Long-term follow-up of patients with CLL treated with allogeneic hematopoietic transplantation

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately, the improved prognosis has been accompanied by the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors, the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies, it is important to know the risk of, and associated risk factors for, hepatic late adverse effects. This review is an update of a previously published Cochrane review.

OBJECTIVES

To evaluate all the existing evidence on the association between antineoplastic treatment (that is, chemotherapy, radiotherapy involving the liver, surgery involving the liver and BMT) for childhood cancer and hepatic late adverse effects.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2018, Issue 1), MEDLINE (1966 to January 2018) and Embase (1980 to January 2018). In addition, we searched reference lists of relevant articles and scanned the conference proceedings of the International Society of Paediatric Oncology (SIOP) (from 2005 to 2017) and American Society of Pediatric Hematology/Oncology (ASPHO) (from 2013 to 2018) electronically.

SELECTION CRITERIA

All studies, except case reports, case series, and studies including fewer than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection and 'risk of bias' assessment. The 'risk of bias' assessment was based on earlier checklists for observational studies. For the original version of the review, two review authors independently performed data extraction. For the update of the review, the data extraction was performed by one reviewer and checked by another reviewer.

MAIN RESULTS

Thirteen new studies were identified for the update of this review. In total, we included 33 cohort studies including 7876 participants investigating hepatic late adverse effects after antineoplastic treatment (especially chemotherapy and radiotherapy) for different types of childhood cancer, both haematological and solid malignancies. All studies had methodological limitations. The prevalence of hepatic late adverse effects, all defined in a biochemical way, varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well-defined as alanine aminotransferase (ALT) above the upper limit of normal, indicating cellular liver injury, resulted in eight studies. In this subgroup, the prevalence of hepatic late adverse effects ranged from 5.8% to 52.8%, with median follow-up durations varying from three to 23 years since cancer diagnosis in studies that reported the median follow-up duration. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal, resulted in five studies, with a prevalence ranging from 0.9% to 44.8%. One study investigated biliary tract injury, defined as gamma-glutamyltransferase (γGT) above the upper limit of normal and above twice the upper limit of normal and reported a prevalence of 5.3% and 0.9%, respectively. Three studies investigated disturbance in biliary function, defined as bilirubin above the upper limit of normal and reported prevalences ranging from 0% to 8.7%. Two studies showed that treatment with radiotherapy involving the liver (especially after a high percentage of the liver irradiated), higher BMI, and longer follow-up time or older age at evaluation increased the risk of cellular liver injury in multivariable analyses. In addition, there was some suggestion that busulfan, thioguanine, hepatic surgery, chronic viral hepatitis C, metabolic syndrome, use of statins, non-Hispanic white ethnicity, and higher alcohol intake (> 14 units per week) increase the risk of cellular liver injury in multivariable analyses. Chronic viral hepatitis was shown to increase the risk of cellular liver injury in six univariable analyses as well. Moreover, one study showed that treatment with radiotherapy involving the liver, higher BMI, higher alcohol intake (> 14 units per week), longer follow-up time, and older age at cancer diagnosis increased the risk of biliary tract injury in a multivariable analysis.

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects among studies with an adequate outcome definition varied considerably from 1% to 53%. Evidence suggests that radiotherapy involving the liver, higher BMI, chronic viral hepatitis and longer follow-up time or older age at follow-up increase the risk of hepatic late adverse effects. In addition, there may be a suggestion that busulfan, thioguanine, hepatic surgery, higher alcohol intake (>14 units per week), metabolic syndrome, use of statins, non-Hispanic white ethnicity, and older age at cancer diagnosis increase the risk of hepatic late adverse effects. High-quality studies are needed to evaluate the effects of different therapy doses, time trends, and associated risk factors after antineoplastic treatment for childhood cancer.

Reduced intensity is preferred over myeloablative conditioning allogeneic HCT in chronic lymphocytic leukemia whenever indicated: A systematic review/meta-analysis

Despite availability of new and more effective therapies for chronic lymphocytic leukemia, presently this disease remains incurable unless eligible patients are offered an allogeneic hematopoietic cell transplant. Recent published clinical practice recommendations on behalf of the American Society for Blood and Marrow Transplantation relegated the role of for allogeneic hematopoietic cell transplantation to later stages of the disease. To our knowledge, no randomized controlled trial has been performed to date comparing myeloablative versus reduced intensity conditioning regimens in chronic lymphocytic leukemia patients eligible for the procedure. We performed a systematic review/meta-analysis to assess the efficacy of allogeneic hematopoietic cell transplantation when using myeloablative or reduced intensity conditioning regimens. We report the results in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Based on lower non-relapse mortality and slightly better overall survival rates, reduced intensity conditioning regimens appear to be the most desirable choice whenever the procedure is indicated for this disease. It appears highly unlikely that a RCT will be ever performed comparing reduced intensity vs. myeloablative allogeneic hematopoietic cell transplantation in chronic lymphocytic leukemia. In the absence of such a study, results of this systematic review/meta-analysis represent the best available evidence supporting this recommendation whenever indicated in patients with chronic lymphocytic leukemia.

Management of chronic lymphocytic leukemia

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) is usually diagnosed in asymptomatic patients with early-stage disease. The standard management approach is careful observation, irrespective of risk factors unless patients meet the International Workshop on CLL (IWCLL) criteria for "active disease," which requires treatment. The initial standard therapy for most patients combines an anti-CD20 antibody (such as rituximab, ofatumumab, or obinutuzumab) with chemotherapy (fludarabine/cyclophosphamide [FC], bendamustine, or chlorambucil) depending on multiple factors including the physical fitness of the patient. However, patients with very high-risk CLL because of a 17p13 deletion (17p-) with or without mutation of TP53 (17p-/TP53mut) have poor responses to chemoimmunotherapy and require alternative treatment regimens containing B-cell receptor (BCR) signaling pathway inhibitors. The BCR signaling pathway inhibitors (ibrutinib targeting Bruton's tyrosine kinase [BTK] and idelalisib targeting phosphatidyl-inositol 3-kinase delta [PI3K-delta], respectively) are currently approved for the treatment of relapsed/refractory CLL and all patients with 17p- (ibrutinib), and in combination with rituximab for relapsed/refractory patients (idelalisib). These agents offer great efficacy, even in chemotherapy refractory CLL, with increased tolerability, safety, and survival. Ongoing studies aim to determine the best therapy combinations with the goal of achieving long-term disease control and the possibility of developing a curative regimen for some patients. CLL is associated with a wide range of infectious, autoimmune, and malignant complications. These complications result in considerable morbidity and mortality that can be minimized by early detection and aggressive management. This active monitoring requires ongoing patient education, provider vigilance, and a team approach to patient care.

Outcomes of Patients With Chronic Lymphocytic Leukemia and Richter's Transformation After Transplantation Failure

PURPOSE

Allogeneic stem-cell transplantation (SCT) induces long-term remission in a fraction of patients with high-risk chronic lymphocytic leukemia (CLL) or Richter's transformation (RT). Our purpose was to determine the outcomes of patients whose disease progressed after allogeneic SCT.

