Fludarabine and granulocyte colony-stimulating factor (G-CSF) in patients with chronic lymphocytic leukemia

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.

[Haematological malignancies in older adults: experience in a geriatric acute care department]

BACKGROUND

Ageing of population due to improvement in life expectancy has increased blood diseases (BD) incidence in the elderly population. In addition, treatments get more and more complex with increasingly late diagnosis as well as concomitant comorbidities.

METHODS

We describe a series of 54 patients with BD, followed-up in an acute care geriatric department. Autonomy, way of life, nutritional status, comorbidities, treatment, mortality and evolution were analyzed.

RESULTS

Mean age at BD was 86+/-6 years (range 75-99) for 29 women and 25 men. Median follow up was 20 months (0-60). Lymphoma was the most frequent BD (44%). Thirty-one patients (57%) received chemotherapy. Mortality rate was 41% (22 patients). Forty patients (74%) were discharged and 25 patients (46%) required enhanced professional assistance. Survival was significantly decreased in patients with albuminemia less than or equal to 30 g/l. IADL score less than or equal to 3, ADL score less than or equal to 5, performance status more than or equal to 2, MMS less than 25 and weight loss more than or equal to 3 kg. After multivariate analysis, only albuminemia less than or equal to 30 g/l tended to predict death (hazard ratio 3.57, 95% confidence interval 0.96-13.3, p=0.06).

CONCLUSION

Our study confirms the importance of nutritional status on survival. A global geriatric evaluation is required for appropriate treatment, as currently available therapeutic protocols are not really adapted for old population. Additional studies should be conducted in this direction.

Due to low infection rates no routine anti-infective prophylaxis is required in younger patients with chronic lymphocytic leukaemia during fludarabine-based first line therapy

The impact of the combination therapy fludarabine plus cyclophosphamide (FC) in comparison with fludarabine alone regarding the incidence and severity of infections among previously untreated patients with chronic lymphocytic leukaemia (CLL) was evaluated within a multicentre phase III study. A total of 375 patients, up to 65 years old, were randomised between fludarabine or FC for first line therapy. No routine anti-infective prophylaxis was provided. A total of 196 infectious episodes, including 33 severe infections, were documented. In the fludarabine arm, 32.9% of the patients developed an infectious complication compared with 39.9% in the FC arm (P = 0.2). No difference was observed in the rate of severe infections (Common Toxicity Criteria grades III and IV) between both treatment arms. Dose reductions were performed more frequently in FC-treated patients. Granulocyte colony-stimulating factor (G-CSF) was administered due to leucopenia in 5% of all patients. A multivariate regression model identified only elevated thymidine kinase, but not the treatment arm, as a statistically independent risk factor for infections. In summary, FC was not associated with a higher rate of infections compared with fludarabine alone. No routine antibiotic or virostatic prophylaxis, or preemptive treatment with G-CSF, is necessary in first line therapy with fludarabine-based regimens in younger patients with CLL, if adequate dose reduction is performed. The combination therapy FC is not associated with a higher rate of infections compared with fludarabine alone. No routine antibiotic or virostatic prophylaxis as well as preemptive treatment with G-CSF is necessary in first line therapy with fludarabine-based regimen in younger patients with CLL, if adequate dose reductions due to cytopenia or previous infections are performed.

Fludarabine in chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common leukaemia in the Western world. Historically, CLL patients have received prednisone- or chlorambucil-containing regimens, resulting in modest responses and a slim chance of long-term survival. The addition of purine nucleoside analogues, specifically fludarabine, to the armamentarium has significantly improved efficacy in treatment-naive or heavily pretreated CLL patients. Since the 1980s, fludarabine monotherapy has demonstrated an improvement in response over historical chemotherapeutic agents. Single-agent fludarabine therapy has expanded into a combination regimen containing cyclophosphamide and has further evolved to incorporate monoclonal antibodies. A review of the fludarabine literature shows that these advancements in fludarabine-containing therapy have enhanced the overall patient response with a potential increase in survival time, thus representing progress towards a superior treatment for CLL.

Immune defects in patients with chronic lymphocytic leukemia

Over the past decade, the introduction of nucleoside analogs and monoclonal antibodies into the treatment of patients with chronic lymphocytic leukemia (CLL) has resulted in higher rates and longer duration of response. This is a significant step towards achieving the ultimate goal of disease-eradication and improved survival. A continuing problem, however, is the susceptibility of these patients to infections. Profound dysregulation of the host immune system in patients with CLL and its impact on the clinical course of the disease are well established. A number of investigators have sought to identify the mechanisms underlying this innate immune dysfunction, which is further exacerbated by the actions of the potent therapeutic agents. The early recognition of infections as well as prophylactic administration of appropriate antibiotics has been the mainstay of managing infections in patients with CLL. Hopefully, increasing understanding of the molecular events underlying the neoplastic change in CLL will lead to more targeted and less immunosuppressive therapeutic modalities. Furthermore, the understanding of the mechanisms of immune dysfunction in CLL is of pivotal importance in the novel immune-based therapeutic strategies currently under development.

