Phase II study of cladribine and cyclophosphamide in patients with chronic lymphocytic leukemia and prolymphocytic leukemia

Chronic lymphocytic leukemia: 2022 update on diagnostic and therapeutic procedures

DISEASE OVERVIEW

Chronic lymphocytic leukemia (CLL) is one of the most frequent types of leukemia. It typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that interfere with the regulation of proliferation and of apoptosis in clonal B-cells.

DIAGNOSIS

The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen as well as typical B-cell markers.

PROGNOSIS AND STAGING

The clinical staging systems provide prognostic information by using the results of physical examination and blood counts. Various biological and genetic markers provide additional prognostic information. Deletions of the short arm of chromosome 17 (del[17p]) and/or mutations of the TP53 gene predict resistance to chemoimmunotherapy and a shorter time to progression with most targeted therapies. The CLL international prognostic index integrates genetic, biological, and clinical variables to identify distinct risk groups of patients with CLL.

THERAPY

Only patients with active or symptomatic disease or with advanced Binet or Rai stages require therapy. When treatment is indicated, several therapeutic options exist: a combination of the B-cell lymphoma 2 (BCL2) inhibitor venetoclax with obinutuzumab, monotherapy with inhibitors of Bruton tyrosine kinase (BTK) such as ibrutinib and acalabrutinib, or chemoimmunotherapy. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds 3 years. If the disease relapses earlier, therapy should be changed using an alternative regimen. Patients with a del(17p) or TP53 mutation are usually resistant to chemotherapy and should, therefore, be treated with targeted agents.

FUTURE CHALLENGES

Combinations of targeted agents are now being investigated to create efficient, potentially curative therapies of CLL with fixed duration. One of the most relevant questions currently addressed in clinical trials is the comparison of monotherapies with BTK inhibitors with fixed duration combination therapies. Moreover, the optimal sequencing of targeted therapies remains to be determined. Alternative therapies are needed for patients with BTK and BCL2 inhibitor double-refractory disease.

Prevention and management of adverse effects of disease modifying treatments in multiple sclerosis

PURPOSE OF REVIEW

To summarize the currently known side effects of the approved therapies of multiple sclerosis and to suggest monitoring procedures.

RECENT FINDINGS

The progress in the treatment of multiple sclerosis with new very effective therapies is accompanied by a number of side effects. Some of these have already been described in the approval studies, but some only after approval in a real world situation. The reason for this is the short duration of the clinical studies, the very heterogeneous patient profile in the real world setting with a number of comorbidities, pretherapies, and wider age range. The side effects may occur during application of therapies or afterwards during the course of the treatment. The side effects may range from mild infections, mild laboratory abnormalities, secondary autoimmune diseases to life-threatening side effects such as progressive multifocal leukoencephalopathy.

SUMMARY

It has to be pointed out that these side effects are not to be considered as final and neurologists should be vigilant against new unknown side effects. The doctor should be aware of these undesirable effects, should weigh the benefits of the therapies against the risks, but at the same time she/he should keep in mind that multiple sclerosis can be a very disabling disease if not treated properly.

Chronic lymphocytic leukemia: 2020 update on diagnosis, risk stratification and treatment

DISEASE OVERVIEW

Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B-cells.

DIAGNOSIS

The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen, as well as typical B-cell markers.

PROGNOSIS

The two similar clinical staging systems, Rai and Binet, create prognostic information by using results of physical examination and blood counts. Various biological and genetic markers also have prognostic value. Deletions of the short arm of chromosome 17 (del [17p]) and/or mutations of the TP53 gene, predict resistance to chemoimmunotherapy and a shorter time to progression, with most targeted therapies. A comprehensive, international prognostic score (CLL-IPI) integrates genetic, biological and clinical variables to identify distinct risk groups of CLL patients.

THERAPY

Only patients with active or symptomatic disease, or with advanced Binet or Rai stages require therapy. When treatment is indicated, several options exist for most CLL patients: a combination of venetoclax with obinutuzumab, ibrutinib monotherapy, or chemoimmunotherapy. For physically fit patients younger than 65 (in particular when presenting with a mutated IGVH gene), chemoimmunotherapy with fludarabine, cyclophosphamide and rituximab remains a standard therapy, since it may have curative potential. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds 3 years. If the disease relapses earlier, therapy should be changed using an alternative regimen. Patients with a del (17p) or TP53 mutation are a different, high-risk category and should be treated with targeted agents. An allogeneic SCT may be considered in relapsing patients with TP53 mutations or del (17p), or patients that are refractory to inhibitor therapy.

FUTURE CHALLENGES

Targeted agents (ibrutinib, idelalisib, venetoclax, obinutuzumab) will be increasingly used in combination to allow for short, but potentially definitive therapies of CLL. It remains to be proven that they generate a superior outcome when compared to monotherapies with inhibitors of Bruton tyrosine kinase, which can also yield long-lasting remissions. Moreover, the optimal sequencing of drug combinations is unknown. Therefore, CLL patients should be treated in clinical trials whenever possible.

Prolymphocytic Leukemia: New Insights in Diagnosis and in Treatment

PURPOSE OF REVIEW

We aimed to produce a comprehensive update on clinical and biological data regarding two rare lymphoid neoplasms, B and T prolymphocytic leukemias, and assess therapeutic management in the light of new molecular insights and the advent of targeted therapies.

RECENT FINDINGS

B cell prolymphocytic leukemia (B-PLL) diagnosis remains challenging in the absence of clear immunophenotypic or cytogenetic signature and overlap with mantle cell lymphoma. New molecular defects have been identified in T cell prolymphocytic leukemia (T-PLL), especially in the JAK STAT pathway. Like in chronic lymphocytic leukemia (CLL), B-PLL treatment depends on the presence of TP53 dysfunction. In T-PLL, alemtuzumab still remains the standard of care. Allogeneic transplantation is the only curable option. Thanks to reduced intensity conditioning regimens, it has become accessible to a larger number of patients. PLL prognosis remains poor with conventional therapies. However, great advances in the understanding of both T- and B-PLL pathogenesis lead to promising new therapeutic agents.