PATIENTS AND METHODS

We retrospectively analyzed the outcomes of 72 patients (52 with CLL and 20 with RT) who underwent allogeneic SCT between 1998 and 2011 and had documented progression after transplantation. Twenty-two (31%) never had a response, and 50 (69%) had a response but experienced relapse after a median of 7 months (range, 2 to 85 months). Forty-eight patients who were receiving or were candidates to receive post-SCT cell-based therapies were not included in this analysis.

RESULTS

The median age at time of transplantation was 58 years (range, 30 to 72 years). Sixty-two patients (86%) received more than two treatment regimens and 37 (51%) received more than three treatment regimens before SCT. Sixty-six patients (92%) had active disease at the time of transplantation. The 2- and 5-year survival rates were 67% and 38% (patients with CLL) and 36% and 0% (patients with RT). The patients who developed acute or chronic graft-versus-host disease had a longer overall survival (OS; P = .05). In a multivariable analysis, RT or low hemoglobin at the time of SCT predicted shorter OS. Chronic graft-versus-host disease and an initial response to SCT predicted longer OS.

CONCLUSION

Patients with CLL in whom allogeneic SCT fails may have a response to and benefit from salvage therapies, and their prognosis is relatively good.

Does total body irradiation conditioning improve outcomes of myeloablative human leukocyte antigen-identical sibling transplantations for chronic lymphocytic leukemia?

An allogeneic hematopoietic cell transplantation from an HLA-identical donor after high-dose (myeloablative) pretransplantation conditioning is an effective therapy for some people with chronic lymphocytic leukemia (CLL). Because CLL is a highly radiosensitive cancer, we hypothesized that total body irradiation (TBI) conditioning regimens may be associated with better outcomes than those without TBI. To answer this, we analyzed data from 180 subjects with CLL receiving myeloablative doses of TBI (n = 126) or not (n = 54), who received transplants from an HLA-identical sibling donor between 1995 and 2007 and reported to the Center for International Blood & Marrow Transplant Research. At 5 years, treatment-related mortality was 48% (95% confidence interval [CI], 39% to 57%) versus 50% (95% CI, 36% to 64%); P = NS. Relapse rates were 17% (95% CI, 11% to 25%) versus 22% (95% CI, 11% to 35%); P = NS. Five-year progression-free survival and overall survival were 34% (95% CI, 26% to 43%) versus 28% (95% CI, 15% to 42%); P = NS and 42% (95% CI, 33% to 51%) versus 33% (95% CI, 19% to 48%); P = NS, respectively. The single most common cause of death in both cohorts was recurrent/progressive CLL. No variable tested in the multivariate analysis was found to significantly affect these outcomes, including having failed fludarabine. Within the limitations of this study, we found no difference in HLA-identical sibling transplantation outcomes between myeloablative TBI and chemotherapy pretransplantation conditioning in persons with CLL.

Immunotherapies in CLL

Chronic lymphocytic leukemia (CLL) is the most frequently diagnosed leukemia in the Western world, yet remains essentially incurable. Although initial chemotherapy response rates are high, patients invariably relapse and subsequently develop resistance to chemotherapy. For the moment, allogeneic hematopoietic stem cell transplant (allo-HSCT) remains the only potentially curative treatment for patients with CLL, but it is associated with high rates of treatment-related mortality. Immune-based treatment strategies to augment the cytotoxic potential of T cells offer exciting new treatment options for patients with CLL, and provide a unique and powerful spectrum of tools distinct from traditional chemotherapy. Among the most novel and promising of these approaches are chimeric antigen receptor (CAR)-based cell therapies that combine advances in genetic engineering and adoptive immunotherapy.

Role of 18F-FDG PET-CT for evaluating the response to reduced-intensity conditioning allogeneic transplant in heavily pre-treated patients with chronic lymphocytic leukemia: preliminary results in nine patients

OBJECTIVE

The aim of our preliminary study was to evaluate the potential role of 18F-FDG PET-CT in monitoring response to reduced-intensity conditioning (RIC) transplant in a small series of chronic lymphocytic leukemia (CLL) patients and to compare the results with those obtained by standard criteria.

METHODS

We retrospectively analyzed 9 consecutive refractory/relapsed CLL patients, who underwent RIC transplant from March 2004 until May 2009. PET-CT was planned at 6-8 months after transplant to assess response and at a mean of 6 months during follow-up. The mean long-term follow-up period was 38 months (range 12-74 months, median 29 months).

RESULTS

The first PET-CT showed abnormal 18F-FDG uptake in five patients, while by standard criteria eight patients showed persistent disease. At the end of follow-up (mean 38 months), all four patients with previously negative scan were still PET negative and in complete remission by standard criteria. All five patients with previously positive scan were still PET positive: one patient died for disease progression and four are alive with disease.

CONCLUSIONS

Our preliminary data, although in a small series of CLL patients, suggest that the metabolic findings revealed at first PET-CT after transplant seem to predict the patient outcome and to assess the metabolic disease status earlier than clinical evaluation by standard criteria. PET-CT performed during follow-up may be useful to early detect disease progression.

Phase II prospective study of treosulfan-based reduced-intensity conditioning in allogeneic HSCT for hematological malignancies from 10/10 HLA-identical unrelated donor

Different RIC regimens were evaluated prior to allo-HSCT in different hematological malignancies. We conducted this prospective study in adult patients with various hematological malignancies in order to evaluate the toxicity and efficacy of treosulfan-based conditioning, followed by allo-HSCT from 10/10 HLA-identical unrelated donors. Conditioning included treosulfan 12 g/m(2)/day i.v. (day -6 to day -4), fludarabine 30 mg/m(2)/day i.v. (day -6 to day -2), and ATG 2.5 mg/kg/day (day -2 to day -1). PBSC were used as HSC source. We included 56 patients (29 AML, 9 MM, 8 MDS, 6 CLL, 3 ALL, and 1 CML) with a median age of 57 years (18-65.5). Fifty-four (96%) patients engrafted; the cumulative incidence of aGVHD grade ≥II at 3 months reached 31%. The cumulative incidence of cGVHD at 18 months was 34% limited and 8% extensive. The median overall survival (OS) was not reached with a 3-year probability of 52%. The cumulative incidence of relapse at 3 years was 25%, and the cumulative incidence of transplant-related mortality (TRM) at 12 and 24 months was 20% and 23%, respectively. Treosulfan appears to be a good alternative for conditioning of MUD transplant patients with promising results in terms of OS, relapse, and TRM.

