Allogeneic hematopoietic cell transplantation following conditioning with 90Y-ibritumomab-tiuxetan

Radioimmunotherapy (RIT) of relapsed lymphoma is gaining increasing importance. Especially the commercially available anti-CD20 antibody 90Y-ibritumomab tiuxetan is currently under investigation in various trials including dose escalation and autologous hematopoietic progenitor cell support. It is not clear, however, whether the implementation of this radiolabeled antibody into another treatment option for relapsed or poor risk lymphoma patients-allogeneic hematopoietic cell transplantation-interferes with or delays successful engraftment. This study reports encouraging results with 2 relapsed lymphoma patients (1 transformed marginal zone lymphoma and 1 mantle cell lymphoma) who underwent allogeneic hematopoietic cell transplantation from HLA-matched donors. The conditioning regimen consisted of Rituximab 250 mg m(-2) on days -21 and -14, 0.4 mCi kg(-1) body weight 90Y-ibritumomab tiuxetan on day -14 and fludarabine (30 mg m(-2)) plus cyclophosphamide (500 mg m(-2)) on days -7 to -3. The data demonstrate that engraftment is fast and reliable with leukocytes >1 x 10(9) L(-1) on day 12 and platelets >50 x 10(9) L(-1) on day 10. Thus, the incorporation of radioimmunotherapy into allogeneic transplant protocols combines established modalities with proven anti-lymphoma activity and, hence, offers an attractive new therapeutic option for relapsed lymphoma patients.

Four versus six courses of a dose-escalated cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) regimen plus etoposide (megaCHOEP) and autologous stem cell transplantation

BACKGROUND

Patients with aggressive lymphoma and high-risk features at the time of diagnosis are reported to have a poor prognosis with standard therapy. Attempts to improve the results achieved with the combination of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) using second-generation or third-generation chemotherapy have failed. In the current study, the authors increased the doses and dose intensity of drugs used for the conventional first-line therapy of aggressive lymphoma and designed a Phase II randomized trial that compared four and six courses of dose-escalated CHOP plus etoposide (megaCHOEP) supported by the transplantation of peripheral blood stem cells.

METHODS

Eighty-four patients age < 60 years with aggressive lymphoma and elevated lactate dehydrogenase (LDH) levels were randomized to receive either 4 (Arm A) or 6 (Arm B) courses of cyclophosphamide, doxorubicin, vincristine, etoposide, and prednisone (megaCHOEP). The last three treatment courses were supported by autologous peripheral blood stem cell transplantation. Although the total doses of cyclophosphamide and etoposide were comparable, the dose intensity during the first 3 treatment courses was planned to be 2.8-fold and 2.0-fold higher, respectively, for patients in Arm A.

RESULTS

Thirty-seven patients in Arm A (90.2%) but only 18 patients in Arm B (69.2%) were able to complete therapy (P = 0.048). The complete response rate was 65.8% in Arm A and 50.0% in Arm B; the disease recurrence rates were 18.5% versus 61.5% (P = 0.011). Freedom from treatment failure at 2 years was 52.5% (95% confidence interval [95% CI], 36.9-68.2%) in Arm A and 23.1% (95% CI, 6.9-39.3%) in Arm B (P = 0.02). The overall survival rate was 70% (95% CI, 54.9-85.0%) in Arm A and 46.2% (95% CI, 27.0-65.3%) in Arm B (P = 0.037).

CONCLUSIONS

The results of the current study demonstrate that dose intensity, in particular early dose intensity, significantly influences disease control with high-dose therapy (HDT) and autologous stem cell transplantation. These results also may explain the failure of HDT with low early dose intensity to improve the results obtained with conventional chemotherapy.

