Prediction of poor outcome in CLL patients following first-line treatment with fludarabine, cyclophosphamide and rituximab

Management strategies for patients with chronic lymphocytic leukaemia harbouring complex karyotype

Chronic lymphocytic leukaemia (CLL) is a heterogeneous disease characterised by the uncontrolled proliferation of mature lymphocytes. A subset of CLL patients harbouring complex karyotype (CK) presents with poor prognosis and limited treatment options. This review aims to discuss the current understanding of such patient subset, including its molecular landscape, diagnostic approaches, treatment modalities and emerging therapies. Furthermore, it outlines strategies for personalised management to improve clinical outcomes in this challenging patient population.

Flow Cytometric MRD Detection in Selected Mature B-Cell Malignancies

The quantification of submicroscopic minimal residual disease (MRD) after therapy proved to have independent prognostic significance in many mature B-cell malignancies. With the advent of routine benchtop cytometers capable of simultaneously analyzing ≥8 colors and with improved standardization, flow cytometry has become the method of choice for MRD assessments in some lymphoma entities. Herein we describe general aspects of flow cytometric standardization. Chronic lymphocytic leukemia (CLL) and multiple myeloma (MM) are used as examples to explain the technical standardization of flow cytometry for MRD detection according to EuroFlow strategies. MRD data acquisition and detailed analysis in MM and CLL is a particular focus of this chapter.

Downhill running does not alter blood C1q availability or complement-dependent cytotoxicity of therapeutic monoclonal antibodies against haematological cancer cell lines in vitro

Complement-dependent cytotoxicity (CDC) is a primary mechanism-of-action of monoclonal antibody (mAb) immunotherapies used to treat haematological cancers, including rituximab and daratumumab. However, mAb efficacy may be limited by reduced bioavailability of complement C1q - which activates the complement classical pathway following interactions with mAb-opsonised target cells. C1q is secreted by phagocytes upon recruitment to sites of muscle damage to facilitate muscular repair, hence we hypothesised that muscle damaging exercise may increase C1q 'spill-over' into blood. Additionally, other complement proteins (e.g., C1s) have been reported to increase following ultra-endurance and resistance exercise. Taken together, we hypothesised that muscle damaging exercise could be harnessed to enhance mAb-mediated CDC. In this study, n = 8 healthy males (28 ± 5-years) completed two 45-minute treadmill running protocols: (1) a flat running protocol at a speed 15% above anaerobic threshold, and (2) a downhill running protocol (- 10% slope) at the same speed. Blood samples were collected before, immediately after, and 1-hour, 24-hours, 2-days, and 4-days after exercise. Isolated serum was assessed for C1q by ELISA, and used to measure mAb (rituximab, daratumumab) mediated CDC against two haematological cancer cell lines (Raji, RPMI-8226) in vitro. Isolated plasma was assessed for markers of inflammation (C-reactive protein [CRP]), and muscle damage (creatine kinase [CK]) by turbidimetry. C1q and CDC activity were not different between running protocols and did not change over time (p > 0.05). Significantly greater perceived muscle soreness (p < 0.001) and fluctuations observed from baseline to 24-hours post-exercise in the downhill running trial in CK (+ 171%) and CRP (+ 66%) suggests some degree of muscle damage was present. It is possible that any increase in C1q post-exercise may have been masked by the increase and subsequent interaction with CRP, which utilises C1q to facilitate muscular repair. This is the first study to investigate whether exercise can increase circulating C1q and improve mAb-mediated CDC and our findings show that downhill running exercise does not increase circulating C1q nor improve CDC in vitro.