Salvage therapy for relapsed chronic lymphocytic leukemia

Chronic lymphocytic leukemia is a common hematologic malignancy with a highly variable clinical course. While the median age at diagnosis is 72 years of age and fewer than 10% of patients are diagnosed before the age of 60 years, the majority of patients who require therapy will ultimately relapse. Advances in upfront therapy and supportive care have dramatically improved initial responses compared with traditional akylator-based chemotherapy. However, comparable results are not generally observed in the salvage setting. Careful planning that takes into account the duration of the initial response, patient age and/or comorbidities, and cytogenetic and molecular profiles are critical for the successful management of patients with relapsed chronic lymphocytic leukemia.

Hepatic late adverse effects after antineoplastic treatment for childhood cancer

BACKGROUND

Survival rates have greatly improved as a result of more effective treatments for childhood cancer. Unfortunately the improved prognosis has resulted in the occurrence of late, treatment-related complications. Liver complications are common during and soon after treatment for childhood cancer. However, among long-term childhood cancer survivors the risk of hepatic late adverse effects is largely unknown. To make informed decisions about future cancer treatment and follow-up policies it is important to know the risk of, and associated risk factors for, hepatic late adverse effects.

OBJECTIVES

To evaluate the existing evidence on the association between antineoplastic treatment for childhood cancer and hepatic late adverse effects.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 2), MEDLINE (1966 to June 2009) and EMBASE (1980 to June 2009). In addition, we searched reference lists of relevant articles and conference proceedings.

SELECTION CRITERIA

All studies except case reports, case series and studies including less than 10 patients that examined the association between antineoplastic treatment for childhood cancer (aged 18 years or less at diagnosis) and hepatic late adverse effects (one year or more after the end of treatment).

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We identified 20 cohort studies investigating hepatic late adverse effects after antineoplastic treatment for childhood cancer. All studies had methodological limitations. The prevalence of hepatic late adverse effects varied widely, between 0% and 84.2%. Selecting studies where the outcome of hepatic late adverse effects was well defined as alanine aminotransferase (ALT) above the upper limit of normal resulted in five studies. In this subgroup the prevalence of hepatic late adverse effects ranged from 8.0% to 52.8%, with follow-up durations varying from one to 27 years after the end of treatment. A more stringent selection process using the outcome definition of ALT as above twice the upper limit of normal resulted in three studies, with a prevalence ranging from 7.9% to 44.8%. Chronic viral hepatitis was identified as a risk factor for hepatic late adverse effects in univariate analyses. It is unclear which specific antineoplastic treatments increase the risk of hepatic late adverse effects

AUTHORS' CONCLUSIONS

The prevalence of hepatic late adverse effects ranged from 7.9% to 52.8% when selecting studies with an adequate outcome definition. It has not been established which childhood cancer treatments result in hepatic late adverse effects. There is a suggestion that chronic viral hepatitis increases the risk of hepatic late adverse effects. More well-designed studies are needed to reliably evaluate the prevalence of, and risk factors for, hepatic late adverse effects after antineoplastic treatment for childhood cancer.

Allogeneic transplantation for chronic lymphocytic leukemia

Even if Chronic lymphocytic leukemia (CLL) often has an indolent behavior with good responsiveness to cytoreductive treatment, about 20% of the patients, so called “poor-risk” patients, show an aggressive course and die within a few years despite early intensive therapies. Criteria for poor-risk disease according to the European Bone Marrow Transplantation (EBMT) CLL Transplant Consensus are: purine analogue refractoriness, early relapse after purine analogue combination therapy, CLL with p53 lesion requiring treatment.

Allogeneic transplant has potential curative role in CLL, however burden with very high transplant related mortality (TRM) rates of 38–50%. A major advance in reducing the short-term morbidity and mortality of allogeneic stem cell transplantation (SCT) has been the introduction of non-myeloablative or reduced intensity conditioning (RIC) regimens to allow engraftment of allogeneic stem cells. There is no doubt that the crucial therapeutic principle of allo-SCT in CLL is graft versus leukemia (GVL) activity.

The major complications of allogeneic SCT in CLL are: chronic graft-versus-host-disease (GVHD) affecting quality of life, high graft rejection and infection rates correlated with preexisting immunosuppression. Disease relapse remains the major cause of failure after RIC allo-HCT in CLL patients.

Sensitive minimal residual disease (MRD) quantification has strong prognostic impact after transplant.

Treatment of patients with fludarabine-refractory chronic lymphocytic leukemia: need for new treatment options

Fludarabine-refractory chronic lymphocytic leukemia is associated with poor survival rates. Chemoimmunotherapy combinations that include purine analogs, alkylating agents, and monoclonal antibodies have shown the highest response rates to date. Intensive treatment approaches can be associated with poor tolerability that is often characterized by deteriorating immune functions and high infection rates. Treatment with some monoclonal antibodies is often complicated by infusion-related adverse events and increased risk of infections. Several novel agents are currently being investigated for this difficult-to-treat patient population. Ofatumumab is an anti-CD20 monoclonal antibody that targets a different epitope from the one targeted by rituximab and, it has shown promising antileukemia activity. Lenalidomide is an immunomodulatory agent that has shown promising activity in patients with fludarabine-refractory chronic lymphocytic leukemia, many of whom had poor prognostic features and bulky disease. Encouraging results have been observed with each of these agents individually. However, given the diverse mechanisms governing CLL pathogenesis and disease progression, ongoing clinical trials combinations of these agents may improve clinical outcomes for this patient population.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: report from the Committee on the Epidemiology and Natural History of Relapse following Allogeneic Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is increasingly being used for treatment of hematologic malignancies, and the immunologic graft-versus-tumor effect (GVT) provides its therapeutic effectiveness. Disease relapse remains a cause of treatment failure in a significant proportion of patients undergoing alloHSCT without improvements over the last 2-3 decades. We summarize here current data and outline future research regarding the epidemiology, risk factors, and outcomes of relapse after alloHSCT. Although some factors (eg, disease status at alloHSCT or graft-versus-host disease [GVHD] effects) are common, other disease-specific factors may be unique. The impact of reduced-intensity regimens on relapse and survival still need to be assessed using contemporary supportive care and comparable patient populations. The outcome of patients relapsing after an alloHSCT generally remains poor even though interventions including donor leukocyte infusions can benefit some patients. Trials examining targeted therapies along with improved safety of alloHSCT may result in improved outcomes, yet selection bias necessitates prospective assessment to gauge the real contribution of any new therapies. Ongoing chronic GVHD (cGVHD) or other residual post-alloHSCT morbidities may limit the applicability of new therapies. Developing strategies to promptly identify patients as alloHSCT candidates, while malignancy is in a more treatable stage, could decrease relapses rates after alloHSCT. Better understanding and monitoring of minimal residual disease posttransplant could lead to novel preemptive treatments of relapse. Analyses of larger cohorts through multicenter collaborations or registries remain essential to probe questions not amenable to single center or prospective studies. Studies need to provide data with detail on disease status, prior treatments, biologic markers, and posttransplant events. Stringent statistical methods to study relapse remain an important area of research. The opportunities for improvement in prevention and management of post-alloHSCT relapse are apparent, but clinical discipline in their careful study remains important.

