Synergistic cytotoxicity of gemcitabine, clofarabine and edelfosine in lymphoma cell lines

Treatments for lymphomas include gemcitabine (Gem) and clofarabine (Clo) which inhibit DNA synthesis. To improve their cytotoxicity, we studied their synergism with the alkyl phospholipid edelfosine (Ed). Exposure of the J45.01 and SUP-T1 (T-cell) and the OCI-LY10 (B-cell) lymphoma cell lines to IC₁₀–IC₂₀ levels of the drugs resulted in strong synergistic cytotoxicity for the 3-drug combination based on various assays of cell proliferation and apoptosis. Cell death correlated with increased phosphorylation of histone 2AX and KAP1, decreased mitochondrial transmembrane potential, increased production of reactive oxygen species and release of pro-apoptotic factors. Caspase 8-negative I9.2 cells were considerably more resistant to [Gem+Clo+Ed] than caspase 8-positive cells. In all three cell lines [Gem+Clo+Ed] decreased the level of phosphorylation of the pro-survival protein AKT and activated the stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) stress signaling pathway, which in J45.01 cells resulted in the phosphorylation and heterodimerization of the transcription factors ATF2 and c-Jun. The observed rational mechanism-based efficacy of [Gem+Clo+Ed] based on the synergistic convergence of several pro-death and anti-apoptotic signaling pathways in three very different cell backgrounds provides a powerful foundation for undertaking clinical trials of this drug combination for the treatment of lymphomas.

Allogeneic hematopoietic SCT in patients with AML following treosulfan/fludarabine conditioning

An alternative reduced-toxicity conditioning regimen for allogeneic transplantation, based on treosulfan and fludarabine, has recently been identified. The safety and efficacy of this new conditioning regimen has been investigated prospectively in patients with AML. A total number of 75 patients with AML in CR were treated with 3 × 14 g/m(2) treosulfan and 5 × 30 mg/m(2) fludarabine, followed by matched sibling or unrelated SCT. Patients were evaluated for engraftment, adverse events, GVHD, and for non-relapse mortality, relapse incidence, overall and disease-free survival (DFS). All patients showed primary engraftment of neutrophils after a median of 20 days. Non-hematological adverse events grade III-IV in severity included mainly infections (59%) and gastrointestinal symptoms (7%). Acute GVHD grade II-IV occurred in 21% and extensive chronic GVHD occurred in 16% of the patients. After a median follow-up of 715 days, the 2-year overall and DFS estimates were 61% and 55%, respectively. The 2-year incidences of relapse and non-relapse mortality reached 34% and 11%, respectively. In summary, our data confirm promising safety and efficacy of the treosulfan-based conditioning therapy in AML patients, ClinicalTrials.gov Identifier: NCT01063660.

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.

Screening and monitoring of MPL W515L mutation with real-time PCR in patients with myelofibrosis undergoing allogeneic-SCT

Monitoring of minimal residual disease (MRD) after allogeneic (allo)-SCT for myelofibrosis (MF) allows recognizing the depth of remission and thus guides application of appropriate therapeutic interventions. MPL W515L/K mutations, which are detected in 5-10% of JAK2V617F-negative patients, may be useful for this purpose. Using a highly sensitive quantitative PCR method, we tested 90 patients with MF who underwent allo-SCT for the presence of MPL W515L/K mutations. Two patients with primary MF were found to harbor MPLW515L while no patient was positive for MPLW515K mutation. Both patients were JAK2V617F negative and cleared the mutation rapidly after allo-SCT and remained negative for a median follow-up of 19 months. The results of molecular monitoring correlated well with other remission parameters such as normalization of peripheral blood counts and morphology and complete donor chimerism. We conclude that MPLW515L can be cleared after allo-SCT and hence may be used as an MRD marker in a proportion of JAK2V617F-negative MF patients.

EBV reactivation and post transplant lymphoproliferative disorders following allogeneic SCT

Fatal problems encountered in allogeneic stem cell transplantation include EBV reactivation and post transplant lymphoproliferative disorders (PTLDs) with high mortality rates. We performed a retrospective analysis in all consecutive adult and pediatric EBV reactivations and PTLD during a period of 8.5 years. There were 26 patients with EBV reactivation/PTLD out of a total of 854 transplantations giving an overall incidence of 3.0%. Specifically, the incidence of EBV-PTLD was 1.3%, whereas that of EBV reactivation was 1.8%. Median age was 46.0 and 11.0 years in the adult and pediatric patients, respectively. There were high rates (54%) of concomitant bacterial, viral, fungal and parasitic infections at the time of EBV manifestation. Variable treatment regimens were applied including in most cases an anti-CD20 regimen often in combination with virustatic compounds, polychemotherapy or donor lymphocytes. The mortality rates were 9 of 11 (82%) in patients with EBV-PTLD and 10 of 15 (67%) in patients with reactivation. Only 7 of 26 patients (27%) are alive after a median follow-up of 758 days (range 24-2751). The high mortality rates of EBV reactivation and of EBV-PTLD irrespective of multimodal treatment approaches emphasize standardization and optimization of post transplant surveillance and treatment strategies to improve control of these often fatal complications.

