Long-term Outcomes with Nonmyeloablative HLA-Identical Related Hematopoietic Cell Transplantation Using Tacrolimus and Mycophenolate Mofetil for Graft-versus-Host Disease Prophylaxis

Nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) from HLA-identical related donors using cyclosporine (CSP) and mycophenolate mofetil (MMF) for postgrafting immunosuppression is effective therapy for hematologic cancers. However, graft-versus-host-disease (GVHD) remains a major cause of morbidity and mortality. Pilot data suggested lower acute GVHD incidence with tacrolimus/MMF compared to historical experience using CSP/MMF after nonmyeloablative HCT. In a phase II multicenter trial, we evaluated the effect of tacrolimus/MMF for GVHD prophylaxis after HLA-identical related donor peripheral blood HCT in patients with hematologic malignancies (n = 150) using conditioning with 2 Gy total body irradiation (TBI) for patients with a preceding (within 6 months) planned autologous HCT (n = 50) or combined with 90 mg/m² fludarabine for those without recent autologous HCT (n = 100). Oral tacrolimus was given from days -3 to 56 (tapered by day +180 if no GVHD). Oral MMF was given from days 0 to 27. Patient median age was 57 (range, 20 to 74) years. The cumulative incidences (CI) of day 100 grade II to IV and III to IV acute GVHD were 27% and 4%, respectively. With median follow-up of 10.3 (range, 3.1 to 14.5) years, the 5-year CI of chronic extensive GVHD was 48%. One-year and 5-year estimates of nonrelapse mortality, relapse/progression, survival, and progression-free survival were 9% and 13%, 35% and 50%, 73% and 53%, and 56% and 37%, respectively. GVHD prophylaxis with tacrolimus/MMF resulted in a low risk of acute GVHD and compared favorably with results from a concurrent trial using CSP/MMF. A randomized phase III trial to investigate tacrolimus/MMF versus CSP/MMF in nonmyeloablative HCT is warranted.

Autologous transplant for relapsed follicular lymphoma: impact of pre-transplant rituximab sensitivity

Patients with rituximab-refractory follicular lymphoma (FL) have limited options. Before the rituximab era, autologous stem cell transplant (ASCT) was shown to improve outcomes in chemotherapy-sensitive, relapsed FL, but the impact of rituximab-sensitivity on these results is unknown. We analyzed 194 consecutive relapsed patients with FL who underwent ASCT at out center and categorized them as rituximab-sensitive (RS, n = 35), rituximab-refractory (RR, n = 65) or no rituximab (NoR, n = 94) if transplanted before rituximab was used. Progression-free survival at 3 years was 85% in RS and 35% in RR patients (p = 0.0004). Only rituximab-sensitivity was significant on multivariate analysis with improved overall survival (OS) (hazard ratio [HR] 0.24, p = 0.01) and progression-free survival (PFS) (HR 0.35, p = 0.006) in RS patients and increased relapse in RR patients (HR 2.11, p = 0.01). Pre-transplant rituximab-sensitivity is a strong independent predictor of post-transplant outcomes in relapsed FL, although one-third of RR patients achieved a PFS of over 3 years with ASCT.

Allo-SCT for multiple myeloma: a review of outcomes at a single transplant center

Allogeneic stem cell transplant for multiple myeloma (MM) is one treatment associated with long-term disease-free survival. The high incidence of treatment-related mortality and relapses, however, are important reasons for controversy about the role of allografting in the management of MM. We reviewed our results of allografting for MM spanning a period of 34 years in order to better define long-term outcomes and identify areas of progress as well as areas requiring improvement. A total of 278 patients received allogeneic marrow or PBSCs after high-dose myeloablative (N=144) or reduced intensity, non-myeloablative (N=134) regimens. In multivariable analysis, adjusting for differences in patient groups, reduced intensity/non-myeloablative transplants were associated with significantly less acute GVHD, lower transplant mortality, better PFS and overall survival. There were no significant differences in relapse, progression or chronic GVHD, when adjusted. In multivariable analysis of patients receiving only non-myeloablative transplants, decreased overall survival and PFS were associated with relapse after a prior autograft and a β2 microglobulin >4.0. Transplant mortality was reduced and only influenced by a prior tandem autograft.

Cytomegalovirus viral load and virus-specific immune reconstitution after peripheral blood stem cell versus bone marrow transplantation

Peripheral blood stem cell (PBSC) products contain more T cells and monocytes when compared with bone marrow (BM), leading to fewer bacterial and fungal infections. Cytomegelovirus (CMV) viral load and disease as well as CMV-specific immune reconstitution were compared in patients enrolled in a randomized trial comparing PSBC and BM transplantation. There was a higher rate of CMV infection and disease during the first 100 days after transplantation among PBSC recipients (any antigenemia/DNAemia: PBSC, 63% vs BM, 42%, P = .04; CMV disease: PBSC, 17% vs BM, 4%, P = .03). By 2 years, CMV disease rates were similar. The early increase in CMV events correlated temporarily with lower CMV-specific CD4(+) T helper and CD8(+) cytotoxic T lymphocyte function at 30 days after transplantation in PBSC recipients. By 3 months after transplantation and thereafter, CMV-specific immune responses were similar between BM and PBSC recipients. In conclusion, higher CMV infection and disease rates occurred in PBSC transplant recipients early after transplantation. These differences may be because of a transient delay in CMV-specific immune reconstitution following PBSC transplantation.

Non-myeloablative allogeneic haematopoietic cell transplantation for relapsed diffuse large B-cell lymphoma: a multicentre experience

Patients with relapsed diffuse large B-cell lymphoma (DLBCL) who have failed or are ineligible for autologous haematopoietic cell transplantation (HCT) have a poor prognosis. We examined the outcomes of non-myeloablative allogeneic HCT in this setting. Thirty-one patients with DLBCL and one patient with Burkitt lymphoma received allogeneic HCT following 2 Gy total body irradiation with or without fludarabine. Median age was 52 years. Twenty-four patients (75%) had undergone prior autologous HCT. Disease status at HCT was complete response (14/32, 44%), partial response (9/32, 28%), or refractory (9/32, 28%). Cumulative incidences of acute graft-versus-host disease (GVHD) grades II-IV, grades III-IV, and chronic GVHD were 53%, 19%, and 47% respectively. With a median follow-up of 45 months, 3-year estimated overall (OS) and progression-free survival (PFS) was 45% and 35% respectively. Three-year cumulative incidences of relapse and non-relapse mortality were 41% and 25% respectively. In multivariate models, chemosensitive disease and receipt of >or=4 lines of treatment before HCT were associated with better OS. Patients with chemosensitive disease had 3-year OS and PFS of 56% and 43% respectively. Non-myeloablative allogeneic HCT can produce long-term disease-free survival in patients with chemosensitive relapsed DLBCL who have failed or are ineligible for autologous HCT.

Nonmyeloablative Allogeneic Hematopoietic Cell Transplantation in Relapsed, Refractory, and Transformed Indolent Non-Hodgkin's Lymphoma

Purpose

Few effective treatment options exist for chemotherapy-refractory indolent or transformed non-Hodgkin's lymphoma (NHL). We examined the outcome of nonmyeloablative allogeneic hematopoietic cell transplantation (HCT) in this setting.

Patients and Methods

Sixty-two patients with indolent or transformed NHL were treated with allogeneic HCT from related (n = 34) or unrelated (n = 28) donors after conditioning with 2 Gy of total-body irradiation with or without fludarabine. Nine unrelated donors were mismatched for ≥ one HLA antigen. Sixteen patients had histologic transformation before HCT. Twenty patients (32%) had progressive disease after previous high-dose therapy with autologous HCT. Median age was 54 years, and patients had received a median of six lines of treatment before HCT. Median follow-up time after HCT was 36.6 months.