A single bout of vigorous intensity exercise enhances the efficacy of rituximab against human chronic lymphocytic leukaemia B-cells ex vivo

Chronic lymphocytic leukaemia (CLL) is characterised by the clonal proliferation and accumulation of mature B-cells and is often treated with rituximab, an anti-CD20 monoclonal antibody immunotherapy. Rituximab often fails to induce stringent disease eradication, due in part to failure of antibody-dependent cellular cytotoxicity (ADCC) which relies on natural killer (NK)-cells binding to rituximab-bound CD20 on B-cells. CLL cells are diffusely spread across lymphoid and other bodily tissues, and ADCC resistance in survival niches may be due to several factors including low NK-cell frequency and a suppressive stromal environment that promotes CLL cell survival. It is well established that exercise bouts induce a transient relocation of NK-cells and B-cells into peripheral blood, which could be harnessed to enhance the efficacy of rituximab in CLL by relocating both target and effector cells together with rituximab in blood. In this pilot study, n = 20 patients with treatment-naïve CLL completed a bout of cycling 15 % above anaerobic threshold for ∼ 30-minutes, with blood samples collected pre-, immediately post-, and 1-hour post-exercise. Flow cytometry revealed that exercise evoked a 254 % increase in effector (CD3-CD56+CD16+) NK-cells in blood, and a 67 % increase in CD5+CD19+CD20+ CLL cells in blood (all p < 0.005). NK-cells were isolated from blood samples pre-, and immediately post-exercise and incubated with primary isolated CLL cells with or without the presence of rituximab to determine specific lysis using a calcein-release assay. Rituximab-mediated cell lysis increased by 129 % following exercise (p < 0.001). Direct NK-cell lysis of CLL cells - independent of rituximab - was unchanged following exercise (p = 0.25). We conclude that exercise improved the efficacy of rituximab-mediated ADCC against autologous CLL cells ex vivo and propose that exercise should be explored as a means of enhancing clinical responses in patients receiving anti-CD20 immunotherapy.

Harnessing the immunomodulatory effects of exercise to enhance the efficacy of monoclonal antibody therapies against B-cell haematological cancers: a narrative review

Therapeutic monoclonal antibodies (mAbs) are standard care for many B-cell haematological cancers. The modes of action for these mAbs include: induction of cancer cell lysis by activating Fcγ-receptors on innate immune cells; opsonising target cells for antibody-dependent cellular cytotoxicity or phagocytosis, and/or triggering the classical complement pathway; the simultaneous binding of cancer cells with T-cells to create an immune synapse and activate perforin-mediated T-cell cytotoxicity against cancer cells; blockade of immune checkpoints to facilitate T-cell cytotoxicity against immunogenic cancer cell clones; and direct delivery of cytotoxic agents via internalisation of mAbs by target cells. While treatment regimens comprising mAb therapy can lead to durable anti-cancer responses, disease relapse is common due to failure of mAb therapy to eradicate minimal residual disease. Factors that limit mAb efficacy include: suboptimal effector cell frequencies, overt immune exhaustion and/or immune anergy, and survival of diffusely spread tumour cells in different stromal niches. In this review, we discuss how immunomodulatory changes arising from exposure to structured bouts of acute exercise might improve mAb treatment efficacy by augmenting (i) antibody-dependent cellular cytotoxicity, (ii) antibody-dependent cellular phagocytosis, (iii) complement-dependent cytotoxicity, (iv) T-cell cytotoxicity, and (v) direct delivery of cytotoxic agents.

Unmutated IGHV1-69 CLL Clone Displays a Distinct Gene Expression Profile by a Comparative qRT-PCR Assay

Chronic Lymphocytic Leukemia (CLL) is a heterogeneous disease characterized by variable clinical courses among different patients. This notion was supported by the possible coexistence of two or more independent CLL clones within the same patients, identified by the characterization of the B cell receptor immunoglobulin (BcR IG) idiotypic sequence. By using the antigen-binding site of the BcR IG as bait, the identification and isolation of aggressive and drug-resistance leukemic B-cell clones could allow a deeper biological and molecular investigation. Indeed, by the screening of phage display libraries, we previously selected a peptide binder of the idiotypic region of CLL BCR IGs expressing the unmutated rearrangement IGHV1-69 and used it as a probe to perform a peptide-based cell sorting by flow cytometry in peripheral blood samples from patients with CLL. Since the IGHV1-69 clones persisted during the follow-up time in both patients, we explored the possibility of these clones having acquired an evolutive advantage compared to the other coexisting clones in terms of a higher expression of genes involved in the survival and apoptosis escape processes. To this end, we studied the expression patterns of a panel of genes involved in apoptosis regulation and in NF-kB-dependent pro-survival signals by comparative qRT-PCR assays. According to the results, IGHV1-69 clones showed a higher expression of pro-survival and anti-apoptotic genes as compared to the other CLL clones with different immunogenetic characteristics. Moreover, these IGHV1-69 clones did not carry any characteristic genetic lesions, indicating the relevance of our approach in performing a comprehensive molecular characterization of single tumor clones, as well as for designing new personalized therapeutic approaches for the most aggressive and persistent tumor clones.