Randomized trial of high-dose adjuvant chemotherapy with autologous hematopoietic stem-cell support versus standard-dose chemotherapy in breast cancer patients with 10 or more positive lymph nodes: overall survival after 6 years of follow-up

Investigation of high-dose chemotherapy (HD-CT) compared with standard-dose chemotherapy (SD-CT) as adjuvant treatment in patients with primary breast cancer and >/=10 axillary lymph nodes. From November 1993 to September 2000, 307 patients were randomized to receive after four cycles of epirubicin (90 mg/m(2)), cyclophosphamide (600 mg/m(2)) i.v. (every 21 days) and either HD-CT of cyclophosphamide (1500 mg/m(2)), thiotepa (150 mg/m(2)) and mitoxantrone (10 mg/m(2)) i.v. for four consecutive days followed by stem cell transplantation or a SD-CT of three cycles CMF (cyclophosphamide 500 mg/m(2), methotrexate 40 mg/m(2), 5-fluorouracil 600 mg/m(2), i.v. on day 1 and 8, respectively, every 28 days). After a median follow-up of 6.1 years, 166 events with respect to event-free survival (EFS) (SD-CT: 91, HD-CT: 75) have been observed. The hazard ratio of HD-CT versus SD-CT is estimated as 0.80 [95% confidence interval (0.59, 1.08)], P = 0.15. The trend to a superiority of HD-CT as compared with SD-CT with respect to EFS seems to be more pronounced in premenopausal patients as compared with postmenopausal patients and in patients with tumor grade 3 as compared with patients with tumor grade 1/2. With a follow-up of 6 years, there was a trend in favor of HD-CT with respect to EFS not being significant. A proper meta-analysis needs to be undertaken for an evaluation of subgroups of patients who might benefit from HD-CT.

Cognitive function in the acute course of allogeneic hematopoietic stem cell transplantation for hematological malignancies

The aim of the study was to assess cognitive performance in patients with hematological malignancies before, and 3 months after, allogeneic hematopoietic stem cell transplant (HSCT). A consecutive sample of 39 patients was assessed before admission with a comprehensive neuropsychological test battery and health-related quality-of-life (HRQoL) questionnaires; 19 of these patients were retested around 100 days post HSCT. Test results were compared with normative data and revealed minimal differences at both time points in the level of group-means. One parameter - simple reaction time - was significantly worse (prolonged) at second measurement after HSCT. According to the definition of an impairment score (more than three impaired functions), 26% of patients were classified as impaired before as well as after HSCT. Neuropsychological test results did not vary systematically according to medical variables such as extent of pretreatment, graft-versus-host-disease (GvHD) and kind of conditioning protocol. As a dimension of HRQoL, self-rated cognitive function was in the normal range before and after HSCT. Significant correlations between HRQoL and neuropsychological parameters were related to symptom scales. This study showed impairments of neuropsychological performance for a subgroup of patients before and after allogeneic HSCT. Systematic effects of conditioning, medical variables or self-rated HRQoL could not be observed.

Fetal and adult liver stem cells for liver regeneration and tissue engineering

For the development of innovative cell-based liver directed therapies, e.g. liver tissue engineering, the use of stem cells might be very attractive to overcome the limitation of donor liver tissue. Liver specific differentiation of embryonic, fetal or adult stem cells is currently under investigation. Different types of fetal liver (stem) cells during development were identified, and their advantageous growth potential and bipotential differentiation capacity were shown. However, ethical and legal issues have to be addressed before using fetal cells. Use of adult stem cells is clinically established, e.g. transplantation of hematopoietic stem cells. Other bone marrow derived liver stem cells might be mesenchymal stem cells (MSC). However, the transdifferentiation potential is still in question due to the observation of cellular fusion in several in vivo experiments. In vitro experiments revealed a crucial role of the environment (e.g. growth factors and extracellular matrix) for specific differentiation of stem cells. Co-cultured liver cells also seemed to be important for hepatic gene expression of MSC. For successful liver cell transplantation, a novel approach of tissue engineering by orthotopic transplantation of gel-immobilized cells could be promising, providing optimal environment for the injected cells. Moreover, an orthotopic tissue engineering approach using bipotential stem cells could lead to a repopulation of the recipients liver with healthy liver and biliary cells, thus providing both hepatic functions and biliary excretion. Future studies have to investigate, which stem cell and environmental conditions would be most suitable for the use of stem cells for liver regeneration or tissue engineering approaches.

[Recovery of peripheral blood lymphocytes in patients with hematological diseases after allogenic non-relative transplantation of hemopoietic stem cells]

AIM

To define impact of lymphopoiesis state on the results of transplantation of hemopoietic stem cells (THSC) by assessment of kinetics of lymphocyte count recovery in early posttransplantation period; to study correlation between THSC results and changes in composition of lymphocyte subpopulation.

MATERIAL AND METHODS

Recipients of 122 non-relative THSC entered the trial. The recipients were adults with various hematological malignancies.

RESULTS

Allogenic non-relative THSC leads to deep and long-lasting lymphopenia, low count of all lymphocyte subpopulations and, as a result, to marked impairment of antiinfectious and antitumor immune response. Kinetics of lymphopoiesis recovery depended on some clinical factors. Of most importance were duration of the disease before THSC, HLA donor and recipient compatibility, the source of stem cells, lymphocyte count in the transplant, administration of immunosuppressive drugs. Conduction of non-myeloablative regimens of conditioning did not reduce severity and duration of lymphopoiesis suppression. The time of lymphoid subpopulations count recovery had a significant influence on THSC results. Long-term lymphopenia increased the risk of severe infectious complications and recurrence. Low (under 500 lymphocytes in 1 mcl) lymphocyte level in peripheral blood one month after the transplantation was a death risk factor for patients after THSC.

CONCLUSION

Dynamics of the recovery of lymphocyte subpopulations can be used for formulating policy of adaptive immunotherapy in patients after THSC.

