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Georg Ledderose

Publications and source records attributed to Georg Ledderose.

12 recordsLinked to original sources
PubMed2006

Long-term follow-up of allogeneic HSCT for CML reveals significant improvement in the outcome over the last decade.

Allogeneic hematopoetic stem cell transplantation (HSCT) is still the only curative therapeutic option for chronic myelogenous leukemia (CML). To examine the development of allogeneic HSCT at our center over the past two decades (decade 1: 1984-1994; decade 2: 1995-2005), all CML patients transplanted in first chronic phase (n = 234) were analyzed with respect to patient characteristics, overall survival, transplant-related mortality (TRM), and relapse incidence. The median follow up time was 54 months (range 1-218). The incidence of acute graft vs host disease (GvHD) degrees II-IV and extensive chronic GvHD were not different between the two decades (p = 0.894 and p = 0.422, respectively). There was also no difference in the relapse incidence (23 vs 26%, p = 0.869). One-year TRM and overall survival were improved in the later decade (33 vs 18%, p = 0.011 and 62 vs 73% at 5 years, p = 0.063, respectively). The major reason for improved outcome in decade 2 was the improved management of acute GvHD and infections in the early phase after transplantation (p = 0.026). In conclusion, the past decade has seen significant improvement in the performance of allogeneic HSCT for CML.

Acute Disease↗
PubMed2006

A comparison of donor lymphocyte infusions or imatinib mesylate for patients with chronic myelogenous leukemia who have relapsed after allogeneic stem cell transplantation.

Imatinib mesylate is highly effective in relapsed chronic myelogenous leukemia (CML) after allogeneic hematopoetic stem cell transplantation (HSCT). However, it is unknown whether imatinib produces durable molecular remissions. The outcome of CML patients transplanted at our center who had received only imatinib for relapse after HSCT was compared with that of patients treated with donor lymphocyte infusions (DLI). Imatinib therapy resulted in a higher incidence of relapse and inferior leukemia-free survival (p=0.006 and p=0.016, respectively). These data suggest that imatinib alone probably does not cure relapse after HSCT.

Adult↗
PubMed2006

Long-term survival in refractory acute myeloid leukemia after sequential treatment with chemotherapy and reduced-intensity conditioning for allogeneic stem cell transplantation.

A sequential regimen of chemotherapy, reduced-intensity conditioning (RIC) for allogeneic stem cell transplantation (SCT), and prophylactic donor lymphocyte transfusion (pDLT) was studied in 103 patients with refractory acute myeloid leukemia (AML). According to published criteria, refractoriness was defined by primary induction failure (PIF; n = 37), early (n = 53), refractory (n = 8), or second (n = 5) relapse. Chemotherapy consisted of fludarabine (4 x 30 mg/m(2)), cytarabine (4 x 2 g/m(2)), and amsacrine (4 x 100 mg/m(2)), followed 4 days later by RIC, comprising 4 Gy total body irradiation (TBI), cyclophosphamide, and antithymocyte globulin. Patients without graft-versus-host disease (GvHD) at day +120 received pDLT in escalating doses. Patients' median age was 51.8 years. Before conditioning, 99 patients had active disease, 3 were aplastic, 1 was in second complete remission (CR2). Forty-one patients had family donors, 62 had unrelated donors. With a 25-month median follow-up, overall survival (OS) at 1, 2, and 4 years was 54%, 40%, and 32%; the respective leukemia-free survival (LFS) was 47%, 37%, and 30%. Patients with PIF showed a 2-year OS of 62.5%. OS was 87% in 17 patients receiving pDLT. One-year cumulative incidence of leukemic death and non-relapse-mortality was 28.7% and 17.2%. In a multivariate analysis, more than 2 courses of prior chemotherapy were the strongest predictor for poor outcome (P = .007; HR = 3.01 [OS]; P = .002; HR = 3.25 [LFS]). These results indicate a high activity of the regimen in refractory AML.

Acute Disease↗
PubMed2006

Clonal karyotype evolution involving ring chromosome 1 with myelodysplastic syndrome subtype RAEB-t progressing into acute leukemia.