Treatment Approaches to Chronic Lymphocytic Leukemia With High-Risk Molecular Features

The clinical course of chronic lymphocytic leukemia (CLL) is highly variable. Over the past decades, several cytogenetic, immunogenetic and molecular features have emerged that identify patients suffering from CLL with high-risk molecular features. These biomarkers can clearly aid prognostication, but may also be capable of predicting the efficacy of various treatment strategies in subgroups of patients. In this narrative review, we discuss treatment approaches to CLL with high-risk molecular features. Specifically, we review and provide a comprehensive overview of clinical trials evaluating the efficacy of chemotherapy, chemoimmunotherapy and novel agent-based treatments in CLL patients with TP53 aberrations, deletion of the long arm of chromosome 11, complex karyotype, unmutated IGHV, B cell receptor stereotypy, and mutations in NOTCH1 or BIRC3. Furthermore, we discuss future pharmaceutical and immunotherapeutic perspectives for CLL with high-risk molecular features, focusing on agents currently under investigation in clinical trials.

Dynamic Risk Profiling Using Serial Tumor Biomarkers for Personalized Outcome Prediction

Accurate prediction of long-term outcomes remains a challenge in the care of cancer patients. Due to the difficulty of serial tumor sampling, previous prediction tools have focused on pretreatment factors. However, emerging non-invasive diagnostics have increased opportunities for serial tumor assessments. We describe the Continuous Individualized Risk Index (CIRI), a method to dynamically determine outcome probabilities for individual patients utilizing risk predictors acquired over time. Similar to "win probability" models in other fields, CIRI provides a real-time probability by integrating risk assessments throughout a patient's course. Applying CIRI to patients with diffuse large B cell lymphoma, we demonstrate improved outcome prediction compared to conventional risk models. We demonstrate CIRI's broader utility in analogous models of chronic lymphocytic leukemia and breast adenocarcinoma and perform a proof-of-concept analysis demonstrating how CIRI could be used to develop predictive biomarkers for therapy selection. We envision that dynamic risk assessment will facilitate personalized medicine and enable innovative therapeutic paradigms.

Flow Cytometric MRD Detection in Selected Mature B-Cell Malignancies

The quantification of submicroscopic minimal residual disease (MRD) after therapy proved to have independent prognostic significance in many mature B-cell malignancies. With the advent of routine benchtop cytometers capable of simultaneously analyzing ≥4 colors and with improved standardization, flow cytometry has become the method of choice for MRD assessments in some lymphoma entities. Herein we describe general aspects of flow cytometric standardization. Chronic lymphocytic leukemia and multiple myeloma (MM) are used as examples to explain the technical standardization of flow cytometry for MRD detection according to EuroFlow strategies. MRD data acquisition and detailed analysis using a newly developed approach (so-called next generation flow, NGF) in MM is a particular focus of this chapter.

Remission maintenance treatment options in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) treatment has come a long way in the last two decades, producing increases in tumor control to the point of generating sizeable numbers of patients with undetectable minimal residual disease and creating overall survival benefits in randomized comparisons. Most of this has been achieved by limited-term treatment approaches including chemotherapeutic and immune-therapeutic drugs. More recently, novel therapies targeting signaling pathways essential for the survival of the neoplastic clones have opened avenues that provide disease control in long-term treatment designs, mostly without producing deep remissions. In this disease, where current treatments are largely unable to effect a cure, prolonged therapy designs using maintenance approaches are explored and 5 randomized studies of maintenance have recently been published. This review shall summarize available results from a systematic literature review in a clinical context and outline basic biology principles that should be heeded in this regard.

