An unusual presentation of a chronic lymphocytic leukemia patient with 17p deletion after reduced-intensity transplantation: Richter syndrome and concomitant graft-versus-host disease--case report

Chronic lymphocytic leukemia (CLL) patients with 17p deletion comprise a challenging subgroup associated with poor overall survival. These patients should be treated with alternative strategies. Reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) can achieve long-term remission in this ultra-high-risk CLL group. Herein, we described a CLL patient with 17p deletion who developed Richter syndrome with extranodal involvement of the liver soon after RIC allo-SCT despite apparent acute graft-versus-host disease. The majority of chronic lymphocytic leukemia (CLL) patients respond well to chemoimmunotherapy. Patients who show ultra-high-risk genetics, such as 17p deletions, comprise a challenging subgroup of patients with poor response to chemoimmunotherapy and median life expectancy <2-3 years at the time of first-line treatment. Current treatment approaches for patients with 17p deletion include agents acting independently from the DNA damage pathway, such as alemtuzumab and high-dose corticosteroids. RIC allo-SCT for consolidation can achieve long-term remission in this ultra-high-risk CLL group.(1,2) Richter syndrome (RS) represents the clinicopathologic transformation of CLL to an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (DLBCL).(3) RS appearing after allo-SCT can be managed by tapering of immunosuppression, followed by dose-escalated donor lymphocyte infusion titrated to the degree of leukemia response and graft-versus-host disease (GVHD) encountered.(4) Herein, we describe a CLL patient with 17p deletion who developed RS with extranodal involvement of the liver soon after RIC allo-SCT despite apparent acute GVHD (aGVHD).

Reduced-intensity conditioning allogeneic stem cell transplantation in malignant lymphoma: current status

Allogeneic stem cell transplantation (allo-SCT) is a potential cure for patients with malignant lymphoma that is based on the graft-versus-lymphoma (GVL) effect. Myeloablative conditioning allo-SCT is associated with high mortality and morbidity, particularly in patients older than 45 years, heavily pretreated patients (prior hematopoietic stem cell transplantation or more than two lines of conventional chemotherapy) or patients affected by other comorbidities. Therefore, conventional allo-SCT is restricted to younger patients (<50 to 55 years) in good physical condition. Over the last decade, allo-SCT with reduced-intensity conditioning (RIC-allo-SCT) has been increasingly used to treat patients with lymphoma. This treatment is associated with lower toxicity and substantial decrease in the incidence of transplant-related mortality, and has the potential to lead to long-term remissions. Therefore, patients who are not suitable to undergo conventional allo-SCT can benefit from the potentially curative GVL effects of allo-SCT. Although RIC-allo-SCT has improved the survival of lymphoma patients, high post-transplant relapse rates or disease progression mainly results in treatment failure. Thus, further improvement is clearly needed. The role and timing of RIC-allo-SCT in the treatment of lymphoma remains unclear. Therefore, more prospective studies should clarify the effectiveness of this method. In this article, we review the recent literature on RIC-allo-SCT as a treatment for major lymphoma subtypes. Areas that require further investigation in the context of clinical trials are also highlighted.

Clinical implications of the molecular genetics of chronic lymphocytic leukemia

Genetics and molecular genetics have contributed to clarify the biological bases of the clinical heterogeneity of chronic lymphocytic leukemia. In recent years, our knowledge of the molecular genetics of chronic lymphocytic leukemia has significantly broadened, offering potential new clinical implications. Mutations of TP53 and ATM add prognostic information independently of fluorescence in situ hybridization cytogenetic stratification. In addition, next generation sequencing technologies have allowed previously unknown genomic alterations in chronic lymphocytic leukemia to be identified. Mutations of NOTCH1, SF3B1 and BIRC3 have been associated with short time to progression and survival. Each of these lesions recognizes a different distribution across different clinical phases and biological subgroups of the disease. The clinical implications of these molecular lesions are in some instances well established, such as in the case of patients with TP53 disruption, who should be considered for alternative therapies/allogeneic stem cell transplant upfront, or in patients with ATM disruption, who are candidates to rituximab-based immunochemotherapy. On the contrary, NOTCH1, SF3B1 and BIRC3 mutations appear to have a specific significance, the clinical value of which is currently being validated, i.e. association to Richter syndrome transformation for NOTCH1 mutations, and short progression-free survival after treatment for SF3B1 mutations. Certainly, these new lesions have helped clarify the molecular bases of chronic lymphocytic leukemia aggressiveness beside TP53 disruption. This review covers the recent advancements in our understanding of the molecular genetics of chronic lymphocytic leukemia and discusses how they are going to translate into clinical implications for patient management.

TP53, SF3B1, and NOTCH1 mutations and outcome of allotransplantation for chronic lymphocytic leukemia: six-year follow-up of the GCLLSG CLL3X trial

This trial update shows that allotransplantation can provide long-term minimal residual disease–negative disease control in poor-risk chronic lymphocytic leukemia. Six-year survival is close to 60% and is independent of the presence of TP53, SF3B1, and NOTCH1 mutations in the tumor clone.