The combination of fludarabine, cyclophosphamide, and granulocyte-macrophage colony-stimulating factor in the treatment of patients with relapsed chronic lymphocytic leukemia and low-grade Non-Hodgkin's lymphoma

PURPOSE

The goal of this study was to evaluate the efficacy of the fludarabine/cyclophosphamide combination in patients with relapsed chronic lymphocytic lymphoma (CLL) and low-grade non-Hodgkin's lymphoma (NHL) and to assess the impact of adding granulocyte-macrophage colony-stimulating factor (GM-CSF) to this regimen in a randomized fashion.

PATIENTS AND METHODS

Thirty-four patients (CLL, n=16; low-grade NHL, n=18) were enrolled. The median number of previous treatments was 2. Patients received <or=6 cycles of fludarabine at 30 mg/m2 per day and cyclophosphamide at 300 mg/m2 per day on days 1-3 of a 28-day cycle. Patients were randomized to supportive care or to receive GM-CSF at 250 mg/m2 per day, starting 24 hours after completion of chemotherapy and continuing up to 48 hours before the next cycle. Those who had received >6 months of previous therapy with an alkylating agent or had preexisting cytopenias received a 25% dose reduction. Twenty-two patients (65%) were randomized to receive GM-CSF. Patients completed a median of 5 cycles of treatment (range, 1-6 cycles). Twenty-seven patients (80%) received >or=3 cycles of treatment and were evaluated for response.

RESULTS

Seven patients (26%) exhibited a complete response; 6 of the 7 had low-grade NHL. Fourteen patients (52%) exhibited a partial response, and 6 patients (22%) had stable disease. Notably, 6 of the 7 patients who exhibited complete response and 9 of 14 patients with partial responses were randomized to the GM-CSF arm. The duration of response ranged from 4 months to 26 months. The toxicities were mainly hematologic. Nineteen patients (70%) experienced >or=1 episode of grade 3/4 neutropenia, but only 4 (15%) experienced febrile neutropenia; 3 of those patients were assigned to the GM-CSF arm.

CONCLUSIONS

The combination of fludarabine and cyclophosphamide is a well-tolerated and effective treatment regimen for patients with relapsed CLL and low-grade NHL. A higher percentage of complete responses were noted in patients with low-grade NHL compared with patients with CLL. Granulocyte-macrophage colony-stimulating factor did not seem to decrease the incidence of febrile neutropenia. However, the higher number of complete and partial responses noted on the GM-CSF arm is intriguing and warrants further investigation.

Infections associated with purine analogs and monoclonal antibodies

Nucleoside analogs and monoclonal antibodies are commonly used to treat lymphoproliferative disorders and have become established as the treatment of choice in chronic lymphocytic leukemia, hairy cell leukemia, and follicular lymphomas, as well as a number of other malignant lymphoid neoplasms. When used in standard doses, these agents have a low incidence of extramedullary side effects resulting in their inclusion in a number of combination regimens. The most important complications associated with these drugs are myelosuppression, immunosuppression and infections. This is further accentuated when they are used in combination with other drugs such as alkylating agents. Several investigators have attempted to delineate the risk factors predicting the risk of infections associated with these agents. Furthermore, risk-based strategies to decrease the incidence of these infectious complications have been proposed.

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.

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.

Immunologic monitoring in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by progressive defects in humoral- and cell-mediated immunity. These defects are manifested as a propensity to develop infections with encapsulated bacteria, and less frequently, with gram-negative enterics. In addition, reactivation of viruses such as herpesvirus is not uncommon. Treatment of the disease further exacerbates immunosuppression by depleting immune effectors and broadening the spectrum of potentially offending pathogens. Risk of infection can potentially be reduced by administration of intravenous immunoglobulin and use of prophylactic antibiotics for individuals who are at high risk. Current work focuses on development of cellular and cytokine therapy to facilitate immune reconstitution in patients with CLL, thereby reducing morbidity and mortality and potentially improving survival.

Infections in Patients with Hematological Cancer: Recent Developments

One of the most common complications involved in treating patients with hematologic cancer is infection. In many cases there are multiple factors that predispose these patients to infections such as neutropenia induced by therapy or bone marrow involvement, hypogammaglobulinemia, T-cell dysfunction, and mucosal damage. In addition, newer therapies have changed the spectrum of infection that is seen in these patients.

In Section I, Dr. Blijlevens discusses mucosal damage as a major risk factor for complications of cytotoxic chemotherapy. She focuses on mucosal barrier injury (MBI) as manifest in the GI tract and will describe a pathological model to explain MBI, evaluate risk factors for development of this syndrome, explain the relationship between MBI and infection, and discuss treatment and prevention of this injury.

Invasive fungal infections continue to represent a significant problem in patients with hematologic cancer. In Section II, Drs. Anaissie and Mahfouz review the latest developments in the diagnosis, prevention, and management of invasive fungal infections with a focus on a risk-adjusted approach to this problem.