Fludarabine and rituximab with escalating doses of lenalidomide followed by lenalidomide/rituximab maintenance in previously untreated chronic lymphocytic leukaemia (CLL): the REVLIRIT CLL-5 AGMT phase I/II study

Despite recent advances, chemoimmunotherapy remains a standard for fit previously untreated chronic lymphocytic leukaemia patients. Lenalidomide had activity in early monotherapy trials, but tumour lysis and flare proved major obstacles in its development. We combined lenalidomide in increasing doses with six cycles of fludarabine and rituximab (FR), followed by lenalidomide/rituximab maintenance. In 45 chemo-naive patients, included in this trial, individual tolerability of the combination was highly divergent and no systematic toxicity determining a maximum tolerated dose was found. Grade 3/4 neutropenia (71%) was high, but only 7% experienced grade 3 infections. No tumour lysis or flare > grade 2 was observed, but skin toxicity proved dose-limiting in nine patients (20%). Overall and complete response rates after induction were 89 and 44% by intention-to-treat, respectively. At a median follow-up of 78.7 months, median progression-free survival (PFS) was 60.3 months. Minimal residual disease and immunoglobulin variable region heavy chain mutation state predicted PFS and TP53 mutation most strongly predicted OS. Baseline clinical factors did not predict tolerance to the immunomodulatory drug lenalidomide, but pretreatment immunophenotypes of T cells showed exhausted memory CD4 cells to predict early dose-limiting non-haematologic events. Overall, combining lenalidomide with FR was feasible and effective, but individual changes in the immune system seemed associated with limiting side effects. clinicaltrials.gov (NCT00738829) and EU Clinical Trials Register (www.clinicaltrialsregister.eu, 2008-001430-27)

Chronic lymphocytic leukaemia

Important advances in understanding the pathogenesis of chronic lymphocytic leukaemia in the past two decades have led to the development of new prognostic tools and novel targeted therapies that have improved clinical outcome. Chronic lymphocytic leukaemia is the most common type of leukaemia in developed countries, and the median age at diagnosis is 72 years. The criteria for initiating treatment rely on the Rai and Binet staging systems and on the presence of disease-related symptoms. For many patients with chronic lymphocytic leukaemia, treatment with chemotherapy and anti-CD20 monoclonal antibodies is the standard of care. The impressive efficacy of kinase inhibitors ibrutinib and idelalisib and the BCL-2 antagonist venetoclax have changed the standard of care in specific subsets of patients. In this Seminar, we review the recent progress in the management of chronic lymphocytic leukaemia and highlight new questions surrounding the optimal disease management.

iwCLL guidelines for diagnosis, indications for treatment, response assessment, and supportive management of CLL

The previous edition of the consensus guidelines of the International Workshop on Chronic Lymphocytic Leukemia (iwCLL), published in 2008, has found broad acceptance by physicians and investigators caring for patients with CLL. Recent advances including the discovery of the genomic landscape of the disease, the development of genetic tests with prognostic relevance, and the detection of minimal residual disease (MRD), coupled with the increased availability of novel targeted agents with impressive efficacy, prompted an international panel to provide updated evidence- and expert opinion-based recommendations. These recommendations include a revised version of the iwCLL response criteria, an update on the use of MRD status for clinical evaluation, and recommendations regarding the assessment and prophylaxis of viral diseases during management of CLL.

Minimal Residual Disease Assessment Improves Prediction of Outcome in Patients With Chronic Lymphocytic Leukemia (CLL) Who Achieve Partial Response: Comprehensive Analysis of Two Phase III Studies of the German CLL Study Group

