European Group for Blood and Marrow Transplantation Registry studies in multiple myeloma

Current concepts on hematopoietic stem cell transplantation outcome registries; Emphases on resource requirements for new registries

There is tremendous variability in size, scope, and resource requirements for registries depending on the number of patients and participating sites. The outcome registries are organized systems to collect uniform data using an observational study methodology. Patient registries are used to determine specified outcomes for a population for predetermined scientific, clinical, or policy purposes. Historically, outcome registries established in the development of hematopoietic stem cell transplantation (HSCT) have now evolved into myriads of locoregional and international transplant activity and outcome resources. Over time, these registries have contributed immensely in determining trends, patterns, and treatment outcomes in HSCT. There is wider variation in the goals, mission, objectives, and outcomes of the ongoing registries depending on the organizational structure. There is a growing trend toward overarching relationship of these registries to serve as complementary and interoperable resources for high potential collaborative research. In addition to capacity building, standardized, accredited, and optimally operational registries can provide unmatched and unparalleled research data that cannot be obtained otherwise. Moving forward, HSCT data collection, collation, and interpretation should be an integral part of the treatment rather than an option. Quality assurance and continuous quality improvement of the data are pivotal for credibility, measurable/quantifiable outcomes, clinically significant impact, and setting new benchmarks.

Autologous Stem Cell Transplantation in Multiple Myeloma in the Era of Novel Drug Induction: A Retrospective Single-Center Analysis

Within this retrospective single-center study, we analyzed the survival of 320 multiple myeloma (MM) patients receiving melphalan high-dose chemotherapy (HDCT) and either single (n = 286) or tandem (n = 34) autologous stem cell transplantation (ASCT) from 1996 to 2012. Additionally, the impact of novel induction regimens was assessed. Median follow-up was 67 months, median overall survival (OS) 62 months, median progression-free survival (PFS) 33 months (95% CI 27-39), and treatment-related death (TRD) 3%. Multivariate analysis revealed age ≥60 years (p = 0.03) and stage 3 according to the International Staging System (p = 0.006) as adverse risk factors regarding PFS. Median OS was significantly better in newly diagnosed MM patients receiving induction therapy with novel agents, e.g., bortezomib, thalidomide, or lenalidomide, compared with a traditional regimen (69 vs. 58 months; p = 0.01). More patients achieved at least a very good partial remission in the period from 2005 to 2012 than from 1996 to 2004 (65 vs. 30%; p < 0.001), with a longer median OS in the later period (71 vs. 52 months, p = 0.027). In conclusion, our analysis confirms HDCT-ASCT as an effective therapeutic strategy in an unselected large myeloma patient cohort with a low TRD rate and improved prognosis due to novel induction strategies.

Impact of Hepatitis B Core Antibody Seropositivity on the Outcome of Autologous Hematopoietic Stem Cell Transplantation for Multiple Myeloma

Hepatitis B core antibody (HBcAb) seropositivity has been associated with a higher rate of hepatitis B virus (HBV) reactivation after chemotherapy, even in patients who are hepatitis B surface antigen (HBsAg) negative. However, little is known about the risk of HBV reactivation after autologous hematopoietic stem cell transplantation (auto-HCT). We evaluated the incidence of HBV reactivation, liver toxicity, and survival in patients with multiple myeloma (MM) who received auto-HCT at our institution. We retrospectively identified 107 MM patients with resolved HBV infection (HBcAb positive, HBsAg negative) and 125 patients with negative HBV serology (control subjects) who were matched for age, timing of auto-HCT from diagnosis, cytogenetics, disease status at transplant, induction therapy, and preparative regimen. All patients underwent auto-HCT between 1991 and 2013. Primary endpoints were HBV reactivation, defined as HBsAg positivity or ≥10-fold increase in HBV DNA, and hepatotoxicity, as defined in the U.S. National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. In the resolved HBV infection group, 52 patients (49%) were HBsAb positive and 24 (22%) had detectable HBV DNA before auto-HCT. Only 1 patient with resolved HBV infection received pre-emptive antiviral therapy with lamivudine, whereas 4 patients received lamivudine (n = 3) or tenofovir (n = 1) at reactivation after auto-HCT for a median duration of 12 months. HBV reactivation occurred in 7 of 107 patients (6.5%) in the resolved HBV group. Median time to HBV reactivation from auto-HCT was 16 months. The cumulative incidence of grade 2 or greater hepatotoxicity was 30% in the resolved HBV infection group and 22% in the control group (hazard ratio, 1.3; 95% confidence interval, .7 to 2.3; P = .4). Nonrelapse mortality for the 2 groups was not statistically different at 2 years (P = .06), although it trended higher in the control group than in the resolved HBV infection group (8% versus 1%). The median progression-free survival (PFS) and overall survival (OS) durations in the resolved HBV infection and control groups were 21 versus 18 months (P = .5) and 53 versus 67 months (P = .2), respectively. Our data suggest that resolved HBV infection in patients undergoing auto-HCT for MM is associated with a low risk of HBV reactivation and hepatotoxicity; these complications were reversible and did not adversely affect the PFS or OS.

The role of tandem stem cell transplantation for multiple myeloma patients

INTRODUCTION

Autologous Stem Cell Transplantation (ASCT) represents the standard treatment in eligible "de-novo" multiple myeloma (MM) patients.

AREAS COVERED

ASCT may be single or tandem, and a single ASCT can be followed by an allogeneic (Allo)-SCT. A systematic review has been conducted to examine the current evidence for the efficacy of using a tandem transplant strategy in MM.

EXPERT OPINION

A tandem ASCT approach should be considered for all patients, although the benefit from the second ASCT in patients who are in complete remission or experience a very good partial response should be answered in a clinical trial. Recent results with the new induction regimens indicate that there is a role for tandem ASCT in the presence of adverse cytogenetic abnormalities. Planned AlloSCT after ASCT has not been found to be superior in the majority of studies and is not recommended outside of a clinical trial. However, single or tandem ASCT are both appropriate options and participation in prospective clinical trials should be encouraged to resolve the debate in the era of novel agents for MM.

New developments in conditioning regimens before auto-SCT in multiple myeloma

The current standard conditioning regimen before auto-SCT in patients with multiple myeloma is melphalan 200 mg/m(2). Several attempts have recently been made to improve this aspect of the high-dose therapy procedure. The scope of this review article is to summarize current knowledge on conditioning regimens in this setting.