The combination of rituximab, bendamustine, and cytarabine for heavily pretreated relapsed/refractory cytogenetically high-risk patients with chronic lymphocytic leukemia

Treatment of patients with B-cell chronic lymphocytic leukemia (CLL) relapsed/refractory (R/R) to conventional treatments is particularly challenging. The combination of bendamustine and cytarabine has demonstrated distinct and synergistic mechanisms of action in preclinical studies on cell lines and primary tumor cells of several B-cell lymphomas, including 17p deleted or TP53 mutated CLL. The efficacy of rituximab (375 mg/m(2) , Day 1), plus bendamustine (70 mg/m(2) , days 1-2), and cytarabine (800 mg/m(2) , Day 1-3; R-BAC), every 28 days for up to four courses, was evaluated in a pilot trial enrolling 13 patients with very selected high-risk R/R CLL. All patients (median age 60 years, range 53-74) had symptomatic Binet stage B or C active disease requiring treatment, were characterized by adverse cytogenetics (17p deletion, 11q deletion, or both), unmutated immunoglobulin heavy-chain variable region, and were heavily pretreated (1-5, median three previous lines). Overall, R-BAC was well tolerated with limited non-hematological toxicity. Major toxicities were transient Grade 3/4 neutropenia and thrombocytopenia in 84% and 85% of patients, respectively. Overall response rate (OR) was 84%, including complete and partial response in 38% and 46% of patients, respectively. Patients with 17p deletion had an OR of 78%. After a median follow-up of 17 months, median progression-free survival was 16 months while median overall survival (OS) was not reached (1-year OS: 75 ± 13%). R-BAC is an active regimen in R/R heavily pretreated high-risk patients with CLL, representing an option for the treatment of patients that are usually refractory to standard therapy.

Risk-stratified adoptive cellular therapy following allogeneic hematopoietic stem cell transplantation for advanced chronic lymphocytic leukaemia

Following reduced intensity-conditioned allogeneic stem cell transplantation (RIC allo-SCT) for chronic lymphocytic leukaemia (CLL), there is an inverse relationship between relapse and extensive chronic graft-versus-host disease (GVHD). We evaluated outcomes in 50 consecutive patients with CLL using the approach of alemtuzumab-based RIC allo-SCT and pre-emptive donor lymphocyte infusions (DLI) for mixed chimerism or minimal residual disease (MRD), with the intention of reducing the risk of GVHD. Forty two patients had high-risk disease, including 30% with 17p deletion (17p-). Of patients who were not in complete remission (CR) entering transplant, 83% subsequently achieved MRD-negative CR. Both MRD detection and uncorrected mixed chimerism were associated with greater risks of treatment failure. Nine of sixteen patients receiving DLI for persistent or relapsed disease subsequently attained MRD-negative CR. With a median follow-up of 4.3 years, 4-year current progression-free survival was 65% and overall survival was 75% (60% and 61% in respectively, patients with 17p-). DLI was associated with a 29% cumulative incidence of severe GVHD and mortality of 6.4%. At last follow-up, 83% of patients in CR were off all immunosuppressive treatment. In conclusion, the directed delivery of allogeneic cellular therapy has the potential to induce durable remissions in high-risk CLL without incurring excessive GVHD.

Immunotherapeutic strategies including transplantation: eradication of disease

Although there have been recent advances with targeted therapies in chronic lymphocytic leukemia (CLL), chemoimmunotherapy remains the treatment of choice; however, this approach is not curative. A key feature of CLL is that it induces a state of immunosuppression, causing increased susceptibility to infections and failure of an antitumor immune response, often worsened by the immunosuppressive effect of treatment. Because of its improved specificity, immunotherapy potentially offers a way out of this dilemma. Allogeneic stem cell transplantation remains the only curative option, but is hampered by the toxicity of GVHD. After many years of promise but little reward, many other immunotherapeutic approaches are now in transition to the clinical setting. Clinical trials including CLL vaccines, CXCR4 antagonists, and adoptive cellular immunotherapies such as chimeric antigen receptor-modified T cells, CD40 ligand gene therapy, and the immunomodulatory drug lenalidomide are ongoing. Results to date suggest that immunotherapeutic approaches for the treatment of CLL might finally be fulfilling their promise.

TP53 aberrations in chronic lymphocytic leukemia

CLL patients harboring TP53 defects remain the most challenging group in terms of designing rational and effective therapy. Irrespective of the treatment employed-chemotherapy, chemoimmunotherapy, or pure biological drugs-median survival of these patients does not exceed 3-4 years. This adverse outcome is caused by a less effective response to therapeutics acting through DNA damage induction and relying on the subsequent initiation of apoptosis as well as by virtually inevitable aggressive relapse. Patient proportions with TP53 defects at diagnosis or before first therapy were reported within the range 5-15 %, but they increase dramatically in pretreated cohorts (reported up to 44 %), and also in patients with Richter transformation (50 % harbor TP53 defects). Currently, most laboratories monitor TP53 defect as presence of 17p deletion using I-FISH, but 23-45 % of TP53-affected patients were shown to harbor only mutation(s). In other patients with intact TP53, the p53 pathway may be impaired by mutations in ATM gene coding for the p53-regulatory kinase; however, prognosis of ATM-defective patients is not as poor as those with TP53 abnormalities. Though many novel agents are under development, the monoclonal antibody alemtuzumab and allogeneic stem cell transplantation remain the basic treatment options for TP53-affected CLL patients.

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.

Autologous Stem Cell Transplantation for Chronic Lymphocytic Leukemia - Still a Valid Treatment Option, or is the Game Over?

Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab (FCR) has been established as the current standard of care for young and fit patients with chronic lymphocytic leukemia (CLL). In the early nineties of the last century, long before the advent of fludarabine or antibody-based strategies, there was realistic hope that myeloablative therapy followed by autologous stem cell transplantation (autoSCT) might be an effective and potentially curative front-line treatment option for suitable patients with CLL. Since then, several prospective trials have disenthralled this hope: although autoSCT can prolong event and progression-free survival if used as part of early front-line treatment, it does not improve overall survival, while it is associated with an increased risk of late adverse events such as secondary malignancies. In addition, autoSCT lacks the potential to overcome the negative impact of biomarkers that confer resistance to chemotherapy or early relapse. The role of autoSCT has also been explored in the context of FCR, and it was demonstrated that its effect is inferior to the currently established optimal treatment regimen. In view of ongoing attempts to improve on FCR, promising clinical activity of new substances even in relapsed/ refractory CLL patients, exciting novel cell therapy approaches and advantages in the understanding of the disease and detection of Minimal Residual Disease (MRD), autoSCT has lost its place as a standard treatment option for CLL.