Randomized trial of high-dose chemotherapy with autologous haematopoietic stem cell support vs. standard-dose chemotherapy in breast cancer patients with 10 or more positive lymph nodes: Overall survival after 6 years of follow up

672

Background: Investigation of high dose chemotherapy (HD-CT) supported by autologous hematopoietic stem cell transplantation compared with standard dose chemotherapy (SD-CT) as adjuvant treatment in patients with primary breast cancer and 10 or more axillary lymph nodes. Methods: Between November 1993 and September 2000 307 patients were randomized to receive the following cycles of Epirubicin (90 mg/m2), Cyclophosphamide (600 mg/m2) intervenously (every 21 days) either HD-CT of Cyclophosphamide (1500 mg/m2), Thiotepa (150 mg/m2) and Mitoxantrone (10 mg/m2) intervenously for 4 consecutive days followed by stem cell transplantation or standard dose chemotherapy SDCT in 3 cycles of Cyclophosphamide (500 mg/m2), Methotrexate (40 mg/m2) and Fluoruracil (600 mg/m2) intervenously on days 1 and 8 every 28 days. The primary end points were event-free survival and overall survival. Results: After a median follow-up of 6.1 years 166 events with respect to event-free survival (SD-CT: 91, HD-CT: 75) and 123 with respect to overall survival (SD-CT: 66 and HD-CT: 57) have been observed. The hazard ratio of HD-CT versus SD-CT is estimated as 0,80, p = 0,15. The hazard ratio for overall survival for high dose chemotherapy versus standard dose chemotherapy is estimated as 0,84, p = 0,33. Analysing the effect of treatment on event-free survival premenopausal patients, patients with tumor grade III and ER-positive patients had a better outcome with HD-CT with an interactive effect of 2.5 and 1.4. The significance was only shown in grade III patients in favour of HD-CT, (p = 0,049). The interactive effect of HD-CT with prognostic factors did not reach significance for overall survival. Conclusion: Even with a follow-up of 6.1 years there was only a trend in favour of high dose chemotherapy with respect to overall survival but without a statistical significance. A proper meta-analysis needs to be undertaken for an evaluation of subgroups of patients which might benefit from this treatment approach.

No significant financial relationships to disclose.

Retroviral vector insertions in T-lymphocytes used for suicide gene therapy occur in gene groups with specific molecular functions

Graft-versus-host disease (GvHD) is a severe complication in the context of allogeneic stem cell transplantation and adoptive immunotherapy. The transfer of a suicide gene into donor T-lymphocytes (TLCs) allows selective elimination of GvHD-causing cells. As retroviral gene transfer into hematopoietic stem cells can induce leukaemia, there is an urgent need also to analyze retroviral integration sites in TLCs. We examined suicide gene-transduced TLCs in four grafts and from four transplanted patients. One-hundred and fifteen integration sites were detected in vitro. Of these 90 could be mapped to the human genome; 50% (45) were located in genes and 32% (29) were detected 10 kb upstream or downstream of transcription start sites. We found a significant overrepresentation of genes encoding for proteins with receptor activity, signal transducer activity, transcription regulator activity, nucleic acid binding activity and translation regulator activity. Similar data were obtained from patient samples. Our results point to preferred vector integration patterns, which are specific for the target cell population and probably independent of selection processes. Thus, future preclinical analysis of the integration repertoire with abundant amounts of transduced cells could allow a prediction also for the in vivo situation, where target cells are scarce.

Neuropsychological function in high-risk breast cancer survivors after stem-cell supported high-dose therapy versus standard-dose chemotherapy: evaluation of long-term treatment effects

BACKGROUND

Studies on cognitive functioning in breast cancer patients point out that a subset of women exhibit chemotherapy-related neuropsychological impairment. Thereby, high-dose therapy may elevate the risk of cognitive dysfunctions. The primary purpose of the study was to evaluate the impact of high-dose versus standard-dose chemotherapy on the late neuropsychological outcome in randomized assigned high-risk breast cancer survivors. Next to focusing prevalence, function specificity and extent of cognitive impairment, the question as to whether doses-dependent group differences occur was investigated.

PATIENTS AND METHODS

Twenty-four high-dose and 23 standard-dose patients 5 years, on average, after treatment underwent a comprehensive neuropsychological assessment. In addition, 29 early-stage breast cancer patients matched for age, education and time since treatment were recruited as a comparison group.

RESULTS

Global cognitive impairment was observed in 8% of high-dose versus 13% of standard-dose compared with 3% of early-stage breast cancer patients. Compared with normative data, all patient groups performed worse on one attention subtest measuring the simple reaction time (P < 0.001 in each case). By contrast, no significant between-group differences on the late neuropsychological outcome were found.

CONCLUSIONS

Five years after treatment, standard-dose patients were slightly, but not significantly, more impaired in cognitive performance than high-dose patients.

Comparable results in patients with acute lymphoblastic leukemia after related and unrelated stem cell transplantation

We report the results of 84 patients with ALL after related (n = 46) or unrelated (n = 38) allogeneic SCT. Mean recipient age was 23 years (range: 1-60) and median follow-up was 18 months (range: 1-133). Forty-three patients were transplanted in CR1; 25 in CR2 or CR3; four were primary refractory; four in PR; eight in relapse. The conditioning regimen consisted of TBI/VP16/CY (n = 76), TBI/VP16 (n = 2), TBI/CY (n = 2), Bu/VP16/CY (n = 4). The OS at 3 years was 45% (44% unrelated, 46% related). Univariate analysis showed a significantly better OS for patients <18 years (P=0.03), mismatched sex-combination (P = 0.03), both with a stronger effect on increasing OS after unrelated SCT. Factors decreasing TRM were patient age <18 years (P = 0.004), patient CMV-seronegativity (P = 0.014), female recipient (P = 0.04). There was no significant difference in TRM and the relapse rate was similar in both donor type groups. Multivariate analysis showed that factors for increased OS which remained significant were mismatched sex-combination (RR: 0.70,95% CI: 0.51-0.93, P = 0.015), patient age < 18 years (RR: 0.66, 95% CI: 0.47-0.93, P = 0.016). A decreased TRM was found for female patients (RR: 0.56, 95% CI: 0.33-0.98, P=0.042), negative CMV status of the patient (RR: 0.57, 95% CI: 0.36-0.90, P = 0.015). Unrelated stem cell transplantation for high-risk ALL patients with no HLA-compatible family donor is justifiable.