Dose-escalated CHOP plus etoposide (MegaCHOEP) followed by repeated stem cell transplantation for primary treatment of aggressive high-risk non-Hodgkin lymphoma

Feasibility, safety, and efficacy of a 4-course high-dose chemotherapy (HDT) protocol including autologous stem cell transplantation (SCT) after courses 2, 3, and 4 was investigated in 110 patients, aged 18 to 60 years, with primary diagnosis of aggressive NHL (aNHL), and lactic dehydrogenase (LDH) levels above normal. At dose level 1 (DL1), course 1 consisted of cyclophosphamide 1500 mg/m2, doxorubicin (Adriamycin) 70 mg/m2, vincristine 2 mg, etoposide 450 mg/m2, and prednisone 500 mg. With courses 2 and 3 cyclophosphamide and etoposide were escalated to 4500 mg/m2 and 600 mg/m2, respectively. With course 4 cyclophosphamide and etoposide were given at 6000 mg/m2 and 1000 mg/m2, respectively. At DL2 etoposide was further increased to 600, 960, 960, and 1480 mg/m2 with courses 1 to 4, respectively. Therapy as per protocol was completed by 81.8% of patients. Overall survival at 5 years was 67.2%, freedom from treatment failure (FFTF) was 62.1%, and treatment-related mortality was 4.5%. There was a trend to better FFTF at DL2 compared to DL1 (66.9% versus 54.2%). Repetitive HDT with escalated CHOP plus etoposide is feasible and effective treatment of patients with aNHL. DL2 of this therapy is being used in an ongoing phase 3 study.

Graft-vs-leukemia activity and graft-vs-host disease induced by allogeneic Th1- and Th2-type CD4+ T cells in mice

INTRODUCTION

The transfer of allogeneic lymphocytes contained in a hematopoietic stem cell graft confers an immune-mediated antileukemic effect, termed the graft-vs-leukemia (GVL) effect. Graft-vs-host disease (GVHD), the most detrimental complication of allogeneic BMT, largely resides within the same lymphocyte population. Therefore, separation of GVL- and GVH-reactions is a long-standing goal of experimental studies dealing with allogeneic transplantation of hematopoietic stem cells.

MATERIALS AND METHODS

The objective of the current study was to assess the potential of Th1- and Th2-type CD4+ T cells in mediating GVHD and GVL effects in a fully allogeneic murine transplant model. BALB/c (H-2d) mice were given a dose of A20 (H-2d, B-cell leukemia) cells two days prior to lethal total body irradiation (TBI) and transplantation of fully mismatched (C57BL/6, H-2b) T-cell depleted (anti-Thy1.2, CD90) bone marrow (TCD-BM) cells. Graded numbers of either unmanipulated, Th1- or Th2-polarized highly enriched CD4+ donor type T cells (10(6) or 10(7)) were administered 2 h posttransplant. Infusion of 10(6) of unmanipulated, Th1-, or Th2-primed CD4+ T cells resulted in moderate GVHD-related mortality (40%, 50%, 10%) and significantly improved long-term survival (50%, 45%, 46% surviving the observation period of 120 days) as compared to animals receiving TCD-BM alone (18%).

RESULTS

The administration of 10(7) unmanipulated or Th1-type CD4+ T cells given shortly after transplantation led to death of all mice within 50 days due to fatal acute GVHD. In contrast, the adoptive transfer of 10(7) Th2-primed CD4+ T cells resulted in significant improvement of long-term survival (80%) compared to the TCD-BM group. This powerful GVL effect was associated with a substantially lower incidence of lethal acute GVHD (10%) if compared to the results of transplantation of Th1-type CD4+ T cells.

CONCLUSION

These results demonstrate that allogeneic Th2-type CD4+ T cells given post BMT can induce GVL effects in a cell-dose-dependent manner without increasing the risk of severe acute GVHD.