Long-term follow-up of reduced-intensity allogeneic stem cell transplantation for chronic lymphocytic leukemia: prognostic model to predict outcome

CLL remains incurable with chemoimmunotherapy, and allogeneic hematopoietic stem cell transplantation (HSCT) offers potential for cure. We assessed the outcomes of 108 CLL patients undergoing first allogeneic HSCTs, 76 with reduced intensity (RIC) and 32 with myeloablative (MAC) conditioning between 1998 and 2009 at Dana-Farber Cancer Institute. With median follow-up 5.9 years in surviving patients, the 5 year OS for the entire cohort is 63% for RIC regimens and 49% for MAC regimens (p=0.18). The risk of death declined significantly starting in 2004 and we found that 5 year OS for HSCT between 2004–2009 was 83% for RIC regimens compared to 47% for MAC regimens (p=0.003). For RIC transplantation, we developed a prognostic model based on predictors of PFS, specifically remission status, LDH, comorbidity score and lymphocyte count, and found 5-year PFS 83% for score 0, 63% for score 1, 24% for score 2, and 6% for score >= 3 (p<0.0001). We conclude that RIC HSCT for CLL in the current era is associated with excellent long-term PFS and OS, and, as potentially curative therapy, should be considered early in the disease course of relapsed high-risk CLL patients.

Complex karyotype predicts for inferior outcomes following reduced-intensity conditioning allogeneic transplant for chronic lymphocytic leukaemia

Complex karyotype (CK) on metaphase cytogenetics discriminates poor outcome in chronic lymphocytic leukaemia (CLL) patients undergoing salvage treatment; we hypothesized that it might provide prognostic information for patients undergoing allogeneic stem cell transplant. Fifty-one CLL patients were analysed following transplant; 18-month overall survival (OS), event-free survival (EFS) and cumulative incidence of progression estimates were 35%, 14% and 63%, respectively, in patients with CK (n = 19) versus 83%, 68% and 29% in patients without (n = 32) (P ≤ 0·0001, P ≤ 0·0001, and P = 0·02). In patients with high-risk interphase cytogenetics, CK remained predictive of worse OS (P = 0·02) and EFS (P = 0·009). These findings support further evaluation of metaphase karyotype in transplant risk assessment.

Diagnostic techniques and therapeutic challenges in patients with TP53 dysfunctional chronic lymphocytic leukemia

Abstract Aberrations of the TP53 pathway, whether by deletion or mutation, are increasingly recognized as one of the most important biological risk factors in chronic lymphocytic leukemia. Yet, there is little consensus on how to assess for TP53 defects in the clinic, and very few clinical studies to guide optimal management of such patients. In this review, we discuss the state-of-the-art in the assessment of the TP53 pathway, and review the evidence-base for therapeutic recommendations.

Alemtuzumab in Combination With Methylprednisolone Is a Highly Effective Induction Regimen for Patients With Chronic Lymphocytic Leukemia and Deletion of TP53: Final Results of the National Cancer Research Institute CLL206 Trial

Purpose

In chronic lymphocytic leukemia (CLL), TP53 deletion/mutation is strongly associated with an adverse outcome and resistance to chemotherapy-based treatment. In contrast, TP53 defects are not associated with resistance to the anti-CD52 monoclonal antibody alemtuzumab or methylprednisolone. In an attempt to improve the treatment of TP53-defective CLL, a multicenter phase II study was developed to evaluate alemtuzumab and methylprednisolone in combination.

Patients and Methods

Thirty-nine patients with TP53-deleted CLL (17 untreated and 22 previously treated) received up to 16 weeks of treatment with alemtuzumab 30 mg three times a week and methylprednisolone 1.0 g/m2 for five consecutive days every 4 weeks. Antimicrobial prophylaxis consisted of cotrimoxazole, itraconazole, and aciclovir (or valganciclovir for asymptomatic cytomegalovirus viremia). The primary end point was response as assigned by an end-point review committee. Secondary end points were safety, progression-free survival (PFS) and overall survival (OS).

Results

The overall response rate, complete response rate (including with incomplete marrow recovery), median PFS, and median OS were 85%, 36%, 11.8 months, and 23.5 months, respectively, in the entire cohort and 88%, 65%, 18.3 months, and 38.9 months, respectively, in previously untreated patients. Grade 3 to 4 hematologic and glucocorticoid-associated toxicity occurred in 67% and 23% of patients, respectively. Grade 3 to 4 infection occurred in 51% of the overall cohort and in 29% of patients less than 60 years of age. Treatment-related mortality was 5%.

Conclusion

Alemtuzumab plus methypredisolone is the most effective induction regimen hitherto reported in TP53-deleted CLL. The risk of infection is age related and, in younger patients, seems only marginally higher than that associated with rituximab, fludarabine, and cyclophosphamide.