Allogeneic stem-cell transplantation in patients with refractory acute leukemia: a long-term follow-up

We examined retrospectively 44 patients with refractory acute leukemia (acute myeloid leukemia (AML)/acute lymphoblastic leukemia=25/19) who underwent allogeneic transplantation at our center between 11/1990 and 04/2004. The median leukemic blasts was 25% and age 28 years (range, 3-56). Twenty-one patients had untreated relapse, 13 failed reinduction, eight in partial remission and two aplastic. Conditioning was myeloablative using cyclophosphamide, busulfan, total-body irradiation and etoposide (Bu/Cy/VP, n=22; TBI/Cy/VP, n=17; others, n=5) followed by marrow or peripheral blood transplant (n=23/21) from unrelated or related donors (n=28/16). All patients had graft-versus-host disease (GVHD) prophylaxis with cyclosporin and methotrexate. One patient experienced late graft failure. Severe acute-GVHD and chronic-GVHD appeared in eight and 14 patients, respectively. Thirteen patients (30%) remain alive after a median of 25.3 months (range, 2.4-134.1); with 31 deaths, mostly from relapse (n=15) and infections (n=12). Overall survival (OS) and progression-free survival (PFS) at 5 years was 28 and 26%, respectively. OS and PFS were significantly better with blasts < or =20% and time to transplant < or =1 year while transplant-related mortality was less with the use of TBI. We conclude that patients with refractory leukemia can benefit from allogeneic BMT, especially with < or =20% marrow blast.

Hepatocytic gene expression in cultured rat mesenchymal stem cells

The origin of liver cells from distinct bone marrow stem cells, eg, hematopoietic stem cells or multipotent adult progenitor cells has been recently described using in vitro studies. Cell culture experiments revealed the key role of growth factors and the organ-specific environment for the induction of liver-specific genes. We investigated the in vitro potential of rat mesenchymal stem cells to differentiate into hepatocytic cells in cocultures with isolated rat liver cells. Rat mesenchymal stem cells (MSCs) propagated in culture, and transduced with green fluorescent protein (GFP) were cloned. Cells from selected clones were either cultured under liver-stimulating conditions, using serum free medium supplemented with HGF, EGF, SCF, and FGF-4 alone on fibronectin-coated surfaces, or cocultured with freshly isolated rat liver cells. Cocultured cells were harvested after two weeks and sorted into GFP-positive (GFP+) and GFP-negative (GFP-) cells. RT-PCR for liver specific markers CK-18 and albumin were performed on the different cell populations. After 2 weeks, the specified culture conditions led to the expression of albumin and CK-18 RNA in GFP-positive sorted MSCs from the cocultures, whereas MSCs cultured without liver cells did not express the studied genes. The results indicate, that when cocultured with liver cells MSCs from the bone marrow have the potential to differentiate toward hepatocytic cells in vitro. We conclude that MSC may possess an enhanced capacity to differentiate into functional liver cells. Additionally, environmental factors seem to be crucial for specific and directed differentiation.

Untersuchungen zur Markierung von mesenchymalen Stammzellen mit unterschiedlichen superparamagnetischen Eisenoxidpartikeln und Nachweisbarkeit in der MRT bei 3T

PURPOSE

In vitro evaluation of labeling efficiency of human mesenchymal stem cells (hMSCs) with different types of superparamagnetic iron oxide nanoparticles as well as detection and quantification by MRI at 3T.

MATERIAL AND METHODS

hMSCs were incubated for 24 hours with 5 ultrasmall superparamagnetic particles of iron oxide (USPIO) contrast agents (1 : 30 - 1 : 30,000) of different size, coating and core compound: Endorem, Resovist, citric acid coated magnetite cores of 3 nm (CMF3), 7 nm (CMF7) and 12 nm (CoF, core: cobalt ferrite). Iron uptake, intracellular retention, detection and quantification were evaluated with MRI up to 5 weeks after incubation by cytological analysis (Prussian blue), atomic absorption spectrometry and MR relaxometry measurements.

RESULTS

An effective labeling of hMSCs was achieved using Resovist, CMF3 and CMF7 with mean iron concentrations of 5.1/1.8, 1.9/1.4 and 1.5/1.0 pg/cell (dilutions 1:30 [933, 2100, 2800 microg Fe/ml]/1 : 300 [93, 210, 280 microg Fe/ml]) compared with 0.58/0.34 and 0.43/0.30 pg/cell (Endorem, CoF, dilution 1 : 30 [400, 4200 microg Fe/ml]/1 : 300 [40, 420 microg Fe/ml] unlabelled control cells: 0.01 pg/cell). Particle uptake correlated with the concentration of USPIO in the incubation medium. Detection of 5 x 10 (4) labelled cells/ml with MRI was possible up to 5 weeks after incubation (Resovist, CMF7 and CMF3). MR relaxometry measurements showed a strong correlation between cellular iron load and R2* (1/T2*), r > 0.78. No changes in cell viability or toxic effects were found.

CONCLUSION

Efficiency of labeling hMSCs with USPIOs depends on coating, size and core compound of used particles. Carboxydextran-coated, clinically approved SPIO (Resovist, 50 nm) or ultrasmall citrate-coated particles (< 10 nm) result in an improved cellular uptake. In principle, the long intracellular retention of particles offers the possibility of cell tracking and migration monitoring in MRI.