Chronic lymphocytic leukemia: 2017 update on diagnosis, risk stratification, and treatment

DISEASE OVERVIEW

Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B cells.

DIAGNOSIS

The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen and B-cell markers.

PROGNOSIS

Two prognostic staging systems exist, the Rai and Binet staging systems, which are established by physical examination and blood counts. Various biological and genetic markers also have prognostic value. Deletions of the short arm of chromosome 17 (del(17p)) and/or mutations of the TP53 gene predict resistance to available chemotherapies. A comprehensive prognostic score (CLL-IPI) using genetic, biological, and clinical variables has recently been developed allowing to classify CLL into very distinct risk groups.

THERAPY

Patients with active or symptomatic disease or with advanced Binet or Rai stages require therapy. For physically fit patients, chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab remains the current standard therapy. For unfit patients, currently available evidence supports two options for a first-line therapy: chlorambucil combined with an anti-CD20 antibody (obinutuzumab or rituximab or ofatumumab) or a continuous therapy with ibrutinib. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds 3 years. If the disease relapses earlier, therapy should be changed using alternative agents such as bendamustine (plus rituximab), alemtuzumab, lenalidomide, ofatumumab, ibrutinib, idelalisib, or venetoclax. Patients with a del(17p) or TP53 mutation can be treated with ibrutinib, venetoclax, or a combination of idelalisib and rituximab. An allogeneic SCT may be considered in relapsing patients with TP53 mutations or del(17p) or patients that are refractory to chemoimmunotherapy and the novel inhibitors.

FUTURE CHALLENGES

The new agents (ibrutinib, idelalisib, venetoclax, and obinutuzumab) hold the potential to significantly improve the outcome of CLL patients. However, their optimal use (in terms of combination, sequence, and duration) remains unknown. Therefore, CLL patients should be treated in clinical trials whenever possible.

Chronic lymphocytic leukemia: 2015 Update on diagnosis, risk stratification, and treatment

DISEASE OVERVIEW

Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B-cells.

DIAGNOSIS

The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen as well as B-cell markers.

PROGNOSIS

Two prognostic staging systems exist, the Rai and Binet staging systems, which are established by physical examination and blood counts. Various biological and genetic markers also have prognostic value. Deletions of the short arm of chromosome 17 (del(17p)) predict resistance to available chemotherapies. Comprehensive prognostic scores are currently being developed.

THERAPY

Patients with active or symptomatic disease or with advanced Binet or Rai stages require therapy. For physical fit patients, chemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab remains the current standard therapy. For unfit patients, treatment with an anti-CD20 antibody (obinutuzumab or rituximab or ofatumumab) plus a milder chemotherapy (Chlorambucil) may be applied. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds two to three years. If the disease relapses earlier, therapy should be changed using alternative agents such as bendamustine (plus rituximab), alemtuzumab, lenalidomide, ofatumumab, ibrutinib, or idelalisib. Patients with a del(17p) or TP53 mutation can be treated with ibrutinib or a combination of idelalisib and rituximab. An allogeneic SCT may be considered in relapsing patients with TP53 mutations or del(17p) or patients that are refractory to repeated chemoimmunotherapies. Future challenges: Several new agents (e.g., ibrutinib, idelalisib, obinutuzumab) hold the potential to improve the outcome of patients with CLL. However, their optimal use (in terms of combination, sequence, and duration) is unknown. Therefore, CLL patients should be treated in clinical trials whenever possible.

Cladribine prolongs progression-free survival and time to second treatment compared to fludarabine and high-dose chlorambucil in chronic lymphocytic leukemia

We conducted a randomized phase III trial to compare the efficacy and safety of two purine analogs, cladribine and fludarabine, with high-dose chlorambucil, in patients with previously untreated chronic lymphocytic leukemia (CLL). Between 1997 and 2004, 223 patients with CLL were randomly assigned to cladribine, fludarabine or chlorambucil, for six cycles of therapy with frequent health-related quality of life assessments. There was no statistical difference for the primary endpoint of overall response with cladribine (70%), fludarabine (67%) and chlorambucil (59%), or complete remission (12%, 7% and 8%), respectively. However, the median progression-free survival (25, 10, 9 months) and median time to second treatment (40, 22, 21 months) were superior with cladribine. There was no significant difference in overall survival (96, 82 and 91 months), nor in toxicity or HRQoL assessments. Monotherapy with cladribine gives superior PFS and longer response duration than fludarabine and chlorambucil as first-line treatment of CLL.

Chronic lymphocytic leukemia: 2013 update on diagnosis, risk stratification and treatment

DISEASE OVERVIEW

Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B-cells.

DIAGNOSIS

The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen as well as B-cell markers.

PROGNOSIS

Two prognostic staging systems exist, the Rai and Binet staging systems, which are established by physical examination and blood counts. Various biological and genetic markers also have prognostic value. Deletions of the short arm of chromosome 17 (del(17p)) predict resistance to most available therapies.

THERAPY

Patients with active or symptomatic disease or with advanced Binet or Rai stages require therapy. For physical fit patients, chemoimmunotherapy with fludarabine, cyclophosphamide and rituximab represents the current standard therapy. For unfit patients, treatment with an anti-CD20 antibody plus a milder chemotherapy (chlorambucil) is currently established as standard treatment. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds two years. If the disease relapses earlier, alternative therapies such as bendamustine alone or with rituximab, alemtuzumab, lenalidomide, or ofatumumab should be used. Patients with a del(17p) or TP53 should be considered for an allogeneic SCT.