High-dose therapy and autologous peripheral blood stem cell transplantation in patients with multiple myeloma

Since its introduction in 1983, high-dose therapy followed by autologous peripheral blood stem cell transplantation is a pillar of the treatment of patients with multiple myeloma. In the last decades, a multitude of clinical trials helped to improve strategies based on high-dose therapy and autologous stem cell transplantation resulting in a continuously prolongation of overall survival of patients. In this chapter we will review the progress, which has been made in order to enhance the mobilisation of autologous stem cells and increase the effectiveness of this treatment.

A Phase II study of (153)Sm-EDTMP and high-dose melphalan as a peripheral blood stem cell conditioning regimen in patients with multiple myeloma

Multiple myeloma (MM) remains an incurable illness affecting nearly 20,000 individuals in the United States per year. High-dose melphalan (HDM) with autologous hematopoietic stem cell support (ASCT) is one of the mainstays of therapy for younger patients, but little advancement has been made with regards to conditioning regimens. We opted to combine (153)Samarium ethylenediaminetetramethylenephosphonate ((153)Sm-EDTMP), a radiopharmaceutical approved for the palliation of pain caused by metastatic bone lesions, with HDM and ASCT in a Phase II study. Individualized doses of (153)Sm were based on dosimetry and were calculated to deliver 40 Gy to the bone marrow. The therapeutic dose of (153)Sm-EDTMP was followed by HDM and ASCT. Forty-six patients with newly diagnosed or relapsed disease were treated. Study patients were compared to 102 patients contemporaneously treated with HDM and ASCT. Fifty-nine percent of study patients achieved a very good partial response (VGPR) or better. With a median follow-up of 7.1 years, the median overall survival and progression free survival (PFS) from study registration was 6.2 years (95% CI 4.6-7.5 years) and 1.5 years (1.1-2.2 years), respectively, which compared favorably to contemporaneously treated non-study patients. Addition of high-dose (153)Sm-EDTMP to melphalan conditioning appears to be safe, well tolerated, and worthy of further study in the context of novel agents and in the Phase III setting.

Long-term outcomes of autologous transplantation in multiple myeloma: significant survival benefit of novel drugs in post-transplantation relapse

BACKGROUND

Autologous stem cell transplantation (autoSCT) has an important role in the treatment of patients with symptomatic multiple myeloma (MM). Treatment options for myeloma have expanded in the past decade, and it seems that patients who are treated with novel drugs such as thalidomide and bortezomib for relapse after autoSCT have longer overall survival (OS).

PATIENTS AND METHODS

Herein, we describe the long-term outcome of a cohort of 185 patients with newly diagnosed MM treated with autoSCT. We have analyzed factors that might predict for long-term survival.

RESULTS

Following autoSCT, the overall response rate was 94% (173 of 185 patients); 29% (53 of 185 patients) were in complete remission (CR). Median time to progression (TTP) and OS from start of therapy were 39.8 months and 77.9 months, respectively. The median follow-up was 103.8 months (range, 60.8-144.8 months); 23% of the patients are alive and disease free, 21% of the patients are alive with relapse, and 56% of the patients have died. On multivariate analysis, factors associated with significantly better OS were International Staging System (ISS) disease stage < III (hazard ratio [HR], 2.6; P < .001), achievement of CR after autoSCT (HR, 2.8; P < .001) and use of thalidomide (HR, 4.3; P < .001) and/or bortezomib (HR, 7.3; P < .001) in posttransplantation relapse treatment. The patients' age, renal impairment, disease status before autoSCT and maintenance therapy with interferon-alpha (IFN-alpha) or IFN-alpha and dexamethasone did not significantly affect TTP and OS after transplantation.

CONCLUSION

According to our results, the achievement of CR after transplantation, ISS stage other than III, and administration of thalidomide or bortezomib in posttransplantation relapse were significant parameters favoring long-term posttransplantation survival.

Cell carriers to deliver oncolytic viruses to sites of myeloma tumor growth

Multiple myeloma (MM) is a disseminated malignancy of antibody secreting plasma cells that localize primarily to the bone marrow. Several studies have illustrated the potential of utilizing oncolytic viruses (measles, vaccinia, Vesicular Stomatitis Virus and coxsackievirus A21) for the treatment of MM, but there are significant barriers that prevent the viruses from reaching sites of myeloma tumor growth after intravenous delivery. The most important barriers are failure to extravasate from tumor blood vessels, mislocalization of the viruses in liver and spleen and neutralization by antiviral antibodies. In this review, we discuss the use of various cell types as carriers to overcome these barriers, emphasizing their relative susceptibilities to virus infection and their variable trafficking properties. Mesenchymal progenitor cells, monocytes and T cells have all shown promise as virus-delivery vehicles capable of accessing sites of myeloma growth. However, a previously unexplored alternative would be to use primary myeloma cells, or even myeloma cell lines, as delivery vehicles. Advantages of this approach are the natural ability of myeloma cells to home to sites of myeloma tumor growth and their compatibility with tumor-specific viruses that cannot propagate in other carrier cell lineages. A potential difficulty associated with the use of myeloma cells for virus delivery is that they must be exposed to supralethal doses of ionizing radiation before they can be safely administered to patients. Preliminary studies are presented in which we demonstrate the feasibility of using irradiated myeloma cells as carriers to deliver oncolytic viruses to sites of myeloma tumor growth in an orthotopic human myeloma model.

Radioiodide imaging and radiovirotherapy of multiple myeloma using VSV(Delta51)-NIS, an attenuated vesicular stomatitis virus encoding the sodium iodide symporter gene

Multiple myeloma is a radiosensitive malignancy that is currently incurable. Here, we generated a novel recombinant vesicular stomatitis virus [VSV(Delta51)-NIS] that has a deletion of methionine 51 in the matrix protein and expresses the human sodium iodide symporter (NIS) gene. VSV(Delta51)-NIS showed specific oncolytic activity against myeloma cell lines and primary myeloma cells and was able to replicate to high titers in myeloma cells in vitro. Iodide uptake assays showed accumulation of radioactive iodide in VSV(Delta51)-NIS-infected myeloma cells that was specific to the function of the NIS transgene. In bg/nd/xid mice with established subcutaneous myeloma tumors, administration of VSV(Delta51)-NIS resulted in high intratumoral virus replication and tumor regression. VSV-associated neurotoxicity was not observed. Intratumoral spread of the infection was monitored noninvasively by serial gamma camera imaging of (123)I-iodide biodistribution. Dosimetry calculations based on these images pointed to the feasibility of combination radiovirotherapy with VSV(Delta51)-NIS plus (131)I. Immunocompetent mice with syngeneic 5TGM1 myeloma tumors (either subcutaneous or orthotopic) showed significant enhancements of tumor regression and survival when VSV(Delta51)-NIS was combined with (131)I. These results show that VSV(Delta51)-NIS is a safe oncolytic agent with significant therapeutic potential in multiple myeloma.