Mesengenic progenitor cells derived from human placenta

Progenitor cells with differentiation capacity along multiple mesengenic lineages are attractive tools for numerous purposes in regenerative medicine. Such mesengenic progenitor cells have been isolated from adult mammalian bone marrow, and we here report placental tissue as an alternative source for these cells. By means of dissection/proteinase digestion techniques, high numbers of viable mononuclear cells were harvested from human placenta at term, and a mesenchymal cell population with characteristic expression of CD9, CD29, and CD73 was obtained in culture. The in vitro growth behavior of such placenta-derived mesengenic cells was similar to that of human bone marrow mesengenic progenitor cells. After in vitro propagation for more than three passages the cells were exclusively of maternal origin. Differentiation experiments showed differentiation potential along osteogenic, chondrogenic, adipogenic, and myogenic lineages. In conclusion, we propose human term placenta as an easily accessible, ample source of multipotent mesengenic progenitor cells.

Gene transfer into human T lymphocytes and natural killer cells by Ad5/F35 chimeric adenoviral vectors

OBJECTIVE

Genetic modification of effector lymphocytes, such as T cells and natural killer (NK) cells, is essential for many approaches to gene-based immunotherapy of cancer. However, transduction of lymphocytes has proven difficult by currently available gene transfer methods. Previous studies have shown that chimeric fiber-modified Ad5/F35 adenoviral vectors are able to efficiently transduce hematopoietic cells including immature progenitors. In this study, we examined the gene transfer into T lymphocytes and NK cells using Ad5/F35 compared with conventional Ad5 adenovectors.

METHODS

Primary T and NK cells were isolated from healthy donors' peripheral blood leukocytes by immunomagnetic selection. Cell lines and primary lymphocytes were transduced with replication-defective Ad5/F35 and Ad5, both containing a GFP reporter gene under the control of a CMV promoter. Transduction efficiencies were monitored by flow cytometry. The function of transduced lymphocytes was assessed by analysis of proliferative responses to mitogenic agents and in mixed leukocyte reactions.

RESULTS

Transgene expression was detected in up to 45% of primary CD3+ T lymphocytes and in up to 60% of primary NK cells using Ad5/F35. In contrast, conventional Ad5 transduced less than 8% and 5% of primary T cells and NK cells, respectively. Transduction efficiencies were similar in CD4+ and CD8+ T lymphocytes, and transgene expression could be detected for up to seven days. Activation of T cells significantly enhanced the efficiency of Ad5/F35-mediated gene transfer. Adenoviral transduction of lymphocytes did not result in any impairment of proliferative functions.

CONCLUSION

The results of this study demonstrate that both T lymphocytes and NK cells can be transduced by chimeric Ad5/F35 adenoviral vectors.

Two-weekly or 3-weekly CHOP chemotherapy with or without etoposide for the treatment of young patients with good-prognosis (normal LDH) aggressive lymphomas: results of the NHL-B1 trial of the DSHNHL

The combination of cyclophosphamide, doxorubicin, vincristine, and prednisone, given every 3 weeks (CHOP-21) is standard chemotherapy for aggressive lymphomas. To determine whether CHOP given every 2 weeks (CHOP-14) or the addition of etoposide (CHOEP-21, CHOEP-14) can improve results in patients ages 18 to 60 years with good prognosis (normal lactic dehydrogenase [LDH] level), 710 patients were randomized to 6 cycles of CHOP-21, CHOP-14, CHOEP-21 (CHOP plus etoposide 100 mg/m2 days 1-3), or CHOEP-14 in a 2 x 2 factorial study design. Patients in the biweekly regimens received granulocyte colony-stimulating factor (G-CSF) starting from day 4. Patients received radiotherapy (36 Gy) to sites of initial bulky disease and extranodal disease. CHOEP achieved better complete remission (87.6% versus 79.4%; P =.003) and 5-year event-free survival rates (69.2% versus 57.6%; P =.004, primary end point) than CHOP, whereas interval reduction improved overall survival (P =.05; P =.044 in the multivariate analysis). Although the CHOEP regimens induced more myelosuppression, all regimens were well tolerated. CHOEP should be the preferred chemotherapy regimen for young patients with good-prognosis (normal LDH level) aggressive lymphoma.