FUTURE CHALLENGES

Several new agents (e.g., ibrutinib, obinutuzumab) hold the potential to change standard of CLL treatment in the next 6-12 months. Therefore, CLL patients should be included into current clinical trials whenever possible.

How I treat prolymphocytic leukemia

T- and B-cell subtypes of prolymphocytic leukemia (PLL) are rare, aggressive lymphoid malignancies with characteristic morphologic, immunophenotypic, cytogenetic, and molecular features. Recent studies have highlighted the role of specific oncogenes, such as TCL-1, MTCP-1, and ATM in the case of T-cell and TP53 mutations in the case of B-cell prolymphocytic leukemia. Despite the advances in the understanding of the biology of these conditions, the prognosis for these patients remains poor with short survival and no curative therapy. The advent of monoclonal antibodies has improved treatment options. Currently, the best treatment for T-PLL is intravenous alemtuzumab, which has resulted in very high response rates of more than 90% when given as first-line treatment and a significant improvement in survival. Consolidation of remissions with autologous or allogeneic stem cell transplantation further prolongs survival, and the latter may offer potential cure. In B-PLL, rituximab-based combination chemo-immunotherapy is effective in fitter patients. TP53 abnormalities are common and, as for chronic lymphocytic leukemia, these patients should be managed using an alemtuzumab-based therapy. The role of allogeneic transplant with nonmyeloablative conditioning needs to be explored further in both T- and B-cell PLL to broaden the patient eligibility for what may be a curative treatment.

A case report of T cell prolymphocytic leukemia and Kaposi sarcoma and a review of T cell prolymphocytic leukemia

T cell prolymphocytic leukemia (T-PLL) is a rare mature T cell lymphoproliferative disease. It has been associated with an aggressive course, a poor response to conventional chemotherapy and a short median survival. Here we present a rare case of concurrent T-PLL and Kaposi sarcoma who achieved a complete hematologic and cytogenetic remission after a very short course of treatment with alemtuzumab. A review of T-PLL was done. In this review, clinical features, laboratory features and current therapeutic strategies of T-PLL are presented.

New and emerging disease modifying therapies for multiple sclerosis

Several disease-modifying drugs (DMDs) are currently approved for the treatment of multiple sclerosis (MS). Recently, there has been increased identification and development of potential new treatments that may modulate the MS disease process, including oral therapies. Many of the newly approved MS therapies, as well as those in ongoing clinical trials, have the advantage of improved efficacy and/or being oral and more convenient, as compared to conventional injectable first-line MS therapies. However, many of these new and emerging MS treatments are known to be associated with serious adverse events, some of which may be potentially life threatening. Of additional concern, there is limited experience and long-term safety data for many of these drugs, and thus the true potential for complications associated with these agents remains ambiguous. With an anticipated explosion in the artillery of available MS therapies in the near future, neurologists will need to carefully weigh drug efficacy, convenience, safety, and tolerability when making therapeutic decisions. In this review, we describe the known mechanisms of action, efficacy, and side-effect profiles of new and emerging MS DMDs.

Oral therapies for multiple sclerosis: a review of agents in phase III development or recently approved

Several disease-modifying therapies are approved for the management of multiple sclerosis (MS). While reasonably effective, these therapies require long-term parenteral self-injection, which is inconvenient for some patients and can be associated with injection-related adverse effects. Consequently, there is a need in MS for an oral therapy option. Currently, five oral therapies are in phase III development or have recently been approved for the treatment of relapsing-remitting MS: cladribine (approved in Russia and Australia), fingolimod (approved in the US and Russia), BG-12 (phase III), laquinimod (phase III) and teriflunomide (phase III). While the availability of oral therapies has been much anticipated by physicians and patients, neurologists will need to be cautious in selecting such therapy, which may appear to have efficacy and convenience advantages versus current therapies, but may also carry novel safety and tolerability concerns. The decision to use these new therapies will most likely be based on an overall assessment of efficacy, safety, tolerability and adherence, the potential need for monitoring and cost effectiveness. The objective of this article is to review the currently available data for each of these new oral therapies, which addresses the mechanism of action, efficacy and safety, and to provide a perspective on the potential future role of these therapies within clinical practice. Although better patient compliance is expected with the oral agents compared with the injectables, the safety profiles of these new oral drugs will have to be watched carefully.

Beyond hairy cell: the activity of cladribine in other hematologic malignancies

Before the contemporary development of rationally designed antineoplastic therapies, cladribine was identified as a lymphocyte-specific agent. Its profound impact on the natural history of hairy cell leukemia, with responses approaching 100% and a median duration of response of nearly a decade after only a single 7-day course, is well known and revolutionized the treatment of hairy cell leukemia. However, cladribine's impressive activity in other lymphoproliferative disorders has been generally underappreciated. Multiple single-arm phase 2 trials have demonstrated cladribine's potency across the full spectrum of lymphoid malignancies. In a limited number of phase 3 trials and cross-study analyses, cladribine compared favorably with fludarabine, another purine nucleoside analog that is more commonly used in the treatment of indolent lymphoid malignancies. Cladribine has been noted to have particular activity among lymphoid disorders with few effective therapies, specifically, chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, marginal zone lymphoma, and mantle cell lymphoma. Recently approved novel agents may act in synergy with cladribine for these conditions and should be incorporated into future clinical studies.

In vivo bioluminescence imaging and histopathopathologic analysis reveal distinct roles for resident and recruited immune effector cells in defense against invasive aspergillosis

Background

Invasive aspergillosis (IA) is a major cause of infectious morbidity and mortality in immune compromised patients. Studies on the pathogenesis of IA have been limited by the difficulty to monitor disease progression in real-time. For real-time monitoring of the infection, we recently engineered a bioluminescent A. fumigatus strain.