Bortezomib-dexamethasone combination in a patient with refractory multiple myeloma and impaired renal function

BACKGROUND

Multiple myeloma (MM) is a hematologic neoplasia characterized by the monoclonal proliferation of bone marrow plasma cells. Renal failure occurs in 20% to 30% of MM patients at diagnosis and in >50% with an advanced form of the disease. For those with advanced MM, often a high-risk group of patients with poor prognosis, salvage treatment for renal failure needs to avoid nephrotoxic drugs.

CASE SUMMARY

We report a case of a 78-year-old white male (weight, 90 kg) presented to the Department of Medical Oncology and Hematology, Istituto Clinico Humanitas, Rozzano, Milan, Italy, with refractory MM immunoglobulin G kappa (IgGkappa), Durie-Salmon Stage IIA, with progressive renal failure after an oral melphalan, prednisone, and thalidomide regimen (4 mg/m2.d, 40 mg/m2.d for 7 days every 6 weeks, and 100 mg/d, respectively). The patient had documented increments of serum monoclonal component (M-protein), anemia, and renal failure with Bence Jones proteinuria (serum creatinine, 2.9 mg/dL; creatinine clearance, 30 mL/min; hemoglobin, 10.9 g/dL; serum IgGkappa M-protein, 3.9 g/dL; proteinuria 3.5 g/d;light-chain level in urine, 1.2 g/L). After 2 cycles with bortezomib at a reduced dose (1.0 mg/m2 twice weekly for 2 weeks followed by a 10-day rest period) to evaluate tolerability and renal toxicity, the patient completed another 3 cycles at the standard dose (1.3 mg/m2) in combination with dexamethasone (20 mg on the day of bortezomib administration and the day after). This led to an improvement of the renal function with a reduction of serum and urinary M-protein (serum creatinine 1.4 mg/dL; serum IgGkappa M-protein, 2.9 g/dL; proteinuria, 2 g/d; kappa light-chain level in urine, 0.7 g/L). The patient developed thrombocytopenia but did not suffer from some of the more severe adverse events associated with bortezomib, such as infection or peripheral neuropathy, even at full dose.

CONCLUSION

We report an elderly patient with refractory MM and progression with renal failure who responded to bortezomib treatment. Bortezomib was well tolerated in this patient.

Oncolytic measles virus targets high CD46 expression on multiple myeloma cells

OBJECTIVE

Multiple myeloma (MM) is an incurable B cell malignancy and novel therapeutics are urgently needed. Live attenuated measles virus (MV) has potent oncolytic activity against MM tumor xenografts. The virus is tumor selective and preferentially targets cells that express high levels of CD46 receptors. However, CD46 levels on MM have not previously been evaluated. In this study, we investigated the potential of CD46 as a target for MM therapy and correlated surface levels of CD46 on MM cells with their susceptibility to MV-induced cytopathic effects.

MATERIALS AND METHODS

CD46 expression on neoplastic plasma cells (PCs) and nonplasma cells (NPCs) from 38 MM patients was analyzed by flow cytometry and receptor numbers were quantitated using BD QuantiBRITE PE beads.

RESULTS

Results showed that malignant PCs expressed significantly higher levels of CD46 receptors compared to NPCs (p < 0.0001). The mean CD46 receptor numbers on PCs and NPCs were 49,130/cell and 7,340/cell, respectively. Potent cytopathic effects of extensive intercellular fusion were observed in measles-infected PCs but not in NPCs. The extent of MV-induced cytopathic effects of cell fusion correlated with CD46 expression levels on the MM cells. Normal plasma cells do not overexpress CD46 and colony-forming assays demonstrated that MV was not cytotoxic to normal bone marrow progenitor cells.

CONCLUSION

The present study establishes CD46 as a surface antigen that is expressed more abundantly on primary MM cells compared to normal hematopoietic cells of various lineages in the bone marrow, making CD46 a promising surface marker for targeted cytoreductive therapy of MM.

Predictive factors for survival in myeloma patients who undergo autologous stem cell transplantation: a single-centre experience in 211 patients

High-dose therapy with autologous stem cell therapy (ASCT) has become the treatment of choice for eligible patients with myeloma. We analysed retrospectively the prognostic influence of pre-transplant characteristics and transplant modalities on response and survival in 211 myeloma patients who were transplanted in our centre between 1994 and 2004. All patients received peripheral blood stem cell support after conditioning with melphalan alone (183 patients), or melphalan and total blood irradiation (28 patients). We evaluated the influence of age, type of multiple myeloma, status prior and post ASCT, previous treatment regimens, time of ASCT from diagnosis, year of autograft, dose of re-infused CD34(+) cells, plasma cell infiltration and beta2-microglobulin at diagnosis on overall survival (OS) and event-free survival (EFS) to define patients with better prognosis. Median OS and EFS from transplantation were 50.9 and 20.1 months, respectively. Median OS from diagnosis was 68.8 months. Transplant-related mortality was 1.4%. Lower beta2-microglobulin levels, achievement of complete remission (CR) post transplant and lower plasma cell infiltration at diagnosis and transplant correlated with longer EFS and OS, whereas CR at transplant and low international prognostic index at transplant correlated with better EFS. Higher CD34(+) cell dose correlated with improved OS. We conclude that ASCT is safe and effective and the outcome is independent of age, time from diagnosis, previous treatment and conditioning regimen.

Results of autologous and allogeneic hematopoietic cell transplant therapy for multiple myeloma

We compared the results of autologous and allogeneic peripheral blood hematopoietic cell transplant (HCT) in 87 patients with multiple myeloma using myeloablative preparative regimen. Autologous transplant (n=70) led to a lower 100-day transplant-related mortality (TRM) of 4% [0-9%] compared to 18% [0-36%] in allogeneic recipients (P=0.02). More frequent complete responses were seen in allogeneic recipients (64% [37-91%] vs 34% [23-45%] in autologous recipients, P=0.09). In autologous recipients, survival at 1 year was 86% [80-95%] and, it fell to 50% [47-75%] at 4 years, whereas in allogeneic recipients, survival at 1 and 4 years remained at 64% [40-87%]. In patients surviving more than one year, 4-year survival was superior in allogeneic (100%) vs autologous recipients (58% [41-75%], P=0.02). A trend toward higher relapse was seen in autologous transplant patients (73% [55-90%] vs 37% [11-63%] in allogeneic transplant patients, P=0.1). We observed good tolerance of myeloablative conditioning regimen followed by either autologous or allogeneic transplant. Although autologous HCT is associated with lower TRM, allogeneic HCT has acceptable TRM, and is more likely to provide a sustained response. Allogeneic HCT may be suitable in younger patients, soon after diagnosis, and in those with chemosensitive disease.