Results

At 3 years, the estimated overall survival (OS) and progression-free survival (PFS) rates were 52% and 43%, respectively, for patients with indolent disease, and 18% and 21%, respectively, for patients with transformed disease. Patients with indolent disease and related donors (n = 26) had 3-year estimated OS and PFS rates of 67% and 54%, respectively. The incidences of grade 2 to 4 acute graft-versus-host disease (GVHD), grade 3 and 4 acute GVHD, and extensive chronic GVHD were 63%, 18%, and 47%, respectively. Among survivors, the median Karnofsky performance status at last follow-up was 85%.

Conclusion

Nonmyeloablative allogeneic HCT can produce durable disease-free survival in patients with relapsed or refractory indolent NHL, even in this relatively elderly and heavily pretreated cohort. Outcomes were particularly good in patients with untransformed disease and related donors, whereas patients with transformed disease did poorly. Long-term survivors reported good overall functional status.

Treatment for acute myelogenous leukemia by low-dose, total-body, irradiation-based conditioning and hematopoietic cell transplantation from related and unrelated donors

PURPOSE

The use of low-dose, irradiation-based preparative regimens have allowed the extension of allografting to older and medically infirm patients. The study reported here assessed outcomes for patients with acute myeloid leukemia (AML) in different stages of their disease, who were not considered candidates for conventional hematopoietic cell transplantation (HCT) because of age and/or other known risk factors and were given minimal conditioning followed by HCT from related or unrelated donors.

PATIENTS AND METHODS

The present study included 122 patients with AML, who were conditioned with 2 Gy total-body irradiation (TBI) on day 0 with or without preceding fludarabine (30 mg/m2/d from days -4 to -2), and given postgrafting cyclosporine at 6.25 mg/kg twice daily from day -3 and mycophenolate mofetil at 15 mg/kg twice daily from day 0.

RESULTS

Durable engraftment was observed in 95% of the patients. Cumulative incidences of acute graft-versus-host disease grades 2 to 4 at 6 months were 35% after related and 42% after unrelated HCT, respectively. With a median follow-up of 44 months (range, 26 to 79 months), 51 patients were alive, of whom 48 were in complete remission (CR). Cumulative nonrelapse mortalities were 10% and 22%, and cumulative mortalities from disease progression were 47% and 33% at 2 years for related and unrelated recipients, respectively. Overall, 2-year survival was 48%, and disease-free survival was 44%. Patients receiving transplantation in CR1 had 2-year overall survivals of 44% after related and 63% after unrelated HCT, respectively.

CONCLUSION

We conclude that HCT from related and unrelated donors after low-dose TBI is a promising treatment for elderly patients with AML.

Randomized trial of allogeneic related bone marrow transplantation versus peripheral blood stem cell transplantation for chronic myeloid leukemia

Seventy-two chronic myeloid leukemia patients were enrolled as part of a larger randomized trial at 3 centers between March 1996 and July 2001 to undergo either HLA-matched related allogeneic bone marrow (BM) or filgrastim (granulocyte colony-stimulating factor)-mobilized peripheral blood stem cell (PBSC) transplantation. Forty patients received BM, and 32 patients received PBSCs. There was no statistically significant difference in the incidence of acute or chronic graft-versus-host disease (GVHD), overall survival, disease-free survival, or non-relapse-related mortality between patients receiving BM or PBSC transplants. The cumulative incidence of grade II to IV acute GVHD was 49% in BM and 55% in PBSC recipients ( P = .48). The cumulative incidence of clinical extensive chronic GVHD was 50% in BM and 59% in PBSC recipients ( P = .46). Among 62 chronic phase chronic myeloid leukemia patients, there was no significant difference in overall survival (87% versus 81%; P = .59), disease-free survival (80% versus 81%; P = .61), or non-relapse-related mortality (13% versus 19%; P = .60) by cell source (BM versus PBSCs). Among chronic phase patients, however, there was a trend toward a higher cumulative incidence of relapse at 3 years in BM recipients (7% versus 0%; P = .10) and a higher cumulative incidence of chronic GVHD in PBSC recipients (59% versus 40%; P = .11). The trend toward a higher relapse incidence in BM recipients persisted with a longer follow-up.

Targeted busulfan and cyclophosphamide as compared to busulfan and TBI as preparative regimens for transplantation in patients with advanced MDS or transformation to AML

Hematopoietic cell transplantation is the only curative therapy for patients with myelodysplasia (MDS). However, treatment-related toxicity and, in patients with advanced MDS (RAEB, RAEB-T) and those who have transformed to AML (tAML), post-transplant relapse continues to be problematic. We reviewed results in 128 patients with advanced MDS and tAML transplanted from HLA-identical related or unrelated donors after preparation with myeloablative conditioning regimens. Seventy-eight patients were conditioned with busulfan (Bu), prescribed dose 16 mg/kg, adjusted to achieve plasma concentrations of 800-900 ng/ml, plus cyclophosphamide (Cy), 2 x 60 mg/kg [tBuCy], and 50 patients were conditioned with Bu 7 mg/kg (without dose adjustment) and total body irradiation (TBI) 6 x 200 cGy given over 3 days [BuTBI]. There was no statistically significant difference in regards to overall survival, relapse-free survival (RFS), or non-relapse mortality (NRM) between the 2 regimens regardless of donor status. However, there was a trend towards higher rates of relapse (HR 1.33, P=0.38) and lower rates of NRM (HR 0.61, P=0.09) in patients conditioned with tBuCy. The increased rate of relapse seen with tBuCy was significant when restricted to only those patients with a diagnosis of RAEB (HR 4.50, P=0.02). Patients given BuTBI had a higher incidence of GvHD; however, the incidence of GvHD regardless of grade did not differ significantly between patients who relapsed and those who did not. Thus, in patients with advanced MDS/tAML, the use of a less toxic conditioning regimen resulted in a non-significant overall gain in RFS largely due to lower rates of NRM. New concepts of conditioning regimens are needed which reduce toxicity without increasing the risk of relapse.

Allogeneic hematopoietic cell transplantation after fludarabine and 2 Gy total body irradiation for relapsed and refractory mantle cell lymphoma

We carried out HLA-matched related (n = 16) and unrelated (n = 17) hematopoietic cell transplantation (HCT) in 33 patients with relapsed and refractory mantle cell lymphoma after nonmyeloablative conditioning with fludarabine and 2 Gy total body irradiation. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. Fourteen patients had failed high-dose autologous HCT. Of the 33 patients studied, 31 had stable engraftment, whereas 2 patients experienced nonfatal graft rejections. The incidences of acute grades II, III, and IV, and chronic graft-versus-host disease (GVHD) were 27%, 17%, 13%, and 64%, respectively. The overall response rate in the 20 patients with measurable disease at the time of HCT was 85% (n = 17; 75% complete remissions [CR] and 10% partial remissions [PR]), whereas 3 patients had progressive disease. Only one of the 17 patients who responded and none of the 13 who received transplants in CR had disease relapse with a median follow-up of 24.6 months. Relapse and nonrelapse mortalities were 9% and 24%, respectively, at 2 years. The Kaplan-Meier probabilities of overall and disease-free survivals at 2 years were 65% and 60%, respectively. Allogeneic HCT after nonmyeloablative conditioning is a promising salvage strategy for patients with relapsed and refractory mantle cell lymphoma. The high response and low relapse rates with this approach suggest that mantle cell lymphoma is susceptible to graft-versus-tumor responses.