Results

In this study, we demonstrate that bioluminescence imaging can track the progression of IA at different anatomic locations in a murine model of disease that recapitulates the natural route of infection. To define the temporal and functional requirements of distinct innate immune cellular subsets in host defense against respiratory A. fumigatus infection, we examined the development and progression of IA using bioluminescence imaging and histopathologic analysis in mice with four different types of pharmacologic or numeric defects in innate immune function that target resident and recruited phagocyte subsets. While bioluminescence imaging can track the progression and location of invasive disease in vivo, signals can be attenuated by severe inflammation and associated tissue hypoxia. However, especially under non-inflammatory conditions, such as cyclophosphamide treatment, an increasing bioluminescence signal reflects the increasing biomass of alive fungal cells.

Conclusions

Imaging studies allowed an in vivo correlation between the onset, peak, and kinetics of hyphal tissue invasion from the lung under conditions of functional or numeric inactivation of phagocytes and sheds light on the germination speed of conidia under the different immunosuppression regimens. Conditions of high inflammation -either mediated by neutrophil influx under corticosteroid treatment or by monocytes recruited during antibody-mediated depletion of neutrophils- were associated with rapid conidial germination and caused an early rise in bioluminescence post-infection. In contrast, 80% alveolar macrophage depletion failed to trigger a bioluminescent signal, consistent with the notion that neutrophil recruitment is essential for early host defense, while alveolar macrophage depletion can be functionally compensated.

Allogeneic hematopoietic cell transplant for prolymphocytic leukemia

The poor prognosis of patients with prolymphocytic leukemia (PLL) has led some clinicians to recommend allogeneic hematopoietic cell transplant (HCT). However, the data to support this approach is limited to case-reports and small case series. We reviewed the database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to determine outcomes after allotransplant for patients with PLL. We identified 47 patients with a median age of 54 years (range: 30-75 years). With a median follow-up of 13 months, progression-free survival (PFS) was 33% (95% confidence interval [CI] 20%-47%) at 1 year. The most common cause of death was relapse or progression in 49%. The cumulative incidence of treatment-related mortality (TRM) at 1-year posttransplant was 28%. The small patient population prohibited prognostic factor analysis, but these data support consideration of allotransplant for PLL. Further study of a larger population of patients is needed to determine which patients are more likely to benefit.

Current status of older and new purine nucleoside analogues in the treatment of lymphoproliferative diseases

For the past few years more and more new cytotoxic agents active in the treatment of hematological malignancies have been synthesized and become available for either in vitro studies or clinical trials. Among them the class of antineoplastic drugs belonging to the purine nucleoside analogues group (PNAs) plays an important role. Three of them: pentostatin (DCF), cladribine (2-CdA) and fludarabine (FA) were approved by Food and Drug Administration (FDA) for the treatment of hematological malignancies. Recently three novel PNAs: clofarabine (CAFdA), nelarabine (ara-G) and forodesine (immucillin H, BCX-1777) have been synthesized and introduced into preclinical studies and clinical trials. These agents seem to be useful mainly for the treatment of human T-cell proliferative disorders and they are currently undergoing clinical trials in lymphoid malignancies. However, there are also several studies suggesting the role of these drugs in B-cell malignancies. This review will summarize current knowledge concerning the mechanism of action, pharmacologic properties, clinical activity and toxicity of PNAs accepted for use in clinical practice, as well as new agents available for clinical trials.

State-of-the-art treatment of chronic lymphocytic leukemia

The last decade has produced rapid progress in the management of chronic lymphocytic leukemia (CLL). Fludarabine, bendamustine and two monoclonal antibodies, alemtuzumab and rituximab, have been approved by the European and/or American regulatory agencies. Several, novel monoclonal antibodies targeting CD20, CD23 or CD40, as well as drugs designed to interfere with proteins regulating the cell cycle, apoptotic machinery, or leukemic microenvironment (eg, flavopiridol, oblimersen, or lenalidomide), are currently being tested in clinical trials. Furthermore, the increased experience with reduced-intensity allogeneic progenitor cell transplantation allows offering this option to physically fit patients. In addition, new prognostic markers that may influence therapeutic decisions have been identified. This review attempts to summarize the current use of these different modalities in CLL therapy.

The role of DNA repair in chronic lymphocytic leukemia pathogenesis and chemotherapy resistance

Front-line therapy for chronic lymphocytic leukemia (CLL) with alkylating agents is associated with low rates of complete remission and no improvement in overall survival. The ability of CLL cells to efficiently repair alkylator-induced damage to DNA might explain this lack of response. Novel strategies that inhibit DNA repair, such as combinations of alkylating agents, purine nucleoside analogues, and immunotherapy, have produced durable clinical and molecular remission in both untreated and relapsed CLL. This review evaluates the contribution of DNA repair processes in the development of resistance to chemotherapy and the impact of therapies that exploit the DNA repair capacity of CLL cells to therapeutic advantage.

Effect of leukocyte inhibitors benzydamine and cyclophosphamide, on lung injury caused by Tityus discrepans scorpion venom

We studied the effects of benzydamine (BZ) and cyclophosphamide (CP) on acute lung injury caused by Tityus discrepans venom. Mice (male, IVIC strain, approximately 25g) were pretreated with either BZ (20microg/g) or CP (100microg/g) i.p. or saline. Envenoming (2microg/g mouse) was induced sc. Lung fraction area occupied by fibrin (FF), nuclei (NF), alveolar space (AS) and parenchyma (PF) were determined. Venom increased FF, NF and PF, significantly, and decreased AS. BZ antagonised venom's effect on FF sharply, antagonised partially effects on PF and AS, but was not able to antagonise effect on NF. CP abolished venom effects on NF, AS and PF, but was not able to antagonise the effect on FF. CP was slightly less effective than BZ in reducing FF. Fibrin deposition was associated to leukocyte sequestration. Blocking pro-inflammatory leukocyte metabolic pathways with BZ diminished FF, suggesting that neutrophil activation, inflammation and coagulation are correlated in the genesis of scorpionism acute lung injury.