Purpose To determine the value of minimal residual disease (MRD) assessments, together with the evaluation of clinical response in chronic lymphocytic leukemia according to the 2008 International Workshop on Chronic Lymphocytic Leukemia criteria. Patients and Methods Progression-free survival (PFS) and overall survival of 554 patients from two randomized trials of the German CLL Study Group (CLL8: fludarabine and cyclophosphamide [FC] v FC plus rituximab; CLL10: FC plus rituximab v bendamustine plus rituximab) were analyzed according to MRD assessed in peripheral blood at a threshold of 10^-4 and clinical response. The prognostic value of different parameters defining a partial response (PR) was further investigated. Results Patients with MRD-negative complete remission (CR), MRD-negative PR, MRD-positive CR, and MRD-positive PR experienced a median PFS from a landmark at end of treatment of 61 months, 54 months, 35 months, and 21 months, respectively. PFS did not differ significantly between MRD-negative CR and MRD-negative PR; however, PFS was longer for MRD-negative PR than for MRD-positive CR ( P = .048) and for MRD-positive CR compared with MRD-positive PR ( P = .002). Compared with MRD-negative CR, only patients with MRD-positive PR had a significantly shorter overall survival (not reached v 72 months; P = .001), whereas there was no detectable difference for patients with MRD-negative PR or MRD-positive CR ( P = 0.612 and P = 0.853, respectively). Patients with MRD-negative PR who presented with residual splenomegaly had only a similar PFS (63 months) compared with patients with MRD-negative CR (61 months; P = .354), whereas patients with MRD-negative PR with lymphadenopathy showed a shorter PFS (31 months; P < .001). Conclusion MRD quantification allows for improved PFS prediction in both patients who achive PR and CR, which thus supports its application in all responders. In contrast to residual lymphadenopathy, persisting splenomegaly does not impact outcome in patients with MRD-negative PR.

Lenalidomide maintenance after first-line therapy for high-risk chronic lymphocytic leukaemia (CLLM1): final results from a randomised, double-blind, phase 3 study

BACKGROUND

The combined use of genetic markers and detectable minimal residual disease identifies patients with chronic lymphocytic leukaemia with poor outcome after first-line chemoimmunotherapy. We aimed to assess lenalidomide maintenance therapy in these high-risk patients.

METHODS

In this randomised, double-blind, phase 3 study (CLLM1; CLL Maintenance 1 of the German CLL Study Group), patients older than 18 years and diagnosed with immunophenotypically confirmed chronic lymphocytic leukaemia with active disease, who responded to chemoimmunotherapy 2-5 months after completion of first-line therapy and who were assessed as having a high risk for an early progression with at least a partial response after four or more cycles of first-line chemoimmunotherapy, were eligible if they had high minimal residual disease levels or intermediate levels combined with an unmutated IGHV gene status or TP53 alterations. Patients were randomly assigned (2:1) to receive either lenalidomide (5 mg) or placebo. Randomisation was done with a fixed block size of three, and was stratified according to the minimal residual disease level achieved after first-line therapy. Maintenance was started with 5 mg daily, and was escalated to the target dose of 15 mg. If tolerated, medication was administered until disease progression. The primary endpoint was progression-free survival according to an independent review. The pre-planned interim analysis done by intention to treat was done after 20% of the calculated progression-free survival events. This study is registered with ClinicalTrials.gov, number NCT01556776; treatment in the lenalidomide group is still ongoing.

FINDINGS

Between July 5, 2012, and March 15, 2016, 468 previously untreated patients with chronic lymphocytic leukaemia were screened for the study; 379 (81%) were not eligible. Recruitment was closed prematurely due to poor accrual after 89 of 200 planned patients were randomly assigned: 60 (67%) enrolled patients were assigned to the lenalidomide group and 29 (33%) to the placebo group, of whom 56 (63%) received lenalidomide and 29 (33%) placebo, with a median of 11·0 (IQR 4·5-20·5) treatment cycles at data cutoff. After a median observation time of 17·9 months (IQR 9·1-28·1), the hazard ratio for progression-free survival assessed by an independent review was 0·168 (95% CI 0·074-0·379). Median progression-free survival was 13·3 months (95% CI 9·9-19·7) in the placebo group and not reached (95% CI 32·3-not evaluable) in the lenalidomide group. The most frequent adverse events were skin disorders (35 patients [63%] in the lenalidomide group vs eight patients [28%] in the placebo group), gastrointestinal disorders (34 [61%] vs eight [28%]), infections (30 [54%] vs 19 [66%]), haematological toxicity (28 [50%] vs five [17%]), and general disorders (28 [50%] vs nine [31%]). One fatal adverse event was reported in each of the treatment groups (one [2%] patient with fatal acute lymphocytic leukaemia in the lenalidomide group and one patient (3%) with fatal multifocal leukoencephalopathy in the placebo group).