Aldehyde dehydrogenase activity as a marker for the quality of hematopoietic stem cell transplants

Taking advantage of fluorescent substrates for their metabolic marker aldehyde dehydrogenase (ALDH), hematopoietic stem cells (HSC) were defined as SSC(lo)ALDH(br) - reflecting their low orthogonal light scattering and bright fluorescence intensity in flow cytometry. Based thereon, we investigated the usefulness of ALDH activity for characterizing HSC graft quality, particularly under stress conditions. We first compared the expression of ALDH vs CD34 in bone marrow and peripheral blood stem cell (PBSC) samples over 7 days. We noted that (i) only ALDH activity but not CD34 expression strongly reflected colony-forming ability over time, and that (ii) PBSC grafts stored at room temperature lost most of their progenitor cells within just 48 h. We then retrospectively related ALDH and CD34 expression as well as granulocyte-macrophage colony-forming units (CFU-GM) potential for 19 cryopreserved allogeneic PBSC grafts to engraftment data. Strikingly, in all six patients who received markedly decreased numbers of SSC(lo)ALDH(br) cells, this was associated not only with almost complete loss of CFU-GM potential but also with delayed establishment/permanent absence of full hematopoietic donor cell chimerism, whereas all other patients showed early complete donor chimerism. In conclusion, we suggest to measure ALDH activity as a surrogate marker for HSC activity, and to transport and store PBSC under controlled cooling conditions.

Hematopoietic stem-cell transplantation from unrelated donors in elderly patients (age>55 years) with hematologic malignancies: older age is no longer a contraindication when using reduced intensity conditioning

Allogeneic stem cell transplantation (SCT) is a potentially curative approach for patients with hematological malignancies. Reduced-intensity conditioning regimens allow SCT in elderly patients; however, there are only limited data on the feasibility and outcomes of unrelated donor SCT in these patients. In this study, we analyzed, retrospectively, data of 36 patients with various hematological malignancies and median age 58 years (range, 55-66), who were given unrelated donor SCT after reduced-intensity conditioning. The preparative regimen consisted of fludarabine combined with oral busulfan (8 mg/kg, n=8), intravenous busulfan (6.4 mg/kg, n=11), treosulfan (30 g/m(2), n=5) or melphalan (100-150 mg/m(2), n=12). Patients were also given serotherapy, ATG (n=32), or alemtuzumab (n=4). The probabilities of overall survival, disease-free survival, and nonrelapse mortality at 1 year after SCT were 52, 43, and 39%, respectively. Acute graft-versus-host disease (GVHD) grade II-IV and chronic GVHD occurred in 31 and 45%, respectively. Multivariable analysis determined that survival rates were higher in patients with chemosensitive disease (HR 4.5), and patients conditioned with intravenous busulfan or treosulfan (HR 3.9). Unrelated donor SCT is feasible in elderly patients, with outcomes that are similar to younger patients. Favorable outcome was observed in patients with myeloid malignancies, and those transplanted in remission and early in the course of disease. Age alone should not be considered a contraindication to unrelated donor SCT.

Secondary acute leukemia following mitoxantrone-based high-dose chemotherapy for primary breast cancer patients

The incidence of secondary myelodysplasia/acute myeloid leukemia (AML) was retrospectively assessed in an international joint study in 305 node-positive breast cancer patients, who received mitoxantrone-based high-dose chemotherapy (HDCT) followed by autologous stem cell support as adjuvant therapy. The median age of the patients was 57 years (range 22-67). In all, 268 patients received peripheral blood stem cells, and 47 patients received autologous bone marrow. After a median follow-up of 57 months (range 10-125), three cases of secondary AML (sAML) were observed, resulting in a cumulative incidence of 0.94%. One case of sAML developed 18 months after HDCT (FAB M3) The karyotype was translocation 15;17 and, after induction therapy, the patient underwent autologous stem cell transplantation, and is in complete remission (CR) of both breast cancer and AML. The second patient developed AML (FAB M4eo with inversion 16) 5 months after HDCT. This patient achieved CR after induction therapy, but died of infectious complication. A third patient developed AML (FAB M4) 6 months after HDCT. She achieved CR after induction therapy, but relapsed and expired 28 months after diagnosis of AML. sAML after mitoxantrone-based HDCT is a possible, but rare complication in breast cancer patients.

High-dose chemotherapy with autologous hematopoietic stem-cell support compared with standard-dose chemotherapy in breast cancer patients with 10 or more positive lymph nodes: first results of a randomized trial

PURPOSE

Investigation of high-dose chemotherapy (HD-CT) followed by autologous hematopoietic stem-cell support compared with standard-dose chemotherapy (SD-CT) as adjuvant treatment in patients with primary breast cancer and 10 or more positive axillary lymph nodes.

PATIENTS AND METHODS

Between November 1993 and September 2000, 307 patients were randomized to receive (following four cycles of epirubicin 90 mg/m(2) and cyclophosphamide 600 mg/m(2), intravenously every 21 days) either HD-CT of cyclophosphamide 1500 mg/m(2), thiotepa 150 mg/m(2), and mitoxantrone 10 mg/m(2), intravenously for 4 consecutive days followed by stem-cell support; or SD-CT in three cycles of cyclophosphamide 500 mg/m(2), methotrexate 40 mg/m(2), and fluorouracil 600 mg/m(2) intravenously on days 1 and 8, every 28 days. The primary end point was event-free survival.

RESULTS

After a median follow-up of 3.8 years, 144 events with respect to event-free survival have been observed (HD-CT: 63 events; SD-CT: 81 events). The first event of failure (HD-CT v SD-CT) was an isolated locoregional recurrence (nine v 11), a distant failure (52 v 68), and death without recurrence (two v two). The estimated relative risk of HD-CT versus SD-CT was 0.75 (95% CI, 0.54 to 1.06; P =.095). Overall survival showed no difference (HD-CT: 40 deaths; SD-CT: 49 deaths).

CONCLUSION

There was a trend in favor of HD-CT with respect to event-free survival, but without statistical significance. Further follow-up and a meta-analysis of all randomized studies will reveal the effect of HD-CT as compared with SD-CT as adjuvant treatment in high-risk primary breast cancer.