Emerging therapy for chronic lymphocytic leukaemia

The presentation, clinical course and prognosis for chronic lymphocytic leukaemia (CLL) is diverse and strategies for therapy reflect this variability. Staging of the disease has assisted in deciding treatment options and more recently the cytogenetic, molecular and surrogate markers of the immunoglobulin heavy chain mutational status, CD38 and ZAP-70, have assisted in further risk stratification. Chemotherapy has been the mainstay of interventional therapy when required and the two most important classes of agents in the treatment of CLL are nucleoside analogues and alkylating agents. Combining these two groups of agents has significantly improved prognosis in this disease. More recently a number of novel agents have been applied to patients with CLL to determine if they represent better therapy. However, allogeneic stem cell transplantation offers perhaps the only realistic chance of a cure in this disease. Clinical trials are still needed to determine the timing and role of this promising treatment modality in the treatment of CLL and, where possible, combined with the emerging awareness of the disease biology, related biological markers and prognostic indicators.

Recent progress in the management of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a clonal disease characterized by proliferation and accumulation of small CD5-positive B cells. More than 50% of patients are asymptomatic at diagnosis and usually require no treatment. However, treatment is needed in the advanced and progressive disease. Chlorambucil with or without steroids has been the drug of choice for many years in previously untreated patients with CLL. The purine nucleoside analogs (PNAs), fludarabine (FA), cladribine (2-CdA-chlorodeoxyadenosine) and pentostatin (DCF, 2'-deoxycoformycin) also have been introduced for treatment of CLL. Significantly higher overall response (OR) and complete response (CR) and longer progression free survival (PFS) in patients with CLL treated with FA or 2-CdA have been confirmed in randomized, multicenter trials and more recently in meta-analysis. However, the median survival time did not differ between patients treated with PNA and alkylating agents. Combination therapies with PNAs and cyclophosphamide and especially with cyclophosphamide and rituximab are more active than monotherapy in terms of OR, CR and PFS. Several reports have shown significant activity of alemtuzumab in previously untreated and pretreated patients even when refractory to FA. Alemtuzumab also can be used in CLL as a preparative regimen before stem cell transplantation (SCT) and to eliminate minimal residual disease (MRD). Recently, several new agents have shown promise in treating CLL, including new monoclonal antibodies, agents targeting bcl-2 family of proteins, antisense oligonucleotides and other agents. Moreover, autologous and allogenic hematopoietic cell transplantations are increasingly considered for treatment of patients with CLL. In this review current therapeutic strategies in CLL are presented.

Rituximab plus cladribine with or without cyclophosphamide in patients with relapsed or refractory chronic lymphocytic leukemia

OBJECTIVES

The aim of our study was to determine the feasibility, effectiveness and toxicity of combined regimens consisting of rituximab and cladribine (2-CdA) (RC) and RC plus cyclophosphamide (RCC) in the treatment of patients with recurrent or refractory chronic lymphocytic leukemia (CLL).

METHODS

The RC regimen consisted of rituximab given on day 1 and 2-CdA (days 2-6). The RCC protocol included rituximab (day 1), 2-CdA (days 2-4) and cyclophosphamide given on days 2-4. The courses were re-administered at time intervals of 4 weeks or longer if severe myelosuppression occurred.

RESULTS

Forty-six patients with CLL entered the study. Eighteen patients were treated with RC and 28 with RCC regimen. The median number of courses administered were three cycles (range 1-6). Three (6.5%) patients (95% CI: 1-14%) achieved a complete response and 31 (67%) patients (95% CI: 50-83%) a partial response. According to the particular regimen, the overall response rate was obtained in 12 (67%) patients treated with RC (95% CI: 45-89%) and in 22 patients (78%) treated with RCC (95% CI: 62-93%). The median progression free survival of responders to RC/RCC regimens was 12 months (range 4-46). Hypersensitivity to rituximab occurred in 16 (33%) patients, mostly during the first infusion of the drug. Grade 3/4 neutropenia was seen in six (13%) patients, grade 3/4 thrombocytopenia in three (9%) patients and grade 3/4 infections were observed in ten (28%) patients.

CONCLUSIONS

These data indicate that both RC and RCC regimens are feasible in heavily pretreated patients with CLL, showing also distinct therapeutic activity and relatively low toxicity, even in patients previously treated with cladribine-based protocols.

Two novel nucleoside ester derivatives of chlorambucil as potential antileukemic prodrugs: a preliminary study

2-Chloro-2'-deoxyadenosine (cladribine) and chlorambucil are two drugs used in the treatment of lymphoid malignancies. We have synthesized 5'-O-esters of cladribine and its parental nucleoside 2'-deoxyadenosine with chlorambucil (2-chloro-2'-deoxyadenosine-chlorambucil and 2'-deoxyadenosine-chlorambucil, respectively) and compared some properties of the esters with regard to their potential use as antileukemic prodrugs. The 5'-O-ester bond showed no spontaneous hydrolysis at pH 7.4, but was susceptible to hydrolysis by porcine liver esterase and enzymes present in human lymphocyte lysate and blood plasma. Both 2-chloro-2'-deoxyadenosine-chlorambucil and 2'-deoxyadenosine-chlorambucil were taken up more avidly than their parental nucleosides by normal and malignant human lymphoid cells. 2-Chloro-2'-deoxyadenosine-chlorambucil was by an order of magnitude more toxic than 2'-deoxyadenosine-chlorambucil to human leukemic MOLT4 cells in culture. On the other hand, 2-chloro-2'-deoxyadenosine-chlorambucil cytotoxicity did not exceed that of its parental 2-chloro-2'-deoxyadenosine in MOLT4 cells, whereas 2'-deoxyadenosine-chlorambucil was considerably more cytotoxic than free chlorambucil in a variety of myeloid and lymphoid human malignant cell lines. Moreover, acute toxicity of 2'-deoxyadenosine-chlorambucil was lower than that of chlorambucil in mice. In summary, 2'-deoxyadenosine-chlorambucil, but not 2-chloro-2'-deoxyadenosine-chlorambucil, shows promise for clinical utility as a chlorambucil prodrug and thus warrants a more detailed study in vivo.

