Long-term survival of sorafenib-treated FLT3-ITD-positive acute myeloid leukaemia patients relapsing after allogeneic stem cell transplantation.

BACKGROUND: Fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD)-positive acute myeloid leukaemia (AML) relapsing after allogeneic stem cell transplantation (allo-SCT) has a dismal prognosis with limited therapeutic options. FLT3-ITD kinase inhibition is a reasonable but palliative experimental treatment alternative in this situation. Information on long-term outcome is not available. METHODS: We performed a long-term follow-up analysis of a previously reported cohort of 29 FLT3-ITD-positive AML patients, which were treated in relapse after allo-SCT with sorafenib monotherapy. FINDINGS: With a median follow-up of 7.5 years, 6 of 29 patients (21%) are still alive. Excluding one patient who received a second allo-SCT, five patients (17%) achieved sustained complete remissions with sorafenib. Four of these patients are in treatment-free remission for a median of 4.4 years. INTERPRETATION: Sorafenib may enable cure of a proportion of very poor risk FLT3-ITD-positive AML relapsing after allo-SCT.

Risk-adapted, treosulfan-based therapy with auto- and allo-SCT for relapsed/refractory aggressive NHL: a prospective phase-II trial.

Since the outcome of relapsed/refractory aggressive non-Hodgkin's lymphoma (NHL) is highly variable, a risk-adapted treatment approach was evaluated. After two cycles of DHAP, patients received high-dose treosulfan/etoposide/carboplatinum (TEC) and autologous stem cell rescue. After TEC, low-risk patients with late relapse (>1 year after first CR who achieved CR after DHAP received no further treatment. Patients with late relapse who achieved CR or PR only after TEC underwent a second cycle of TEC. High-risk patients with early relapse/refractory disease received treosulfan/fludarabine followed by allogeneic transplantation. Rituximab was added in patients with B-cell lymphoma (86%). At entry, 36% of all 57 patients had refractory disease, 32% early and 32% late relapse. During DHAP treatment, progression occurred in 32% of patients. Of 33 patients who received TEC, 5 received second TEC and 15 allogeneic transplantation. Main toxicity after TEC was oral mucositis (CTC grades 3 and 4 in 50% and 13%, respectively). In total, 42% patients achieved CR. Median OS was 21.4 months for all patients and 32.6 for those who underwent allogeneic transplantation. International prognostic index (IPI) at study entry was highly discriminative at predicting OS (P<0.0001). Risk-adapted, treosulfan-based therapy with auto- and allo-SCT is feasible. Long-term survival is possible with allogeneic transplantation.

High activity of sorafenib in FLT3-ITD-positive acute myeloid leukemia synergizes with allo-immune effects to induce sustained responses.

Preliminary evidence suggests that the multikinase inhibitor sorafenib has clinical activity in FLT3-ITD-positive (FLT3-ITD) acute myeloid leukemia (AML). However, the quality and sustainability of achievable remissions and clinical variables that influence the outcome of sorafenib monotherapy are largely undefined. To address these questions, we evaluated sorafenib monotherapy in 65 FLT3-ITD AML patients treated at 23 centers. All but two patients had relapsed or were chemotherapy-refractory after a median of three prior chemotherapy cycles. Twenty-nine patients (45%) had undergone prior allogeneic stem cell transplantation (allo-SCT). The documented best responses were: hematological remission in 24 patients (37%), bone marrow remission in 5 patients (8%), complete remission (with and without normalization of peripheral blood counts) in 15 patients (23%) and molecular remission with undetectable FLT3-ITD mRNA in 10 patients (15%), respectively. Seventeen of the patients without prior allo-SCT (47%) developed sorafenib resistance after a median treatment duration of 136 days (range, 56-270 days). In contrast, allo-SCT patients developed sorafenib resistance less frequently (38%) and significantly later (197 days, range 38-225 days; P=0.03). Sustained remissions were seen exclusively in the allo-SCT cohort. Thus, sorafenib monotherapy has significant activity in FLT3-ITD AML and may synergize with allogeneic immune effects to induce durable remissions.