PS-341–mediated selective targeting of multiple myeloma cells by synergistic increase in ionizing radiation-induced apoptosis

OBJECTIVE

Multiple myeloma remains incurable with current therapy. The proteosome inhibitor, PS-341, has shown objective clinical responses in relapsed refractory myeloma patients. We investigated the potential of enhancing the radiosensitivity of myeloma cells by combining with PS-341; the underlying mechanisms were delineated.

MATERIALS AND METHODS

Clonogenic assays were used to evaluate cell survival after exposure to PS-341, ionizing radiation (IR), or PS-341 followed by IR. Apoptosis was studied by annexin V-propidium iodide staining and caspase activation. Cell-cycle phase distribution of cells was determined. Nuclear factor-kappaB (NF-kappaB) activity was monitored by enzyme-linked immunosorbent assay and Western blotting. The expression of death receptor Fas/APO-1/CD95 was analyzed by flow cytometry. The consequential caspase-8 activation was detected by Western blotting.

RESULTS

In clonogenic assays, sequential exposure to nontoxic doses of PS-341 (10 nM) and IR (6 Gy) resulted in synergistic inhibition of proliferation of myeloma cells by modulating the apoptotic sensitivity of these cells. Biochemically, sublethal dose of IR led to potent induction of NF-kappaB activity, and this response was significantly inhibited by pretreatment with PS-341, or by the NF-kappaB inhibitory peptide SN-50. Enhanced Fas expression was seen in myeloma cells exposed sequentially to PS-341 and IR. Finally, PS-341 sensitized primary myeloma (CD138+ve) cells to IR but had little effect on CD138-ve bone marrow cells from myeloma patients.

CONCLUSION

These data indicate that PS-341 can sensitize myeloma cells to IR by both intrinsic and extrinsic apoptotic pathways. The study indicates improved therapeutic benefits in treatment of multiple myeloma by combining PS-341 with conventional radiotherapy.

Randomized comparison of granulocyte colony-stimulating factor versus granulocyte-macrophage colony-stimulating factor plus intensive chemotherapy for peripheral blood stem cell mobilization and autologous transplantation in multiple myeloma

Autologous peripheral blood stem cell transplantation for multiple myeloma offers higher response rates and improved survival compared with conventional chemotherapy. However, successful autografting requires effective cytoreduction and rapid hematologic reconstitution. We conducted a prospective randomized clinical trial to assess the efficacy of 2 cycles of priming chemotherapy with either granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) for peripheral blood stem cell mobilization followed by autologous transplantation. The major study end points were the comparative utility of G-CSF versus GM-CSF, the percentage of patients achieving complete response after transplantation, and overall and progression-free survival. Priming chemotherapy included cyclophosphamide (4 g/m2), mitoxantrone (8 g/m2 every day for 2 days), and dexamethasone (20 mg/m2 every 12 hours for 2 days) followed by randomization to either G-CSF or GM-CSF daily until completion of leukapheresis. Conditioning for transplantation included cyclophosphamide (75 mg/kg every day for 2 days) plus total body irradiation (165 cGy twice daily for 3 days), and patients received maintenance immunotherapy with interferon alpha. Seventy-two patients were randomized, and 64 underwent autologous transplantation. The median age at transplantation was 52 years, and the median time from diagnosis to transplantation was 10 months; 58% of the patients had received >4 cycles of pretransplantation chemotherapy. The median number of CD34+ cells obtained after mobilization was 16.4 x 10(6)/kg in the G-CSF arm versus 12.8 x 10(6)/kg in the GM-CSF arm (P = .8). Neutrophil recovery was faster in the G-CSF group after both cycle 1 (median, 13 days with G-CSF and 16 days with GM-CSF; P < .01) and cycle 2 (median, 13 days versus 17 days in the 2 groups, respectively; P = .03). Although platelet recovery was similar after cycle 1, platelet recovery to >100000/microL was notably faster in the G-CSF group both after cycle 2 and after transplantation (P = .03). Response and overall and disease-free survival were similar in both cohorts. Overall, 23% of the patients achieved a complete response after priming chemotherapy, which improved to 33% after transplantation. An additional 47% attained a partial response after transplantation, for a total response rate of 80%. With a median follow-up of 2 years (range, 0.7-8 years), the overall survival was 88% (95% confidence interval [CI], 80%-96%) at 1 year and 65% (95% CI, 51%-79%) at 3 years. Progression-free survival was 73% (95% CI, 62%-84%) at 1 year and 40% (95% CI, 26%-54%) at 3 years. Relapse or progressive disease was the most common cause of death (25 [83%] of 30 deaths). We conclude that mobilization with chemotherapy plus G-CSF versus GM-CSF results in similar CD34+ progenitor collections, even in patients exposed to multiple cycles of alkylator-based chemotherapy. Earlier neutrophil and platelet recovery was seen with G-CSF priming. Two cycles of priming chemotherapy plus autologous transplantation yields survival rates similar to those in published reports, including those using tandem transplantation.

Prognostic factors for survival after autologous transplantation: a single centre experience in 133 multiple myeloma patients

Autologous stem cell transplantation (ASCT) has an established role in the treatment of symptomatic multiple myeloma (MM). Our aim was to analyse the impact of selected prognostic parameters on the survival of patients with MM after ASCT. The new International Staging System (ISS) was also evaluated. A total of 133 MM patients were transplanted in our centre between 1995 and 2002. Following ASCT, 35% of patients were in complete remission (CR) and 60% were in partial remission (PR). The median progression-free (PFS) and overall (OS) survival from transplantation were 29.5 and 68.8 months, respectively. Transplant-related mortality (TRM) was 3%. On multivariate analysis, factors associated with significantly shorter OS were lack of CR after transplant (P = 0.002, hazard ratio (HR): 3.1), stage 3 according to ISS (P = 0.001, HR: 3.0) and age at transplant over 60 years (P = 0.035, HR: 2.0). The status of disease before ASCT did not significantly affect PFS and OS after transplantation. We conclude that ASCT is a safe and effective procedure in MM patients, associated with low TRM. The survival after ASCT was dependent on response after ASCT, stage according to ISS and age.