Risk categories and refractory CLL in the era of chemoimmunotherapy

Standardized criteria for diagnosis and response evaluation in chronic lymphocytic leukemia (CLL) are essential to achieve comparability of results and improvement of clinical care. With the increasing range of therapeutic options, the treatment context is important when defining refractory CLL. Refractory CLL has been defined as no response or response lasting ≤ 6 months from last therapy. This subgroup has a very poor outcome, and many trials use this group as an entry point for early drug development. With the intensification of first-line regimens, the proportion of patients with refractory CLL using these criteria decreases. This has immediate consequences for recruitment of patients into trials as well as salvage strategies. Conversely, patients who are not refractory according to the traditional definition but who have suboptimal or short response to intense therapy also have a very poor outcome. In this Perspective, we discuss recent results that may lead to a reassessment of risk categories in CLL focusing on fit patients who are eligible for all treatment options. We cover aspects of the history and biologic basis for refractory CLL and will focus on how emerging data on treatment failure from large trials using chemoimmunotherapy may help to define risk groups in CLL.

Novel therapies and their integration into allogeneic stem cell transplant for chronic lymphocytic leukemia

Over the past decade, numerous advances have been made in elucidating the biology of and improving treatment for chronic lymphocytic leukemia (CLL). These studies have led to identification of select CLL patient groups that generally have short survival dating from time of treatment or initial disease relapse who benefit from more aggressive therapeutic interventions. Allogeneic transplantation represents the only potentially curative option for CLL, but fully ablative regimens applied in the past have been associated with significant morbidity and mortality. Reduced-intensity preparative regimens has made application of allogeneic transplant to CLL patients much more feasible and increased the number of patients proceeding to this modality. Arising from this has been establishment of guidelines where allogeneic stem cell transplantation should be considered in CLL. Introduction of new targeted therapies with less morbidity, which can produce durable remissions has the potential to redefine where transplantation is initiated in CLL. This review briefly summarizes the field of allogeneic stem cell transplant in CLL and the interface of new therapeutics with this modality.

Can prognostic factors be used to direct therapy in chronic lymphocytic leukemia?

Chronic lymphocytic leukemia (CLL) shows a heterogeneous clinical course, which can be explained in part by prognostic factors. Most patients do not need treatment at the time of first diagnosis. The identification of prognostic factors is of major interest if strategies can be devised to treat patients according to their individual risk profile or biological subgroup. Currently, in spite of a wealth of prognostic factors, individualized treatment approaches in different genetic or risk groups are the exemption in CLL. This review summarizes the most important prognostic and predictive factors in CLL, with particular emphasis on factors affecting treatment decisions in clinical trials and routine practice.

State-of-the-Art Management of Patients Suffering from Chronic Lymphocytic Leukemia

The management of chronic lymphocytic leukemia (CLL) has evolved dramatically in the last decade. For the first time, clinical intervention has been shown to alter the natural history of the disease. Considerable efforts are focussing on better patient selection and response prediction, and it is expected that the publication of the first 200 CLL genomes will spark new insights into risk stratification of CLL patients. Besides, many new agents are being evaluated on their own and in combination therapy in early and late Phase clinical studies. Here, we provide a general clinical introduction into CLL including diagnosis and prognostic markers followed by a summary of the current state-of-the-art treatment. We point to areas of continued clinical research in particular for patients with co-morbidities and highlight the challenges in managing refractory disease.

The importance of IGHV mutational status in del(11q) and del(17p) chronic lymphocytic leukemia

BACKGROUND

Most patients with CLL with a poor-risk cytogenetic profile have an unmutated IGHV sequence. Limited clinical information exists for patients with CLL who have a poor-risk cytogenetic profile and a mutated or good-risk IGHV status. We retrospectively screened all patients with CLL seen at our institution from 2006 onward who harbored a del(11q) or del(17p) CLL detected by fluorescence in situ hybridization (FISH) analysis for whom an IGHV analysis was requested. In 66 evaluable patients, 50 (76%) had an unmutated IGHV sequence. Thirty-nine patients (59%) had del(11q) and 27 patients (41%) had del(17p); no patient in this series had both del(11q) and del(17p). The patients' initial clinical presentations were similar in both mutational groups. Patients with an unmutated IGHV sequence were more likely to receive treatment and to have a shorter survival, with an estimated 3-year overall survival (OS) of 81% compared with 100% in the group with a mutated IGHV sequence (log rank, P = .06). These data suggest that IGHV mutational status has prognostic relevance even in patients with CLL who are defined as poor risk by genomic FISH analysis.

Chronic lymphocytic leukaemia with 17p deletion: a retrospective analysis of prognostic factors and therapy results

Patients with chronic lymphocytic leukaemia (CLL) whose tumour cells harbour a 17p deletion (17p-) are universally considered to have a poor prognosis. The deletion can be detected at diagnosis or during the evolution of the disease, particularly in patients who have received chemotherapy. We sought to evaluate the natural history of patients with 17p- CLL, identify predictive factors within this prognostic subgroup, and evaluate the results of different therapeutic approaches. Data from 294 patients with 17p- CLL followed up at 20 different institutions was retrospectively collected and analysed. Median age was 68 (range 27-98) years at the time of fluorescence in situ hybridization analysis. After 17p- documentation, 52% received treatment, achieving an overall response rate of 50%. Median overall survival was 41 months, and was significantly shorter in patients with elevated beta(2)-microglobulin concentration (P < 0·001), B symptoms (P = 0·016), higher percentage of cells with deletion (P < 0·001), and acquired deletions (P = 0·012). These findings suggest that patients with 17p- CLL have a variable prognosis that can be refined using simple clinical and laboratory features, including 17p- clone size, beta2-microglobulin concentration, presence of B symptoms and type of deletion (de novo versus acquired).

Hematopoietic Stem Cell Allografting for Chronic Lymphocytic Leukemia: A Focus on Reduced-Intensity Conditioning Regimens

Background

Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only known treatment modality that currently offers a potential cure to patients with chronic lymphocytic leukemia (CLL). A better understanding of the role of adoptive immunotherapy and its consequent bona fide graft-vs-leukemia (GVL) effect has resulted in a reduction of the ablative intensity and toxicity of preparative allo-HCT regimens.