INTERPRETATION

Lenalidomide is an efficacious maintenance therapy reducing the relative risk of progression in first-line patients with chronic lymphocytic leukaemia who do not achieve minimal residual disease negative disease state following chemoimmunotherapy approaches. The toxicity seems to be acceptable considering the poor prognosis of the eligible patients. The trial independently confirms the clinical significance of a novel, minimal residual disease-based algorithm to predict short progression-free survival, which might be incorporated in future clinical trials to identify candidates for additional maintenance treatment.

FUNDING

Celgene Corporation.

The role of combined fludarabine, cyclophosphamide and rituximab chemoimmunotherapy in chronic lymphocytic leukemia: current evidence and controversies

Chemoimmunotherapy (CIT) has become a cornerstone in the treatment of patients with chronic lymphocytic leukemia (CLL). The combination of fludarabine, cyclophosphamide and rituximab (FCR) has emerged as the standard of care for therapy of previously untreated patients with CLL who are younger than 65 years and have no significant comorbidities. In this article, we review the role of FCR in the current treatment paradigm for CLL.

ESMO consensus conference on malignant lymphoma: general perspectives and recommendations for prognostic tools in mature B-cell lymphomas and chronic lymphocytic leukaemia

The European Society for Medical Oncology (ESMO) consensus conference on mature B-cell lymphomas and chronic lymphocytic leukaemia (CLL) was held on 20 June 2015 in Lugano, Switzerland, and included a multidisciplinary panel of 25 leading experts. The aim of the conference was to develop recommendations on critical subjects difficult to consider in detail in the ESMO Clinical Practice Guidelines. The following areas were identified: (i) the elderly patient, (ii) prognostic factors suitable for clinical use and (iii) the 'ultra-high-risk' group. Before the conference, the expert panel was divided into three working groups; each group focused on one of these areas in order to address four clinically relevant questions relating to that topic. All relevant scientific literature, as identified by the experts, was reviewed in advance. During the consensus conference, each working group developed recommendations to address each of the four questions assigned to their group. These recommendations were then presented to the entire panel and a consensus was reached. This manuscript presents recommendations dedicated to the second area of interest, i.e. prognostic factors suitable for clinical use. The four topics [i.e. interim positron emission tomography (PET), TP53 mutations, cell of origin (COO) and minimal residual disease (MRD)] were primarily chosen because of the bulk of available data together with the lack of clear guidance regarding their use in clinical practice and within clinical trials. Results, including a summary of evidence supporting each recommendation, are detailed in this manuscript. The panel acknowledged that detection of TP53 inactivation by deletion or mutation in CLL should be implemented in clinical practice (level of evidence I, strength of recommendation A). Due to their potentially high prognostic value, at least in some lymphoma entities, implementation of interim PET, COO and MRD was highly recommended in the context of clinical trials. All expert panel members approved this final article.

Chronic Lymphocytic Leukemia in the Elderly, Which Investigations Are Necessary: A Map for the Practicing Oncologist

BACKGROUND

Chronic lymphocytic leukemia (CLL), the most prevalent leukemia in the Western world, is predominantly a disease of older individuals who also have other comorbidities as well as declining organ and bone marrow reserve. Although chemoimmunotherapy is the frontline therapy for fit CLL patients who can tolerate the therapy, many elderly patients cannot tolerate such intense therapy.

METHODS

The authors first reviewed the most recent findings concerning CLL cytogenetics, molecular biology, and prognostic models. They then surveyed recent and ongoing trials of novel CLL agents and strategies, with a focus on those most relevant to elderly patients.

RESULTS

Novel therapies, revised staging procedures, and careful assessment of individual patients' frailty and functional status will allow clinicians to provide optimal care management for older CLL patients.

CONCLUSION

Therapy for the elderly CLL population must be tailored to each patient's fitness level and comorbid conditions, with special consideration for the potential quality-of-life impacts of various treatment recommendations.