A phase I study of 153Sm-EDTMP with fixed high-dose melphalan as a peripheral blood stem cell conditioning regimen in patients with multiple myeloma

Despite response rates of 30% after high-dose chemotherapy with autologous hematopoietic stem cell transplant, patients with multiple myeloma are not cured. 153Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP; Quadramet) is a short-range, beta-emitting therapeutic radiopharmaceutical with avid skeletal uptake. In total, 12 patients were treated with escalating doses of 153Sm-EDTMP (N=3/group; 6, 12, 19.8, and 30 mCi/kg) and a fixed dose of melphalan (200 mg/m(2)). No dose limiting toxicity was seen. To better standardize the marrow compartment radiation dose, the study was modified such that an additional six patients were treated at a targeted absorbed radiation dose to the red marrow of 40 Gy based on a trace labeled infusion 1 week prior to the therapy. Despite rapid elimination of unbound radiopharmaceutical via kidneys and bladder, no episodes of nephrotoxicity, hemorrhagic cystitis, or delayed radiation nephritis were observed with a median follow-up of 31 months (range 8.5-44). Median times to ANC>0.5 and platelet >20 x 10(6)/l were 12 and 11 days, respectively, with no graft failures. Overall response rate was 94% including seven very good partial responses and five complete responses. Addition of 153Sm EDTMP to melphalan conditioning appears to be safe, well-tolerated and worthy of further study.

Benefit and Timing of Second Transplantations in Multiple Myeloma: Clinical Findings and Methodological Limitations in a European Group for Blood and Marrow Transplantation Registry Study

Purpose

To use European Group for Blood and Marrow Transplantation registry data to assess the benefit and optimal timing of a double-autologous transplantation strategy for patients with myeloma.

Patients and Methods

7,452 transplantation patients described as being either in a multiple graft program (“planned”) or not, were analyzed on an intention-to-treat basis. Subsequent multivariate analyses concentrated on the real occurrence of second transplantation, survival, relapse, and transplant-related mortality.

Results

Although the transplantation rate in the planned group failed to reach 60%, the median survival from transplantation is 60 months for the planned, compared with 51 months for the remainder group. While the hazard ratio of the planned group is 0.89 (95% CI, 0.79 to 1.00; P =.05) before approximately 70 months, this “effect” is reversed after 70 months, with the hazard ratio estimated as 3.01 (95% CI, 1.07 to 8.46; P = .04). A time-dependent multivariate Cox analysis shows that, taking patients without a second transplantation as a reference group, those receiving a second transplantation in first remission (ie, before relapse) show an increased probability of transplant-related mortality, especially if the transplantation is performed more than 12 months after the first, and the reduction of the risk of relapse is less than when the transplantation is performed earlier. Performing a second transplantation after relapse does not seem to prolong survival, though a second transplantation before relapse is associated with a higher probability of mortality.

Conclusion

To improve survival of tandem autologous transplantation in multiple myeloma, the second transplantation should preferably be performed before relapse and within 6 to 12 months of the first transplantation.

Multiple myeloma

Multiple myeloma is a malignant disease of plasma cells that manifests as one or more of lytic bone lesions, monoclonal protein in the blood or urine, and disease in the bone marrow. Treatment for myeloma has changed beyond recognition in the past decade, and now includes state of the art supportive treatment and infusional chemotherapy courses, followed for younger patients by high-dose melphalan and an autologous transplant. Patients younger than 70 years can now expect a doubling of median survival to 5 years, a 20% chance of surviving longer than 10 years, and a 50% chance of attaining complete morphological and biochemical remission. Bisphosphonate control of bone disease is essential. Exploitation of the understanding of the biology of myeloma has led to the development of biological treatments, such as thalidomide, CC-5013, and bortezomib, which target the myeloma cell and the bone-marrow microenvironment, which plays a crucial part in the disease's pathogenesis. These treatments will hold the key to future success.

Primary treatment of multiple myeloma with thalidomide, vincristine, liposomal doxorubicin and dexamethasone(T-VAD doxil): a phase II multicenter study

BACKGROUND

High-dose chemotherapy with autologous stem cell transplantation after initial cytoreductive chemotherapy with the combination vincristine, doxorubicin and dexamethasone (VAD) is considered an effective therapy for many patients with newly diagnosed, symptomatic multiple myeloma. Response to initial cytoreductive chemotherapy is important for the long-term outcome of such patients. Thalidomide has recently shown significant antimyeloma activity. We studied the efficacy and toxicity of the combination of a liposomal doxorubicin-containing VAD regimen with thalidomide, administered on an outpatient basis, as initial cytoreductive treatment in previously untreated patients with symptomatic myeloma.

PATIENTS AND METHODS

Thirty-nine myeloma patients were treated with vincristine 2 mg intravenously (i.v.), liposomal doxorubicin 40 mg/m(2) i.v. administered as single dose on day 1, and dexamethasone 40 mg per os daily for 4 days. Dexamethasone was also given on days 15-18 of the first cycle of treatment. The regimen was administered every 4 weeks for four courses. Thalidomide was given daily at a dose of 200 mg at bedtime. Response to treatment was evaluated after four cycles of treatment. After completion of four cycles, the patients were allowed to proceed to high-dose chemotherapy or to receive two additional cycles of the same treatment.

RESULTS

On an intention-to-treat basis, 29 of the 39 patients (74%) responded to treatment. Four patients (10%) achieved complete and 25 (64%) partial response. Three patients (8%) showed minor response and seven (18%) were rated as non-responders. Major grade 3 or 4 toxicities consisted of neutropenia (15%), thrombocytopenia (15%), deep vein thrombosis (10%), constipation (10%), skin rash (5%) and peripheral neuropathy (5%). Two patients (5%) experienced early death due to infection.

CONCLUSIONS

The combination of vincristine, liposomal doxorubicin, and dexamethasone (VAD doxil) with thalidomide is an effective and relatively well-tolerated initial cytoreductive treatment. Prospective randomized studies are required in order to assess the effect of this regimen on the long-term outcome of patients with multiple myeloma.

Treatment of multiple myeloma

Autologous peripheral blood stem cell (PBSC)-supported high-dose melphalan is now considered standard therapy for myeloma, at least for younger patients. The markedly reduced toxicity of allotransplants using nonmyeloablative regimens (mini-allotransplantations) may hold promise for more widely exploiting the well-documented graft-versus-myeloma (GVM) effect. New active drugs include immunomodulatory agents, such as thalidomide and CC-5013 (Revimid; Celgene, Warren, NJ), and the proteasome inhibitor, PS 341 (Velcade; Millenium, Cambridge, MA), all of which not only target myeloma cells directly but also exert an indirect effect by suppressing growth and survival signals elaborated by the bone marrow microenvironment's interaction with myeloma cells. Among the prognostic factors evaluated, cytogenetic abnormalities (CAs), which are present in one third of patients with newly diagnosed disease, identify a particularly poor prognosis subgroup with a median survival not exceeding 2 to 3 years. By contrast, in the absence of CAs, 4-year survival rates of 80% to 90% can be obtained with tandem autotransplantations. Fundamental and clinical research should, therefore, focus on the molecular and biologic mechanisms of treatment failure in the high-risk subgroup.