Reduced-intensity conditioning prior to allogeneic transplantation of hematopoietic stem cells: the need for T cells early after transplantation to induce a graft-versus-lymphoma effect

In patients with poor-risk relapse of aggressive lymphoma, reduced-intensity conditioning followed by allogeneic PBSCT may have its limitations because of rapid regrowth of the tumor. We tried to address this problem by intermediate-intensity conditioning followed by allogeneic SCT. A total of 21 patients received fludarabine, busulfan and cyclophosphamide prior to allogeneic SCT. In the first 10 patients, GVHD prophylaxis by CD34+ selection of the grafts was employed (group I). The next 11 patients received nonmanipulated grafts and mycophenolat mofetil plus cyclosporinA (group II). In group I, no GVHD was observed. In contrast, patients in group II had a significant risk of acute GVHD (aGVHD) (six patients with grade II-IV acute GVHD). However, in group I, all surviving patients progressed within 9 months. In contrast, eight of nine surviving patients of group II remain in remission after a median observation time of 10.5 months (range 4-22 months). Survival differed significantly between the groups (P=0.004). Multivariate analysis identified intensive GVHD prophylaxis as important risk factor for survival. These results support the existence of a clinically relevant GVL effect in aggressive lymphoma. T-cell depletion (or CD34 selection) of grafts is not recommended in patients with poor-risk aggressive NHL.

Enhanced antileukemic activity of allogeneic peripheral blood progenitor cell transplants following donor treatment with the combination of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) in a murine transplantation model

Allogeneic peripheral blood progenitor cells (PBPCs) have mostly been mobilized by granulocyte colony-stimulating factor (G-CSF). There is neither clinical nor experimental data available addressing the question if other hematopoietic growth factors or combinations thereof might influence engraftment, graft-versus-host disease (GvHD), and graft-versus-leukemia (GvL) effects after allogeneic peripheral blood progenitor cell transplantation (PBPCT). We used a murine model to investigate these parameters after transplantation of PBPCs mobilized with G-CSF and SCF either alone or in combination. Treatment of splenectomized DBA and Balb/c mice with 250 microg/kg/day G-CSF for 5 days resulted in an increase of CFU-gm from 0 to 53/microl. The highest progenitor cell numbers (147/microl) were observed after treatment with 100 microg/kg/day SCF administered in conjunction with G-SCF. No differences were detected with regard to the number of T cells (CD3+), T cell subsets (CD4+, CD8+), B cells (CD19+) and NK cells (NK1.1+) in PBPC grafts mobilized by G-CSF plus SCF compared to those mobilized with G-CSF alone. The antileukemic activity of syngeneic and MHC-identical allogeneic PBPC grafts was investigated in lethally irradiated Balb/c mice bearing the B-lymphatic leukemia cell line A20. In this model, PBPCs mobilized by G-CSF plus SCF exerted a significantly higher antileukemic activity compared to grafts mobilized by G-CSF alone (94 vs 71% freedom from leukemia at day 100, P<0.05). The antileukemic effect was lowest after BMT (38% freedom from leukemia). Since significant differences in the incidence of lethal GvHD were not observed, improved GVL-activity resulted in superior overall survival. Our data demonstrate that the utilization of specific hematopoietic growth factors not only improve the yield of hematopoietic progenitor cells but can also significantly enhance the immunotherapeutic potential of allografts.

The impact of autologous stem cell transplantation on the prognosis of mantle cell lymphoma: a joint analysis of two prospective studies with 46 patients

INTRODUCTION

The purpose of this analysis was to investigate if early sequential high-dose therapy with autologous stem cell transplantation (ASCT) can improve the poor prognosis of patients with disseminated mantle cell lymphoma (MCL).