The impact of the age of HLA-identical siblings on mobilization and collection of PBSCs for allogeneic hematopoietic cell transplantation.

With the increasing age of patients undergoing allogeneic hematopoietic cell transplantation (HCT), the age of matched related sibling donors (MRDs) is expected to increase. Donor safety and the impact of donors' age on mobilization, collection of peripheral hematopoietic progenitor cells (HPCs), subsequent engraftment and the incidence of GVHD were retrospectively analyzed. A total of 167 patients received HCT from an MRD. Median donors' age was 48 years (67 (40%) donors were ≥50 years including 34 donors ≥60 years). Side effects under mobilization and apheresis were age independent. Grafts from donors <50 years contained more CD34+ cells (median 9 × 10(6)/kg recipient's body weight (RBW)) compared with older donors (median 5.9 × 10(6)/kg RBW) (P<0.0005), whereas harvests from donors ≥60 years contained more natural killer (NK) cells (P=0.003). Engraftment occurred at a median of 12 days after HCT irrespective of donors' age. Increasing age of MRD did not preclude successful mobilization, collection of HPC and engraftment. In the context of more NK cells in grafts from elderly donors, the impact of donors' age on outcome after HCT warrants further studies. Although short-term toxicities of apheresis were not increased with increasing age, long-term donor safety remains an important issue.

Plerixafor with and without chemotherapy in poor mobilizers: results from the German compassionate use program.

The CXCR4-inhibitor plerixafor mobilizes hematopoietic stem cells amplifying the effects of granulocyte-CSF (G-CSF). Before approval plerixafor was used in a compassionate use program (CUP) for patients who failed a previous mobilization. In the German CUP 60 patients from 23 centers (median age 56.5 years (2-75)) were given 240 µg/kg plerixafor SC 9-11 h before apheresis. A total of 78.3% (47/60) received G-CSF for 4 days before plerixafor administration; 76.6% of those (36/47) yielded at least 2.0 × 10(6) CD34(+) cells/µL. The median cell yield was 3.35 × 10(6) CD34+ cells/kg (0-29.53). Nine patients received plerixafor alone or with G-CSF for less than 4 days mobilizing a median of 3.30 × 10(6) CD34+ cells/kg (1.6-5.6). There was no significant difference between G-CSF application for 4 days and for a shorter period of time (P=0.157). A total of 47 patients received plerixafor plus G-CSF combined with chemotherapy yielding a median of 3.28 × 10(6) CD34+ cells/kg (0-24.79). In all, 40 of 60 patients (66.7%) proceeded to transplantation, and achieved a timely and stable engraftment. Side effects were rare and manageable. In conclusion, mobilization with plerixafor in poor mobilizers is safe and results in a sufficient stem cell harvest in the majority of patients.

Hydronephrosis Resulting from Bilateral Ureteral Stenosis: A Late Complication of Polyoma BK Virus Cystitis?

We report here a case of acute lymphoblastic leukemia in remission presenting a late-onset bilateral hydronephrosis probably due to polyoma BK virus-induced proliferation of bladder endothelium on both ostii. The diagnosis was made virologically by BK virus Polymerase Chain Reaction (PCR) detection in the absence of any other bladder disease. Awareness of this late complication is necessary not only in patients after renal transplantation but also in patients after hematopoietic stem cell transplantation from matched unrelated donor.

UVA (UVA-1) therapy for the treatment of acute GVHD of the skin.