Recent advances in chronic lymphocytic leukemia

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

Chronic lymphocytic leukemia: diagnosis and treatment

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

Pentostatin for the Treatment of Indolent Lymphoproliferative Disorders

Purine analogues have been shown to be active in a variety of B- and T-cell malignancies. Among them, pentostatin is also a tight binding inhibitor of adenosine deaminase (ADA), a key enzyme of purine metabolism. ADA is present in all human tissues, with the highest levels in the lymphoid system. Early clinical trials with pentostatin used high doses for acute lymphoblastic leukemias, which were characterized by high levels of ADA. Through the efforts of a few investigators, low-dose regimens that are active and well tolerated for indolent lymphoid malignancies have been developed. Myelosuppressive adverse effects have been shown to be minimal using these schedules. Lymphoplasmacytic lymphoma (LL) is an indolent chronic B-cell lymphoproliferative disorder moderately responsive to alkylating agents. All of the purine analogues have shown activity in LL. However, the advantage of pentostatin over the other agents is the relatively specific toxicity to lymphoid cells and the paucity of myelosuppression as a single agent. No direct comparisons of the agents have been investigated, although pentostatin may be considered to be preferred since it has not been associated with toxicity to myeloid progenitors in colony assays. This is of significance for patients who might benefit from high-dose chemotherapy with autologous stem cell transplantation.

Purine Analogue-Based Chemotherapy Regimens for Second-Line Therapy in Patients With Chronic Lymphocytic Leukemia

A dramatic change has occurred in the management of chronic lymphocytic leukemia (CLL) over the past 20 years. The use of newer therapies, including the purine analogues, has resulted in higher frequencies of response. Combination therapy with purine analogues, alkylators, and/or monoclonal antibodies represents a promising new approach to the treatment of patients with CLL. The most commonly studied regimens have utilized fludarabine, but severe myelosuppression and immunosuppression of these combinations require close attention to dosing and schedule. Of the purine analogues that show activity in CLL, pentostatin appears to be the least myelosuppressive. These combination strategies are associated with high-quality responses in the majority of patients and may one day lead to improved survival or possibly even a cure for patients with CLL.

Chronic Lymphocytic Leukemia: Recent Advances in Diagnosis and Treatment

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

Changes in the natural history of progressive multifocal leukoencephalopathy in HIV-negative lymphoproliferative disorders: impact of novel therapies

The aims of this study were to evaluate the clinical characteristics of HIV-negative patients affected by lymphoproliferative disorders (LPD) who developed progressive multifocal leukoencephalopathy (PML), to delineate the risk factors, and to analyze whether the new antineoplastic therapies are changing the natural history of this infectious disease. We retrospectively analyzed 46 cases with confirmed LPD-associated PML published from 1958 to 2004. Patients were stratified according to two different time periods: group A included patients diagnosed before 1989, and group B included patients diagnosed since 1990, after introduction of purine analogues. Group A patients (n = 22) had received alkylating agents and/or radiotherapy, and the majority (63.6%) had advanced Hodgkin disease. At univariate analysis, uncontrolled Hodgkin disease was the only risk factor for PML. In group B patients (n = 24), the most frequent treatments received were purine analogues (58.3%) and high-dose therapy with hematopoietic stem cell transplantation (33.3%; HDT/HSCT). B-cell chronic lymphocytic leukemia (45.8%) and aggressive non-Hodgkin lymphoma (24.9%) were the most frequent underlying LPDs. Patients treated with purine analogues were more likely to have active LPD, lower CD4 cell counts, and to be older and male than were HSCT recipients. The median interval from purine analogues or HDT/HSCT to PML was 11 months. In HDT/HSCT recipients, this interval was delayed for 10 months when peri-transplantation rituximab was used. Univariate analysis identified age >55 years, male sex, and CD4 cell counts <or=0.2 x 10(9)/L as risk factors for PML in patients treated with purine analogues. Mortality rates were 95.4% (group A patients), 90% (purine analogues), and 62.5% (HDT/HSCT recipients). At univariate analysis, the only factor that significantly correlated with recovery from infection was female sex. Our findings indicate (1) the possible reduction in reported cases associated with Hodgkin disease and the increasing number of published cases associated with the new antineoplastic therapies (purine analogues and HDT/HSCT); (2) among patients treated with purine analogues, PML is more common in male patients with CD4 cell counts <or=0.2 x 10(9)/L; (3) the use of rituximab after HDT/HSCT seems to delay the onset of PML; and (4) the prognosis is slightly better in transplant recipients.

Pentostatin/Cyclophosphamide with or Without Rituximab: An Effective Regimen for Patients with Waldenström's Macroglobulinemia/Lymphoplasmacytic Lymphoma

BACKGROUND

Pentostatin has demonstrated significant activity as a single agent in patients with low-grade B-cell and T-cell lymphomas and is less myelosuppressive than other purine analogues.

PATIENTS AND METHODS

We conducted a phase II trial with the combination regimen of PC-R (pentostatin/cyclophosphamide with or without rituximab) in 14 patients with Waldenstrom's macroglobulinemia (WM) and 3 patients with lymphoplasmacytic lymphoma (LL) without monoclonal serum immunoglobulin M (IgM), followed by a maintenance regimen with rituximab (375 mg/m2 every 3 months) for patients exhibiting a complete response (CR) or a partial response (PR) after 4-6 cycles. Nine patients were untreated, and 8 had been previously treated with 1-3 regimens. The first 9 patients received PC therapy (pentostatin 4 mg/m2 plus cyclophosphamide 600 mg/m2), and 8 patients received the same combination with rituximab 375 mg/m2 on day 1. Cycles were repeated every 3 weeks.