Karyotypic evolution is a well-known phenomenon in patients with malignant hematological disorders during disease progression. We describe a 50-year-old male patient who had originally presented with pancytopenia in October 1992. The diagnosis of a myelodysplastic syndrome (MDS) FAB subtype RAEB-t was established in April 1993 by histological bone marrow (BM) examination, and therapy with low-dose cytosine arabinoside was initiated. In a phase of partial hematological remission, cytogenetic assessment in August 1993 revealed a ring chromosome 1 in 13 of 21 metaphases beside BM cells with normal karyotypes [46,XY,r(1)(p35q31)/46,XY]. One month later, the patient progressed to an acute myeloid leukemia (AML), subtype M4 with 40% BM blasts and cytogenetic examination showed clonal evolution by the appearance of additional numerical aberrations in addition to the ring chromosome [46,XY,r(1),+8,-21/45,XY,r(1),+8,-21,-22/46, XY]. Intensive chemotherapy and radiotherapy was applied to induce remission in preparation for allogeneic bone marrow transplantation (BMT) from the patient's HLA-compatible son. After BMT, complete remission was clinically, hematologically and cytogenetically (normal male karyotype) confirmed. A complete hematopoietic chimerism was demonstrated. A relapse in January 1997 was successfully treated using donor lymphocyte infusion and donor peripheral blood stem cells (PB-SC) in combination with GM-CSF as immunostimulating agent in April 1997, and the patient's clinical condition remained stable as of January 2005. This is an interesting case of a patient with AML secondary to MDS. With the ring chromosome 1 we also describe a rare cytogenetic abnormality that predicted the poor prognosis of the patient, but the patient could be cured by adoptive immunotherapy and the application of donor's PB-SC. This case confirms the value of cytogenetic analysis in characterizing the malignant clone in hematological neoplasias, the importance of controlling the quality of an induced remission and of the detection of a progress of the disease.

Acute Disease↗
PubMed2005

Sustained complete molecular remissions after treatment with imatinib-mesylate in patients with failure after allogeneic stem cell transplantation for chronic myelogenous leukemia: results of a prospective phase II open-label multicenter study.

PURPOSE: In the era of molecular therapy of chronic myelogenous leukemia (CML) applying BCR-ABL tyrosine kinase inhibitors, the usefulness of molecular end points, in particular, quantitative polymerase chain reaction (PCR) for BCR-ABL in monitoring responses has been broadly accepted. Therefore, we have designed a prospective phase II trial in CML, which, for the first time, evaluated the feasibility and safety of molecular end points as surrogate markers to guide through a stratified treatment algorithm within a multicenter trial. PATIENTS AND METHODS: As a clinical model, we adopted minimal residual disease (MRD) found in relapse after allogeneic stem cell transplantation (SCT) in CML. Forty-four patients were enrolled and received the BCR-ABL tyrosine kinase inhibitor imatinib (IM) at a starting dose of 400 mg/d. The quality of molecular responses achieved then decided on discontinuation of IM or dose escalation up to 800 mg/d, and finally, on application of donor lymphocyte infusions. Results Seventy percent of patients achieved a complete molecular response (CMR), defined as nested PCR-negativity for BCR-ABL in three consecutive samples. Interestingly, in four out of 10 patients who discontinued IM, CMR was durable even after cessation of IM with a median follow-up of 494 days. This suggests the possibility of long-term tumor control in a subset of patients. CONCLUSION: The treatment strategy showed that IM treatment was well-tolerated and highly efficacious in MRD after allogeneic SCT. Moreover, this study demonstrated that evaluation of a molecular end point within a multicenter trial can be a safe and effective tool for clinical decision making.

Adult↗
PubMed2005

Sequential regimen of chemotherapy, reduced-intensity conditioning for allogeneic stem-cell transplantation, and prophylactic donor lymphocyte transfusion in high-risk acute myeloid leukemia and myelodysplastic syndrome.