Molecular prediction of durable remission after first-line fludarabine-cyclophosphamide-rituximab in chronic lymphocytic leukemia

Fludarabine, cyclophosphamide, and rituximab (FCR) has represented a significant treatment advancement in chronic lymphocytic leukemia (CLL). In the new scenario of targeted agents, there is an increasing interest in identifying patients who gain the maximum benefit from FCR. In this observational multicenter retrospective analysis of 404 CLL patients receiving frontline FCR, the combination of three biomarkers that are widely tested before treatment (IGHV mutation status, 11q deletion and 17p deletion; available in 80% of the study cohort) allowed to identify a very low-risk category of patients carrying mutated IGHV genes but neither 11q or 17p deletion that accounted for 28% of all cases. The majority of very low-risk patients (71%) remained free of progression after treatment and their hazard of relapse decreased after 4 years from FCR. The life expectancy of very low-risk patients (91% at 5 years) was superimposable to that observed in the matched normal general population, indicating that neither the disease nor complications of its treatment affected survival in this favorable CLL group. These findings need a prospective validation and may be helpful for the design of clinical trials aimed at comparing FCR to new targeted treatments of CLL, and, possibly, for optimized disease management.

Three newly approved drugs for chronic lymphocytic leukemia: incorporating ibrutinib, idelalisib, and obinutuzumab into clinical practice

Three agents have received Food and Drug Administration (FDA) approval for treatment of chronic lymphocytic leukemia (CLL) within the past year. Ibrutinib and idelalisib block B-cell receptor signaling through inhibition of Bruton tyrosine kinase and phosphatidylinositol 3-kinase δ molecules respectively, interfering with several pathways required for leukemia cell survival. Idelalisib has shown efficacy in the relapsed setting and is currently approved by the FDA for use in combination with rituximab. Ibrutinib has been studied in patients with relapsed CLL and as frontline therapy. In the relapsed setting, these agents produce durable remissions, and might be preferable to re-treatment with chemoimmunotherapy for many patients. Ibrutinib is also effective treatment for patients with deletion 17p and is approved by the FDA as frontline therapy in this patient group, although it does not appear to completely abrogate this adverse prognostic factor. These agents have a unique side effect profile and longer follow-up is required to further understand tolerability and rare adverse effects. Obinutuzumab is a type-2 monoclonal anti-CD20 antibody which results in direct and antibody-dependent cell-mediated cytotoxicity of leukemia cells. It is approved by the FDA for use in combination with chlorambucil, and has shown efficacy in the frontline setting in patients unfit for more intensive chemoimmunotherapy. It produces increased response rates and minimal residual disease negativity compared with chlorambucil/rituximab and is associated with an advantage in progression-free survival but not yet overall survival. These agents underscore our advancement in the understanding of the biology of CLL and will improve outcomes for many patients with CLL.

Mechanisms of action of fludarabine nucleoside against human Raji lymphoma cells

Fludarabine (2-FaraAMP) is a purine analog that is effective against chronic lymphocytic leukemia (CLL) and non-Hodgkins lymphoma (NHL). For some cases of CLL, 2-FaraAMP as a single agent can clear the blood of leukemia cells, but leukemia stem cells usually remain protected in sanctuary sites. It is clear that 2-FaraAMP has multiple mechanisms of action that may collectively result in strand breaks in DNA, accumulation of phosphorylated p53 and apoptosis. We have demonstrated using the human Burkitt's lymphoma B-cell line, Raji, that p53, p63 and p73 all accumulate in the nucleus, following treatment of cells with fludarabine nucleoside (2-FaraA). In addition, phosphorylated p53 accumulates in the cytosol and at mitochondria. Using sophisticated methods of proteomic analysis with mass spectrometry, proteins that become differentially abundant after treatment of cells with 2-FaraA have been identified, providing considerable additional information about the cellular responses of B-lymphoid cancers to this purine analog. The levels of proteins involved in the unfolded protein response increase, indicating that endoplasmic reticulum stress is likely to be one mechanism for induction of apoptosis. The levels of a number of proteins found on the outer plasma membrane change on cells treated with 2-FaraA, suggesting that signaling from the B-cell antigen receptor (BCR) is stimulated, resulting in induction of apoptosis through the intrinsic pathway. Increased levels of the cell surface proteins, CD50, CD100 and ECE-1, would promote survival of these cells; the balance between these survival and death responses would determine the fate of the cell.