Long-wavelength UVA (340-400 nm UVA-1) phototherapy has been reported to be effective in atopic dermatitis, localized scleroderma and T-cell-derived skin diseases. We retrospectively investigated 70 patients with acute cutaneous GVHD after allogeneic haematopoietic cell transplantation or donor lymphocyte infusion. Complete and partial responses with a median duration of 10 months were achieved in 49 (70%) and 17 (24.3%) patients, respectively. Overall, 47 (67.1%) patients were not treated with systemic steroids. Furthermore, immunosuppression could be tapered in 24 (34.3%) patients while they were receiving UVA-1 treatment. Responses were seen irrespective of age or type of conditioning. Treatment was very well tolerated. After a median follow-up of 18 (range 10-60) months, three patients developed epithelial skin neoplasia. We conclude that UVA-1 therapy is feasible, well tolerated and can be an effective treatment for acute GVHD of the skin, thereby avoiding the use of systemic steroids and/or allowing a more rapid tapering of systemic immunosuppression in a substantial number of patients. The results of this retrospective analysis warrant larger, prospective studies and the effectiveness of UVA-1 therapy should be compared with other established treatment modalities.

Early related or unrelated haematopoietic cell transplantation results in higher overall survival and leukaemia-free survival compared with conventional chemotherapy in high-risk acute myeloid leukaemia patients in first complete remission.

Between 1996 and 2004, a total of 708 patients were enrolled in the acute myeloid leukaemia (AML) '96 and '02 studies of the East German Study Group (OSHO). Of these, 138 patients (19.5%) had unfavourable cytogenetics defined as complex karyotype, del (5q)/-5, del (7q)/-7, abn (3q26) and abn (11q23). In all, 77 (56%) achieved complete remission 1 (CR1) after induction chemotherapy and were eligible for haematopoietic cell transplantation (HCT). HCT was performed after a median of two cycles of consolidation chemotherapy (CT) in the AML '96 and one cycle in the AML '02 study (P=0.03). After a median follow-up of 19 months, overall survival (OS) at two years was significantly better in the donor group (52+/-9%) versus the no-donor group (24+/-8%; P=0.005). Differences in outcomes were mainly because of a lower relapse incidence in patients after HCT (39+/-11%) compared with a higher relapse incidence in patients undergoing CT (77+/-10%; P=0.0005). Treatment-related mortality was low and not statistically significantly different between the two treatment groups (15+/-7 and 5+/-5% for HCT and chemotherapy, respectively; P=0.49).We conclude that early HCT from related or unrelated donors led to significantly better OS and leukaemia-free survival compared with chemotherapy in patients with unfavourable karyotype.

Long-term follow-up of peripheral blood stem cell transplantation from mismatched related and unrelated donors.

Allogeneic stem cell transplantation (SCT) is best performed with an HLA-identical sibling donor (matched related donor, MRD) to reduce the risk of early complications such as acute graft-vs.-host disease (aGvHD). However, as only about 30% of recipients have an MRD for this potentially curative approach, the use of family donors with one or two mismatches in the HLA-antigens (mismatch related donor, MMRD) or fully matched unrelated donors (MUD) (''alternative donors'') has been introduced in the allogeneic SCT setting in recent years. To evaluate the feasibility of allogeneic SCT from alternative donors by using peripheral blood stem cells (PBSC) we initiated a prospective, phase II study in 1996. From April 1996 to July 1998, 18 patients with various hematological malignancies underwent allogeneic SCT from alternative donors (two patients with MUD and 16 patients with MMRD). All patients received stable engraftment and none of the patients had graft rejection. The rate of aGvHD (grades II-IV) and the relapse rate at last follow-up (seven to nine yr after SCT) were with 40% and 24%, respectively, comparable with those found in patients receiving allogeneic SCT from MRD. However, five yr after allogeneic SCT only 17% were alive, which was mainly due to the treatment-related mortality (TRM) rate of 59%. We conclude that allogeneic PBSC transplantation by using alternative donors is associated with an unsatisfying long-term TRM rate. The significance of TRM and particular late deaths has to be evaluated further in this transplantation setting.

Antithymocyte globulin for the prevention of graft-versus-host disease after unrelated hematopoietic stem cell transplantation for acute myeloid leukemia: results from the multicenter German cooperative study group.