Adoptive immunotherapy with donor lymphocyte infusions after allogeneic hematopoietic cell transplantation following nonmyeloablative conditioning

This study retrospectively analyzed data from 446 patients given hematopoietic cell transplants from HLA-matched related or unrelated donors after conditioning with 2 Gy total body irradiation with or without fludarabine and postgrafting immunosuppression with mycophenolate mofetil and cyclosporine following grafting. Fifty-three of 446 patients received donor lymphocyte infusion (DLI) with a median CD3 dose of 1 × 107 cells/kg. Their diagnoses included myelodysplastic syndrome (n = 10), acute leukemia (n = 10), chronic leukemia (n = 11), multiple myeloma (n = 9), lymphoma (n = 9), and solid tumors (n = 4). Patients received DLI for persistent disease (n = 8), disease relapse (n = 17), progressive disease (n = 12), low donor chimerism with disease (n = 11), or low chimerism with disease remission (n = 5). Seventeen of the 53 patients (32%) are alive with a median follow-up of 30 months; 5 are in complete remission (CR), 2 are in partial remission (PR), and 10 have stable or progressive disease. Nine of 53 patients (17%) developed grades II to IV acute graft-versus-host disease. Of 48 patients receiving DLI for treatment of disease, 7 achieved CR and 5 PR, with an overall response rate of 25%. Six of 16 patients who received DLI for chimerism had increases in donor chimerism leading to sustained engraftment, whereas 10 eventually rejected their grafts. In conclusion, DLI is a potential treatment strategy, with acceptable toxicity, for patients with persistent, relapsed, or progressive disease after nonmyeloablative hematopoietic cell transplantation.

Allografting with nonmyeloablative conditioning following cytoreductive autografts for the treatment of patients with multiple myeloma

The full potential of a graft-versus-myeloma effect after allogeneic hematopoietic cell transplantation (HCT) for patients with multiple myeloma (MM) has not been realized because of excessive early transplantation-related mortality (TRM) with conventional HCT. Autologous HCTs have been characterized by almost universal disease recurrences. The current trial combined autologous HCT with subsequent nonmyeloablative allogeneic HCT to maintain the benefits of both approaches with acceptable toxicity. Fifty-four patients, 52 years of age (median; range, 29-71 years), with previously treated stage II or III MM (52% refractory or relapsed disease) were given melphalan 200 mg/m2 and autologous HC transplants. Regimen-related toxicities after autologous HCT were moderate with a median of 6 days of neutropenia, 7 days of hospitalization, and 1 death from infection. Forty to 229 days later (median, 62 days), 52 patients received a single fraction dose of 2 Gy total body irradiation and HC transplants from HLA-identical siblings with postgrafting immunosuppression with mycophenolate mofetil (MMF) and cyclosporine (CSP). Patients experienced medians of 0 days of hospitalization, neutropenia, and thrombocytopenia. Sustained engraftment was uniform. With a median follow-up of 552 days after allografting, overall survival is 78%. One patient (2%) died before day 100 from disease progression. Thirty-eight percent of patients developed acute graft-versus-host disease (GVHD; grade II in all but 4 cases) and 46% chronic GVHD requiring therapy. Tumor responses occurred slowly. Thus far, 57% of patients have achieved complete remissions and 26% have achieved partial remissions for an overall response of 83%. Despite being evaluated in elderly patients with MM, this 2-step approach has reduced the acute toxicities of allogeneic HCT while achieving potent antitumor activities.

HLA-matched unrelated donor hematopoietic cell transplantation after nonmyeloablative conditioning for patients with hematologic malignancies

A hematopoietic cell transplantation (HCT) approach was developed for elderly or ill patients with hematologic malignancies that employed nonmyeloablative conditioning to avoid common regimen-related toxicities and relied on graft-versus-tumor effects for control of malignancy. Eighty-nine patients, median age 53 years, were given fludarabine (90 mg/m2) and 2 Gy total body irradiation. Marrow (n = 18) or granulocyte colony-stimulating factor (G-CSF)-stimulated peripheral blood mononuclear cells (G-PBMCs; n = 71) were transplanted from unrelated donors matched for human leukocyte antigen A (HLA-A), -B, -C antigens and -DRB1 and -DQB1 alleles. Postgrafting immunosuppression included mycophenolate mofetil and cyclosporine. Donor T-cell chimerism was higher for G-PBMCs compared with marrow recipients. Durable engraftment was observed in 85% of G-PBMCs and 56% of marrow recipients. Cumulative probabilities of grade II, III, and IV acute graft-versus-host disease (GVHD) were 42%, 8%, and 2%, respectively. Nonrelapse mortality at day 100 and at 1 year was 11% and 16%, respectively. One-year overall survivals and progression-free survivals were 52% and 38%, respectively. G-PBMC recipients had improved survival (57% vs 33%) and progression-free survival (44% vs 17%) compared with marrow recipients. HLA-matched unrelated donor HCT after nonmyeloablative conditioning is feasible in patients ineligible for conventional HCT. G-PBMCs conferred higher donor T-cell chimerism, greater durable engraftment, and better progression-free and overall survivals compared with marrow.

Autologous stem cell transplantation for Hodgkin's disease: busulfan, melphalan and thiotepa compared to a radiation-based regimen

We evaluated prognostic factors and treatment outcome of patients with relapsed/refractory Hodgkin's disease (HD) receiving autologous stem cell transplantation (ASCT). In total, 92 patients received total body irradiation, cyclophosphamide and etoposide (TBI/CY/E) (n=42) or busulfan, melphalan and thiotepa (Bu/Mel/T) (n=50) supported with ASCT. A total of 33 (66%) patients receiving the Bu/Mel/T regimen had a prior history of dose-limiting irradiation. Mucositis, hepatic and pulmonary toxicities were the main causes of morbidity and mortality, irrespective of the conditioning regimen. The transplant-related mortality was 15%. With a median follow-up of 6 years (range 2.5-11), the cumulative probabilities of survival, event-free survival (EFS) and relapse at 6 years were 55, 51 and 32%. The 6-year Kaplan-Meier (KM) probabilities of EFS for patients with less advanced disease (patients in first chemotherapy-responsive relapse or second remission (n=42)) and more advanced disease (all other patients (n=50)) were 60 and 44%. No differences in toxicities and efficacy between the conditioning regimens were found. ASCT is an effective treatment for patients with refractory/relapsed HD. Female patients and patients with less advanced disease at transplant had a better outcome. Patients with prior irradiation benefited from the Bu/Mel/T regimen.

Infectious complications after autologous CD34-selected peripheral blood stem cell transplantation

CD34 selection of peripheral hematopoietic blood stem cell products has been applied to reduce the risk of relapse after an autologous transplantation. However, CD34 selection is also associated with a significant reduction in T-cells, natural killer cells, and monocytes, and these reductions may influence immune reconstitution and thus increase the risk for infections. An increased incidence of cytomegalovirus (CMV) disease in patients receiving CD34-selected transplants has been reported. In this study, the incidence rate of infections other than CMV is reported in 32 patients who underwent myeloablative therapy followed by the infusion of CD34-selected autologous peripheral blood stem cells (PBSC) and compared to the rate in a contemporaneous group of 273 patients who received unselected autologous PBSC during the same time period. Infection surveillance and prevention strategies were identical between the 2 groups. More non-CMV infections occurred in the recipients of CD34-selected PBSC than in recipients of unselected PBSC (78% versus 30%, P < .0001). The differences in the rates of viral infections were mainly due to dermatomal and disseminated varicella-zoster virus (VZV) (any VZV, 26% versus 4%, P = .002; disseminated VZV, 11% versus 0.3%, P = .03) and parainfluenza 3 virus infections (13% versus 3%, P = .04). Bacterial infections were also more common among CD34-selected PBSC transplant recipients (34% versus 16%, P = .01), whereas fungal infections were not significantly different between the groups. In multivariable logistic regression models, the effect of CD34 selection on infection risk remained significant for viral infections and overall non-CMV infections. Infection-related mortality was not significantly different between the groups. In conclusion, the incidence of viral and bacterial infections appears to be increased in recipients of CD34-selected autologous PBSC transplants. Because the risk for infections approaches that seen in allogeneic transplant recipients, infection surveillance, diagnostic work-up, and prevention strategies similar to those used in allogeneic recipients are warranted.