Methods

The authors review the published data of reduced-intensity conditioning (RIC) allo-HCT in patients with CLL.

Results

RIC allo-HCT has reduced the transplant associated morbidity and mortality of the procedure and has consequently broadened applicability of allo-HCT to patients with CLL who are generally of more advanced age (> 60 years) and who often have associated comorbidities.

Conclusions

Published literature supports the use of RIC allo-HCT for these patients once a suitable donor is identified, provided they fulfill acceptable consensus criteria for hematopoietic stem cell allografting. Several studies have shown that T-cell-replete RIC allo-HCT is also capable of overcoming the adverse effect of poor prognostic factors in CLL such as del(17p), unmutated IgVH, or ZAP-70 expression. Continued clinical trials to identify the optimal regimen for RIC allo-HCT for patients with CLL are warranted.

Transplant in chronic lymphocytic leukemia: to do it or not and if so, when and how?

Most patients with chronic lymphocytic leukemia (CLL) have an indolent clinical course, but the disease remains incurable with standard therapy and the prognosis is dismal for those patients with disease refractory to available treatment options. The only potentially curative treatment is allogeneic hematopoietic stem cell transplantation (SCT), but since CLL is a disease of elderly patients, few patients are candidates for myeloablative allogeneic SCT. Although autologous SCT is feasible and has low treatment-related mortality, it is not curative. The widespread adoption of reduced-intensity conditioning (RIC) allogeneic SCT has made this approach applicable to the elderly patient population with CLL. This approach relies on the documented graft-versus-leukemia (GVL) effect and is strong in CLL. Steps to further decrease the morbidity and mortality of the RIC SCT and in particular to reduce the incidence of chronic extensive graft-versus-host disease (GVHD) remain a major focus. Many potential treatments are available for CLL, and appropriate patient selection and SCT timing remain controversial and the focus of ongoing clinical trials. The use of SCT must always be weighed against the risk of the underlying disease, particularly in a setting where improvements in treatment are leading to improved outcome. The major challenge remains how to identify which patients with CLL merit this approach and where in the treatment course this treatment can be applied optimally.

SIE, SIES, GITMO updated clinical recommendations for the management of chronic lymphocytic leukemia

By using GRADE system we updated the guidelines for management of CLL issued in 2006 from SIE, SIES and GITMO group. We recommended fludarabine, cyclophosphamide, rituximab (FCR) in younger and selected older patients with a good fitness status, no unfavourable genetics (deletion 17p and/or p53 mutations), and a less toxic treatment in nonfit and elderly patients. In patients without unfavourable genetics, relapsed after 24 months the same initial treatment including rituximab can be considered. In patients with unfavourable genetics, refractory or relapsed within 24 months from a prior fludarabine-based treatment, allogeneic SCT or experimental treatments should be given.

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.

Acquired genomic copy number aberrations and survival in chronic lymphocytic leukemia

Genomic aberrations are of predominant importance to the biology and clinical outcome of patients with chronic lymphocytic leukemia (CLL), and FISH-based genomic risk classifications are routinely used in clinical decision making in CLL. One of the known limitations of CLL FISH is the inability to comprehensively interrogate the CLL genome for genomic changes. In an effort at overcoming the existing limitations in CLL genome analysis, we have analyzed high-purity DNA isolated from FACS-sorted CD19(+) cells and paired CD3(+) or buccal cells from 255 patients with CLL for acquired genomic copy number aberrations (aCNAs) with the use of ultra-high-density Affymetrix SNP 6.0 arrays. Overall, ≥ 2 subchromosomal aCNAs were found in 39% (100 of 255) of all cases analyzed, whereas ≥ 3 subchromosomal aCNAs were detected in 20% (50 of 255) of cases. Subsequently, we have correlated genomic lesion loads (genomic complexity) with the clinical outcome measures time to first therapy and overall survival. With the use of multivariate analyses incorporating the most important prognostic factors in CLL together with SNP 6.0 array-based genomic lesion loads at various thresholds, we identify elevated CLL genomic complexity as an independent and powerful marker for the identification of patients with aggressive CLL and short survival.

Autologous stem cell transplantation as a first-line treatment strategy for chronic lymphocytic leukemia: a multicenter, randomized, controlled trial from the SFGM-TC and GFLLC

Long-term responses have been reported after autologous stem cell transplantation (ASCT) for chronic lymphocytic leukemia (CLL). We conducted a prospective, randomized trial of ASCT in previously untreated CLL patients. We enrolled 241 patients < 66 years of age with Binet stage B or C CLL. They received 3 courses of mini-CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone/prednisolone) and then 3 courses of fludarabine. Patients in complete response (CR) were then randomized to ASCT or observation, whereas the other patients were randomized to dexamethasone, high-dose aracytin, cisplatin (DHAP) salvage followed by either ASCT or 3 courses of fludarabine plus cyclophosphamide (FC). The primary end point was event-free survival (EFS). After up-front treatment, 105 patients entered CR and were randomized between ASCT (n = 52) and observation (n = 53); their respective 3-year EFS rates were 79.8% and 35.5%; the adjusted hazard ratio was 0.3 (95% CI: 0.1-0.7; P = .003). Ninety-four patients who did not enter CR were randomized between ASCT (n = 46) and FC (n = 48); their respective 3-year EFS rates were 48.9% and 44.4%, respectively; the adjusted hazard ratio was 1.7 (95% CI: 0.9-3.2; P = .13). No difference in overall survival was found between the 2 response subgroups. In young CLL patients in CR, ASCT consolidation markedly delayed disease progression. No difference was observed between ASCT and FC in patients requiring DHAP salvage.