A total of 155 patients with acute myeloid leukemia (AML) received hematopoietic stem cell transplants from unrelated donors after standard conditioning. Clinical outcome after the use of two different antithymocyte globulins for the prevention of graft-versus-host disease (GvHD) was analyzed in a retrospective study as follows: rabbit ATG (Thymoglobulin Sangstat/Genzyme, n=49, median age 42 years, 53% in CR, further ATG-S); rabbit ATG (ATG-Fresenius, n=38, median age 42 years, 58% in CR, further ATG-F) or no ATG (n=68, median age 36 years, 55% in CR). The groups were comparable regarding disease status at transplant, age, CMV status and cytogenetics. Grade III-IV acute GvHD was found in 15% in the ATG and 27% in the no ATG group (P=0.44). The most important independent risk factors for chronic GvHD (cGvHD) were the use of ATG, disease status at transplant and conditioning. cGvHD developed significantly more frequently in no ATG group. With the median follow-up of 34 months, the 5-year survival is 42% for those transplanted in CR. To conclude, these data demonstrate that the transplants performed in CR, with ATG, are associated with a good outcome, low incidence of cGvHD and no increase of relapse.

Sequential application of chemotherapy and monoclonal CD 20 antibody: successful treatment of advanced composite-lymphoma.

We describe successful treatment of a 38-year-old patient with composite lymphoma stage IV(A), who presented with multifocal enlarged lymph nodes. The lymph node histology showed classic morphologic features of Hodgkin's disease, mixed cellularity subtype and follicular B-cell lymphoma. Immunophenotypic analysis showed immunoreactivity for CD20, CD10 and Ki-67 in the malignant small cell population. The areas of Hodgkin's disease demonstrated positive immunoreactivity for CD30 and CD20 in the Hodgkin's cells. Both cell populations were bcl2-oncoprotein positive. Eight courses of dose-escalated BEACOPP were administered. Restaging after chemotherapy showed radiological partial remission, but biopsy confirmed persisting follicular B-cell lymphoma without bone marrow infiltration and no evidence of Hodgkin's disease. He was treated with monoclonal CD 20-antibody (Rituximab) 10 mg/kg weekly for eight consecutive weeks due to marked positivity of CD 20-antigen in follicular lymphoma cells. This treatment was well tolerated and final staging showed complete remission of the composite lymphoma. This patient continues to be in remission 28 months after the end of the treatment. In conclusion, in the very rare case of composite lymphoma a combination of chemotherapy and subsequent immunotherapy might be considered as a promising therapeutic option.

Dose-escalated treosulphan in combination with cyclophosphamide as a new preparative regimen for allogeneic haematopoietic stem cell transplantation in patients with an increased risk for regimen-related complications.

Treosulphan has recently demonstrated antileukaemic activity and potent haematopoietic stem cell toxicity. Dose-escalated treosulphan (3 x 12 or 3 x 14 g/m2) combined with cyclophosphamide (Cy) was chosen for a new preparative regimen before allogeneic haematopoietic stem cell transplantation in 18 patients (median age 44, range 19-64 years) with haematological malignancies, considered ineligible for other myeloablative preparative regimens. Pharmacokinetic studies demonstrated rapid treosulphan plasma clearance and a dose-dependent increase of its maximum plasma concentrations and area under the concentration-time curves. Rapid and sustained white blood cell and platelet recovery and full donor chimerism was attained in all evaluable patients. Nonhaematological regimen-related CTC grades 3-4 adverse events were transient and predominantly consisted of cardiac (28%), gastrointestinal (39%), and hepatic (39%) toxicities. The 1-year nonrelapse mortality was 22%. Principal causes of transplant-related lethal events were infections in three of four affected patients. Only one patient died from regimen-related cardiac toxicity. The 1-year relapse estimate is 22%, overall and progression-free survival estimates are 67 and 56%, respectively. In conclusion, this new treosulphan and Cy combination is an effective, comparatively well-tolerated myeloablative preparative regimen even in patients with an increased risk for regimen-related toxic complications.

Peracute onset of severe tumor lysis syndrome immediately after 4 Gy fractionated TBI as part of reduced intensity preparative regimen in a patient with T-ALL with high tumor burden.