Single versus double autologous stem-cell transplantation for multiple myeloma

BACKGROUND

We conducted a randomized trial of the treatment of multiple myeloma with high-dose chemotherapy followed by either one or two successive autologous stem-cell transplantations.

METHODS

At the time of diagnosis, 399 previously untreated patients under the age of 60 years were randomly assigned to receive a single or double transplant.

RESULTS

A complete or a very good partial response was achieved by 42 percent of patients in the single-transplant group and 50 percent of patients in the double-transplant group (P=0.10). The probability of surviving event-free for seven years after the diagnosis was 10 percent in the single-transplant group and 20 percent in the double-transplant group (P=0.03). The estimated overall seven-year survival rate was 21 percent in the single-transplant group and 42 percent in the double-transplant group (P=0.01). Among patients who did not have a very good partial response within three months after one transplantation, the probability of surviving seven years was 11 percent in the single-transplant group and 43 percent in the double-transplant group (P<0.001). Four factors were significantly related to survival: base-line serum levels of beta2-microglobulin (P<0.01) and lactate dehydrogenase (P<0.01), age (P<0.05), and treatment group (P<0.01).

CONCLUSIONS

As compared with a single autologous stem-cell transplantation after high-dose chemotherapy, double transplantation improves overall survival among patients with myeloma, especially those who do not have a very good partial response after undergoing one transplantation.

Breakthroughs in the management of multiple myeloma

Although multiple myeloma remains a terminal illness, the past four decades have seen a dramatic change in the outlook for a newly diagnosed patient in terms of therapies available, supportive care and insight into the pathogenesis of this disease. Among the newer agents available for treatment, thalidomide has been resurrected and discovered to be a valuable therapy for myeloma. Thalidomide appears to work, at least in part, through its anti-angiogenic properties, but much remains to be learned about its mechanism of action as well as optimal administration regimens. With the development of increasingly more potent bisphosphonates it has become possible to diminish the painful skeletal complications of myeloma, one of the most devastating problems of this disease. The most recent generation of bisphosphonates, pamidronic acid and zoledronic acid, have provided a statistically significant decrease in the skeletal complications of myeloma when used in a prophylactic manner. These agents appear to work by inhibiting osteoclast function. Progressive improvement in cytogenetic techniques has now demonstrated that almost all patients with myeloma have chromosomal abnormalities, some of which appear to confer varying degrees of prognostic significance. In particular, the changes in chromosome 13 are associated with an unusually poor outcome. These findings are serving as a guide toward learning more about the pathogenesis of myeloma as well as in identifying potential targets for therapy. Stem cell transplantation has emerged as the standard treatment for the large majority of patients with myeloma following the demonstration of superior complete remission and survival, both disease-free and overall, in a French randomised trial. Unfortunately, virtually all patients will eventually relapse following autologous stem cell transplantation, prompting continuing efforts such as tandem transplants, CD34+ selection, as well as modifications in the conditioning regimen to improve outcomes. Allogeneic bone marrow transplants appear to offer a better chance for a possible cure of myeloma but have been associated with an unusually high mortality. However, this approach is being revived with the advent of the less toxic non-myeloablative transplant that has provided an 81% short-term survival in a trial combining this approach with an initial conventional autologous bone marrow transplant. Immunotherapy with dendritic cells appears now to be a feasible way to enhance innate or acquired immunity to help eliminate minimal residual disease following autologous bone marrow transplant. Unfortunately, a cure for myeloma remains elusive but the continuing advances in management may significantly prolong survival in affected patients.

An UK myeloma forum phase II study of thalidomide; long term follow-up and recommendations for treatment

Myeloma remains incurable with conventional treatment in the vast majority of patients. The introduction of thalidomide in 1999 for the treatment of relapsed disease offers the opportunity to treat patients who have developed myelotoxicity or who are refractory to conventional chemotherapy. The optimal schedule remains unresolved and only two studies have reported long term follow-up data. We report a phase II low dose escalation study of thalidomide with long term follow-up showing overall survival (OS) of 19 months and progression free survival (PFS) of 14 months. In addition we report on the side effects and toxicity and give recommendations for the use of thalidomide in the relapsed setting based upon these findings.

Therapy-related myelodysplasia and/or acute myeloid leukaemia after autologous haematopoietic progenitor cell transplantation in a prospective single centre cohort of 221 patients

To evaluate the incidence and the predictive signs of therapy-related myelodysplasia and/or acute myeloid leukaemia (tMDS/tAML), we undertook a prospective study over a 4-year period of 221 patients who underwent autologous haematopoietic progenitor cell transplantation. Only seven patients (3.1%) were identified to have tMDS/tAML. Peripheral cytopenia was the first sign; diagnosis could be achieved by cytological analysis of bone marrow smears using World Health Organization criteria. All patients presented with bi- or trilineage dysplasia. Haematopoietic reconstitution was significantly delayed in patients progressing to tMDS/tAML compared with the control group. Typical cytogenetic abnormalities were observed in five of seven patients. The mean time interval between transplantation and cytological diagnosis, or detection of cytogenetic abnormalities, was 20.0 months and 31.2 months respectively. Pantelomeric fluorescence analysis using quantitative fluorescence in situ hybridization enabled us to make two major observations: (i) the fluorescence intensity in metaphases of all autografted patients was weak, and highly variable between tMDS patients; (ii) a drastic reduction of the telomere fluorescence intensity was observed in two patients who rapidly evolved to acute leukaemia. In conclusion, early detection of tMDS/tAML could be achieved by close follow-up of the bone marrow repopulation, and confirmed by cytological bone marrow examination and cytogenetic study. Our results address the implication of several factors, such as the initial telomeric status, and the effect of cytogenetic abnormalities and clonal expansion on bone marrow repopulation.