PATIENTS AND METHODS

A joint analysis of two parallel single center studies was performed. Both were characterized by a sequential high-dose therapy consisting of an intensive chemotherapy ('HAM' or 'Dexa-BEAM') for mobilization of peripheral blood stem cells and induction of minimal disease followed by a total body irradiation-containing myeloablative regimen and ASCT. Forty-six patients with reference panel-confirmed stage III/IV MCL were included. Thirty-four patients were accrued to the protocol immediately after diagnosis ('upfront ASCT' group). These 34 patients received a standard first-line regimen prior to mobilization. The remaining 12 patients were put on the protocol later during the course of their disease ('delayed ASCT' group).

RESULTS

All patients were in remission after mobilization chemotherapy and proceeded to ASCT; there were no exclusions due to poor response, poor mobilization, or patient refusal. With a follow-up of 24 (2-73) months post transplant, the event-free and overall survival probabilities at 2 years were 77 and 100% for the upfront ASCT group compared to 30% (P=0.0007) and 54% (P=0.0016) for the delayed ASCT group. Event-free and overall survival tended to be longer in the upfront ASCT group than in the delayed ASCT group also if calculated from initial diagnosis (76 and 93% vs 42 and 63%, respectively, at 4 years after diagnosis; median follow-up 35 months), although this was not statistically significant. Besides timing of ASCT, only spleen size was identified as an independent predictor of survival by univariate and multivariate analysis.

CONCLUSION

ASCT is not curative but may improve the prognosis of patients with MCL if performed as part of an intensive first-line treatment strategy. In contrast, the benefits of this approach for salvaging individuals with relapsed disease appear to be limited.

Elevated blood drug levels obtained from indwelling silicon catheters during oral cyclosporine A administration

Cyclosporine A (CsA) may be bound to and released from the inner surface of central venous catheters resulting in spuriously elevated blood drug levels. We observed this phenomenon in a boy transplanted because of aplastic anemia up to 9 weeks after CsA had been switched from intravenous to oral administration. In comparison to phlebotomy, simultaneous blood sampling from the double lumen catheter resulted in a greater than 10-fold, or two-fold increase in drug levels, respectively, depending on whether or not the line used for prior CsA infusion was selected. Thus, prolonged binding of CsA to the inner surface of venous catheters should also be considered during oral administration.

Expression, cellular distribution and protein binding of the glioma amplified sequence (GAS41), a highly conserved putative transcription factor

The glioma amplified sequence 41 (GAS41) was previously isolated by microdissection mediated cDNA capture from the glioblastoma multiforme cell line TX3868 and shown to be frequently amplified in human gliomas. We determined the complete cDNA sequence of the GAS41 gene, demonstrated that the GAS41 protein is evolutionarily conserved, specifically at the N-terminus, and identified the yeast transcription factor tf2f domain within the GAS41 sequence. A human multiple-tissue Northern blot revealed ubiquitous expression of GAS41 with the highest expression in human brain. After generating polyclonal antibodies we found GAS41 protein expression in the nucleus of the TX3868 cell line by Western blot analysis and immunofluorescence microscopy. The nuclear localization was confirmed for several human tumors including gliomas of different grades of malignancy. In neuroblastoma however, GAS41 was found in the nucleoli but not in the nucleoplasm. Yeast two-hybrid screening of the TX3868 cell line identified the nuclear mitotic apparatus protein (NuMA), the KIAA1009 protein, and prefoldin subunit 1 (PFDN1) as potential interacting partners of GAS41. We generated a polyclonal antibody against the KIAA1009 protein and we demonstrated that the KIAA1009 protein is a nuclear protein, which appears to be co-localized with the GAS41 protein and NuMA.

