The role of cytotoxic therapy with hematopoietic stem cell transplantation in the therapy of multiple myeloma: an evidence-based review

The Role of Cytotoxic Therapy with Hematopoietic Stem Cell Transplantation in the Therapy of Acute Lymphoblastic Leukemia in Adults: An Evidence-based Review

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute lymphoblastic leukemia in adults (> or =15 years) is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published medical literature and for grading the quality and strength of the evidence, and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented and were reached unanimously by a panel of acute lymphoblastic leukemia experts. The priority areas of needed future research for adult acute lymphoblastic leukemia are: definition of patients at high risk in first complete remission, beyond Philadelphia chromosome positive; outcomes of SCT in older (>50 years) adults; determination if reduced intensity versus myeloablative conditioning regimens yield an equivalent graft-versus-leukemia effect with reduced toxicity; monitoring of minimal residual disease to achieve disease control before SCT; and the use of cord blood and other alternative sources of stem cells for use in adult SCT recipients.

Results of a phase I/II trial adding carmustine (300 mg/m2) to melphalan (200 mg/m2) in multiple myeloma patients undergoing autologous stem cell transplantation

Autologous stem cell transplantation (SCT) with high-dose melphalan (HDM, 200 mg/m2) is the most effective therapy for multiple myeloma. To determine the feasibility of combining carmustine (300 mg/m2) with HDM, we enrolled 49 patients with previously treated Durie-Salmon stage II/III myeloma (32M/17W, median age 53) on a phase I/II trial involving escalating doses of melphalan (160, 180, 200 mg/m2). The median beta2-microglobulin was 2.5 (0-9.3); marrow karyotypes were normal in 88%. The phase I dose-limiting toxicity was > or =grade 2 pulmonary toxicity 2 months post-SCT. Other endpoints were response rate and progression-free survival (PFS). HDM was safely escalated to 200 mg/m2; treatment-related mortality was 2% and > or =grade 2 pulmonary toxicity 10%. The complete (CR) and near complete (nCR) response rate was 49%. With a median post-SCT follow-up of 2.9 years, the PFS and overall survival (OS) post-SCT were 2.3 and 4.7 years. PFS for those with CR or nCR was 3.1 years while for those with stable disease (SD) it was 1.3 years (P=0.06). We conclude that carmustine can be combined with HDM for myeloma with minimal pulmonary toxicity and a high response rate.

The Role of Cytotoxic Therapy with Hematopoietic Stem Cell Transplantation in the Therapy of Acute Lymphoblastic Leukemia in Children: An Evidence-Based Review

Evidence supporting the role of hematopoietic stem cell transplantation (SCT) in the therapy of acute lymphoblastic leukemia (ALL) in children is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations based on the evidence are presented in a table in this review (Summary of Treatment Recommendations Made by the Expert Panel for Pediatric Acute Lymphoblastic Leukemia) and were reached unanimously by a panel of ALL experts. The priority areas of needed future research in pediatric ALL are unrelated marrow or blood donor versus unrelated cord blood donor allogeneic SCT; alternative, nonfamily allogeneic donor versus autologous SCT; better methods for identifying high-relapse-risk patients; assessments of the effect of current chemotherapy regimens on early relapse; and use of pre-SCT detection of minimal residual disease to predict post-SCT outcomes.

Evolving transplant options for multiple myeloma: autologous and nonmyeloablative allogenic

High-dose chemotherapy supported by a single autologous hemopoietic stem cell transplant is considered by many to be the "standard of care" for suitable newly diagnosed patients with multiple myeloma. The majority of myeloma patients, however, still die from their disease. Approaches to improve response and overall survival rates include tandem autologous transplants, nonmyeloablative allogenic transplants, and posttransplant maintenance and immunotherapy strategies. Support for tandem autologous transplantation comes from single-center studies as well as the recently reported large IMF94 trial that demonstrated a statistically significant increase in both event-free and overall survival for the double transplant arm. A number of subsequent, but as yet less mature, studies have been presented recently. Although there is some support for the conclusions of the IMF94 trial, the exact place of this therapy is yet to be resolved. Reduced intensity allogeneic transplantation has been proposed as an alternative to conventional allogenic transplantation as a means of reducing the high transplant-related morbidity and mortality of the latter procedure while still retaining the advantages of the allogeneic graft. Preliminary reports suggest a reduction of acute transplant-related complications, although graft-versus-host disease remains a significant issue. Finally, a variety of posttransplant strategies and novel therapeutic agents are in active development.

High-dose cyclophosphamide as an effective therapy for a patient with refractory multiple myeloma relapsing after autologous stem cell transplantation

Alkylating agents are often used to treat patients with multiple myeloma (MM). However, it is not common for high-dose cyclophosphamide (CPM) therapy to be used as a treatment for MM. Herein, we report a case of refractory MM associated with hypercalcemia. We decided to give her high-dose CPM. After this treatment, the serum calcium level decreased and the tumor mass in the iliac bone was reduced. This therapy is potentially useful for patients with refractory MM.

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.