Hematopoietic stem cell transplantation for hematological malignancies in Europe

Hematopoietic stem cell transplants (HSCTs) are considered the best treatment option for many hematological malignancies, and transplant numbers have increased five-fold during the last decade. Only a few controlled prospective studies are available, and different opinions prevail. Data from 118 167 HSCT (36% allogeneic, 64% autologous) collected within the EBMT activity survey from 1990 to 2001 were used to assess trends over time, transplant rates and coefficient of variation (CV) of transplant rates among European countries for acute myeloid leukemia (AML; 18.5%), acute lymphocytic leukemia (ALL; 12%), chronic myeloid leukemia (CML; 11.5%), myelodysplastic syndromes (MDS; 3%), lymphoproliferative disorders (LPS; 36.3%) and multiple myeloma (MM; 18.7%). Transplant rates increased in all countries and for all indications from 1990 to 2001 from 1.7-fold (CML) to 24.8-fold (MM). Transplant rates have declined for CML since 1999. Autologous HSCT are the preferred choice for LPS and MM, allogeneic HSCT for ALL and myeloid malignancies. CVs of less than 50% suggest consensus for allogeneic HSCT in AML, ALL, CML, MDS and NHL, for autologous HSCT in LPS and MM. These data give an overview of the current status of HSCT for hematological malignancies in Europe and provide objective information for health-care providers and patient counselling.

Oncolytic measles viruses displaying a single-chain antibody against CD38, a myeloma cell marker

Live attenuated measles virus (MV-Edm) has potent oncolytic activity against myeloma xenografts in mice. Therapy of multiple myeloma, a disseminated plasma cell malignancy, would require systemic administration of the virus. Thus, the virus should ideally be targeted to infect only myeloma cells to minimize collateral damage to normal tissues: viral binding to its natural receptors must be ablated and a new specificity domain that targets entry into myeloma cells be added. This study covers 2 critical steps toward generating such a retargeted virus: (1) a new specificity domain against the plasma cell marker CD38 was constructed in the form of a single-chain antibody (scFv) and (2) display of that scFv on the measles viral envelope glycoprotein successfully redirected virus entry through CD38 expressed on target cells devoid of the natural MV receptors. The anti-CD38 scFv was tethered to the C-terminus of the hemagglutinin (H) glycoprotein of MV-Edm through a Factor Xa protease cleavable linker. Immunoblot analysis demonstrated that the scFv was efficiently incorporated into recombinant viral particles. Replication of MV-alpha CD38 was not hindered by the scFv, reaching titers comparable to MV-Edm. Chinese hamster ovary (CHO) cells were resistant to infection by MV-Edm and MV-alpha CD38. In contrast, CHO cells expressing CD38 became susceptible to infection by MV-alpha CD38 but not MV-Edm. Removal of the displayed scFv rendered MV-alpha CD38 noninfectious on CHO-CD38 cells. Tumorigenicity of CHO-CD38 cells in immunocompromised mice was significantly attenuated by MV-alpha CD38, resulting in enhanced survival of these mice compared with the control group.

Adjusted conditioning for allogeneic transplantation in a single center setting: mixed chimerism heralds relapse

The role of mixed chimerism on subsequent relapse was prospectively evaluated in an allotransplant program. Sixty-six patients with median age of 54 and mainly high-risk hematologic disease and/or solid tumors had individually adjusted non-myeloablative conditioning. Thirty-nine donors were siblings and 27 unrelated. Frequent chimerism analyses supported immune manipulation including donor lymphocyte infusions. The need for transfusions, i.v. fluids, and antibiotics, and weight loss was less than in a control cohort. Most patients had immediate full and consistent donor chimerism; one-third required immune manipulation. Eight of ten evaluable CML patients were BCR/ABL-negative at days 14-58 post-transplant. Mixed chimerism frequently preceded relapse, and the relapse rate was 38% in 26 patients with mixed chimerism vs. 11% among 35 with consistent full donor chimerism (p = 0.015). The current transplant- and disease-related mortality were 11 and 9%, respectively, among 35 non-high-risk patients, and 35 and 10% for 29 high-risk patients with hematologic malignancy. With a median follow-up of 15 months the 2-year overall survival is 73% for non-high-risk, and 46% for high-risk patients. Adjusted conditioning reduces early toxicity and resource requirements without impairing tumor control, probably due to a rapid establishment of the graft-versus-cancer effect. Mixed chimerism heralded relapse, and tumor-related mortality is not greater with adjusted than with conventional conditioning.

CD34+-selected versus unmanipulated autologous stem cell transplantation in multiple myeloma: impact on dendritic and immune recovery and on complications due to infection

BACKGROUND

Large-scale CD34+ enrichment has been demonstrated a safe method in autologous transplantation for multiple myeloma. However, the high CD34+ enrichment and the consequent plasma cell purging result in concomitant T-cell and dendritic-cell (DC) depletion, theoretically increasing the risk of life-threatening infections.

PATIENTS AND METHODS

We evaluated immunological and dendritic reconstitution in 72 myeloma patients who had undergone CD34+-selected (n = 45) and unmanipulated (n = 27) stem cell transplant, and its correlation with infections.

RESULTS

Haematological recovery occurred promptly in all patients. Only a slight delay in platelet recovery to >50 x 10(9)/l was observed in patients receiving CD34+-enriched graft. Natural killer (NK) cell count recovered in all patients within 2 months and B-cell count had recovered by 6 months post-transplant in both groups. CD3 cells remained lower than normal in both groups. CD8 cells increased above the normal level, reaching a peak at day 90, and lowered to normal level within 1 year post-transplant. CD4 lymphocytes remained <50% of normal, especially in selected patients. In both groups, both DC1 and DC2 counts were already significantly lower than in normal individuals before conditioning therapy. Pre-conditioning levels of DC1 were reached in unmanipulated patients at day 30 and became normal at 6 months. In selected patients, DC1 pre-transplant level was observed at day 60 and was maintained thereafter. DC2 recovery showed a similar trend. In unselected patients, DC2 count increased to pre-conditioning level at haematological recovery and was normal after 1 year. In selected transplants, DC2 increased more slowly than DC1 in the same patients: pre-transplant level was detected at day 90 but was still significantly lower than normal 1 year after transplant. The incidence of infection was similar in both groups. Sepsis had Gram+ aetiology in the majority of cases. After engraftment only viral infections were recorded, mostly due to herpes reactivation, with no difference between groups.

DISCUSSION

In spite of a delay in immune recovery, CD34 enrichment is not associated with a significant increase of complications due to infection. Relatively fast NK cell recovery to pre-transplant levels and the presence of functionally efficient DCs can justify the low incidence of infections.

Advances in the treatment of multiple myeloma: the role of thalidomide

Multiple myeloma (MM) accounts for 1% of all malignancies and 10% of malignant hematological neoplasms. In spite of high-dose therapy with stem cell rescue, relapse and disease resistance are common events in the course of the disease. Thalidomide (Thal) has been successfully used in such situations and it's use has also been expanded to the up-front therapy and as adjuvant to stem cell transplantation. Here, we review the underlying concepts and current clinical data regarding Thal in the treatment of MM.