PURPOSE: To improve the effect of allogeneic stem-cell transplantation by sequential use of intensive chemotherapy, reduced-intensity conditioning (RIC), and prophylactic donor lymphocyte transfusions (pDLTs) in high-risk acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). PATIENTS AND METHODS: In a prospective study of 75 consecutive patients (median age, 52.3 years), high risk was defined by progressive or refractory disease (n = 59), second remission after early relapse (n = 8), or first remission with poor prognosis based on cytogenetics or delayed response to induction therapy (n = 8). Unfavorable karyotypes were found in 49% of informative patients, and 68 patients had medical contraindications against standard conditioning. Fludarabine (30 mg/m2), cytarabine (2 g/m2), and amsacrine (100 mg/m2) for 4 days were used for cytoreduction. After 3 days of rest, RIC consisted of 4 Gy total-body irradiation, antithymocyte globulin, and 80 to 120 mg/kg cyclophosphamide. Thirty-one patients had an HLA-identical sibling donor; 44 patients had an unrelated and/or HLA-mismatched donor. pDLT was given from day +120 in patients who were not receiving immunosuppression and were free of graft-versus-host disease (GvHD). RESULTS: Complete remission was induced in 66 patients (88%). With a median follow-up of 35.1 months (range, 13.6 to 47.6 months), 2-year overall and leukemia-free survival were 42% and 40%, respectively. Outcome of patients with refractory disease or with complex cytogenetic aberrations was identical to that of better prognostic subgroups. Survival was best in patients who received high CD34+ cell numbers, and in patients with limited GvHD. CONCLUSION: Sequential use of intensive chemotherapy, RIC transplantation, and pDLT represents a promising approach to the treatment of high-risk AML and MDS, particularly in patients with most unfavorable prognoses.

Adolescent↗
PubMed2005

Early molecular response to posttransplantation imatinib determines outcome in MRD+ Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL).

In adult Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), minimal residual disease (MRD) after stem cell transplantation (SCT) is associated with a relapse probability exceeding 90%. Starting imatinib in the setting of MRD may decrease this high relapse rate. In this prospective multicenter study, 27 Ph+ ALL patients received imatinib upon detection of MRD after SCT. Bcr-abl transcripts became undetectable in 14 (52%) of 27 patients, after a median of 1.5 months (0.9-3.7 months) ((early)CR(mol)). All patients who achieved an (early)CR(mol) remained in remission for the duration of imatinib treatment; 3 patients relapsed after imatinib was discontinued. Failure to achieve polymerase chain reaction (PCR) negativity shortly after starting imatinib predicted relapse, which occurred in 12 (92%) of 13 patients after a median of 3 months. Disease-free survival (DFS) in (early)CR(mol) patients is 91% +/- 9% and 54% +/- 21% after 12 and 24 months, respectively, compared with 8% +/- 7% after 12 months in patients remaining MRD+ (P < .001). In conclusion, approximately half of patients with Ph+ ALL receiving imatinib for MRD positivity after SCT experience prolonged DFS, which can be anticipated by the rapid achievement of a molecular complete remission (CR). Continued detection of bcr-abl transcripts after 2 to 3 months on imatinib identifies patients who will ultimately experience relapse and in whom additional or alternative antileukemic treatment should be initiated.

Adolescent↗
PubMed2004

In-vivo generation of leukaemia-derived dendritic cells.

Adoptive immunotherapy with transfusion of donor lymphocytes in allogeneic stem cell chimeras has been successful in the treatment of recurrent chronic myelogenous leukaemia (CML) and some patients with acute myeloid leukaemia (AML). The hypothesis that the graft-vs-leukaemia effect (GVL) is promoted by leukaemia-derived dendritic cells has been supported by the concurrent treatment of patients with cytokines that are known to induce differentiation of leukaemia cells towards dendritic cells. In combination with donor lymphocyte transfusions, treatment with interferon-alpha and granulocyte-macrophage colony-stimulating factor has been studied in patients with recurrent CML and AML, and pre-emptively in patients with high-risk AML. Long-term remissions have been observed in cytokine-treated patients, indicating the beneficial effect of cytokine stimulation of GVL reactions. This is likely to be due to differentiation of leukaemia progenitor cells towards dendritic cells in vivo.

Cell Lineage↗
PubMed2003

Tolerance and chimerism.