Allogeneic hematopoietic cell transplantation for chronic lymphocytic leukemia: ready for prime time?

The development of reduced intensity conditioning regimens has increased the number of patients diagnosed with chronic lymphocytic leukemia that are referred for allogeneic hematopoietic cell transplantation (allo-HCT). However, given the toxicity of allo-HCT, it should only be offered to eligible patients whose life expectancy is significantly reduced by the disease. Accordingly, the European Group of Blood and Marrow Transplantation has recently identified those patients in whom allo-HCT could be a reasonable therapeutic approach. In this review, we have evaluated the outcome of chronic lymphocytic leukemia patients undergoing allo-HCT, either after conventional or reduced intensity conditioning regimens, in the context of current nontransplantation strategies. We have also analyzed the most important predisposing factors that might interfere with the procedure as well as posttransplantation complications that are particularly common in these patients. Finally, we have addressed the most relevant factors when deciding what patients should be considered for allo-HCT and the timing of the procedure.

The role of stem cell transplantation in the management of chronic lymphocytic leukaemia

The majority of patients diagnosed with chronic lymphocytic leukaemia (CLL) will ultimately die of their disease. Stem cell transplantation (SCT) remains the only treatment modality capable of cure, but has traditionally been associated with very high morbidity and mortality. We review the results of myeloablative autologous and allogeneic SCT in CLL, discuss the evolution of the new non-myeloablative approaches, and make recommendations for when SCT should be considered in patients with CLL.

The effect of in vivo T cell depletion with alemtuzumab on reduced-intensity allogeneic hematopoietic cell transplantation for chronic lymphocytic leukemia

Reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation is increasingly considered for patients with chronic lymphocytic leukemia (CLL). To investigate the impact of in vivo T cell depletion with alemtuzumab on the incidence of graft-versus-host disease (GVHD), nonrelapse mortality (NRM), progression-free survival (PFS), and overall survival (OS), we retrospectively analyzed the outcomes of 62 consecutive CLL patients conditioned with fludarabine and melphalan at 4 institutions. For GVHD prophylaxis, 41 patients (cohort 1) received alemtuzumab and cyclosporin; and 21 patients (cohort 2) received cyclosporin plus methotrexate or mycophenolate. Donors were 50 siblings and 12 unrelated volunteers. Twenty-two (36%) patients received donor lymphocyte infusions (DLI), 20 (49%) from cohort 1 and 2 (10%) from cohort 2 (P=.002). Grade III-IV acute GVHD (aGVHD) was observed in 20% and 38% of patients from cohorts 1 and 2, respectively (P=.14). Extensive chronic GVHD (cGVHD) was observed in 10% and 48% of patients from cohorts 1 and 2, respectively (P=.03). There was a trend toward a higher viral infection rate in cohort 1 compared to cohort 2 (68% versus 43%, P=.062), but the incidence of cytomegalovirus (CMV) reactivation was not significantly different. The 3-year OS, PFS, NRM, and relapse rates were 65%, 39%, 28%, and 32%, respectively, for cohort 1; and 57%, 47%, 34%, and 20%, respectively, for cohort 2 (P=.629, P=.361, P=.735, and P=0.112, respectively). In conclusion, both methods of GVHD prophylaxis were equivalent in terms of survival. The administration of alemtuzumab led to reduced cGVHD, possibly improving quality of life.

Long-term outcome of allogeneic stem cell transplantation in chronic lymphocytic leukemia: analysis after a minimum follow-up of 5 years

In order to evaluate the long-term results of allogeneic stem cell transplantation (ASCT) in B-cell chronic lymphocytic leukemia (CLL), we reviewed the outcome of 12 consecutive CLL patients, who underwent ASCT at the Mayo Clinic prior to July, 2004. Median age was 44 years (range 18-55) and median time from diagnosis to transplant 58.5 months. All patients had failed prior fludarabine-based chemotherapy and all but two patients had chemo-resistant refractory disease at time of transplant. A 'myeloablative' conditioning regimen was used in 11 patients and 'reduced intensity' in one. Bone marrow was the source of hematopoietic stem cells in 10 patients and peripheral blood in two. Donors were matched sibling in nine patients, unrelated in two and partial phenotypic match father in one. Grade II-IV acute and chronic graft versus host disease was documented in five and four patients, respectively. To date, six patients (50%) have died including four early deaths from infection. Complete remission (CR) was documented in eight patients (66.7%) post-transplant; six are currently alive whereas one died at 7 months from infection while still in CR and one relapsed 7 months post-transplant and died later. One CR patient relapsed after 4.5 years but was successfully re-transplanted and remains in second CR for 6.5+ years. Another patient recently relapsed after 10.5 years of CR. Duration of ASCT-induced CR in the remaining four patients was 6.5+, 8.5+, 9+ and 10+ years. All surviving patients displayed excellent performance status without ongoing chronic graft versus host disease. We conclude that ASCT is an effective salvage therapy for fludarabine-refractory CLL but late relapses can occur.

Five-year follow-up of patients with advanced chronic lymphocytic leukemia treated with allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning

PURPOSE

We reported encouraging early results of allogeneic hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning in 64 patients who had advanced chronic lymphocytic leukemia (CLL). Here, we have extended the follow-up to a median of 5 years and have included data on an additional 18 patients.

PATIENTS AND METHODS

Eighty-two patients, age 42 to 72 years, who had fludarabine-refractory CLL were conditioned with 2 Gy total-body irradiation alone or combined with fludarabine followed by HCT from related (n = 52) or unrelated (n = 30) donors.

RESULTS

Complete remission (CR) and partial remission were achieved in 55% and 15% of patients, respectively. Higher CR rates were noted after unrelated HCT (67% v 48%). The 5-year incidences of nonrelapse mortality (NRM), progression/relapse, overall survival, and progression-free survival were 23%, 38%, 50%, and 39%, respectively. Among 25 patients initially reported in CR, 8% relapsed and 8% died as a result of NRM, whereas 84% have remained alive and in CR. Among 14 responding patients who were tested and who had molecular eradication of their disease, two died as a result of NRM, two relapsed, and 10 have remained negative. At 5 years, 76% of living patients were entirely well, whereas 24% continued to receive immunosuppression for chronic graft-versus-host disease; the median performance status in each group was 100% and 90%, respectively. Lymphadenopathy > or = 5 cm, but not cytogenetic abnormalities at HCT, predicted relapse. In a risk-stratification model, patients who had lymphadenopathy less than 5 cm and no comorbidities had a 5-year OS of 71%.

CONCLUSION

Nonmyeloablative HCT resulted in a median survival of 5 years for patients who had fludarabine-refractory CLL with sustained remissions and in the continued resolution of chronic graft-versus-host disease in surviving patients.