Autologous stem cell transplantation in multiple myeloma: improved survival in nonsecretory multiple myeloma but lack of influence of age, status at transplant, previous treatment and conditioning regimen. A single-centre experience in 127 patients

High-dose therapy with autologous stem cell transplantation (ASCT) has become the treatment of choice for symptomatic eligible patients with multiple myeloma (MM). We report our centre experience and analyse retrospectively the prognostic influence of pretransplant characteristics and transplant modalities on response and survival. A total of 127 MM patients (median age: 55.2 years) were transplanted between 1994 and 2001. In all, 69 patients had IgG, 28 IgA, 23 light chain, one IgD and six non secretory MM. At the time of autograft, 6% of patients were in complete remission (CR), 73% in partial remission (PR), 12% showed minor response to previous treatment and 9% had stable or refractory disease. Prior to autograft, 79% of cases had received only one line of chemotherapy and 21% two or more lines. All patients received PBSC support after conditioning with 200 mg/m(2) melphalan alone (100 patients) or melphalan and TBI (27 patients). We evaluated the influence of age (using as cutoff value the ages of 55, 60 and 65 years), type of MM, status pre- and post-ASCT, number of lines of previous regimens, time of ASCT from diagnosis, year of autograft, dose of reinfused CD34+ cells, plasma cell infiltration and beta(2)-microglobulin at diagnosis on overall (OS) and progression-free survivals (PFS) to define patients with better prognosis. Following ASCT, 15% of patients were in CR and 81% in PR, while only two patients progressed. Median OS and PFS from transplantation were 50.4 and 23.5 months, respectively. Median OS from diagnosis was 79.7 months. Transplant-related mortality was 2.3%. Low levels of beta(2)-microglobulin and the achievement of CR post-transplant correlated with longer PFS (P<0.03 and P<0.01, respectively). The median PFS was 36.1, 23.9, 21.1 and 16.4 months for nonsecretory, IgG, IgA and light chain subtypes, respectively. Age was not an important prognostic factor at a cutoff value of 55 or 60 years. We conclude that ASCT is a safe and effective procedure even in resistant cases. The outcome was independent of age, time from diagnosis, previous treatment and conditioning regimen, but there was a tendency for better survival in the nonsecretory patients.

Transplantation as salvage therapy for high-risk patients with myeloma in relapse

Patients with myeloma relapsing after tandem transplant have a poor survival and treatment options are limited. The role of additional salvage transplant procedures for these patients is unknown. To evaluate the benefit and identify prognostic factors, the outcome of 76 consecutive patients with recurrent myeloma after tandem transplant receiving salvage transplants (ST) was analyzed. Prior to ST, 23 patients (30%) had shown chemosensitive response to preceding salvage chemotherapy: two complete remissions (CR); eight near CRs (nCR: only immunofixation positive); 13 partial remissions (PR >or=75% reduction in M protein). Fifty received an autologous transplant, 22 a sibling-matched allogeneic transplant, and four a matched-unrelated allogeneic transplant. Overall response after ST was 59%: eight CRs (11%); 14 nCRs (18%); 23 PRs (30%). Overall survival (OS) at 2 years was 19%; 2 year event-free survival rate (EFS) 7%. On univariate analysis for survival, only pre-transplant chemosensitive relapse (P < 0.05), serum albumin >3 g/dl (P = 0.001), normal LDH (P = 0.04), and long interval between the second transplant and relapse/progression were significant beneficial factors. In a Cox proportional hazard model, chemosensitive relapse, and albumin >3 g/dl were significant for better OS: hazard ratio (HR) 1.4, 1.7, respectively, while normal LDH, and absence of CA13 were significant for better EFS: HR 1.8, 1.7, respectively. Patients with albumin >3 g/dl who had chemosensitive disease before ST (n = 16) had a median survival of 16 months, compared to 7 months (n = 34) and 2 months (n = 26) for patients with only one (n = 34) or no favorable prognostic factors (n = 28), respectively (P < 0.001). Their survival at 2 years post-ST was 43%, 17% and 11%, respectively. Our study suggests further transplantation should only be considered in the setting of a clinical trial in patients with favorable prognostic factors.

Thalidomide in the management of multiple myeloma

The discovery that multiple myeloma is associated with new vessel formation and is correlated with survival and proliferation led initially to the use of thalidomide for patients with relapsed or refractory disease. The outcome with conventional chemotherapy in this setting has historically been very poor. New insights into the biology of the disease suggests that thalidomide may work via a number of other mechanisms and the advent of the thalidomide analogues with their differential effects on survival and proliferation pathways has opened up a new era in the understanding and treatment of the disease. The encouraging results from phase I/II trials of these agents has meant that for the first time in 50 years there is the opportunity to improve outcome. Further work is in progress to define how best to use these drugs and their role in treatment at different stages of the disease.

Non-myeloablative transplantation

The concept of utilizing enhanced immunosuppression rather than myeloablative cytotoxic conditioning has allowed the engraftment of allogeneic stem cells from related and unrelated donors with lower early transplant-related mortality (TRM) and morbidity. This approach shifts tumor eradication to the graft-vs-host immune response directed against minor histocompatibility antigens expressed on tumor cells. This is not without risk, as the long-term effects of graft-versus-host disease (GVHD), it's treatment, or resulting complications and immunodeficiency may be life threatening. However, this approach does allow the application of a potentially curative procedure to elderly or medically infirm patients who would not tolerate high-dose conditioning regimens. Section I, by Dr. Sandmaier, describes the current use of nonmyeloablative regimens and matched related or unrelated donors for the treatment of patients with CLL, CML, acute leukemia, MDS, lymphoma, and myeloma. In Section II, Dr. Maloney discusses the use of cytoreductive autologous followed by planned non-myeloablative allografts as treatment for patients with myeloma or NHL. This tandem transplant approach has a lower TRM than conventional high dose allografting. The nonmyeloablative allograft may allow the graft-versus-tumor (GVT) immune response to eradicate the minimal residual disease that causes nearly all patients with low-grade NHL or myeloma to relapse following autologous transplantation. In Section III, Dr. Mackinnon discusses the risks and benefits of T cell depletion strategies to prevent acute GVHD, while retaining GVT activity by planned donor lymphocyte infusions. Finally, in Section IV, Dr. Shizuru discusses the relationship between GVHD and GVT activity. Future studies, employing a greater understanding of these issues and the separation of GVHD from GVT activity by immunization or T cell cloning, may allow nonmyeloablative allogeneic transplantation to be safer and more effective.