We report a 30-year-old patient with therapy-refractory T-ALL undergoing unrelated allogeneic PBSCT. He developed severe tumor lysis syndrome (TLS) with extreme biochemical changes, cardiac and neurological symptoms and dialysis-dependent acute renal failure after TBI (4 Gy) on the first day of reduced intensity conditioning (RIC) for unrelated allogeneic PBSCT. The patient's clinical condition was stabilized after beginning daily hemodialysis and treatment for disturbed electrolytes, metabolic acidosis and plasma coagulation, as well as reduction of uric acid by rasburicase. The conditioning therapy and the allogenic PBSCT were scheduled according to the preparative regimen. According to our knowledge, severe TLS induced by 4 Gy TBI has not been reported so far. Regimen-related toxicity using RIC regimen was mild, allowing 30-50% of the patients to have an entirely outpatient transplantation. However, we would like to point out that severe TLS could also complicate PBSCT using RIC regimens in patients with relatively radiation-sensitive malignancies and high tumor burden.

Reduced intensity preparative regimens for allogeneic hematopoietic stem cell transplantation: a single center experience.

According to recent reports, fast engraftment with minimal transplant-related toxicity and mortality (TRT, TRM) can be achieved by using reduced-intensity preparative regimens in allogeneic hematopoietic stem cell transplantation (HSCT). We report our experience with related (39%) and unrelated (61%) HSCT in 44 high risk patients (AML, ALL, CML, CLL) receiving either busulfan/fludarabine or busulfane/fludarabine/ATG or TBI/fludarabine as reduced-intensity preparative regimens. Organ toxicity was minimal with mild mucositis and no major bleeding. Acute GVHD was recorded in 64% of the patients. Twenty-three patients achieved complete remission after transplantation, and complete chimerism was obtained in all patients with stable engraftment (35 patients). Twenty-nine patients died: 15 due to relapse/progression, 14 due to TRM. Survival with median follow-up of 18.5 months was significantly better in patients with matched related transplants compared to patients with other transplants. However, there was no difference between related and unrelated transplants with regard to engraftment, TRM and GVHD. In conclusion, our results in high-risk patients transplanted in CR or with smoldering leukemia from a related donor are encouraging, although a longer follow-up and a larger group of patients is needed in order to evaluate the role of different reduced-intensity preparative regimens in unrelated and related HSCT.

Gene therapy for sarcoma.

Soft tissue sarcomas are mesenchymal tumors which respond poorly to systemic therapy. Recent studies suggest a higher response rate with an increased doxorubicin dosage. However, this was parallel with a profound hematotoxicity in 75% of patients. Transfer of the human multidrug resistance 1 (MDR1) gene to normal hematopoietic stem cells and transplantation may significantly reduce the hematotoxicity of anthracyclin-based chemotherapy. To test this concept of supportive gene therapy in advance of a clinical study, we transduced mobilized peripheral blood progenitor cells (PBPC) with the retroviral vector SF91m3 containing the human MDR1 gene, transplanted these cells to immune-deficient mice, allowed 6 weeks for engraftment to occur and treated the animals with MDR1-based chemotherapy. In the MDR1-transduced group the human leukocytes were significantly protected from the toxicity of chemotherapy (p < 0.05). While the gene transfer rate was in the range of 10% and thus comparable to recent clinical trials, the gene expression was 59% of transduced cells and thus significantly higher than previously reported for less-advanced vectors. On the other hand, ifosfamide, a drug which has been used successfully for stem cell mobilization, is active in soft tissue sarcoma. Due to these favorable characteristics sarcoma is an attractive target to test the efficacy of MDR1 gene therapy in a clinical setting. Gene therapeutic strategies may also be used to directly target sarcoma cells, e.g. by transfer of suicide genes. We found that adenoassociated virus 2 (AAV-2) vectors efficiently transduce human HS-1 and HT1080 sarcoma cells (>90%) while other tumor cell lines and primary human PBPC were less susceptible. The thymidine kinase (TK) suicide gene was cloned into an AAV-2 vector and a complete kill of TK-transduced HS-1 and HT1080 cells was observed following exposure to aciclovir or ganciclovir (GCV), while >90% of mock-transduced HS-1 cells survived at these dosages. Transplantation of those sarcoma cells to nonobese diabetic (NOD)/LtSz-severe-combined immunodeficient (scid)/scid (NOD/SCID) mice resulted in a survival of >5 months in the AAV-TK-transduced/GCV-treated group, while the mice in the mock-transduced/GCV-treated group had died after 3 weeks. These data show that soft tissue sarcomas are a particularly suitable model system for the development and clinical testing of new gene therapeutic concepts.