Treatment options for high-risk chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common form of leukaemia in the Western world. The natural history of CLL is extremely variable with a survival time from initial diagnosis that ranges from 2 to more than 20 years. Understanding the clinical diversity and allowing the subclassification of CLL into various prognostic groups not only assists in predicting future outcome for patients, but also helps to direct treatment decisions. Chlorambucil and fludarabine were the standard therapy for CLL for decades. Randomized studies have reported superior overall response and progression-free survival (PFS) for fludarabine compared with alkylator-based therapy and for the fludarabine-cyclophospamide (FC) combination over fludarabine alone. More recently the addition of rituximab to the FC regimen (R-FC) has shown significant improvement in overall response, PFS and overall survival compared with FC alone. However, there are patients for whom this regimen still provides less satisfactory results. Within the above studies CLL patients who have some of the poorer prognostic markers, such as unmutated IgVH genes and/or high beta-2 microglobulin (B2M), and those who fail to achieve a minimal residual disease (MRD) negative remission are likely to have a shorter PFS compared with those without these features. Various strategies have been explored to improve the outcome for such patients. These include the addition of agents to a frontline R-FC regimen, use of consolidation and consideration of maintenance. The only group that can be clearly identified pretreatment for whom conventional fludarabine-based therapies produce significantly inferior response rates, PFS and overall survival are the patients who harbour a genetic fault; deletion or mutation or a combination of deletion and mutation of tumour protein p53 (TP53). TP53 inactivation is a less common finding at first treatment but becomes much more common in fludarabine-refractory patients. Alemtuzumab and high-dose corticosteroids have been shown to be effective in this group of CLL patients. Trials combining these two agents have shown improved responses, particularly for those patients with bulky nodal disease for whom alemtuzumab alone may be insufficient. Since the duration of responses remains relatively short, suitable patients should be considered for allogeneic stem cell transplantation according to the European Group for Blood and Marrow Transplantation (EBMT) guidelines. Furthermore, there are a number of other new treatments on the horizon, including humanized antibodies directed against novel targets and small-molecule inhibitors.

Stem cell transplantation for indolent lymphoma and chronic lymphocytic leukemia

The indolent lymphomas, including chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) remain incurable with standard therapy. Autologous hematopoietic stem cell transplantation (HSCT) is feasible and has low treatment-related mortality in follicular lymphoma, but there are questions relating to optimal timing of the procedure, conditioning regimen, and late effects. Myeloablative allogeneic HSCT is associated with high treatment-related morbidity and mortality, few late relapses, but is applicable to only a small number of patients. The major focus of HSCT in these lymphomas has been with reduced-intensity conditioning (RIC) allogeneic HSCT, which is applicable to the age distribution of these diseases and which exploits the graft-versus-lymphoma effect in these diseases. Steps to further decrease the morbidity and mortality of the RIC HSCT and in particular to reduce the incidence of chronic extensive graft-versus-host disease (GVHD) while maintaining tumor control remain the major focus. Many potential treatments are available for indolent lymphomas and CLL, and appropriate patient selection and the timing of HSCT remain controversial. The use of HSCT must always be weighed against the risk of the underlying disease, particularly in a setting where improvements in treatment are leading to improved outcome.

Clinicobiologic importance of cytogenetic lesions in chronic lymphocytic leukemia

Molecular cytogenetic lesions play a major role in the pathogenesis of chronic lymphocytic leukemia (CLL) and represent important prognostic markers. Besides FISH, conventional banding analysis using effective mitogens is important for an accurate assessment of the cytogenetic profile of CLL. The most frequent aberrations are represented by 13q-, 11q-, +12, 6q- and 14q32/IGH translocations and 17p-. Chromosome translocations and complex karyotype may occur in up to 30 and 16% of the cases, respectively. The frequency of 17p- and 11q- is higher in patients requiring treatment and in relapsed/refractory patients, reflecting the association of these rearrangements with unfavorable prognosis. Mutations of the TP53 gene may also confer an inferior outcome, as is the case with 14q32 translocations and unbalanced translocations. Evidence was provided that distinct treatment approaches may be effective in specific cytogenetic entities of CLL, making molecular cytogenetic investigations a necessary tool for a modern diagnostic work-up in CLL.

Importance of genetics in chronic lymphocytic leukemia

Recurrent losses or gains of genomic material as well as mutations of key tumor suppressors (ATM and TP53) have been identified in chronic lymphocytic leukemia (CLL). These aberrations are important "drivers" of the disease and some of its clinical characteristics. There is a remarkable heterogeneity in the clinical course between patient subgroups with distinct genetic features. While some mutations are associated with poor outcome (particularly 17p- and TP53 mutation and to a lesser extend 11q-) others are linked to a favorable outcome (13q- as sole aberration; mutated IGHV). Our improved understanding of the clinical course of specific genetic subgroups is beginning to be translated into genotype specific treatment approaches where genetic subgroups (e.g. 17p-) are channeled into separate treatment protocols. This review will summarize the most important genetic aberrations in CLL and how our improved knowledge of the genetic make-up of leukemic cells may translate into improved treatment results.

What is the best frontline therapy for patients with CLL and 17p deletion?