HLA-matched related hematopoietic cell transplantation for chronic-phase CML using a targeted busulfan and cyclophosphamide preparative regimen

Allogeneic blood or marrow transplantation (BMT) is a curative therapy for chronic myeloid leukemia (CML). We have previously reported that the pharmacologic targeting of busulfan combined with cyclophosphamide (TBU/CY) can minimize regimen-related toxicity while preserving antileukemic effects. We report here on 131 consecutive chronic-phase CML patients treated with allogeneic related BMT using a TBU/CY preparative regimen, where the busulfan dose was targeted to achieve a steady-state plasma concentration of at least 900 ng/mL. The median age of the patients was 43 years (range, 14-66 years). Estimates of the probabilities of nonrelapse mortality, relapse, survival, and disease-free survival 3 years after transplantation were 14%, 8%, 86%, and 78%, respectively. Age had no statistically significant effect on survival. Although approximately 60% of the patients developed clinically extensive chronic graft-versus-host disease, the median Karnofsky score at last contact date among survivors was 95%. Of surviving patients, 11% were molecularly positive for the bcr-abl mRNA at last contact, with a median level of bcr-abl transcripts of 4.6 copies/microg RNA. These data suggest that TBU/CY is a very effective preparative regimen for CML in chronic phase, associated with an expected survival at 3 years of approximately 85%, with most patients being in molecular remission.

Predictive factors for outcome of allogeneic hematopoietic cell transplantation for adult acute lymphoblastic leukemia

Between January 1990 and December 1997, 182 adults with acute lymphoblastic leukemia (ALL) received allogeneic hematopoietic cell transplants according to Fred Hutchinson Cancer Research Center protocols. Patients eligible for transplantation included those in first remission, especially those at high risk of relapse (n = 41), and any patient in second or later remissions (n = 46) or in relapse (n = 95). The median patient age was 29.4 years (range, 18.0-57.6 years), and the median duration of disease was 13.3 months (range, 2.4-221.9 months). Fifty-six patients had Philadelphia chromosome-positive ALL. Most patients (n = 169) received a conditioning regimen of cyclophosphamide 120 mg/kg plus 12.0 to 15.75 Gy of total body irradiation and a combination of cyclosporine and methotrexate as graft-versus-host disease (GVHD) prophylaxis. One hundred twenty-one patients received stem cells from HLA-identical donors (88 related donors and 33 unrelated donors), and 61 received stem cells from HLA-mismatched donors (26 related donors and 35 unrelated donors). Actuarial disease-free survival at 5 years was 21% for all patients, 43% for patients in first remission, 24% for patients in second or later remissions, and 9% for patients in relapse. Univariate and multivariate Cox regression analyses were performed to identify factors associated with survival, relapse, nonrelapse mortality, and disease-free survival. Factors significantly associated (P <.01) with improved survival and disease-free survival included younger age and being in first remission. Lower disease-free survival was associated with receiving cyclosporine alone as GVHD prophylaxis (P <.01). Risk of relapse correlated only with disease status at transplantation: patients who underwent transplantation in relapse had a 9-fold increased risk compared with patients who underwent transplantation in first remission. Acute or chronic GVHD had no significant effect on relapse. Increased nonrelapse mortality was associated with HLA-mismatched donors, a positive cytomegalovirus serology before transplantation, and GVHD prophylaxis with only cyclosporine. Patients with Philadelphia chromosome-positive ALL had survival and relapse rates similar to patients with normal cytogenetics.

Hematopoietic stem cell transplantation for advanced myelodysplastic syndrome after conditioning with busulfan and fractionated total body irradiation is associated with low relapse rate but considerable nonrelapse mortality

The objectives of this study were to develop transplantation regimens for patients with advanced myelodysplastic syndrome (MDS) that would be associated with low transplantation-related mortality and improved relapse-free survival. Sixty patients with advanced MDS or acute myeloid leukemia evolving from MDS (sAML), 12 to 62 years old (median, 40 years), were conditioned with busulfan (7 mg/kg) and TBI (6 x 200 cGy) (BU/TBI) and received transplants from related (n = 20) or unrelated donors (n = 40). By French-American-British (FAB) criteria, 21 patients had refractory anemia with excess blasts (RAEB), 16 had RAEB in transformation (RAEB-T), 15 had sAML, and 8 had chronic myelomonocytic leukemia (CMML). By International Prognostic Scoring System (IPSS) criteria, 1 patient had low, 10 had intermediate-1, 13 had intermediate-2, and 31 had high-risk MDS (5 patients had proliferative CMML). All evaluable patients achieved sustained engraftment. The cumulative incidence (CI) of acute GVHD grades II to IV was 83% with unrelated donors and 85% with related donors. The CI of relapse was 25% at 3 years. The incidence of nonrelapse mortality (NRM) at 100 days was 38%. The Kaplan-Meier estimate of survival was 26% at 3 years. Major causes of death were relapse, organ failure, GVHD, and infection. In multivariate analysis, improved relapse-free survival was associated with good cytogenetic risk (P = .002) and shorter disease duration (P = .004). NRM was increased with longer disease duration (P = .0002), positive cytomegalovirus serology (P = .02), and male sex (P = .02). Relapse was associated with poor cytogenetic risk (P = .0004). Thus, BU/TBI conditioning as used in this trial was associated with relapse rates comparable to those observed with a previously used more intensive regimen combining BU/TBI with cyclophosphamide. However, despite the omission of cyclophosphamide, transplantation-related morbidity and mortality were considerable, particularly with transplants from unrelated donors. Future trials should explore the efficacy and tolerability of reduced-intensity conditioning regimens.

Incidence and outcome of bacterial and fungal infections following nonmyeloablative compared with myeloablative allogeneic hematopoietic stem cell transplantation: a matched control study

Infections contribute significantly to morbidity and mortality after myeloablative allogeneic hematopoietic stem cell transplantation (HSCT). Whether recipients of nonmyeloablative HSCT have different posttransplantation infection risk was unknown. We therefore analyzed the incidence and risk of bacteremia during the first 100 days and of fungal infection during the first 365 days posttransplantation for 56 consecutive patients with hematological malignant disease who received nonmyeloablative HSCT (case patients). We compared the results with those among 112 control patients who received conventional myeloablative HSCT during the same years (January 1997-April 2000). Control patients were matched (2:1) for cytomegalovirus (CMV) risk group, HSC source, donor type, age, and underlying disease. Most donors (93%) were HLA-matched and related. Case patients had shorter periods of neutropenia (absolute neutrophil count, <100/mm3) than did control patients (median, 0 days; range, 0-11 versus 9 days; range, 4-25; P < .0001). This finding was associated with fewer episodes of bacteremia during the first 30 days (9% versus 27%; P = .01) and a trend to fewer episodes of bacteremia during the first 100 days posttransplantation (27% versus 41%, P = .07). Overall survival was significantly improved in case patients compared with control patients (day 100, 93% versus 81%; P = .04). During the first year posttransplantation, invasive aspergillosis occurred at a similar rate (case patients, 15%; control patients, 9%; P value not significant). Multivariate risk factor analyses identified neutropenia and CMV disease as the major factors associated with bacteremia and aspergillosis, respectively. We conclude that shorter periods of severe neutropenia in nonmyeloablative HSCT are associated with decreased risk of early bacteremia, although risk of fungal infection late after HSCT persists. This risk is an important consideration for the future development of preventive strategies.

Low-dose total body irradiation (TBI) and fludarabine followed by hematopoietic cell transplantation (HCT) from HLA-matched or mismatched unrelated donors and postgrafting immunosuppression with cyclosporine and mycophenolate mofetil (MMF) can induce durable complete chimerism and sustained remissions in patients with hematological diseases

Toxicities of high-dose conditioning regimens have limited the use of conventional unrelated donor hematopoietic cell transplantation (HCT) to younger, medically fit patients. Based on preclinical studies, an HCT approach has been developed for elderly or medically infirm patients with HLA-matched or mismatched unrelated donors. In this study, 52 patients with hematological diseases were included. Most (88%) had preceding unsuccessful conventional HCT or refractory/advanced disease. Patients were treated with fludarabine 30 mg/m(2)/d from days -4 to -2, 2 Gy total body irradiation on day 0, cyclosporine at 6.25 mg/kg twice daily from day -3, and mycophenolate mofetil at 15 mg/kg twice daily from day 0. Durable donor chimerism was attained in 88% of the patients. By day 28, a median of 100% of CD56(+) cells were of donor origin. Granulocyte and T-cell donor chimerism increased to medians of 100% on day 56 and day 180 (range, 55%-100%), respectively. Acute GVHD, grade II, was seen in 42% (CI, 29%-56%); grade III in 8% (CI, 0%-15%); and grade IV in 13% (CI, 4%-23%) of patients; it was fatal in 9%. The 100-day transplantation-related mortality was 11%. Complete remissions, including molecular remissions, were seen in 45% of patients with measurable disease before transplantation. Mortality from disease progression was 27% at one year. With a median follow-up of 19 months, 18 of the 52 patients (35%) were alive and 25% were in remission. HCT from HLA-matched or mismatched unrelated donors can be performed with a reduced intensity conditioning regimen in patients ineligible for conventional HCT.