Detection of disseminated epithelial cancer cells by liquid culture--factors interfering with the standardization of assays

BACKGROUND

Immunocytochemistry is the standard method for detection of disseminated breast-cancer cells. Tumor-cell enrichment by cell culture has been used by several investigators, however assays published have not been well-standardized.

METHODS

Breast-cancer cells from two lines were diluted in hemopoietic cells of varying origins and cultured in different media and different flasks. Factors influencing successful tumor-cell amplification by liquid culture were identified by investigation of 277 cultures. Parallel clinical samples, consisting of BM aspirations, leukapheresis samples and peripheral blood samples obtained from women with breast cancer, were investigated in 113 cultures. Cancer-cell detection by cell culture could be compared to immunocytochemistry in 101 cases.

RESULTS

The frequency of tumor-cell detection was not improved by liquid culture, but a significant correlation between conventional tumor-cell detection and detection after liquid culture was found. Factors influencing tumor-cell amplification in the dilution assay could not be transferred to the investigation of clinical samples. It was concluded that culture-enrichment of disseminated cancer cells was very complex, and could be influenced by a variety of factors-even when a model system was used.

DISCUSSION

It should be recognized that culture-enriched cancer cells probably represent a highly selected population of disseminated cancer cells, despite the significant correlation between tumor cells detected by conventional methods and following conventional methods after liquid culture. There is currently no evidence to suggest that cancer-cell amplification by cell culture could become a standardized technique for the detection of disseminated epithelial tumor cells.

A new conditioning regimen involving total marrow irradiation, busulfan and cyclophosphamide followed by autologous PBSCT in patients with advanced multiple myeloma

The overall survival of patients with advanced multiple myeloma (MM) undergoing high-dose chemotherapy and autologous stem cell transplantation (SCT) depends mainly on the quality of response. Thus, to improve the response rate, a new intensified high-dose chemoradiotherapy was evaluated in a phase I/II study. After induction chemotherapy, 89 patients (median age 51 years, range 32-60 years) with MM stage II/III received a conditioning regimen with total marrow irradiation (9 Gy), busulfan (12 mg/kg) and cyclophosphamide (120 mg/kg) followed by SCT. Regimen-related toxicity according to WHO criteria and response rates defined by EBMT/IBMTR were analyzed. The main toxicity was mucositis grade III/IV in 76%, and fever grade >I in 75% of patients. Three patients developed reversible veno-occlusive disease. Transplant-related mortality was 2%. Among patients with de novo and pretreated MM, a CR rate of 48 and 41%, respectively, was documented. With a median follow-up of 45 months, the actuarial median durations of event-free survival (EFS) and overall survival (OS) after transplant were 29 and 61 months for the whole group, 36 and 85 months for patients with de novo MM, respectively. Thus, administration of this intensified conditioning regimen was associated with tolerable toxicity, a high response rate and long EFS and OS.

ATG as part of the conditioning regimen reduces transplant-related mortality (TRM) and improves overall survival after unrelated stem cell transplantation in patients with chronic myelogenous leukemia (CML)

Matched unrelated donor transplants have an increased risk of severe graft-versus-host disease and transplant-related mortality (TRM). ATG has been introduced to decrease GvHD and to facilitate engraftment. We conducted a retrospective analysis of 333 patients with chronic myelogenous leukemia, who were treated with Fresenius ATG (n=145, average=90 mg/kg bw, range 40-90 mg/kg bw) or standard immunosuppression without ATG (n=188). Both groups were comparable regarding distribution of age, sex, HLA-matched vs mismatched donors. ATG Fresenius led to a faster leukocyte engraftment, decreased the incidence of acute GvHD and TRM (P=0.01 and P=0.03) and led to a significant better overall survival (70 vs 57%, P=0.03). We concluded that a prospective randomized study is needed to evaluate the definite role of ATG in hemopoietic stem cell transplantation.

Evidence of a graft-versus-leukemia effect in chronic lymphocytic leukemia after reduced-intensity conditioning and allogeneic stem-cell transplantation: the Cooperative German Transplant Study Group

PURPOSE

To study whether hematopoietic stem-cell transplantation (HSCT) after reduced-intensity conditioning is effective and tolerable in patients with advanced chronic lymphocytic leukemia (CLL).

PATIENTS AND METHODS

Thirty patients with advanced B-cell CLL were included into the study. After reduced-intensity conditioning with fludarabine, busulfan, and antithymocyte globulin, patients received a transplant from related (n = 15) or unrelated donors (n = 15). Minimal residual disease (MRD) was monitored with a clone-specific polymerase chain reaction.

RESULTS

After a median follow-up of 2 years, 23 patients are alive (to date). Neutrophil and platelet engraftment occurred after a median of 17.5 and 15 days, respectively. Acute graft-versus-host disease (GVHD) grade 2 to 4 was observed in 17 patients (56%), and chronic GVHD was observed in 21 patients (75%). Twelve patients (40%) achieved a complete remission (CR), and 16 patients (53%) achieved a partial remission. Late CR occurred up to 2 years after transplantation. MRD was monitored in eight patients with CR. All patients achieved a molecular CR. At last follow-up, six patients were in ongoing molecular CR. Causes of death were treatment-related complications in four patients and progressive disease in three patients. The probability of overall survival, progression-free survival, and nonrelapse mortality at 2 years was 72% (95% confidence interval [CI], 54% to 90%), 67% (95% CI, 49% to 85%), and 15% (95% CI, 1% to 29%), respectively.

CONCLUSION

Treatment-related mortality after reduced-intensity conditioning followed by allogeneic HSCT was low. The procedure induced molecular remissions in patients with advanced CLL. The observation of late remissions provided evidence of a graft-versus-leukemia effect.