Outcomes after allogeneic hematopoietic cell transplantation with nonmyeloablative or myeloablative conditioning regimens for treatment of lymphoma and chronic lymphocytic leukemia

Allogeneic conventional hematopoietic cell transplantation (HCT) can be curative treatment for lymphoid malignancies, but it has been characterized by high nonrelapse mortality (NRM). Here, we compared outcomes among patients with lymphoma or chronic lymphocytic leukemia given either nonmyeloablative (n = 152) or myeloablative (n = 68) conditioning. Outcomes were stratified by the HCT-specific comorbidity index. Patients in the nonmyeloablative group were older, had more previous treatment and more comorbidities, more frequently had unrelated donors, and more often had malignancy in remission compared with patients in the myeloablative group. Patients with indolent versus aggressive malignancies were equally distributed among both cohorts. After HCT, patients without comorbidities both in the nonmyeloablative and myeloablative cohorts had comparable NRM (P = .74), overall survival (P = .75), and progression-free survival (P = .40). No significant differences were observed (P = .91, P = .89, and P = .40, respectively) after adjustment for pretransplantation variables. Patients with comorbidities experienced lower NRM (P = .009) and better survival (P = .04) after nonmyeloablative conditioning. These differences became more significant (P < .001 and .007, respectively) after adjustment for other variables. Further, nonmyeloablative patients with comorbidities had favorable adjusted progression-free survival (P = .01). Patients without comorbidities could be enrolled in prospective randomized studies comparing different conditioning intensities. Younger patients with comorbidities might benefit from reduced conditioning intensity.

The role of stem-cell transplantation in chronic lympocytic leukemia risk-adapted therapy

Because of the lack of a curative treatment for chronic lymphocytic leukemia (CLL) and the poor prognosis of patients refractory to the newer and more effective therapies for this disease, stem-cell transplantation (SCT) is being increasingly performed in patients with CLL. The available evidence indicates that autologous SCT may prolong survival in highly selected patients, but does not result in cure. Conversely, allogeneic SCT may cure a proportion of patients, including those who are refractory to purine-analog-based therapy or with other unfavorable risk parameters, but at the cost of high morbidity and mortality. Reduced-intensity conditioning (non-myeloablative) regimens may contribute to reducing toxic deaths while preserving the antileukemic effect of the allograft, and results are encouraging in patients with chemosensitive disease. Ongoing randomized studies will hopefully contribute to clarification of the role of SCT in the management of CLL. Meanwhile, SCT in patients with CLL should be performed only within clinical studies.

Risk assessment in haemotopoietic stem cell transplantation: disease and disease stage

This chapter addresses the impact of the disease and disease status on the outcome of stem-cell transplantation. In consideration of the other topics addressed within this volume we have elected to focus on allogeneic rather than autologous transplantation. Furthermore we have not tried to be comprehensive and discuss the role of disease status in all conditions amenable to allografting, but rather to review the evidence that exists for selected haematological malignancies. Where possible we have made some clear recommendations, but where evidence is less clear we have indicated the ongoing controversies.

Predictors of improved progression-free survival after nonmyeloablative allogeneic stem cell transplantation for advanced chronic lymphocytic leukemia

Although chronic lymphocytic leukemia (CLL) remains an incurable disease with standard chemotherapy, the appropriate role and timing of transplantation are unclear. In this analysis, we report the outcomes of 46 patients with advanced CLL who underwent nonmyeloablative stem cell transplantation (NST) from HLA-matched unrelated (67%) or related (33%) donors. Fludarabine (30 mg/m2 x 4) and low-dose intravenous busulfan (0.8 mg/kg/day x 4) were used for conditioning. The 2-year overall survival (OS) and progression-free survival (PFS) rates in this refractory patient population were 54% and 34%, respectively, with a median follow-up of 20 months. The primary cause of treatment failure was relapse, with a 2-year cumulative incidence of 48%. High hematopoietic donor chimerism > or = 75% at day +30 was a significant predictor of 2-year PFS (47% vs 11%; P = .03). In multivariate analysis, chemotherapy-refractory disease at transplantation was associated with a 3.2-fold risk of progression (P = .01) and a 4.6-fold risk of death (P = .02). Increasing number of previous therapies and increasing bone marrow involvement were also associated with decreased PFS and OS. These results suggest that NST using fludarabine and low-dose intravenous busulfan is a reasonable treatment option for patients with advanced CLL, but that NST earlier in the disease course will likely be needed to achieve long-term disease control in a high proportion of patients.

Graft-versus-leukemia in chronic lymphocytic leukemia

Immune-mediated anti-leukemia effects, often termed graft-versus-leukemia (GvL), operate after bone marrow or blood cell transplants for acute lymphoblastic leukemia, acute myelogenous leukemia and chronic myelogenous leukemia. Sometimes the magnitude of this anti-leukemia effect exceeds that of high-dose anti-leukemia drugs and radiation and can result in leukemia cure. We analyzed leukemia relapse data after transplants for chronic lymphocytic leukemia (CLL) in this context. These data support the notion of a strong GvL effect in CLL. However, as most of these data are from studies of allotransplants, it is uncertain whether GvL operates in settings where the anti-leukemia effector cells and target CLL cells are genetically identical except for leukemia-related mutations. It is also uncertain whether GvL is distinct from GvHD. These potential limitations have important implications on whether immune therapy of CLL will work in non-allotransplant settings.

Indications for allogeneic stem cell transplantation in chronic lymphocytic leukemia: the EBMT transplant consensus

The aim of this project was to identify situations where allogeneic stem cell transplantation (allo-SCT) might be considered as a preferred treatment option for patients with B-cell chronic lymphocytic leukemia (CLL). Based on a MEDLINE search and additional sources, a consented proposal was drafted, refined and approved upon final discussion by an international expert panel. Key elements of the consensus are (1) allo-SCT is a procedure with evidence-based efficacy in poor-risk CLL; (2) although definition of 'poor-risk CLL' requires further investigation, allo-SCT is a reasonable treatment option for younger patients with (i) non-response or early relapse (within 12 months) after purine analogues, (ii) relapse within 24 months after having achieved a response with purine-analogue-based combination therapy or autologous transplantation, and (iii) patients with p53 abnormalities requiring treatment; and (3) optimum transplant strategies may vary according to distinct clinical situations and should be defined in prospective trials. This is the first attempt to define standard indications for allo-SCT in CLL. Nevertheless, whenever possible, allo-SCT should be performed within disease-specific prospective clinical protocols in order to continuously refine transplant indications according to new developments in risk assessment and treatment of CLL.

Role of allogeneic transplantation in low-grade lymphoma and chronic lymphocytic leukemia

PURPOSE OF REVIEW

Indolent lymphoproliferative disorders are incurable with conventional chemotherapy. Exploring the potential of allogeneic transplantation to eradicate disease has therefore been of interest for some time. This review reports on recent developments in this field to evaluate the current status of stem cell transplantation in the management of these conditions.