Engraftment of early erythroid progenitors is not delayed after non-myeloablative major ABO-incompatible haematopoietic stem cell transplantation

We hypothesized that patients undergoing major ABO-incompatible non-myeloablative haematopoietic stem cell transplantation (nm-HSCT) might experience prolonged haemolysis after transplant due to the delayed disappearance of host plasma cells producing anti-donor isohaemagglutinins (HAs). To address this question, we analysed data from 107 consecutive patients transplanted with allogeneic peripheral blood stem cells from human leucocyte antigen-matched (related, n = 84; unrelated, n = 23) donors after non-myeloablative conditioning (200 cGy total body irradiation +/- fludarabine). In total, 23 out of the 107 patients received major or major/minor ABO-incompatible transplants. Red blood cell (RBC) transfusion requirements during the first 120 d post transplant were higher in major ABO-mismatched than in ABO-matched recipients (0.12 vs 0.03 median units RBC concentrate/d, P = 0.04). Two patients developed transient pure red cell aplasia, which had resolved spontaneously by 9 months after transplant. Major ABO incompatibility did not influence rates of engraftment. Patients with sustained engraftment experienced gradual declines of anti-donor HAs, and the estimated median time to reaching IgM and IgG titres of < 1:1 was at least 133 d in evaluable patients, approximately twice longer than reported after myeloablative conditioning. There was a strong correlation between degrees of donor chimaerism in erythroid burst-forming units, granulocyte macrophage colony-forming units and granulocytes, indicating that donor erythroid engraftment, defined by early erythroid progenitors, was as prompt as myeloid engraftment. In conclusion, our data suggest that major ABO-incompatibility is not a barrier to successful non-myeloablative HSCT.

Curative therapy of advanced essential thrombocythemia or polycythemia vera by hemopoietic stem cell transplantation

Twenty-five patients with advanced essential thrombocythemia (ET; n = 13) or polycythemia vera (PV; n = 12) received hemopoietic stem cell transplants (HSCT) at the Fred Hutchinson Cancer Research Center. In most cases the indication to perform an HSCT was myelofibrosis with splenomegaly and peripheral blood cytopenias or the development of a myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Patients were 18-60 (median 43) years old with intervals from diagnosis to HSCT of 8-348 (median 168) months. All but five patients had been treated with cytotoxic agents, and nine patients were splenectomized before transplant. Conditioning was performed with chemotherapy only or chemotherapy plus total body irradiation regimens followed by the infusion of either marrow (n = 19) or peripheral blood stem cells (n = 6) from related (n = 16) or unrelated (n = 9) donors. All evaluable patients showed sustained neutrophil engraftment. Nine patients (seven with AML/MDS, two with myelofibrosis) died of transplant-related complications, and 16 are surviving, 14 of them in continuous unmaintained remission. With a median follow-up of 41 (range 5-116) months after transplant, survival at 3 years is 64%. These data provide evidence that HSCT can be a curative treatment for patients with advanced PV and ET.

Allogeneic related donor hematopoietic stem cell transplantation for treatment of chronic lymphocytic leukemia

Between 1980 and 1999, 25 patients with chronic lymphocytic leukemia (CLL) received related donor hematopoietic stem cell transplants. Median patient age was 46.6 years. Preparative regimens included busulfan (BU) plus cyclophosphamide (CY), CY plus TBI, and etoposide, CY plus TBI. Twenty-one donors were HLA-identical siblings, one was a DR mismatched sibling, and three were identical twins. Bone marrow was the source of hematopoietic stem cells in 22 cases and G-CSF stimulated peripheral blood in three cases. Most patients received methotrexate and cyclosporine for GVHD prophylaxis. Fourteen patients developed grades 2-4 acute GVHD and 10 developed clinical extensive chronic GVHD. Late clearance of CLL cells was associated with the development of chronic GVHD in one patient. Two patients had recurrent CLL. Nonrelapse mortality at day 100 was 57% for the seven patients conditioned with BU/CY and 17% for the 18 patients conditioned with TBI-containing regimens. Actuarial survival at 5 years for the 25 patients is 32%. All patients who received BU/CY died within 3 years of transplant. For the 14 patients transplanted since 1992 and who received TBI, actuarial 5-year survival is 56%. The maximum response of CLL to hematopoietic cell transplantation may be delayed, but long-term disease-free survival can be achieved.

Incidence and outcome of cytomegalovirus infections following nonmyeloablative compared with myeloablative allogeneic stem cell transplantation, a matched control study

Nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT) is increasingly being explored as therapy in patients who are not eligible for conventional myeloablative HSCT. Whether these transplants are associated with reduced risk of transplantation-related infections is unknown. We analyzed the incidence of posttransplantation cytomegalovirus (CMV) infections in 56 consecutive mycophenolate mofetil (MMF) patients with hematologic malignancies who underwent nonmyeloablative HSCT (TBI, 2Gy, day 0; MMF/cyclosporine after transplantation). In addition, 18 of 56 patients received 30 mg/m(2)/d fludarabine on days -4 to -2. Most donors were HLA matched and related (93%). Each case patient was matched to 2 controls who were treated by conventional HSCT during the same time period (January 1997 through April 2000). Matching criteria included CMV risk group, HSC source, donor type, age, and underlying diseases. No CMV disease occurred in the low (donor and recipient serologically negative) and intermediate (donor serologically positive and recipient negative) CMV risk groups during the first 100 days. Among cases at high risk for CMV (seropositive recipients), trends to less CMV antigenemia (P =.11), viremia (P =.16), and disease (P =.08) compared with controls were observed; all severe manifestations combined (CMV viremia and disease) were significantly reduced among cases (P =.01). However, by day 365, the overall incidence of CMV disease became similar in both groups. The onset of CMV disease was significantly delayed among case patients compared with controls (median, 130 days versus 52 days; P =.02). It was concluded that CMV disease was significantly delayed in nonmyeloablative cases, but that the overall 1-year incidence was similar to myeloablative HSCT patients. Therefore, nonmyeloablative HSCT patients should receive CMV surveillance beyond day 100 and pre-emptive ganciclovir treatment similar to that of myeloablative HSCT patients.

Nonmyeloablative hematopoietic cell transplantation: status quo and future perspectives

In nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT), high-dose cytotoxic therapy as the conceptual basis for treating hematopoietic malignancies has been replaced by graft-versus-tumor effects. The use of potent pre- and postgrafting immunosuppression derived from preclinical studies has allowed omission of myeloablative cytotoxic therapy without compromising hematopoietic donor cell engraftment. This results in a marked reduction in transplant-related toxicities that makes older or medically infirm patients candidates for this treatment option. This patient group is more representative of the population with cancer and would have been ineligible for conventional HSCT. Initial results in patients with a variety of hematologic malignancies have been encouraging with documented sustained cytogenetic and molecular remissions in a substantial number of sometimes heavily pretreated and previously refractory patients. Even though patients with hematologic malignancies will likely require conversion to full donor hematopoiesis for long-term disease control, a state of mixed hematopoietic chimerism might suffice to "cure" the disease phenotypes in various nonmalignant diseases. Strategies aimed at optimizing peritransplant immunosuppression may eventually eliminate the need for pretransplant total body irradiation, which is relevant for minimizing late toxicities. Enhancing graft-versus-tumor effects by virtue of postgrafting vaccination of recipients against tumor-specific antigens may help to use this transplant approach more effectively in the treatment of solid tumors.