Allogeneic stem cell transplantation after a fludarabine/busulfan-based reduced-intensity conditioning in patients with myelodysplastic syndrome or secondary acute myeloid leukemia

We report the feasibility and efficacy of a fludarabine/busulfan-based dose-reduced conditioning regimen followed by stem cell transplantation from related ( n=19) or unrelated HLA-matched donors ( n=18) in 37 patients with myelodysplastic syndrome (MDS) or secondary acute myeloid leukemia (sAML) who were not eligible for a standard myeloablative conditioning regimen. The conditioning regimen consisted of fludarabine (120-180 mg/m(2)), busulfan (8 mg/kg p.o. or 6.4 mg/kg i.v.), and antithymocyte globulin ( n=25). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine ( n=36) and a short course of methotrexate ( n=29) or mycophenolate mofetil ( n=3). The median age of the patients was 55 years (range: 23-72). The reasons to perform a dose-reduced conditioning were reduced performance status ( n=14), age ( n=12), prior autologous ( n=5) or allogeneic ( n=1) transplantation, or prior/active fungal infection ( n=5). Diagnoses at transplantation were refractory anemia (RA) ( n=8), refractory anemia with excess of blasts (RAEB) ( n=6), RAEB in transformation (RAEB-T) ( n=13), chronic myelomonocytic leukemia (CMML) ( n=3), and sAML ( n=7). Stem cell sources were peripheral blood stem cells (PBSC) ( n=29) or bone marrow ( n=8). One patient received a T-cell-depleted peripheral stem cell graft. Two primary graft failures were observed (6%). Engraftment of leukocytes (>1.0x10(9)/l) and platelets (>20x10(9)/l) was seen after a median of 14 days. Acute GVHD grade II-IV was seen in 37%, while severe grade III/IV GVHD was observed in six patients (17%). Chronic GVHD was seen in 13 patients (48%). There were ten deaths (27%) due to treatment (TRM). The probability of TRM was higher in patients with unrelated donors (45 vs 12%, p=0.03) and in patients with poor cytogenetics in comparison to those with a low or intermediate karyotype (75 vs 20%, p=0.009). During follow-up 12 patients relapsed (32%). Patients without chronic GVHD had a significantly higher probability of relapse compared to those with chronic GVHD (70 vs 15%, p=0.02). After a median follow-up of 20 months, the 3-year estimated disease-free survival (DFS) is 38% [95% confidence interval (CI): 21-55%] and the overall survival (OS) is 39% (95% CI: 22-56%). The OS and DFS after related and unrelated transplantations was 45% (95% CI: 19-71%) vs 31% (95% CI: 9-53%) (n.s.) and 51% (95% CI: 29-73%) vs 25% (95% CI: 4-47%) (n.s.), respectively. We conclude that dose-reduced conditioning followed by allogeneic stem cell transplantation from related or unrelated donors is an effective treatment approach in patients with MDS/sAML and might cure a substantial number of patients who are not eligible for a standard allogeneic transplantation.

Non-overt disseminated intravascular coagulation in patients during treatment with antithymocyte globulin for unrelated allogeneic hematopoietic stem cell transplantation

We assessed the effect of rabbit antithymocyte globulin manufactured by Fresenius (ATG-F) on the hemostatic system in patients (n=12) with various hematological malignancies undergoing hematopoietic stem cell transplantation (HSCT) from HLA-matched unrelated donors. For this purpose, we monitored different parameters of coagulation before, during and after the administration of ATG-F. As a control group, we recruited patients (n=10) undergoing HSCT from their HLA-identical siblings who did not receive ATG-F as part of their preparative regimens. At 24 and 48 h after ATG-F treatment had been initiated, we found a temporary rise in D-Dimer, tissue factor, soluble thrombomodulin and thrombin-antithrombin III complex levels and a significant decrease of platelet counts in patients treated with ATG-F as compared to the control group. No differences between the two groups could be detected with regard to global coagulation tests as well as the incidence of bleeding manifestations, thromboembolic complications or the development of vascular-occlusive-disease of the liver. This temporary state of a stressed but compensated coagulation system under ATG-F therapy can be addressed as nonovert disseminated intravascular coagulation (DIC). The effect was independent from the different conditioning regimens and eased off after cessation of ATG-F. We conclude that ATG-F can induce nonovert DIC in patients receiving antithymocyte globulin as part of their conditioning regimen for HSCT.

Low incidence of secondary myelodysplasia and acute myeloid leukemia after high-dose chemotherapy as adjuvant therapy for breast cancer patients: a study by the Solid Tumors Working Party of the European Group for Blood and Marrow Transplantation

BACKGROUND

To determine the incidence of secondary myelodysplasia (sMDS) or acute myeloid leukemia (AML) in node-positive breast cancer patients who received high-dose chemotherapy (HDCT) followed by autologous stem-cell support as adjuvant therapy.

PATIENTS AND METHODS

The incidence of sMDS/AML was retrospectively assessed in 364 node-positive breast cancer patients who received HDCT followed by autologous stem-cell support as adjuvant therapy between November 1989 and December 1997 and were reported to the European Group for Blood and Marrow Transplantation registry.

RESULTS

The median age of the patients was 45 years (range 22-62 years). Two hundred and ninety-one patients received peripheral blood stem cells and 55 patients received autologous bone marrow as stem-cell support. The most frequently used conditioning regimen was the STAMP-V regimen (32%), followed by melphalan-thiotepa (22%) and melphalan-mitoxantrone-cyclophosphamide (21%). The 5-year probability of overall survival is 71% (95% CI 65% to 77%). After a median follow-up of 48 months (range 1-108 months) only one case of AML was observed, resulting in a crude incidence of 0.27%. This case of AML was observed 18 months after HDCT consisting of three cycles of epirubicin and cyclophosphamide with a cumulative dose of epirubicin 960 mg and cyclophosphamide 19 g. The French-American-British type of AML was M4, and the cytogenetic analysis showed a translocation t(9;11)(p22;q23). After complete remission following high-dose cytarabine and idarubicin the patient relapsed and died.