RECENT FINDINGS

Most recent studies examine the application of reduced intensity regimens in follicular non-Hodgkin's lymphoma and chronic lymphocytic leukemia. Interest is particularly focused on assessing the potency of the allogeneic graft-versus-malignancy effect, whether achieved by T cells infused at the time of transplant, or by the administration of exogenous donor lymphocytes at relapse or progression following transplant. Furthermore, the discovery of molecular/genetic factors that permit identification of patients with poor prognosis chronic lymphocytic leukemia has led to interest in identifying whether the allogeneic effect can overcome the impact of these factors.

SUMMARY

Encouraging evidence is accumulating for the efficacy of reduced intensity transplantation in indolent lymphoproliferative disorders. Allogeneic graft-versus-malignancy effects can be demonstrated and durable responses to donor lymphocytes are being reported. More follow-up is required, however, before the curative potential of allogeneic transplantation can be assessed. The appropriate timing of transplant and the choice of regimen remains unclear.

Recent advances in chronic lymphocytic leukemia

Chronic lymphocytic leukemia is a low-grade B-lineage lymphoid malignancy. Based on recent findings, the disease appears to be more heterogeneous than previously thought. Many cases may require no treatment at all unless patients become symptomatic or develop signs of rapid progression. Even in this setting, treatment is noncurative and is directed at reducing the symptoms. Recently described molecular risk features may help delineate at initial diagnosis which patients will have a more aggressive course. Newer treatment regimens incorporating purine nucleoside analogs and monoclonal antibodies have increased the rate of molecular complete remissions, which may lead to increased survival. Reduced intensity conditioning regimens have made the potentially curative modality of allogeneic transplantation more widely available. All of these recent treatments have significant risks of infectious complications, which must be carefully weighed against the risks posed by the underlying disease, and many low-risk asymptomatic patients do not require any treatment. A proposed risk-based treatment algorithm will be discussed.

Chronic lymphocytic leukemia: diagnosis and treatment

Traditionally, the goal of therapy in chronic lymphocytic leukemia (CLL) has been palliative, with first-line therapy using alkylating agents and/or involved field radiotherapy (depending on the stage of disease and sites of involvement) because of the older age of affected patients and the low rate of complete remissions (CRs) with no improvement in overall survival despite treatment. With increasing knowledge about the biology, molecular genetics, and prognostic factors of the disease, the philosophy of care for patients with CLL has evolved from palliation to aiming for a potential cure, especially in younger patients. Furthermore, multiple treatment options have emerged, including purine analogues, monoclonal antibodies, and potentially stem cell transplantation. These have been associated with higher frequencies of CRs and longer durations of responses compared to conventional chemotherapy. In addition, a subset of patients treated with chemoimmunotherapy can achieve durable CRs and molecular remissions. This may translate into improved disease-free survival and potentially a "cure." Because of the heterogeneous nature of CLL, new prognostic markers are currently being incorporated into clinical trials to determine their role in routine clinical practice. This review summarizes current therapeutic regimens that are being evaluated in patients with CLL and management of disease-related complications.

Clinical significance of minimal residual disease, as assessed by different techniques, after stem cell transplantation for chronic lymphocytic leukemia

We analyzed minimal residual disease (MRD) by consensus polymerase chain reaction (PCR), quantitative PCR (qPCR), and flow cytometry in 40 patients with chronic lymphocytic leukemia (CLL) who underwent stem cell transplantation; 97.4%, 89%, and 100% of the patients could be studied by consensus PCR, qPCR, and flow cytometry, respectively. Overall, 164 of 248 samples were negative for MRD by consensus PCR. Among those, CLL cells were detected by qPCR and by flow cytometry in 77 (47%) and 39 (23%) of the 164 samples, respectively. All 84 samples positive on PCR had detectable CLL cells by qPCR and flow cytometry. A good correlation was seen between MRD levels by flow cytometry and by qPCR (n = 254; r = 0.826; P < .001). Fifteen of 25 patients receiving autografts suffered a relapse, with increasing levels of MRD being observed before relapse in all of them. MRD detection within the first 6 months after autologous transplantation identified patients with a high relapse risk. In contrast, in allografted patients (n = 15) MRD did not correlate with outcome. In conclusion, quantitative methods to assess MRD (flow cytometry and qPCR) are more accurate than consensus PCR to predict clinical evolution. These results might be useful to investigate treatments aimed at preventing relapse in patients with CLL who have received an autograft.

Chronic Lymphocytic Leukemia: Recent Advances in Diagnosis and Treatment

Chronic lymphocytic leukemia (CLL) is a low-grade B-lineage lymphoid malignancy but may have more heterogeneity than previously thought. Many cases require no treatment at all because of an indolent course, while other patients become symptomatic or develop signs of rapid progression. Treatment is usually noncurative and is directed at reducing the symptoms. Some molecular risk features may help delineate, at initial diagnosis, which patients will have a more aggressive course. Newer CLL treatment regimens incorporating purine nucleoside analogues and monoclonal antibodies have increased the rate of molecular complete remissions, which may lead to better survival times. Reduced intensity allogeneic transplant conditioning regimens have made the potentially curative modality more widely available. All these treatments have significant risks for infectious complications, which must be carefully weighed against the risks posed by the underlying disease. A proposed risk-based treatment algorithm is discussed.

Allogeneic Transplant with Reduced Intensity Conditioning Regimens may Overcome the Poor Prognosis of B-Cell Chronic Lymphocytic Leukemia with Unmutated Immunoglobulin Variable Heavy-Chain Gene and Chromosomal Abnormalities (11q− and 17p−)

PURPOSE

To evaluate the efficacy of reduced intensity conditioning (RIC) allogeneic transplant in 30 patients with poor-prognosis chronic lymphocytic leukemia (CLL) and/or high-risk molecular/cytogenetic characteristics.

EXPERIMENTAL DESIGN

Eighty-three percent of patients had active disease at the moment of transplant. That is, 14 of the 23 patients analyzed (60%) had unmutated immunoglobulin variable heavy-chain gene (IgV(H)) status; 8 of 25 patients (32%) had 11q-, with four of them also displaying unmutated IgV(H); and six (24%) had 17p- (five were also unmutated).

RESULTS

After a median follow-up of 47.3 months, all 22 patients alive are disease free; overall survival and event-free survival (EFS) at 6 years were 70% and 72%, respectively. According to molecular/cytogenetic characteristics, overall survival and EFS for unmutated CLL and/or with 11q- aberration (n = 13) were 90% and 92%, respectively, not significantly different to those with normal in situ hybridization, 13q- and +12, or mutated CLL (n = 7). All six patients with 17p deletion were transplanted with active disease, including three with refractory disease; all except one reached complete remission after the transplant and two are alive and disease free. Nonrelapse mortality (NRM) was 20%; more than two lines before transplant is an independent prognostic factor for NRM (P = 0,02), EFS (P = 0.02), and overall survival (P = 0.01). Patients older than 55 years have a higher risk of NRM (hazard ratio, 12.8; 95% confidence interval, 1.5-111). Minimal residual disease was monitored by multiparametric flow cytometry in 21 patients. Clearance of CD79/CD5/CD19/CD23 cells in bone marrow was achieved in 68% and 94% of the patients at days 100 and 360, respectively.