The significance of bcr-abl molecular detection in chronic myeloid leukemia patients "late," 18 months or more after transplantation

The bcr-abl chimeric messenger RNA is frequently detected in chronic myeloid leukemia (CML) patients after bone marrow transplantation. It was previously reported that the relapse risk of bcr-abl detection 6 to 12 months after transplantation was greater than 40%. This risk decreased as the time between transplantation and detection increased. To further define the relapse risk associated with bcr-abl molecular detection in "late" CML survivors, 379 consecutive CML patients alive at 18 months after transplantation or later were studied. Ninety of 379 patients (24%) had at least one positive bcr-abl test 18 months after transplantation or later; 13 of 90 bcr-abl-positive patients (14%) and 3 of 289 bcr-abl-negative patients (1.0%) relapsed. The median time from bcr-abl detection to relapse was 916 days (range, 251-2654 days). The hazard ratio of relapse associated with bcr-abl detection was 19.2 (P <.0001). The stage of disease, chronic graft-versus-host disease, and the donor type did not alter the association between bcr-abl and relapse. Quantification of bcr-abl was performed on 344 samples from 85 bcr-abl-positive patients by means of a real-time quantitative reverse transcriptase-polymerase chain reaction assay. The median bcr-abl change of patients who relapsed was significantly greater than those that remained in remission (P =.002). The median bcr-abl level at relapse was 40 443 bcr-abl copies per microg RNA (range, 960-299 552). Of 73 bcr-abl-positive patients who failed to relapse, 69% had only one positive test at a median of 24 copies bcr-abl per microg RNA. The detection of bcr-abl is common following transplantation. The prognostic significance of a qualitative bcr-abl can be refined by quantitative assays and thus may target patients who would benefit from early intervention.

Nonmyeloablative hematopoietic stem cell transplantation: transplantation for the 21st century

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy to achieve allogeneic engraftment and control of underlying disease. For engraftment purposes, preclinical studies and clinical observations have shown that conditioning regimens can be markedly reduced in intensity, resulting in reduced treatment toxicities. Preclinical canine studies demonstrated that the use of potent pre- and postgrafting immunosuppression allows for reduction in conditioning regimens while facilitating development of stable mixed chimerism. If attenuated conditioning regimens can be successfully translated to human stem cell transplantation, an improved safety profile will allow potentially curative treatment to a more representative patient profile not currently offered such therapy. Mixed chimerism could prove curative of disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. For patients with hematopoietic malignancy, spontaneous conversion to full donor hematopoeisis after stem cell transplant may prove curative by virtue of graft versus host reactions directed against the malignancy, however infusion of additional donor lymphocytes may be needed to treat persistent disease.

Myeloablation and autologous peripheral blood stem cell rescue results in hematologic and clinical responses in patients with myeloid metaplasia with myelofibrosis

Current therapeutic options for myeloid metaplasia with myelofibrosis (MMM) are limited. A pilot study was conducted of autologous peripheral blood stem cell (PBSC) collection in 27, followed by transplantation in 21 patients with MMM. The median age was 59 (range 45-75) years. PBSCs were mobilized at steady state (n = 2), after granulocyte colony-stimulating factor (G-CSF) alone (n = 17), or after anthracycline-cytarabine induction plus G-CSF (n = 8). A median of 11.6 x 10(6) (range 0 to 410 x 10(6)) CD34(+) cells per kilogram were collected. Twenty-one patients then underwent myeloablation with oral busulfan (16 mg/kg) and PBSC transplantation. The median times to neutrophil and platelet recovery after transplantation were 21 (range 10-96) and 21 (range, 13 to > or = 246) days, respectively. Five patients received back-up PBSC infusion because of delayed neutrophil or platelet recovery. The median follow-up is 390 (range 70-1623) days after transplantation, and the 2-year actuarial survival is 61%. After transplantion, 6 patients died: 3 of nonrelapse causes (1 within 100 days of PBSC infusion) and 3 of disease progression. Erythroid response (hemoglobin > or = 100 g/L [10 gm/dL] without transfusion for > or = 8 weeks) occurred in 10 of 17 anemic patients. Four of 8 patients with a platelet count less than 100 x 10(9)/L (100 000/microL) responded with a durable platelet count more than 100 x 10(9)/L (100 000/microL). Symptomatic splenomegaly improved in 7 of 10 patients. It is concluded that (1) PBSC collection was feasible and stable engraftment occurred after transplantation in most patients with MMM, (2) myeloablation with busulfan was associated with acceptable toxicity, (3) a significant proportion of patients derived clinical benefit after treatment, and (4) further investigation of this novel approach is warranted. (Blood. 2001;98:586-593)

Non-myeloablative hematopoietic stem cell transplantation

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy in attempts to eradicate underlying diseases and achieve allogeneic engraftment. Preclinical studies and clinical observations have shown that to achieve engraftment conditioning regimens could be markedly reduced in intensity with reduction in treatment toxicities. The use of potent pre- and postgrafting immunosuppression facilitated stable mixed hematopoietic chimerism in a preclinical canine model. The initial clinical experiences with attenuated conditioning regimens have shown promise as a modality to achieve human stem cell transplantation with an improved safety profile. This may allow offering potentially curative hematopoietic stem cell transplantation (HSCT) to a more representative patient population (older and sicker) who are currently not eligible for such therapy. Obtaining a state of mixed hematopoietic chimerism could prove curative of the disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. On the other hand, patients with hematopoietic malignancy will likely require conversion to full donor hematopoeisis by virtue of graft-versus-host (GVH) reactions directed against both recipient hematopoiesis and underlying malignancy. The infusion of additional donor lymphocytes has been proposed by many groups to augment graft versus tumor responses, but most likely more specific strategies will need to be developed to improve efficacy and avoid nonspecific GVH reactions.

Nonmyeloablative hematopoietic cell transplantation. Replacing high-dose cytotoxic therapy by the graft-versus-tumor effect

Conventional allografting produces considerable regimen-related toxicities that generally limit this treatment to patients younger than 55 years and in otherwise good medical condition. T cell-mediated graft-versus-tumor (GVT) effects are known to play an important role in the elimination of malignant disease after allotransplants. A minimally myelosuppressive regimen that relies on immunosuppression for allogeneic engraftment was developed to reduce toxicities while optimizing GVT effects. Pre-transplant total-body irradiation (200 cGy) followed by post-transplant immunosuppression with cyclosporine (CSP) and mycophenolate mofetil (MMF) permitted human leukocyte antigen (HLA)-matched sibling donor hematopoietic cell engraftment in 82% of patients (n = 55) without prior high-dose therapy. The addition of fludarabine (90 mg/m2) facilitated engraftment in all 28 subsequent patients. Overall, fatal progression of underlying disease occurred in 20% of patients after transplant. Non-relapse mortality occurred in 11% of patients. Toxicities were low. Grade 2-4 acute graft-versus-host disease (GVHD) associated with primary engraftment developed in 47% of patients, and was readily controlled in all but two patients. Donor lymphocyte infusions (DLI) were not very effective at converting a low degree of mixed donor/host chimerism to full donor chimerism; however, the addition of fludarabine reduced the need for DLI. With a median follow-up of 244 days, 68% of patients were alive, with 42% of patients in complete remission, including molecular remissions. Remissions occurred gradually over periods of weeks to a year. If long-term efficacy is demonstrated, such a strategy would expand treatment options for patients who would otherwise be excluded from conventional allografting.