RESULTS

An objective tumor response after PC and PC-R was confirmed in 11 of 17 evaluable patients (64.7%), with 2 CRs (11.7%) and 9 PRs (52.9%). In patients who received rituximab (n = 13) simultaneously or subsequently, the overall response rate was 76.9%. Grade 2/3 nausea and grade 2 vomiting was generally mild based on World Health Organization criteria. Grade 3 hematologic toxicity occurred after 9 of 49 cycles (18.3%), and grade 4 toxicity occurred after 2 cycles (4%). Ten patients were subsequently treated with rituximab every 3 months for 2-9 cycles to date (median, 4 cycles). No patients have had disease relapse to date, and all exhibited stable IgM serum levels. In 3 patients with a PR after completion of chemotherapy, remission has improved further, with normalization of the IgM level in 1 patient and another patient exhibiting a CR.

CONCLUSION

Our data indicate that PC-R is safe and highly effective in patients with WM. Maintenance therapy with rituximab for WM as a single infusion every 3 months can be administered safely and can improve remission status.

Therapy of chronic lymphocytic leukemia with purine analogs and monoclonal antibodies

B-cell chronic lymphocytic leukemia (CLL) is a clonal hematopoietic disorder characterized by proliferation and accumulation of small lymphocytes. It is the most common form of leukemia in North America and Europe. The management of CLL is determined by the stage and activity of the disease. Several randomized studies indicate that cytotoxic therapy based on alkylating agents in the indolent phase of disease, does not prolong the survival time of CLL patients. Chlorambucil, with or without steroids, has been for many years the drug of choice in previously untreated patients with this leukemia. Alternative treatment approaches, including new purine nucleoside analogs (PNA), such as fludarabine and 2-chlorodeoxyadenosine (cladribine) have also shown activity in CLL. The randomized studies have indicated a higher overall response, complete remission rates and longer response duration in patients treated initially with PNA than with chlorambucil or cyclophosphamide based combination regimens. These agents alone or in combinations, seem to be the treatment of choice for patients failing standard therapies. The monoclonal antibodies directed against CD52 antigen (alemtuzumab, Campath-1H) and CD20 antigen (rituximab) demonstrate also significant activity in CLL patients. These agents have significant single-agent activity, distinct mechanism of action and generally, favorable toxicity profiles. Both antibodies achieved the most promising results in the treatment of patients with relapsed or refractory CLL. More recently the effect of alemtuzumab in previously untreated patients has been also investigated and results are very encouraging. A multicenter prospective randomized study comparing alemtuzumab and chlorambucil as first line therapies are ongoing and preliminary results show acceptable toxicity profile of monoclonal antibody.

Prolymphocytic leukemia

Prolymphocytic leukemia is a rare chronic lymphoproliferative disorder that includes two subtypes, B cell and T cell, each with its own distinct clinical, laboratory and pathological features. T-cell prolymphocytic leukemia has an aggressive course with short median survival and poor response to chemotherapy. With the use of the purine analogue pentostatin more than half of patients will have a major response and a minority will have a complete remission, usually lasting months. With the introduction of alemtuzumab, most patients who progressed despite treatment with pentostatin had a major response with a complete remission rate higher than that obtained with pentostatin when used as a first line. Unfortunately, progression still follows shortly. We recommend alemtuzumab as initial therapy and offer stem cell transplant (SCT) to selected young, healthy patients who respond. Although B-cell prolymphocytic leukemia is also a progressive disease, some patients can achieve a prolonged progression-free-survival with fludarabine. Patients presenting with massive splenomegaly may be effectively palliated with splenic irradiation or splenectomy. Rituximab is a promising agent and further investigations are warranted to better define its role in treatment of this disorder.

Hematopoietic cell transplantation after nonmyeloablative conditioning for advanced chronic lymphocytic leukemia

PURPOSE

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Advances in the diagnosis and treatment of chronic lymphocytic leukemia

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

An update on the management of chronic lymphocytic leukaemia

Despite the lack of long-term survival data, the impressive results obtained with fludarabine- and rituximab-based therapies have altered the philosophy of the management of patients with chronic lymphocytic leukaemia (CLL). Therapy with chemoimmunotherapy appears to give higher responses with more patients achieving complete remission and some molecular remission. This may potentially translate into improved disease-free survival, and potentially a 'cure'. Treatment options for patients who develop resistance to fludarabine continue to be limited. This review summarises current chemo-, immuno-, and chemoimmunotherapeutic regimens that are being currently evaluated in patients with CLL.

Chronic Lymphocytic Leukemia (CLL): First-Line Treatment

For the past ten years, there has been a dynamic development of new therapeutic compounds and prognostic parameters for chronic lymphocytic leukemia (CLL). Hematologists and oncologists are challenged to use these new possibilities for an optimized, risk- and fitness-adapted treatment strategy, with the goal of achieving long-term remissions and preserving a good quality of life. This review is intended to summarize the current knowledge on first-line treatment of CLL.

Chronic Lymphocytic Leukemia (CLL): First-Line Treatment

For the past ten years, there has been a dynamic development of new therapeutic compounds and prognostic parameters for chronic lymphocytic leukemia (CLL). Hematologists and oncologists are challenged to use these new possibilities for an optimized, risk- and fitness-adapted treatment strategy, with the goal of achieving long-term remissions and preserving a good quality of life. This review is intended to summarize the current knowledge on first-line treatment of CLL.