CONCLUSIONS

In contrast to patients with malignant lymphoma there seems to be no increased risk of sMDS/AML after HDCT in breast cancer. Continued monitoring is required to confirm this low incidence after a longer follow-up period.

Reduced non-relapse mortality after reduced intensity conditioning in advanced chronic lymphocytic leukemia

We studied in 30 patients with progressive or relapsing chronic lymphocytic leukemia (CLL) if hematopoietic stem cell transplantation (HSCT) after conditioning with fludarabine, busulfan and ATG is effective and if treatment related mortality can be reduced compared to myeloablative conditioning regimens. Patients had 15 matched related and 15 matched unrelated donors. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine alone or a combination with "short course" methotrexate or mycophenolate mofetil. The median follow-up is 24 months. At last follow up 11 patients were in complete and 13 in partial remission. Six patients had stable or progressive disease. Late complete remissions occurred up to one year after transplantation and the number of patients with CR is still increasing. Four patients died due to treatment related complications resulting in a probability of treatment-related mortality of 15% (CI 95%, 1% to 29%) at 2 years. The probability of overall survival and progression free survival at two years was 79% and 61%, respectively. In conclusion, HSCT after reduced conditioning may lower the treatment-related toxicity and has the capacity to induce complete remissions.

Imatinib mesylate (STI571) in preparation for allogeneic hematopoietic stem cell transplantation and donor lymphocyte infusions in patients with Philadelphia-positive acute leukemias

Chronic myeloid leukemia in blast crisis (BC) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) are associated with extremely poor outcome. Allogeneic transplantation during BC or active leukemia is most often unsuccessful due to high-rates of both treatment-related complications and relapse. Long-term results are significantly better if a second chronic phase or remission can be achieved prior to transplantation. Similarly, DLI given for the treatment of post-transplant relapse is more successful when given during a second remission. In this study we report our results with a previously unreported approach consisting of short-term treatment with imatinib mesylate (formerly, STI571) to induce or maintain remission, followed by allogeneic transplantation or DLI and the impact on transplantation/DLI outcome. Sixteen patients were treated either in preparation for transplantation (n = 12), for DLI (n = 1), or for both (n = 3). Ten had CML in BC; seven myeloid and three lymphoid BC. Six patients had Ph(+) ALL. The donors were matched unrelated (n = 9), matched siblings (n = 5) or haplo-identical (n = 2). Eleven of 15 patients given imatinib pre-transplant were transplanted in complete hematologic response. Engraftment and GVHD rates were not different from expected. Seven patients had grade II-III hepatic toxicity after transplantation. After a median follow-up of 10 months (range, 3-16 months) six remain alive, two after further therapy. The 1-year survival rate was 25%. Four patients were given imatinib prior to DLI, all had complete response. Two remain in remission >6 months from relapse. In conclusion, treatment with imatinib allows transplantation in a more favorable status or maintaining remission with low toxicity until transplantation is feasible. Pre-transplant imatinib seems safe and not associated with excess post-transplant complications. Imatinib may have substantial activity in combination with DLI. Further study of a larger group of patients is required to assess the impact on long-term outcome and the role of post-transplant imatinib in controlling residual disease.

Molecular methods for detection and quantification of myeloma cells after bone marrow transplantation: comparison between real-time quantitative and nested PCR

Multiple myeloma is characterized by malignant plasma cell-infiltration of bone marrow. Treatment with high-dose therapy results in a high rate of clinical remissions, but almost all patients ultimately relapse. Clinical staging and detection of relapse are limited in sensitivity. Therefore, we established molecular methods based on the highly clone-specific CDR regions of the immunoglobulin VH locus for sensitive and specific detection of residual myeloma cells after bone marrow transplantation. VDJ rearrangements were identified using a set of VH primers and a JH primer. Clone-specific rearrangements were detected by comparison with germ-line sequences. With the nested PCR approach, first-round amplification with the consensus primers was done followed by second amplification with myeloma-specific primers. The real-time quantitative PCR was performed using a myeloma-specific forward primer in combination with a JH consensus TaqMan probe and reverse primer. Sensitivity was tested using dilutions of myeloma cell lines into mononuclear cells. Nested PCR had a sensitivity of 10(-6) and TaqMan PCR of 10(-4) to 10(-5). Specificity was determined by testing different cell lines and patients' probes. These results were confirmed by follow up of 2 patients after allogeneic transplantation with dose-reduced conditioning. Molecular methods are very sensitive and specific tools for follow up of myeloma patients after allogeneic transplantation. By using the quantitative approach, it is possible to see kinetics of bone marrow tumor load, which can be used to guide therapeutic decisions like donor leukocyte infusions (DLI).

A novel 'sort-suicide' fusion gene vector for T cell manipulation

Retroviral suicide gene vectors have successfully been used in clinical studies to improve the safety of adoptive immunotherapy with allogeneic T lymphocytes in the treatment of malignant and viral diseases. At the same time these studies have revealed several problems that are yet to be resolved including impaired T cell function due to long ex vivo culture. Here we present new retroviral vectors co-expressing truncated CD34, a gene transfer marker which ensures rapid enrichment of transduced cells using commercially available GMP-approved devices, and a splice-corrected variant of Herpes simplex virus thymidine kinase (scHSVtk) which confers high sensitivity to the prodrug ganciclovir. We show that a retroviral hybrid vector, MP71, based on the myeloproliferative sarcoma virus (MPSV) and the murine embryonic stem cell virus (MESV), encoding a tCD34/scHSVtk fusion protein mediates high expression of the 'sort-suicide' selection marker, thereby allowing for highly efficient purification and selective elimination of transduced cells.