Cyclophosphamide and antithymocyte globulin to condition patients with aplastic anemia for allogeneic marrow transplantations: the experience in four centers

This report summarizes the experience with a conditioning regimen of cyclophosphamide and antithymocyte globulin in patients with severe aplastic anemia given HLA-matched related marrow grafts at 4 transplantation centers. Enrolled were 94 consecutive patients, of whom 87 had received multiple transfusions and 38 had failed immunosuppressive therapy. Their ages ranged from 2 to 59 years. After transplantation, 89 patients received a methotrexate/cyclosporine regimen for graft-versus-host disease (GVHD) prevention. Cyclosporine with or without prednisone was given in 4 patients, and no immunosuppression was given in 1 patient. Ninety-six percent of patients had sustained grafts, whereas 4% rejected grafts between 2 and 7 months after transplantation. Of the 4 rejecting patients, 3 are alive with successful second engraftments. Acute grade II GVHD was seen in 21% of patients, grade III in 7%, and grade IV in 1% of patients. Chronic GVHD was seen in 32% of patients, most of whom responded completely to immunosuppressive therapy. With a median follow-up of 6.0 years (range, 0.5-11.6 years), the survival rate was 88%. No unusual long-term side effects have been seen with the regimen. We conclude that the cyclophosphamide/antithymocyte globulin regimen combined with methotrexate/cyclosporine after transplantation is well tolerated and effective in heavily pretreated patients with aplastic anemia.

Haemopoietic stem cell transplantation for advanced polycythaemia vera or essential thrombocythaemia

Ten patients with polycythaemia vera (PV) and nine with essential thrombocythaemia (ET) received a haemopoietic stem cell transplant (HSCT) at the Fred Hutchinson Cancer Research Center between May 1988 and March 2000. HSCT was performed because of progression to the spent phase of the disease with myelofibrosis and splenomegaly in 10 patients and evolution into a myelodysplastic syndrome (MDS) or acute myelogenous leukaemia (AML) in nine patients. Patients were 18-59 years old (median 43). The interval from diagnosis to HSCT was 77-300 months (median 170). Seven patients were splenectomized before transplantation, and all but five had been treated with cytotoxic agents. Eleven patients received a transplant from a related, and eight from an unrelated, donor following conditioning with chemotherapy only or chemotherapy plus total body irradiation regimens. All evaluable patients achieved sustained engraftment. Twelve patients are surviving 5-116 months (median 41) after transplant, 10 in continued complete remission, one in haematological remission with residual marrow fibrosis and one with mixed haemopoietic chimaerism currently receiving therapy with interferon. Seven patients (six with AML/MDS and one with myelofibrosis) died of transplant-related complications. These data show that HSCT can provide curative therapy for patients with PV and ET with advanced disease.

Second allogeneic transplantation after failure of first autologous transplantation

We evaluated the outcome of second allogeneic bone marrow transplantations (BMTs) in 59 patients aged 1-57 years who relapsed after initial autologous transplantation. Patients received a second transplantation for recurrent acute myeloid leukemia (AML) (n = 24), acute lymphoblastic leukemia (ALL) (n = 13), lymphoma (n = 18), multiple myeloma (n = 3), or chronic myelogenous leukemia (n = 1) from an HLA-matched related (n = 14), mismatched related (n = 25), or matched unrelated (n = 20) donor. The probabilities of nonrelapse mortality, relapse, and disease-free survival (DFS) 2 years after the second BMT were 51%, 26%, and 23%, respectively. The 2-year DFS estimates for AML, ALL, and lymphoma were 46%, 23%, and 0%. Univariate analysis demonstrated that superior DFS was associated with age < or =17 years at the time of the second transplantation, remission before the second transplantation, total-body irradiation-based preparative regimen for the second transplantation, and the diagnosis of AML. These data demonstrate that an allogeneic transplantation after a failed autologous transplantation can result in disease-free survivors, especially in the young. The outcomes after a second transplantation for patients aged >17 years and for those with lymphoma were especially grim. These data suggest that pediatric patients may be appropriate candidates for a second transplantation. In adults, however, the use of an allogeneic transplantation as salvage therapy after failure of the initial autologous transplantation is generally unsuccessful. Alternative experimental strategies, such as low-dose nonmyeloablative allogeneic minitransplantations, should be considered.

High-dose busulfan, melphalan, and thiotepa followed by autologous peripheral blood stem cell transplantation in patients with aggressive lymphoma or relapsed Hodgkin's disease

The purpose of this study was to evaluate the efficacy of high-dose chemotherapy with busulfan (Bu), melphalan (Mel), and thiotepa (TT), and of autologous peripheral blood stem cell (PBSC) infusion in patients with aggressive non-Hodgkin's lymphoma (NHL) or relapsed Hodgkin's disease (HD). Forty patients, 23 with intermediate (n= 18) or high-grade (n=5) NHL and 17 with HD received Bu (12 mg/kg), Mel (100 mg/kg), TT (450-500 mg/m2) [corrected], and autologous PBSC infusion. Of 27 patients with more advanced disease, 16 had primary refractory disease, 8 were in refractory relapse, and 3 were in third remission. Of 13 patients with less advanced disease, 7 were in untreated or responding first relapse and 3 were in second remission, whereas 3 with high-grade NHL were in first remission. Twenty-nine patients (73%) had received prior radiotherapy (RT) prohibiting a total-body irradiation (TBI)-based conditioning regimen. The projected 2-year probabilities of survival, event-free survival, and relapse for all patients were 0.60, 0.46, and 0.31 (0.85, 0.85, and 0.15 for patients with less advanced disease and 0.48, 0.30, and 0.37 for patients with more advanced disease). The probability of nonrelapse mortality in the first 100 days was 0.17. Severe idiopathic pneumonia syndrome was not observed in any patients with less advanced disease and in only one patient with more advanced disease. A regimen of BuMelTT is well tolerated in patients with aggressive NHL or relapsed HD, and results obtained to date are at least equivalent to other published regimens, including TBI-based regimens. This regimen appears to be a particularly attractive alternative for patients who have already received dose-limiting RT and should be evaluated further in prospective, randomized studies.

Methotrexate and cyclosporine for graft-vs.-host disease prevention: what length of therapy with cyclosporine?

One hundred three patients with leukemia, aplastic anemia, or myelodysplastic syndrome were treated by marrow transplantation from genotypically HLA-identical siblings (n = 92) or HLA haploidentical family members differing for one HLA antigen on the nonshared haplotype (n = 11). To prevent graft-vs.-host disease (GVHD), they were administered postgrafting immunosuppression with a short course of intermittent methotrexate with daily cyclosporine for no more than 11 days. Customarily, we have given cyclosporine for 180 days after transplant. In the current study, we asked whether cyclosporine could be stopped earlier without affecting the risk of chronic GVHD. By day 60, patients who never had acute GVHD, or whose acute GVHD had resolved, were randomized to have cyclosporine stopped (n = 52) or continued for the usual 180 days (n = 51). Results were analyzed with a median follow-up of 9.3 years after transplant, and showed that patients in whom cyclosporine was discontinued on day 60 had a significantly more rapid onset (p = 0.001), but not a significantly higher overall incidence of chronic GVHD than those in whom the drug was stopped on day 180 (43 vs. 54%; p = 0.26). Transplant-related mortality was comparable among patients without preceding acute GVHD, regardless of when cyclosporine was discontinued (11% for both study arms). However, transplant-related mortality appeared to increase among patients with preceding acute GVHD in whom cyclosporine was stopped by day 60 (38 vs. 17%). Results suggest that cyclosporine can safely be discontinued early in patients who never had evidence of acute GVHD, while those with preceding acute GVHD would benefit from a longer course of the drug. Because of the relatively small sample sizes, these results would best be treated as promising preliminary findings that should be confirmed in larger randomized studies.