CONCLUSION

According to these results, RIC allogeneic transplant could overcome the adverse prognosis of patients with unmutated CLL as well as those with 11q- or 17p-.

Results of alemtuzumab-based reduced-intensity allogeneic transplantation for chronic lymphocytic leukemia: a British Society of Blood and Marrow Transplantation Study

We report results in 41 consecutive patients with chronic lymphocytic leukemia (CLL) who underwent allogeneic hematopoietic cell transplantation (HCT) after fludarabine, melphalan, and alemtuzumab conditioning. Donors were 24 HLA-matched siblings and 17 unrelated volunteers, 4 of them mismatched with recipients. All but 3 patients had initial hematologic recovery, but 5 more patients had secondary graft failure. Median intervals to neutrophil (greater than 0.5 x 10(9)/L) and platelet (greater than 20 x 10(9)/L) recovery were 14 days (range, 9-30 days) and 11 days (range, 8-45 days), respectively. Eleven (27%) patients had relapses and received escalated donor lymphocyte infusions, but only 3 of them had sustained responses. Acute and chronic graft-versus-host disease (GVHD) was observed in 17 (41%) and 13 (33%) patients, respectively. Seventeen (41%) patients have died, 5 of progressive disease. The 2-year overall survival and transplantation-related mortality (TRM) rates were 51% (95% confidence interval [CI], 33%-69%) and 26% (95% CI, 14%-46%), respectively. The alemtuzumabbased regimen was feasible and effective in patients with CLL with a relatively low rate of GVHD. However, TRM remains relatively high as a result of a variety of viral and fungal infections. Studies are ongoing to address the efficacy of reduced doses of alemtuzumab in this group of immunosuppressed patients.

Revisiting the role of hematopoietic stem cell transplantation in chronic lymphocytic leukemia

Since the advent of hematopoietic stem cell transplantation more than 40 years ago, numerous methods of transplantation have been developed, modified and improved upon. Although hematopoietic stem cell transplantation has been used in a variety of malignant diseases since then, its use in the treatment of chronic lymphocytic leukemia has recently started to gain interest. Patients with chronic lymphocytic leukemia are generally elderly, and because of its relatively benign course, they were not considered suitable candidates for hematopoietic stem cell transplantation. Nonetheless, there have been marked improvements in transplantation techniques, including better conditioning regimens that have decreased treatment-related morbidity and mortality. In this article, the authors review the most recent data on hematopoietic stem cell transplantation in chronic lymphocytic leukemia as well as the change in risk stratification based on newer prognostic factors and its impact on treatment decisions in chronic lymphocytic leukemia.

The graft-versus-lymphoma effect: clinical review and future opportunities

Numerous lines of preclinical and clinical evidence support the existence of a graft-versus-leukemia effect, but less evidence supporting a comparable graft-versus-lymphoma effect exists. We review here current clinical data addressing the graft-versus-lymphoma effect, including comparisons of autologous, syngeneic, and allogeneic transplantation; responses to immunomodulation; and responses to nonmyeloablative stem cell transplantation. Despite several limitations of the data, we believe that there is sufficient evidence suggesting a significant graft-versus-lymphoma effect. In addition, we discuss approaches for clinical management of lymphoma patients, opportunities for mechanistic studies afforded by donor leukocyte infusions and nonmyeloablative transplantation, and suggestions for clinical studies to further define the magnitude and applicability of the graft-versus-lymphoma effect.

How I treat refractory CLL

Therapy for patients with chronic lymphocytic leukemia (CLL) has greatly changed over the past few years. After years of stagnation, with treatment revolving around the use of rather ineffective drugs such as alkylators, many patients are now being treated with more effective agents such as purine analogs either alone or combined with other drugs and/or monoclonal antibodies. Treatment of patients refractory to these treatments is particularly challenging and should be decided only upon a careful evaluation of the disease, patient characteristics, and prognostic factors. Refractory disease should be clearly separated from relapsing disease. The only curative therapy for patients with CLL, including those with refractory disease, is allogeneic stem cell transplantation. However, the use of allogeneic transplantation is limited because of the advanced age of most patients and the high transplant-related mortality (TRM). Transplants with nonmyeloablative regimens may reduce TRM and allow more patients to receive transplants more safely. For patients in whom an allogeneic transplantation is not feasible or in whom it is deemed inappropriate, participation in phase 2 trials should be encouraged. Finally, to investigate mechanisms to overcome resistance to therapy in CLL and to identify patients that might gain benefit from early, intensive therapies (eg, based on biologic markers) constitute a challenge that needs active investigation.

Myeloablative allografting for chronic lymphocytic leukemia: evidence for a potent graft-versus-leukemia effect associated with graft-versus-host disease

In all, 30 patients with CLL proceeded to myeloablative allogeneic BMT using related (n=20, 67%) or unrelated (n=10) donors, at the Princess Margaret Hospital (Toronto) (n=20) or the Leukemia/BMT Program of BC (Vancouver) (n=10), from 1989 to 2001. Median (range) interval from diagnosis to BMT was 4.8 (0.3-13) years, median number of prior therapies was three and median age 48 years. The preparative regimen included total body irradiation in 15 (50%). In all, 14 of 30 patients (47%) are alive, with median (range) follow up of 4.3 (2.4-10.5) years. All are in complete remission, two following therapy for post-BMT progression. Actuarial overall (OS) and event-free survival (EFS) at 5 years is 39% (OS 48% for related donor and 20% for unrelated donor BMT); cumulative incidence of nonrelapse mortality (NRM) and relapse is 47 and 19%, respectively. Both acute (RR=0.008, P=0.01) and chronic (RR=0.006, P=0.02) Graft-versus-host disease (GVHD) were associated with markedly decreased risk of relapse. Patients receiving grafts from unrelated donors had increased NRM (RR=3.6, P=0.02) and decreased OS (RR of death=3.4, P=0.002). Allogeneic BMT has resulted in long-term EFS in approximately 40% of patients with CLL. There is evidence for a strong graft-versus-leukemia effect associated with acute and chronic GVHD, resulting in near complete protection from relapse.

Unrelated Donor Marrow Transplantation for B-Cell Chronic Lymphocytic Leukemia After Using Myeloablative Conditioning: Results From the Center for International Blood and Marrow Transplant Research

Purpose

To determine the role of myeloablative conditioning and unrelated donor (URD) bone marrow transplantation in the treatment of patients with advanced B-cell chronic lymphocytic leukemia (CLL).

Patients and Methods

A total of 38 CLL patients received a matched URD transplant using bone marrow procured by the National Marrow Donor Program. The median age was 45 years (range, 26 to 57 years), the median time from diagnosis was 51 months, and the median number of prior chemotherapy regimens was three. Fifty-five percent of patients were chemotherapy refractory and 89% had received fludarabine. Conditioning included total-body irradiation in 92% of patients. Graft-versus-host disease (GVHD) prophylaxis consisted of methotrexate with cyclosporine or tacrolimus for 82% of patients.