The dose of infused lymphocytes in the autograft directly correlates with clinical outcome after autologous peripheral blood hematopoietic stem cell transplantation in multiple myeloma

Absolute lymphocyte count at day 15 (ALC-15) after autologous peripheral blood hematopoietic stem cell transplantation (APHSCT) is an independent prognostic factor for survival in multiple myeloma (MM); however, factors affecting ALC-15 in MM remain unknown. We hypothesized that the dose of infused peripheral blood autograft lymphocytes (autograft absolute lymphocyte count: A-ALC) impacts ALC-15 recovery. Between 1989 and 2001, 267 consecutive MM patients underwent APHSCT. We set out to determine the correlation between A-ALC and ALC-15 and the utility of A-ALC as a marker for ALC-15 recovery. A-ALC was found to be both a strong predictor for area under curve (AUC=0.93; P=0.0001) and strongly correlated with (r(s)=0.83; P=0.0001) ALC-15 recovery. Higher infused A-ALC was significantly correlated with an ALC-15>/=500/microl. In addition, median post-transplant overall survival (OS) and time to progression (TTP) were longer in patients who received an A-ALC>/=0.5 x 10(9) lymphocytes/kg versus A-ALC <0.5 x 10(9) lymphocytes/kg (58 vs 30 months, P=0.00022; 22 vs 15 months, P<0.00012, respectively). Multivariate analysis demonstrated A-ALC as an independent prognostic indicator for OS and TTP. These results indicate that an infused dose of autograft lymphocytes significantly impacts clinical outcome post-APHSCT in MM.

Graft-versus-myeloma effect following antithymocyte globulin-based reduced intensity conditioning allogeneic stem cell transplantation

In all, 41 multiple myeloma (MM) patients received an antithymocyte globulin (ATG), fludarabine, and busulfan-based reduced intensity conditioning (RIC) for allogeneic stem cell transplantation (allo-SCT) from HLA-identical siblings. In total, 29 patients (70%) were in partial remission, one patient in complete remission, and 11 (27%) with progressive disease at the time of allo-SCT. Median time between diagnosis and allo-SCT was 24 months. The cumulative incidences of grade II-IV and grade III-IV acute graft-versus-host disease (GVHD) were 36% (95% CI, 21-51%) and 7% (95% CI, 2-20%), respectively. Overall, 10 patients developed limited chronic GVHD, whereas seven developed an extensive form (cumulative incidence, 41% (95% CI, 26-56%) at 2 years). With a median follow-up of 389 days, the overall cumulative incidence of transplant-related mortality (TRM) was 17% (95% CI, 6-28%). In all, 11 patients (27%) are in continuous complete remission, and the Kaplan-Meier estimates of overall survival (OS) and progression-free survival (PFS) at 2 years were 62% (95% CI, 47-76%) and 41% (95% CI, 23-62%), respectively. PFS and OS were significantly higher in patients with chronic GVHD as compared to patients without chronic GVHD (P=0.006 for PFS and P=0.01 for OS). Collectively, these data demonstrate that RIC allo-SCT can mediate a potentially curative graft-versus-myeloma effect with an acceptable incidence of toxicity and TRM.

Outcomes of autologous stem cell transplantation in patients with multiple myeloma who received dexamethasone-based nonmyelosuppressive induction therapy

High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) improves survival in myeloma (MM). The role of induction therapy on outcomes of ASCT in MM has not been systematically studied. Nonmyelosuppressive (NMS) steroid-based induction can be used in MM, with the potential of reducing neutropenias and other toxic effects prior to ASCT. NMS induction however could be associated with poorer outcomes if disease control or stem cell collection were inadequate. We studied outcomes of 136 MM patients who underwent HDC and ASCT as part of their initial therapy between March 1998 and December 2000. Of these, 46 received HDC and ASCT without any exposure to myelosuppressive agents, 39 received myelosuppressive therapy for disease control and/or stem cell collection, and 51 received alkylating agent-based initial treatment. We compared OS and EFS rates, stem cell collectability, and contamination of the grafts with monoclonal plasma cells. After a median of 33 months, response rates, EFS and OS rates were comparable in the three groups of patients. Adequacy of stem cell collection and plasma cell contamination were similar. Our data support the hypothesis that NMS induction for patients with MM is safe and effective and does not compromise the results of HDC.

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.

Therapy strategies for multiple myeloma: current status

Multiple myeloma (MM) is characterized by infiltration of bone marrow with a clone of neoplastic plasma cells. Impaired hematopoiesis and reduced production of functional immunoglobulins, as well as the induction of pathognomonic osteolytic lesions primarily contribute to the morbidity of patients with MM. Conventional chemotherapy is the treatment of choice for older patients, whereas those under 60 years benefit significantly from high-dose therapy followed by stem-cell rescue. The use of tandem transplantation, developed to further escalate the conditioning dose, has achieved additional improvement in survival. Interferon-alpha and glucocorticoids are effective as maintenance measures in MM but remain controversial because of their associated high costs and considerable toxicity. The resurrection of an old drug, thalidomide, for the therapy of MM and the development of potent immunomodulatory derivatives are highly promising new treatments that target MM cell-host interactions and the bone-marrow microenvironment, as well as the myeloma cell itself. The importance of the use of bisphosphonates for the prevention or amelioration of skeletal complications and hypercalcemia is well established. New generations of bisphosphonates show potent antitumor activity, again emphasising the importance of targeting the microenvironment of the plasma-cell clone.