Marrow transplantation for chronic myeloid leukemia: the influence of plasma busulfan levels on the outcome of transplantation

The influence of busulfan (BU) plasma concentration on outcome of transplantation from HLA identical family members for the treatment of chronic myelogenous leukemia (CML) was examined in 45 patients transplanted in chronic phase (CP) (n = 39) or accelerated phase (AP) (n = 6). All patients received the same regimen of BU, 16 mg/kg orally and cyclophosphamide (CY), 120 mg/kg intravenously. Plasma concentrations of BU at steady state (C(SS)BU) during the dosing interval were measured for each patient. The mean C(SS)BU was 917 ng/mL (range, 642 to 1,749; median, 917; standard deviation, 213). Of patients with C(SS)BU below the median, seven (five of 18 in CP and two of four in AP) developed persistent cytogenetic relapse and three of these patients died. There were no relapses in patients with C(SS)BU above the median. The difference in the cumulative incidence of relapse between the two groups was statistically significant (P = .0003). C(SS)BU was the only statistically significant determinant of relapse in univariable or multivariable analysis. The 3-year survival estimates were 0.82 and 0.64 for patients with C(SS)BU above and below the median (P = .33). There was no statistically significant association of C(SS)BU with survival or nonrelapse mortality, although the power to detect a difference in survival between 0.82 and 0.64 was only 0.24, similarly C(SS)BU above the median was not associated with an increased risk of severe regimen-related toxicity. We conclude that low BU plasma levels are associated with an increased risk of relapse.

Interleukin-2 after autologous stem cell transplantation for hematologic malignancy: a phase I/II study

The success of autologous stem cell transplantation (ASCT) for hematologic malignancy is limited largely by a high relapse rate. It is postulated that IL-2 administered after ASCT may eliminate minimal residual disease and thereby reduce relapses. A phase I/II study was performed to identify a regimen of IL-2 (Chiron) that could be given early after ASCT in phase III trials. In the phase I study, beginning a median of 46 days after ASCT for hematologic malignancy, cohorts of three to four patients received escalating doses of 'induction' IL-2 of 9, 10, or 12 x 10(6) IU/m2/day for 4 or 5 days by continuous i.v. infusion (CIV), followed by a 4-day rest period, and then 1.6 x 10(6) IU/m2/day of maintenance IL-2 by CIV for 10 days. The maximum tolerated dose (MTD) of induction IL-2 was 9 x 10(6) IU/m2/day x 4. In the phase II study, 52 patients received the MTD. Eighty percent of patients completed induction IL-2. Most patients exhibited some degree of capillary leak. One patient died of CMV pneumonia and one died of ARDS. Maintenance IL-2 was well tolerated. In the phase I/II study, 16 of 31 patients with non-Hodgkin lymphoma (NHL), 3/8 with Hodgkin disease (HD), 4/17 with AML, and 4/5 with ALL remain in CR. Two of six multiple myeloma (MM) patients remain in PR. Although the regimen of IL-2 identified had significant side-effects in some patients, it was well tolerated in the majority of patients. Phase III prospectively randomized clinical trials are in progress to determine if this IL-2 regimen will decrease the relapse rate after ASCT for AML and NHL.

Allogeneic marrow transplantation for multiple myeloma: an analysis of risk factors on outcome

Between September 1987 and December 1994, 80 patients with multiple myeloma (MM) received high-dose busulfan and cyclophosphamide without (n = 57) or with modified total body irradiation (n = 23) followed by marrow from allogeneic donors. At transplant, 71% of the patients had disease that was refractory to chemotherapy. Thirty-five patients died of transplant-related causes within 100 days and 11 deaths occurred later. The actuarial probabilities of survival and progression-free survival were .24 +/- 0.17 and .20 +/- 0.10 at 4.5 years. Complete remissions were obtained in 36% of patients who had actuarial probabilities of survival and event-free survival of .50 +/- 0.21 and .43 +/- 0.17 at 4.5 years. In a multivariate analysis, adverse risk factors for outcome endpoints included: transplantation greater than 1 year from diagnosis; beta-2 microglobulin > 2.5 at transplant; female patients transplanted from male donors; patients who had received greater than eight cycles of chemotherapy before transplant and Durie stage 3 disease at the time of transplant. These results indicate that allografting for patients with MM can result in long-term disease-free survival for a minority of patients. Efforts to reduce transplant-related mortality should focus on earlier transplantation, less toxic treatment regimens, better supportive care, and improved prevention and treatment of graft-versus-host disease (GVHD).

High-dose fractionated total-body irradiation, etoposide and cyclophosphamide for treatment of malignant lymphoma: comparison of autologous bone marrow and peripheral blood stem cells

Consecutive patients with non-Hodgkin's lymphoma (NHL, n = 133) or Hodgkin's disease (HD, n = 20) were treated with 12.0 Gy of fractionated total body irradiation, etoposide 60 mg/kg, and CY 100 mg/kg followed by infusion of autologous hematopoietic stem cells. Seventy-nine patients received purged (n = 62) or unpurged BM (n = 17), and 74 received unpurged PBSCs alone (n = 56) or with BM (n = 18). The median day for achieving a sustained granulocyte count of 0.5 x 10(9)/I was 14 range (7-66) for BM recipients and 10 (7-30) for PBSC +/- BM recipients (P = 0.03). A platelet count of 20 x 10(9)/I was achieved at a median of day 24 (6-145) in BM recipients and day 11 (range, 7-56) in PBSC +/- BM recipients (P = 0.007). The median number of platelet units transfused was 86 (0-1432) for BM recipients and 30 (6-786) for PBSC +/- BM recipients (P = 0.001). The median number of hospital days was 36 (10-88) for BM recipients and 27 (14-76) for PBSC +/- BM recipients (P = 0.0001). The unadjusted Kaplan-Meier (KM) estimates of survival, event-free survival (EFS) and relapse at 2 years were 0.57, 0.45 and 0.43 for patients receiving BM and 0.55, 0.36 and 0.59 for patients receiving PBSC +/- BM. After adjusting for confounding variables, the estimated relative risk (RR) of death from any cause was 0.92 (P = 0.75), of relapse was 1.25 (P = 0.39), of non-relapse mortality was 0.71 (P = 0.42) and of mortality and/or relapse was 1.17 (P = 0.48) for patients receiving PBSC +/- BM as compared to BM. For 46 patients with NHL receiving unpurged PBSC alone, the unadjusted KM estimate of relapse was 0.61 compared with 0.48 for 52 comparable patients receiving purged BM, while the RR for relapse for patients receiving unpurged PBSCs was 1.37 (P = 0.33) after adjusting for other significant covariates. These data confirm previous observations that patients who receive PBSC +/- BM have faster engraftment, fewer transfusions and shorter hospital stays than patients who receive only BM. There were no statistically significant differences between the two groups in survival, relapse, death from causes other than relapse and event-free survival.

Autologous transplantation with peripheral blood stem cells collected after granulocyte colony-stimulating factor in patients with acute myelogenous leukemia

The use of peripheral blood stem cells (PBSC) with or without bone marrow (BM) in patients with acute myelogenous leukemia (AML) undergoing autologous transplantation in untreated first relapse (Rel1) or in second remission (CR2) was evaluated in a phase II study. Twenty-three patients with AML in untreated Rel1 (n = 8) and CR2 (n = 15) underwent autologous transplant using PBSC with (n = 19) or without (n = 4) BM. Six patients received busulfan (BU) and cyclophosphamide (CY) and 17 received BU, CY and total body irradiation prior to transplant. The median number of CD34+ cells infused was 4.81 x 10(6)/kg (range 0.04-15). Fifteen of 23 patients received post-transplant interleukin-2 (IL-2) at a median of 43 days (range 11-93) in an attempt to decrease relapses. The median day of recovery of granulocytes to 0.5 x 10(9)/I was 12 (range 8-27) and platelets to 20 x 10(9)/I was 15 (range 8-103). Patients received a median of 4 units (range 0-20) of red blood cells and 29 units (range 4-252) of platelets. The probability of 100 day non-relapse mortality was 0.14. The probabilities of survival and relapse at 2 years were 0.24 and 0.65, respectively. The probabilities of relapse in patients receiving (n = 15) and not receiving (n = 8) interleukin-2 (IL-2) were 0.59 and 0.74, respectively (P = 0.1). Overall, seven of 23 (30%) patients are alive and continuously disease-free at a median of 483 days (range 113-835) post-transplant. These data demonstrate that the infusion of PBSC collected after rhG-CSF corrected engraftment problems previously observed with autologous BM transplants in patients with AML but was associated with a high relapse rate.