have shorter median progression-free survival (PFS) with kinase- and BCL2-inhibitors (KI, BCL2i). Allogeneic hematopoietic stem cell transplantation (alloHCT) may result in sustained PFS, especially in younger patients because of its age-dependent non-relapse mortality (NRM) risk, but outcome data are lacking for this population.
Risk factors for 2-year NRM and 8-year PFS were identified in patients < 50 years in an updated European Society for Blood and Marrow Transplantation registry cohort (n = 197; median follow-up, 90.4 months) by Cox regression modeling, and predicted probabilities of NRM and PFS of 2 reference patients with favorable or unfavorable characteristics were plotted.
Predictors for poor 8-year PFS were no remission at the time of alloHCT (hazard ratio HR, 1.7; 95% confidence interval CI, 1.1-2.5) and partially human leukocyte antigen (HLA)-mismatched unrelated donor (HR, 2.8; 95% CI, 1.5-5.2). The latter variable also predicted a higher risk of 2-year NRM (HR, 4.0; 95% CI, 1.4-11.6) compared with HLA-matched sibling donors. Predicted 2-year NRM and 8-year PFS of a high cytogenetic risk (del(17p) and/or del(11q)) patient in remission with a matched related donor were 12% (95% CI, 3%-22%) and 54% (95% CI, 38%-69%), and for an unresponsive patient with a female partially HLA-matched unrelated donor 37% (95% CI, 12%-62%) and 38% (95% CI, 13%-63%).
Low predicted NRM and high 8-year PFS in favorable transplant high cytogenetic risk patients compares favorably with outcomes with KI or BCL2i. Taking into account the amount of uncertainty for predicting survival after alloHCT and after sequential administration of KI and BCL2i, alloHCT remains a valid option for younger patients with high cytogenetic risk chronic lymphocytic leukemia with a well-HLA-matched donor.
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Controversy persists about mixed chimerism (mCh) occurring in the hearts of patients after orthotopic cardiac transplantation in comparison with allogeneic bone marrow (BM) and peripheral blood ...stem-cell (PBSC) transplants. Cadaver hearts were examined after sex-mismatched transplantation by immunophenotyping combined with dual color fluorescence in situ hybridization (X and Y chromosome-specific probes). A striking disparity in the extent of mCh depending on the different transplantation procedures was recognizable. After allografting with PBSCs, 1.7% chimeric cardiomyocytes were detectable contrasting 5.4% of donor cells after full BM transplantation. In cardiac transplants, host-type endothelial cells (16.2%) and myocytes (14.3%) of the vessel walls were more often encountered than after BM and PBSC allografting. A sprouting of vascular structures into the donor heart after orthotopic cardiac transplantation has to be assumed, as does a pivotal role of the mesenchymal stem cells of the BM in the development of mCh.
Scant knowledge exists about the dynamics of fibro-osteosclerotic bone marrow (BM) lesions and regeneration of hematopoiesis following allogeneic peripheral stem cell transplantation (SCT) in chronic ...idiopathic myelofibrosis. Therefore, an immunohistochemical and morphometric study was performed on BM biopsies in 20 patients before and at standardized intervals (days 30 through 384) following SCT. In responding patients, a total regression of the pretransplant increased fibrosis was completed in the posttransplant period after about six months, while the extent of osteosclerosis did not change significantly during observation time. The quantity of CD61+ megakaryocytes including precursors was strikingly variable after SCT and, by using planimetric methods, atypical microforms exhibiting a dysplastic aspect could be demonstrated. These anomalies may be responsible for posttransplant thrombocytopenia. CD34+ progenitor cells were increased before transplantation, however, their number declined rapidly to normal values in responding patients. Nucleated erythroid precursors revealed a decreased amount before and after SCT accounting for anemia. Large clusters of this cell lineage indicated an initial hematopoietic reconstitution comparable with the expansion of the neutrophil granulopoiesis. Proliferative activity and apoptosis showed an increase until one year after SCT that implied a still regenerating hematopoiesis in keeping with an enhanced cell turnover.
To elucidate its potential role in the framework of bone marrow transplantation, we studied the toxicologic and pharmacologic properties of high doses of the triepoxide derivate ...1,2,4-triglycidylurazol (TGU) in a preclinical dog model. Dose-dependent and dose-limiting gastrointestinal toxicity occurred in a dose range between 40 and 75 mg/kg, with the lethal dose for 50% of animals (LD50) being estimated at 60 mg/kg. Severe and life-threatening hematologic toxicity developed at all dose levels examined but was generally reversible. The combination of TGU and total-body irradiation produced synergistic gastrointestinal toxicity, necessitating reductions of the TGU dose by 50% as compared with the single-agent dose. In contrast, the combination of TGU and high-dose busulfan resulted in no apparent nonhematologic synergistic toxicities. The immunosuppressive properties of TGU given in this combination enabled sustained histocompatible allogeneic marrow engraftment in three of four animals. The pharmacokinetics of TGU were not influenced by prior total-body irradiation or high-dose busulfan. We conclude that the myelotoxic, pharmacologic and immunosuppressive properties of high-dose TGU observed in this preclinical model seem to render the drug particularly suitable for use in regimens preparatory to bone marrow transplantation.