Assessment of pentachlorophenol-exposed timber workers using a test-of-poisoning model

Sixty-two former New Zealand timber workers who were exposed to pentachlorophenol (PCP) at work were interviewed, examined, and assessed both by laboratory investigations and psychometrically for clinical syndromes that could be related to PCP exposure. Three such syndromes were identified: an acute complex of fever, headaches, upper and lower respiratory tract and eye irritation, skin disease, and foul smelling and discolored sweat; a chronic fatigue syndrome, beginning while still at work and frequently persisting; and a delayed encephalopathy. Neither of the sustained syndromes was considered characteristic of PCP poisoning, and many confounders were identified. An exposure index and a test-of-poisoning score had a statistically insignificant correlation.

Autologous stem cell transplantation for follicular lymphoma: no benefit for early transplant?

Autologous stem cell transplantation (SCT) is widely used as salvage treatment for patients with relapsed follicular lymphoma (FL). Although SCT can induce prolonged remissions, it does not appear to be curative in the vast majority of patients. The purpose of this study was to investigate if incorporation of SCT into first-line therapy can improve its efficacy. Fifty-five patients underwent sequential high-dose therapy as up-front (n=33) or salvage treatment (n=22) for advanced stage FL at our institution. Treatment consisted of intensive chemotherapy with dexamethasone, carmustine (BCNU), etoposide, cytarabine, and melphalan (Dexa-BEAM) for mobilization of peripheral stem cells and reduction of tumor load, followed by one of three different myeloablative regimens and SCT. With a median follow-up of 4 years, projected event-free survival (EFS) and overall survival (OS) at 4 years post transplant was 59% and 84%, respectively, with no evidence of plateau in the survival curves. By univariate and multivariate analysis weighing age, sex, stage, BM and extranodal involvement, timing of transplant, ex vivo purging, and conditioning regimen [total body irradiation (TBI) vs non-TBI], the only significant factor predicting for superior EFS and OS was up-front vs salvage transplant (4-year EFS 76% vs 38%, p=0.02; 4-year OS 92% vs 73%, p=0.033). However, when calculated from diagnosis, EFS and OS of the up-front and salvage groups were virtually identical, implying that the longer survival post SCT in the up-front group was completely compensated by the longer interval between diagnosis and transplant in the salvage group. Median OS from diagnosis was 13.5 years. Except for one case of anaplastic large cell lymphoma, secondary neoplasms have not occurred to date. In conclusion, our data indicate that SCT might improve the prognosis of patients with disseminated FL, although it is probably not curative even if applied early during the course of the disease. The optimum timing of SCT remains to be determined by the ongoing randomized multicenter trial of the German Low-grade Lymphoma Study Group. The impact of radiotherapy on the success of SCT does not seem to be as essential as originally believed.

Novel tankyrase-related gene detected with meningioma-specific sera

In many meningiomas, alterations of chromosome 22 can be found, and the NF2 (neurofibromatosis type 2) gene, in particular, is of great interest as a putative gene involved in meningioma. Because the NF2 gene is not mutated in all meningiomas, additional genes may be involved. Instead of looking for alterations directly at the DNA level, we used the immune response of meningioma patients to identify immunogenic antigens that may be associated with the disease. We screened a fetal brain cDNA expression library with sera pools from different patients bearing meningioma classified according to the three WHO grades, using the serological identification of antigens by recombinant expression cloning immunological screening method. Here, we report the finding of a new tankyrase-related protein. We found 16 overlapping clones with homologies to tankyrase when we screened the library with the common-type meningioma sera pool and 2 such clones when we screened the library with the atypical meningioma sera. The anaplastic meningioma sera did not identify any tankyrase-related clones. We tested some of the newly identified clones with 13 single sera, 6 of which (37.5%) reacted positively with the tankyrase-related clones. In addition, we screened the tankyrase-related clone with six sera pools from individuals without obvious disease. Although 1 of 24 (4.2%) normal sera reacted with the tankyrase-related clone, we found a striking difference in the frequency of reactivity to this clone by sera from patients bearing tumors corresponding to the three WHO meningioma grades; common-type sera was the most frequently reactive. Northern blot analysis demonstrates expression of the novel tankyrase gene in two common-type meningiomas from patients with immune response.