Results

Twenty-one patients (58%) achieved complete response and six (17%) achieved partial response. Incidences of grades 2 to 4 acute GVHD were 45% at 100 days and incidences of chronic GVHD were 85% at 5 years. Eleven patients are alive and disease free at a median of 6 years (range, 3.0 to 9.0 years). Five-year overall survival, failure-free survival, disease progression rates, and treatment-related mortality (TRM) were 33%, 30%, 32%, and 38% respectively.

Conclusion

These data demonstrate that lasting remissions can be achieved after URD transplantation in patients with advanced CLL. High TRM suggest that myeloablative conditioning and HLA-mismatched donors should be avoided in future protocols, and it is mandatory to investigate transplant strategies with a lower morbidity and mortality, including the use of nonmyeloablative regimens.

Hematopoietic cell transplantation after nonmyeloablative conditioning for advanced chronic lymphocytic leukemia

PURPOSE

Patients with chemotherapy-refractory chronic lymphocytic leukemia (CLL) have a short life expectancy. The aim of this study was to analyze the outcome of patients with advanced CLL when treated with nonmyeloablative conditioning and hematopoietic cell transplantation (HCT).

PATIENTS AND METHODS

Sixty-four patients diagnosed with advanced CLL were treated with nonmyeloablative conditioning (2 Gy total-body irradiation with [n = 53] or without [n = 11] fludarabine) and HCT from related (n = 44) or unrelated (n = 20) donors. An adapted form of the Charlson comorbidity index was used to assess pretransplantation comorbidities.

RESULTS

Sixty-one of 64 patients had sustained engraftment, whereas three patients rejected their grafts. The incidences of grades 2, 3, and 4 acute and chronic graft-versus-host disease were 39%, 14%, 2%, and 50%, respectively. Three patients who underwent transplantation in complete remission (CR) remained in CR. The overall response rate among 61 patients with measurable disease was 67% (50% CR), whereas 5% had stable disease. All patients with morphologic CR who were tested by polymerase chain reaction (n = 11) achieved negative molecular results, and one of these patients subsequently experienced disease relapse. The 2-year incidence of relapse/progression was 26%, whereas the 2-year relapse and nonrelapse mortalities were 18% and 22%, respectively. Two-year rates of overall and disease-free survivals were 60% and 52%, respectively. Unrelated HCT resulted in higher CR and lower relapse rates than related HCT, suggesting more effective graft-versus-leukemia activity.

CONCLUSION

CLL is susceptible to graft-versus-leukemia effects, and allogeneic HCT after nonmyeloablative conditioning might prolong median survival for patients with advanced CLL.

Allogeneic stem-cell transplantation may overcome the adverse prognosis of unmutated VH gene in patients with chronic lymphocytic leukemia

PURPOSE

To investigate whether allogeneic stem-cell transplantation (allo-SCT) may overcome the negative impact of unmutated VH genes in the outcome of patients with chronic lymphocytic leukemia (CLL).

PATIENTS AND METHODS

We analyzed the outcome of patients who underwent SCT according to their VH mutational status.

RESULTS

Thirty-four patients (14 allo-SCT and 20 autologous SCT [auto-SCT]) presented unmutated VH genes and 16 patients presented mutated VH genes (nine allo-SCT and seven auto-SCT). Tumoral burden pre-SCT was significantly higher in the allo-SCT patients independent of the VH mutational status. The risk of relapse was significantly higher after auto-SCT (5-year risk, 61%; 95% CI, 44% to 84%) than after allo-SCT (5-year risk 12%, 95% CI, 3% to 44%; P < .05). In the unmutated group, 13 of 20 auto-SCT and two of 14 allo-SCT patients experienced disease progression, with a risk of relapse at 5 years of 66% (95% CI, 48% to 93%) v 17% (95% CI, 5% to 60%), respectively (P = .01).

CONCLUSION

These results show that allo-SCT may overcome the unfavorable effect of unmutated VH genes in patients with CLL.

Allogeneic immune replacement as cancer immunotherapy

The graft-versus-leukaemia (GVL) reaction that occurs after allogeneic haematopoietic cell transplantation (HCT) can cure patients with a variety of haematological malignancies. A heightened appreciation of the GVL effect has resulted in the development of reduced intensity transplant approaches, where antitumour effects occur predominantly as a consequence of the transplanted donor immune system. The recent success of these transplants in patients with acute and chronic leukaemias has led to trials investigating for graft-versus-tumour (GVT) effects in patients with treatment-refractory metastatic solid tumours. This review discusses evidence that immune replacement following allogeneic HCT is a potent form of cancer immunotherapy for patients with haematological and non-haematological malignancies.

The role of allogeneic transplantation in non-Hodgkin's lymphoma

The evolution of combination chemotherapy regimens, combined with improvements in supportive care, has incrementally improved survival outcomes for patients with non-Hodgkin's lymphomas (NHL). Although 40-60% of younger patients with diffuse large cell lymphoma can now expect to be cured, significant numbers will either fail to achieve a remission or relapse after attaining a remission. In addition, certain histological subtypes are associated with particularly poor prognoses with combination chemotherapy alone (e.g. mantle cell lymphoma, B-cell prolymphocytic leukaemia). Relatively few of these patients can achieve long-term responses. Other NHL subtypes, whilst associated with more favourable prognoses in terms of overall survival, are rarely, if ever, cured (e.g. most low grade NHL including follicular lymphoma, chronic lymphocytic leukaemia and small lymphocytic lymphoma). For these reasons dose escalation and allogeneic transplantation have been investigated as potential ways of improving outcome, although this has mainly been in the setting of advanced disease. Any possible benefits have frequently been out-weighed by procedural morbidity and mortality. The parallel development of transplantation approaches that limit procedural toxicity along with advances in supportive care require that the role of allogeneic haematopoietic stem cell transplantation in the management of lymphoma be re-evaluated.

Advances in the diagnosis and treatment of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a low-grade B-lineage lymphoid malignancy, which is often not treated until patients become symptomatic or develop signs of rapid progression. Even in this setting, treatment is non-curative and is directed at reducing the symptoms from an increasing disease burden. Newer treatment regimens incorporating purine nucleoside analogs have increased the rate of successful remission induction in CLL patients. Recent combination chemoimmunotherapy regimens have produced frequent complete molecular remissions, and early evidence suggests this may result in an improved long-term survival. Allogeneic hematopoietic cell transplantation is the only curative therapy for CLL but is infrequently used due to the older age of most patients, although reduced intensity conditioning regimens have reduced the toxicity of allogeneic transplantation. This review will summarize recent advances in the management of CLL, including prognostic factors, combination chemotherapy including nucleoside analogs and monoclonal antibodies, and reduced intensity allogeneic transplant conditioning regimens.