Allogeneic HSCT has been established as the only curative treatment option for patients with chronic myeloid leukemia (CML). However, after the advent of tyrosine kinase inhibitors (TKI) the ...proportion of transplanted patients has decreased dramatically. After imatinib failure, most patients receive second or third line therapy with alternative TKIs. In an important minority of patients, SCT is performed too late as more patients are transplanted after disease progression to accelerated phase or blast crisis than in first chronic phase (CP, Saussele et al. BMT 2012). A possible reason is the uncertainty on long-term outcome after SC T in the imatinib-era as reports are scarce and accurate comparative data on the impact of salvage TKI therapy vs allogeneic transplantation are missing.
We therefore investigated the outcome of transplanted patients within the CML study IV. Preliminary data were published (Saussele et al. BLOOD 2010). Here, we sought to re-evaluate the outcome of these patients with a longer follow-up.
In July 2002, the German CML-Study Group activated a prospective randomized trial comparing different imatinib based strategies in CP CML. Elective early HSCT was considered for patients with EBMT score 0–1 for those with high disease risk, and after imatinib failure.
By the end of March 2012, 1551 patients were randomized. In 2008, HSCT was documented in 84 patients. One patient was not evaluable any more due to withdrawal of consent. 52 patients were male (65%), 23 high risk patients (28%) according to the Euro CML score. Median age at diagnosis was 37 years (range, 16-62), median time to HSCT was 12.6 months (range, 3.5-54). EBMT score was 0-1 in 8 (10%), 2 in 10 (12%), 3-4 in 44 (55%), and >=5 in 18 patients (23%), three patients were missing. Median follow-up after HSCT was 86.9 months (range, 0.3-122). Based on the indication for HSCT three groups are defined: 1) early HSCT, n= 19 (23%; low EBMT score (n=9), high risk patients (n=7), patient request (n=3); 2) HSCT after imatinib failure or intolerance in first CP (n=36 patients, 43%), and 3) HSCT in second CP or higher, accelerated phase or blast crisis (n=28 patients, 34%). 26 patients died, 13 deaths were transplant related, 9 CML related 4 either unrelated or unknown. Overall survival rate at 6 years after HSCT was 89% (95%-confidence interval (CI): 72-99%) for group 1, 80% (95%-CI: 66-91%) for group 2, and 49% (31-68%) for group 3.
A matched pair analysis could be performed for 53 transplanted patients of group 1 and 2. To each of the transplanted patients two imatinib-treated patients could be matched with regard to age, sex, risk profile, disease phase, and interval to transplantation. Median follow up of this population was 87 months. Overall survival after 8 years was 83% (95%-CI: 71-92%) for transplanted and 89% (95%-CI: 82-94%) for imatinib treated patients without any statistical difference.
Data from this update with a longer follow-up support the role of HSCT as an attractive and important salvage therapy for CML patients with imatinib failure or intolerance. In a matched pair comparison of transplanted and non-transplanted patients, we did not find significant differences.
Saussele:Novartis: Honoraria, Research Funding, Travel Other; Bristol-Myers Squibb: Honoraria, Research Funding, Travel, Travel Other; Pfizer: Honoraria, Travel, Travel Other. Müller:Novartis: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; ARIAD: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Equity Ownership. Hanfstein:Novartis: Research Funding; Bristol-Myers Squibb: Honoraria. Hochhaus:Novartis: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria; ARIAD: Honoraria, Research Funding; Pfizer: Consultancy, Research Funding. Pfirrmann:Novartis: Consultancy; Bristol-Myers Squibb: Honoraria. Hehlmann:Bristol-Myers Squibb: Research Funding; Novartis: Research Funding.
Objectives: In patients with refractory chronic lymphocytic leukemia (CLL), the potential to cure is unique to allogeneic stem cell transplantation (HSCT). Clearance of minimal residual disease by ...suspected graft-versus-leukemia effects has been described elegantly and documented in several independent patient cohorts. Yet data from large numbers of patients which support the concept of cure by allogeneic transplantation have not been published. With the advent of new targeted therapies for patients with advanced chemo-refractory CLL, this information becomes crucial for clinical decision making and patient counselling. Therefore, we aimed at the description of long-term survival outcomes, and the estimation of excess mortality compared to the age- and sex-matched general population.