Biological and clinical significance of clonogenic assays in patients with myelodysplastic syndromes.

Biological and clinical significance of growth pattern of hematopoietic progenitors were investigated in 117 patients with primary myelodysplastic syndromes (MDSs) at referral. Abnormal (i.e., "leukemic" or absent) growth of GM colonies (CFU-GM) and GM clusters was found in 47% of patients with "advanced" MDS (RAEB, RAEB-t, and CMML) and in 15% of "low-risk" (RA/RARS) patients. In vitro erythropoiesis was decreased in most of the patients, with significantly lower number of BFU-E in "advanced" MDS than in RA/RARS patients. Megakaryocyte progenitors (CFU-MK) were very low or absent in almost all the patients, regardless of the FAB type. Significant correlation was demonstrated between the number of BFU-E and hemoglobin concentration and between number of CFU-MK and platelet count. Growth capacity of GM progenitors appears to be in proportion to "myeloproliferative" capacity of the malignant clone. T-cell depletion had no influence on growth capacity of hematopoietic progenitors, nor did colony growth respond in a dose-dependent manner to different concentrations of LCM. Growth capacity of MDS hematopoietic progenitors was independent of Bournemouth score, of the presence and type of cytogenetic abnormality, and of the expression of CD95 and caspase-3 antigens on bone marrow cells. However, in patients with "abnormal" growth of GM progenitors, CD34 antigen expression was significantly higher than in patients with "normal" growth. "Abnormal" GM growth was found to be independently predictive regarding the survival and the risk for AML development. In contrast, the prognostic value of erythroid and megakaryocyte cultures was found to be limited.

No difference in graft-versus-host disease, relapse, and survival comparing peripheral stem cells to bone marrow using unrelated donors.

The clinical results in 107 patients receiving a peripheral blood stem cell (PBSC) graft mobilized by granulocyte colony-stimulating factor (G-CSF) from HLA-A, -B, and -DR-compatible unrelated donors were compared to 107 matched controls receiving unrelated bone marrow (BM) transplants. Engraftment was achieved in 94% of the patients in both groups. The PBSC graft contained significantly more nucleated cells, CD34(+), CD3(+), and CD56(+) cells (P <.001), and resulted in a significantly shorter time-to-neutrophil (15 versus 19 days) and platelet engraftment (20 versus 27 days), compared to the BM control group (P <.001). Probabilities of acute graft-versus-host disease (GVHD) grades II to IV were 35% and 32% (not significant [NS]) and of chronic GVHD 61% and 76% (NS) in the PBSC and BM groups, respectively. There was no difference between the 2 groups in bacteremia, cytomegalovirus reactivation or disease, and fungal infection. The 3-year transplant-related mortality (TRM) rates were 42% in the PBSC group and 31% in the BM controls (P =.7) and the survival rates were 46% and 51%, respectively. The probability of relapse was 25% and 31% in both groups (NS), resulting in disease-free survival rates of 43% in the PBSC group and 46% in the BM controls (NS). In the multivariate analysis, early disease, acute GVHD grade 0 to I, and presence of chronic GVHD were independent factors associated with a better disease-free survival in this study. PBSC from HLA-compatible unrelated donors can be used safely as an alternative to BM for stem cell transplantation.