Management of chronic lymphocytic leukemia in elderly patients

SUMMARY 

Chronic lymphocytic leukemia (CLL) is most commonly diagnosed in patients older than 65 years. Although CLL is commonly believed to be indolent in elderly patients, several studies have shown that CLL reduces life expectancy. In elderly patients who need treatment for CLL, evaluation of disease-specific risk factors should be accompanied by measurement of fitness status and co-morbidities so that a treatment option can be selected that best fits the individual patient's goals of therapy. To help define such treatments, a number of recently conducted clinical trials have included elderly or unfit patients. Although purine analog-containing regimens are still recommended for elderly patients who are fit, new approaches are rapidly expanding the treatment options for elderly and unfit individuals.

Transplantation in chronic lymphocytic leukemia: does it still matter in the era of novel targeted therapies?

Allogeneic stem cell transplantation (HSCT) offers the only potentially curative approach in chronic lymphocytic leukemia (CLL). However, this applies only to a minority of patients, and is associated with significant treatment-related mortality and morbidity. HSCT must therefore always be considered in view of other, potentially less toxic therapies. Several new agents demonstrate impressive and durable responses in high-risk patients who might be candidates for HSCT. Therefore the choice of HSCT versus a novel agent is one that must be gauged on a patient-by-patient basis; this will change as data mature on the use of these novel agents in CLL.

Modern treatment in chronic lymphocytic leukemia: impact on survival and efficacy in high-risk subgroups

Treatment of chronic lymphocytic leukemia (CLL) has dramatically changed over the last years, with significant improvement in overall survival (OS) and increased efficacy in genetically defined "high-risk" disease. Besides prospective clinical trials usually enrolling young and fit patients, retrospective studies were performed comparing the outcome of patients belonging to different age groups and showing longer survival in patients diagnosed in the most recent periods. In patients younger than 70 years the 10-year relative survival was 43-53% in the 1980s as compared with 59-63% in the 2000s. Likewise, the 10-year relative survival in patients >70 years was 22-42% in the 1980s and 46-55% in the 2000s. Improved outcome derived in part by the introduction of effective regimens in genetically defined "high-risk" disease (i.e., 17p-, 11q-, TP53, NOTCH1, SF3B1 mutations), especially in the younger and/or fit patients. The unfavorable prognostic significance of 11q- was overcome by chemoimmunotherapy. High-dose steroids with anti-CD52 appeared to improve the response rate in 17p-/TP53 mutated cases and allogeneic transplantation achieved prolonged disease control irrespective of high-risk disease. Further improvement is being generated by the new anti-CD20 obinutuzumab in the elderly and by mechanism-based treatment using kinase-targeting agents or anti-BCL2 molecules yielding high-response rate and impressive progression-free survival in the chemorefractory setting as well as in previously untreated patients.

Prognostic factors in chronic lymphocytic leukemia: a conceptual approach

SUMMARY 

Prognostic assessment is an essential component in the management of patients with chronic lymphocytic leukemia. Prognostic factors (e.g., clinical stage, lymphocyte doubling time and IGHV mutational status/ZAP70 expression), allow predicting time to disease progression and need of therapy and also provide a rough estimate of the overall survival. The most important predictor of survival in patients requiring intervention is response to therapy and its degree, patients with undetectable minimal residual disease following therapy having a much better outcome than those with an inferior response. Given the increasing number of treatment modalities for CLL, the identification of predictive factors is important. Unfortunately, with the only exception of del(17p)/TP53 mutations that predict a poor response to purine analogs-based therapy and del(11q) that correlates with inferior response to fludarabine given as single agent, there are not reliable predictors of response. Well-conducted studies aimed at identifying prognostic and, particularly, predictive factors are needed. New prognostic and predictive parameters should demonstrate superiority over already well validated markers and be helpful in the management of patients with CLL.