Therapy of Chronic Lymphocytic Leukaemia with Purine Nucleoside Analogues

Chronic lymphocytic leukaemia (CLL) is a neoplastic disease of unknown aetiology characterised by an absolute lymphocytosis in peripheral blood and bone marrow. The disease is diagnosed most commonly in the elderly with the median age at diagnosis being about 65 years. The purine nucleoside analogues (PNAs) fludarabine, cladribine (2-chlorodeoxyadenosine) and pentostatin (2'-deoxycoformycin) are highly active in CLL, both in previously treated and in refractory or relapsed patients. These three agents share similar chemical structures and mechanisms of action such as induction of apoptosis. However, they also exhibit significant differences, especially in their interactions with enzymes involved in adenosine and deoxyadenosine metabolism. Recent randomised studies suggest that fludarabine and cladribine have similar activity in CLL. However, clinical observations indicate the existence of cross-resistance between fludarabine and cladribine. Patients who received PNAs as their initial therapy and achieved long-lasting response can be successfully retreated with the same agent. PNAs administered in combination with other chemotherapeutic agents and/or monoclonal antibodies may produce higher response rates, including complete response (CR) or molecular CR, compared with PNAs alone or other treatment regimens. Management decisions are more difficult in elderly patients because of the apparent increase in toxicity of PNAs in this population. In elderly patients, we recommend chlorambucil as the first-line treatment, with PNAs in lower doses in refractory or relapsed patients. Myelosuppression and infections, including opportunistic varieties, are the most frequent adverse effects in patients with CLL treated with PNAs. Therefore, some investigators recommend routine antibacterial and antiviral prophylaxis during and after PNA treatment. This review presents current results and treatment strategies with the use of PNAs in CLL, especially in elderly patients.

The place of cladribine in the treatment of chronic lymphocytic leukemia: a 10-year experience in Poland

Cladribine (2-CdA) is structurally similar to another purine analog, fludarabine (FA), recently accepted in several centers as the first-line treatment in chronic lymphocytic leukemia (CLL). Unfortunately, there is less experience with the use of 2-CdA than with FA in patients with CLL in the majority of Western countries. In the last decade we performed several phase II studies and two phase III randomized trials to evaluate the activity and toxicity of 2-CdA in previously treated and untreated patients with CLL. We have also compared the results of Polish studies with the data presented by other investigators. Similarly to FA this agent has been found to be more effective in previously untreated CLL than in patients refractory to or relapsed after conventional therapy with alkylating agents. In different studies the overall response (OR) rate ranged from 70 to 85% and complete response (CR) from 10 to 47%. Higher CR and OR rates in CLL patients treated with 2-CdA and prednisone than with chlorambucil and prednisone were confirmed in our multicenter, randomized study. Subsequently, we performed a multicenter, randomized study comparing 2-CdA alone with a combination of 2-CdA and cyclophosphamide (CC) or cyclophosphamide and mitoxantrone (CMC). Our updated results seem to indicate that the CC program used as a first-line therapy in CLL gives higher CR and OR and better elimination of minimal residual disease (MRD) than 2-CdA alone. CC is also less myelotoxic than CMC. More recently, we have undertaken a phase II study to determine the efficacy and toxicity of 2-CdA combined with the anti-CD20 monoclonal antibody rituximab in CLL and other refractory or relapsed indolent lymphoproliferative disorders. The preliminary results seem to be better than in similar patients previously treated in our institution with 2-CdA alone. In conclusion, the studies performed in the last decade in Poland and other countries have shown that 2-CdA used alone or in combination with other agents is, similarly to FA, a highly active and relatively safe agent in previously treated and untreated patients with CLL.

Activity of lung neutrophils and matrix metalloproteinases in cyclophosphamide-treated mice with experimental sepsis

Sepsis in patients receiving chemotherapy may result in acute respiratory distress syndrome, despite decreased number of blood neutrophils [polymorphonuclear neutrophils (PMNs)]. In the present study, we investigated the correlation of cyclophosphamide (CY)-induced neutropenia with the destructive potential of lung PMN in respect to formation of septic acute lung injury (ALI). Mice were treated with 250 mg/kg of CY or saline (control) and subjected to cecal ligation and puncture (CLP) or sham operation. ALI was verified by histological examination. Lung PMNs and matrix metalloproteinases (MMPs) were assessed by flow cytometry and gelatin zymography. CLP in CY-treated mice induced a typical lung injury. Despite profound neutropenia, CY treatment did not attenuate CLP-induced ALI. This might relate to only a partial suppression of PMN: CY has significantly reduced PMN influx into the lungs (P = 0.008) and suppressed their oxidative metabolism, but had no suppressive effect on degranulation (P = 0.227) and even induced MMP-9 activity (P = 0.0003). In CY-untreated animals, peak of CLP-induced ALI coincided with massive PMN influx (P = 0.013), their maximal degranulation (P = 0.014) and activation of lung MMP-9 (P = 0.002). These findings may indicate an important role of the residual lung PMN and activation of MMP-9 in septic lung injury during CY chemotherapy.

Advances in chemotherapy for chronic lymphocytic leukemia

While chemotherapy based on alkylating agents has been the standard treatment of chronic lymphocytic leukemia (CLL) for decades, purine analogues and their combinations have emerged as effective new therapies for previously untreated and pretreated patients. As single agents, fludarabine and cladribine are the most promising, showing higher remission rates compared to chlorambucil. For younger and physically fit patients, the combination of fludarabine and cyclophosphamide has shown benefit. Fludarabine plus epirubicin appears equally potent. The addition of monoclonal antibodies, such as rituximab and alemtuzumab, to purine analogues alone or in combination seems to be even more effective for chemotherapy-naive and pretreated CLL patients. Another promising agent in the armamentarium of therapies for CLL is bendamustine, which has properties of both an alkylating agent and a purine analogue. Clinical trials are ongoing with novel drugs that interfere with cell cycle regulation and signaling molecules in CLL, including flavopiridol, UCN-01, bryostatin 1, depsipeptide, and oblimersen. It remains to be seen whether these chemotherapeutic approaches offer real benefit for patients by prolonging survival with an improved quality of life.