Chronic lymphocytic leukemia (CLL) is a lymphoproliferative disease with significant variation in disease progression, response to therapy, and survival outcome. Deletions of 17p or mutations of TP53 have been identified as one of the poorest prognostic factors, being predictive of short time for disease progression, lack of response to therapy, short response duration, and short overall survival. The treatment of patients with CLL has improved significantly with the development of chemoimmunotherapy, but this benefit was not pronounced in patients with 17p deletion. We compare various treatment strategies used in these patients, including FCR-like chemoimmunotherapy, alemtuzumab, other antibody combinations, or novel targeted therapies with promising results. Allogeneic stem cell transplantation offers the possibility for long-term disease control in these patients and should be considered early in younger, transplant-eligible patients. The current state of therapy is far from optimal and resources should be applied to studying therapeutic options for patients who have CLL with loss of p53 function.

Limited clinical relevance of imaging techniques in the follow-up of patients with advanced chronic lymphocytic leukemia: results of a meta-analysis

The clinical value of imaging is well established for the follow-up of many lymphoid malignancies but not for chronic lymphocytic leukemia (CLL). A meta-analysis was performed with the dataset of 3 German CLL Study Group phase 3 trials (CLL4, CLL5, and CLL8) that included 1372 patients receiving first-line therapy for CLL. Response as well as progression during follow-up was reassessed according to the National Cancer Institute Working Group1996 criteria. A total of 481 events were counted as progressive disease during treatment or follow-up. Of these, 372 progressions (77%) were detected by clinical symptoms or blood counts. Computed tomography (CT) scans or ultrasound were relevant in 44 and 29 cases (9% and 6%), respectively. The decision for relapse treatment was determined by CT scan or ultrasound results in only 2 of 176 patients (1%). CT scan results had an impact on the prognosis of patients in complete remission only after the administration of conventional chemotherapy but not after chemoimmunotherapy. In conclusion, physical examination and blood count remain the methods of choice for staging and clinical follow-up of patients with CLL as recommended by the International Workshop on Chronic Lymphocytic Leukemia 2008 guidelines. These trials are registered at http://www.isrctn.org as ISRCTN 75653261 and ISRCTN 36294212 and at http://www.clinicaltrials.gov as NCT00281918.

Allogeneic stem cell transplantation for chronic lymphocytic leukemia: lessons to be learned from minimal residual disease studies

Allogeneic stem cell transplantation (alloSCT) is a potentially curative treatment strategy for poor-risk chronic lymphocytic leukemia (CLL). The crucial anti-leukemic principle of alloSCT in CLL appears to be the graft-versus-leukemia effect (GVL). Evidence for GVL in CLL is particularly provided by studies analysing the kinetics of minimal residual disease (MRD). The purpose of this review is to summarize the methodologies of MRD assessment, its proven benefits and its further perspectives for optimizing the outcome of transplantation. Proven value of quantitative MRD monitoring by RQ-PCR or MRD-flow consists in using it as an indicator of long-term disease control and potential cure. As MRD kinetics correlates with GVL activity, its suitability for guiding GVL-inducing immunomodulation is currently under investigation. In conclusion, quantitative MRD monitoring seems to be mandatory to assure safe and effective immunotherapy in the context of alloSCT for CLL, which should, however, be best performed within clinical studies.

Moving from prognostic to predictive factors in chronic lymphocytic leukaemia (CLL)

Many prognostic factors have been identified in chronic lymphocytic leukaemia (CLL). Based on the assessment of B cell receptor (BCR) structure and function, a subdivision into subtypes is possible (e.g., immunoglobulin heavy chain variable gene segment (IGHV) unmutated and mutated, V3-21 usage) with distinct biological and clinical characteristics. Recurrent genomic aberrations (i.e., 11q and 17p deletion) and gene mutations (i.e., TP53 and ATM) help to define biological and clinical subgroups. In addition, serum markers (e.g., thymidine kinase (TK) and beta2-microglobulin (beta2-MG)), cellular markers (e.g., CD38 and ZAP70) and clinical staging have an impact on outcome in CLL. The biological characterisation of CLL has not only led to progress in outcome prediction but also has begun to be translated into novel treatment strategies. Nonetheless, most factors associated with prognosis have not been thoroughly interrogated for their predictive value in the light of different therapeutic approaches. With a growing number of agents acting on specific biological targets and being used in different clinical situations, the future is likely to bring the identification of predictive factors in CLL.

The treatment of relapsed refractory chronic lymphocytic leukemia

Despite the widespread use of highly effective chemoimmunotherapy (CIT), fludarabine-refractory chronic lymphocytic leukemia (CLL) remains a challenging clinical problem associated with poor overall survival (OS). The traditional definition, which includes those patients with no response or relapse within 6 months of fludarabine, is evolving with the recognition that even patients with longer remissions of up to several years after CIT have poor subsequent treatment response and survival. Approved therapeutic options for these patients remain limited, and the goal of therapy for physically fit patients is often to achieve adequate cytoreduction to proceed to allogeneic stem cell transplantation (alloSCT). Fortunately, several novel targeted therapeutics in clinical trials hold promise of significant benefit for this patient population. This review discusses the activity of available and novel therapeutics in fludarabine-refractory or fludarabine-resistant CLL as well as recently updated data on alloSCT in CLL.

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: Report from the Committee on Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation

Relapse is a major cause of treatment failure after allogeneic hematopoietic stem cell transplantation (alloHSCT). Treatment options for relapse have been inadequate, and the majority of patients ultimately die of their disease. There is no standard approach to treating relapse after alloHSCT. Withdrawal of immune suppression and donor lymphocyte infusions are commonly used for all diseases; although these interventions are remarkably effective for relapsed chronic myelogenous leukemia, they have limited efficacy in other hematologic malignancies. Conventional and novel chemotherapy, monoclonal antibody therapy, targeted therapies, and second transplants have been utilized in a variety of relapsed diseases, but reports on these therapies are generally anecdotal and retrospective. As such, there is an immediate need for well-designed, disease-specific trials for treatment of relapse after alloHSCT. This report summarizes current treatment options under investigation for relapse after alloHSCT in a disease-specific manner. In addition, recommendations are provided for specific areas of research necessary in the treatment of relapse after alloHSCT.