Stem-cell transplantation from human leukocyte antigen (HLA)-haploidentical family members carries a high risk of rejection and graft-versus-host disease (GVHD) if donor and recipient differ by more than one HLA antigen. The authors have developed treatment protocols from studies in dog leukocyte antigen-haploidentical dogs that prevent rejection and modify GVHD to the extent that patients with aggressive hematologic neoplasia can be treated with success. Principal improvements have been achieved in the use of cyclophosphamide and total-body irradiation for conditioning and T-cell depletion for prevention of GVHD. More recently, the combination of marrow and CD6-depleted mobilized donor blood cells (MDBC) has been introduced for HLA-haploidentical transplantation on the basis that CD6-depleted MDBC contain immunoregulatory cells besides stem cells and natural killer cells. Clinical results are reported on 36 patients with high-risk hematologic neoplasia. The results encourage the use of HLA-haploidentical stem-cell transplantation at an earlier stage of the disease. This method could also be of use for tolerance induction in organ transplantation.

Animals↗
PubMed2003

Adoptive immunotherapy in chimeras with donor lymphocytes.

Allogeneic stem cell transplantation has a well-defined indication in the treatment of hematological malignancies. The beneficial immune effect of allogeneic marrow transplantation has long been known, but only recently have methods been developed to separate the graft-versus-leukemia (GVL) effect from graft-versus-host disease (GVHD). Animal experiments have shown that lymphocytes from the marrow donor can be transfused without causing severe GVHD if stable chimerism and tolerance is established. First clinical studies have been preformed in patients with recurrent chronic myelogenous leukemia. In these patients complete molecular remissions were induced that persist without further maintenance treatment. These results have been confirmed in larger multicenter studies in Europe and the USA. The best results were obtained in chronic myelogenous leukemia (CML); repeated successes have been reported in relapsing acute myeloid leukemia (AML), myelodysplastic syndromes and multiple myeloma (MMY), and rare responses were reported for acute lymphoid leukemia. Contrary to animal experiments GVHD has been observed in human patients although to a lesser extent than expected in transplants not given immunosuppression. Secondly myelosuppression has been observed in patients treated with relapsing CML. In CML the incidence of GVHD could be reduced by depleting CD8+ T cells from the donor lymphocyte concentrate. Alternatively only small numbers of T lymphocytes can be transfused and in the case of failing responses, the numbers of donor lymphocytes may be increased. Results in recurrent AML have been improved by the use of low-dose cytosine arabinoside, granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor mobilized blood cells as compared to lymphocytes only. In MMY the response rate is higher than in AML, but the remissions are of limited duration in most patients. Several protocols have been designed to include preemptive donor lymphocyte transfusion in patients with a high relapse risk after transplantation. Problems remain to avoid chronic GVHD and to circumvent the immune escape mechanisms of leukemia.

Adoptive Transfer↗
PubMed2002

Hematopoietic stem cell transplantation after reduced-intensity conditioning as treatment of sickle cell disease.

OBJECTIVE: Sickle cell disease generates considerable morbidity and mortality. Allogeneic hematopoietic stem cell transplantation (SCT) has the potential of curing the disease and halting end-organ damage. However, in older patients this treatment is associated with a significant risk of toxicity and death. SCT after reduced-intensity conditioning (RIC) might be a safer approach for the treatment of sickle cell disease. MATERIALS AND METHODS: A 22-year-old male had experienced multiple, life-threatening hemolytic crises. We treated him with G-CSF-mobilized stem cells from his heterozygote, human leukocyte antigen-matched brother after RIC with fludarabine and cyclophosphamide. GVHD prophylaxis consisted of cyclosporine (CyA) and mycophenolate mofetil (MMF). Chimerism of peripheral blood mononuclear cells was evaluated using short tandem repeat analysis and hemoglobin analysis was performed by high-performance liquid chromatography. RESULTS: There were no major treatment-related toxicities. At day +30 after transplantation the patient had mixed hematopoietic chimerism, which later converted to full chimerism. Hemoglobin analysis revealed 3.4% HbA(2), 1.0% HbF, and 41.2% HbS, which essentially is the same hemoglobin partition as in his brother's blood. MMF was discontinued on day +35 and CyA on day +120. After discontinuation of CyA the patient developed mild chronic GVHD, which resolved with continued CyA, low-dose steroids, and the retinoid isotretinoin. He is doing well on day +315 without evidence of GVHD. CONCLUSIONS: Allogeneic SCT after RIC is feasible in adult patients with sickle cell disease. Mixed chimerism is sufficient to relieve disease-related symptoms and is possibly correlated with less acute GVHD.

Adult↗