Patients and Methods: Data from patients with CLL who had received a first allogeneic HSCT from an HLA-identical sibling (SIB) or alternative donor between January 2000 and December 2010, and who were registered with the EBMT database, were analyzed. Patients with Richter’s syndrome and with syngeneic donors were excluded from this analysis. Survival probabilities were calculated by means of the Kaplan-Meier estimator both in the total population, and in patients who passed the 2- and 5-year landmark without previous relapse or progression. Excess mortality of the landmark populations compared to an age-, sex- and calendar year-matched general population was estimated with a Cox regression model for relative survival using the R-package “relsurv”.
Results: In total 2589 patients were included into the analysis. The median follow-up of patients alive at the end of follow-up was 4.0 years (range: 1 to 161 months). The median age at HSCT was 55 years (range: 12 to 74 years). One hundred and fifty eight patients (6.1%) were below 40 years of age at the time of transplantation. Seventy-four percent of patients were male. The remission status at the time of transplantation was reported as complete remission in 15%, partial remission in 47%, and stable disease or progressive disease in 32%. Information on the remission status was not available for 6% of the patients. Fifty-one percent of the patients had an HLA-matched sibling donor and seventy-seven percent of patients received reduced-intensity conditioning.
For the whole cohort of patients, the 5- and 10-year overall survival (OS), progression-free survival (PFS), and non-relapse mortality (NRM) were 45%, 35%, 36%, and 35%, 28%, 40%, respectively. The cumulative incidence of relapse (CIR) was 21% at two years, 29% at five years, and 32% at ten years. A total of 1023 patients and 394 patients were alive without relapse or progression, and in follow-up at two and five years after HSCT. Five years after patients had passed the 2- and 5-year landmark, OS, CIR and NRM were 73%, 22%, 16%, and 83%, 11%, 10% respectively.
Compared to the general population excess mortality of the 5-year landmark population in the subsequent five years was estimated to be 3% for male patients at an age of 45 years, 10% for male patients at an age of 55 years, and 24% for male patients at an age of 65 years (see Figure 1). For female patients in this 5-year landmark population, the corresponding excess mortality rates were 4%, 11%, and 27%.
Patients without progression and with CR at any time from HSCT to the two and five-year landmarks had a slightly better outcome than those who had never had CR. Surprisingly, this was not a result of a lower CIR but of a lower NRM.
Conclusion: Long-term follow-up data derived from the EBMT registry show a steady decline in hazard of relapse after allogeneic HSCT, yet relapse continues to be a threat. Moreover, even patients alive and disease-free after 5 years are still confronted with substantial NRM. These results show that there is room for improvement of long-term patient care.
By comparing mortality of younger patients who passed the 5-year landmark with the general population, only marginal excess mortality was observed, while elderly patients still had substantial excess mortality beyond this landmark. Nevertheless, the results indicate that a significant fraction of patients can be cured by allogeneic HSCT.
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No relevant conflicts of interest to declare.
An immunohistochemical and morphometric study was performed on 363 trephine biopsies of the bone marrow derived from 127 patients with chronic myeloid leukemia at standardized end points before and ...after allogeneic bone marrow transplantation (BMT). The purpose of this investigation was to evaluate features of CD61+ megakaryopoiesis related to successful engraftment. Further, we tried to elucidate possible associations of this lineage, including precursor cells, with the platelet count and reticulin fibrosis during the pretransplant and, specifically, post-transplant periods. A significant correlation was recognizable between the quantity of CD61+ megakaryocytes and the platelet values before BMT and also after completed hematopoietic recovery. In the very early post-transplant period, which is associated with severe thrombocytopenia, patchy regeneration of disarranged hematopoiesis occurred, including dysplastic megakaryocytes. According to planimetric measurements after BMT, the atypical micromegakaryocytes characteristic for chronic myeloid leukemia disappeared, and the engrafted donor bone marrow revealed a prevalence of normal-size cells of this lineage. On the other hand, normalization of megakaryocyte size was absent in sequential examinations of the few patients with a leukemic relapse who had a predominance of atypical dwarf forms comparable with chronic myeloid leukemia. Before BMT occurred, reticulin fiber density was significantly correlated with the number of CD61+ megakaryocytes and its precursor cell population. In 34 patients with myelofibrosis that occurred after myelo-ablative therapy and BMT, an initial regression was followed by an insidious recurrence of fibers concentrated in the areas of regenerating hematopoiesis. This postgraft reappearance of reticulin fibrosis was significantly associated with the quantity of megakaryocytes. Regarding engraftment parameters, pretransplant presence of (reticulin) myelofibrosis exerted a distinctive impact because of a delayed hematopoietic reconstitution according to standard clinical criteria. In line with this finding, slowed engraftment was also significantly related with higher pretransplant megakaryocyte and platelet counts.
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