Allogeneic stem cell transplantation provides durable disease control in poor-risk chronic lymphocytic leukemia: long-term clinical and MRD results of the German CLL Study Group CLL3X trial

The purpose of this prospective multicenter phase 2 trial was to investigate the long-term outcome of reduced-intensity conditioning allogeneic stem cell transplantation (alloSCT) in patients with poor-risk chronic lymphocytic leukemia. Conditioning was fludarabine/ cyclophosphamide-based. Longitudinal quantitative monitoring of minimal residual disease (MRD) was performed centrally by MRD-flow or real-time quantitative polymerase chain reaction. One hundred eligible patients were enrolled, and 90 patients proceeded to alloSCT. With a median follow-up of 46 months (7-102 months), 4-year nonrelapse mortality, event-free survival (EFS) and overall survival (OS) were 23%, 42%, and 65%, respectively. Of 52 patients with MRD monitoring available, 27 (52%) were alive and MRD negative at 12 months after transplant. Four-year EFS of this subset was 89% with all event-free patients except for 2 being MRD negative at the most recent assessment. EFS was similar for all genetic subsets, including 17p deletion (17p−). In multivariate analyses, uncontrolled disease at alloSCT and in vivo T-cell depletion with alemtuzumab, but not 17p−, previous purine analogue refractoriness, or donor source (human leukocyte antigen-identical siblings or unrelated donors) had an adverse impact on EFS and OS. In conclusion, alloSCT for poor-risk chronic lymphocytic leukemia can result in long-term MRD-negative survival in up to one-half of the patients independent of the underlying genomic risk profile. This trial is registered at http://clinicaltrials.gov as NCT00281983.

Addition of rituximab to fludarabine and cyclophosphamide in patients with chronic lymphocytic leukaemia: a randomised, open-label, phase 3 trial

BACKGROUND

On the basis of promising results that were reported in several phase 2 trials, we investigated whether the addition of the monoclonal antibody rituximab to first-line chemotherapy with fludarabine and cyclophosphamide would improve the outcome of patients with chronic lymphocytic leukaemia.

METHODS

Treatment-naive, physically fit patients (aged 30-81 years) with CD20-positive chronic lymphocytic leukaemia were randomly assigned in a one-to-one ratio to receive six courses of intravenous fludarabine (25 mg/m(2) per day) and cyclophosphamide (250 mg/m(2) per day) for the first 3 days of each 28-day treatment course with or without rituximab (375 mg/m(2) on day 0 of first course, and 500 mg/m(2) on day 1 of second to sixth courses) in 190 centres in 11 countries. Investigators and patients were not masked to the computer-generated treatment assignment. The primary endpoint was progression-free survival (PFS). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00281918.

FINDINGS

408 patients were assigned to fludarabine, cyclophosphamide, and rituximab (chemoimmunotherapy group) and 409 to fludarabine and cyclophosphamide (chemotherapy group); all patients were analysed. At 3 years after randomisation, 65% of patients in the chemoimmunotherapy group were free of progression compared with 45% in the chemotherapy group (hazard ratio 0·56 [95% CI 0·46-0·69], p<0·0001); 87% were alive versus 83%, respectively (0·67 [0·48-0·92]; p=0·01). Chemoimmunotherapy was more frequently associated with grade 3 and 4 neutropenia (136 [34%] of 404 vs 83 [21%] of 396; p<0·0001) and leucocytopenia (97 [24%] vs 48 [12%]; p<0·0001). Other side-effects, including severe infections, were not increased. There were eight (2%) treatment-related deaths in the chemoimmunotherapy group compared with ten (3%) in the chemotherapy group.

INTERPRETATION

Chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab improves progression-free survival and overall survival in patients with chronic lymphocytic leukaemia. Moreover, the results suggest that the choice of a specific first-line treatment changes the natural course of chronic lymphocytic leukaemia.

FUNDING

F Hoffmann-La Roche.

Chronic lymphocytic leukemia: new concepts for future therapy

Over the past several years, we have witnessed rapid advances in our understanding of the biology and treatment of chronic lymphocytic leukemia (CLL). New prognostic factors have been characterized that help identify patients at high risk of rapid disease progression, refractoriness to treatment, and short overall survival (OS). These advances have led to a significant paradigm shift in the management of CLL. Novel therapeutic strategies, including combinations of monoclonal antibodies with conventional chemotherapy, have dramatically improved response rates, remission duration, and recently, OS. However, these benefits do not appear to extend to certain patient subsets, especially those with unfavorable clinical or cytogenetic risk factors. The majority of patients with CLL will invariably relapse following first-line therapy and can acquire high-risk genetic abnormalities. Repeated treatment leads to eventual therapeutic refractoriness and shortened survival compared with age-matched healthy individuals. Several novel agents and strategies, including next-generation anti-CD20 monoclonal antibodies, the alkylating agent bendamustine, the immunomodulatory agent lenalidomide, the cyclin-dependent kinase inhibitor flavopiridol, and small-molecule Bcl2 inhibitors, are currently under clinical investigation as novel agents that will hopefully improve treatment outcomes for CLL. Though allogeneic stem cell transplantation offers curative potential, it also presents clinical challenges in terms of patient appropriateness, donor availability, and timing. The merits and challenges of incorporating these treatment modalities into the treatment algorithm for patients with CLL, as discussed by a panel of experts in CLL, are outlined in this article.