Finally, in Section III, Dr. O’Brien reviews infections associated with newer therapeutic regimens in hematologic cancers. The spectrum of infections has changed with the use of purine analogs and the advent of monoclonal antibodies. The profound T-cell suppression associated with these therapies has led to the emergence of previously rare infections such as cytomegalovirus. An approach to both prophylaxis and management of these infections is discussed.

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

BACKGROUND

One of the mechanisms of action of cladribine is the inhibition of DNA repair of damage caused by radiation, alkylating agents, or other drugs. To determine its antitumor activity in combination with cyclophosphamide, we initiated a Phase II trial of the two agents in patients with advanced chronic lymphocytic leukemia (CLL) or prolymphocytic leukemia (PLL).

METHODS

Twenty-nine patients with refractory or recurrent CLL or PLL received cladribine 4 mg/m(2)/day and cyclophosphamide 350 mg/m(2)/day (both administered intravenously) for 3 days every 4 weeks.

RESULTS

Eleven patients (38%), nine with CLL and two with PLL, had a response. The median duration of response was 12 months. Severe extrahematologic toxicity (National Cancer Institute Grade 3-4) occurred in two patients, consisting of skin rash in one patient and progressive multifocal leukoencephalopathy in the other. The most common form of hematologic toxicity was severe neutropenia, which developed after 25% of the 84 courses was administered. Severe thrombocytopenia and anemia developed after 12% and 7% of the courses, respectively, and five episodes of anemia were immunomediated. In addition, three major infections resulted in the death of one patient.

CONCLUSIONS

Although inferior to the combination fludarabine plus cyclophosphamide, this regimen showed interesting activity in patients with advanced CLL or PLL. Myelosuppression was the major dose-limiting toxic effect.

Selection of autologous CD4+ T-cells for adoptive T-cell substitution in patients with CD23+ B-cell CLL

BACKGROUND

B-cell CLL (B-CLL) is accompanied by a progressive decrease in cellular immune functions, and treatment-related immunosuppression can further aggravate T-cell immunodeficiency. To reduce the risks of T-cell depletion, it seems feasible to collect autologous CD4+ cells at an early disease stage and subsequently reinfuse them during periods of profound T-cell depletion.

METHOD

We describe a two-step cell-selection method to obtain highly enriched CD4+ T-cells from leukapheresis compounds of patients with CD23+ B-CLL. The double selection procedure was performed using the CellPro Ceperate device, and consisted of CD4+ selection followed by CD23 purging to further remove contaminating CD23+ B-cells from the CD4+ cell fraction. The results of eight runs performed with leukapheresis material obtained from eight patients with CD23+ B-CLL at different disease stages are presented.

RESULTS

The CD4/CD23 double cell-selection procedure resulted in the purification of > 90% CD4+ cells. Median recovery of CD4+ T lymphocytes after selection was 46%, and was negatively affected by the initial tumor cell load. The final T-cell fraction still contained lymphocytes of the B-CLL clone, as determined by FACS and PCR. The cell-processing procedure had no impact on T-cell function, as assessed by the in vitro production of the cytokine interferon-gamma. Moreover, the selected CD4+ cells retained their capacity to co-stimulate mitogen-induced B-cell IgG production in vitro.

CONCLUSION

The described CD4 selection/CD23 depletion strategy is a suitable approach to obtaining high numbers of functional active autologous CD4+ T cells for adoptive T-cell transfer in patients with CD23+ BCLL.

Re-treatment with cladribine-based regimens in relapsed patients with B-cell chronic lymphocytic leukemia. Efficacy and toxicity in comparison with previous treatment

The aim of the study was to determine the effectiveness and toxicity of cladribine (2-CdA) used alone or in combination with prednisone (P) or cyclophosphamide and mitoxantrone in re-treatment of patients with progressive B-cell chronic lymphocytic leukemia (B-CLL). We analyzed treatment outcome in 40 patients who had responded to previous treatment with 2-CdA-based regimens. Criteria for re-treatment were the same as for the first treatment. The patients were retreated with the same agents if they responded to the first treatment and then relapsed with progressive disease not earlier than 3 months after achieving the first response. Eight patients received 2-CdA alone (0.12 mg kg(-1) d(-1)) i.v. for 5 d, and 21 patients additionally were given P (30 mg m(-2) d(-1)) orally, also for 5 d. Eleven patients received 2-CdA for 3 d combined with cyclophosphamide (650 mg m(-2)) i.v. and mitoxantrone (10 mg m(-2)) i.v. on day 1 (CMC regimen). The cycles were repeated usually at 4 wk intervals or longer if severe myelosuppression or infections occurred. The therapy was finished if complete remission (CR) was achieved or until maximum of six courses. Overall response (OR) in re-treatment was obtained in 16 out of 40 (40%) patients (95% CI 16-64), including 62% after 2-CdA, 33% after 2-CdA +P and 36% after CMC. CR was obtained in four (10%) patients. Residual disease evaluated in the patients with CR by surface immunophenotyping had been demonstrated in 5 out of 16 (31%) patients after the first treatment and in one out of four (25%) patients after re-treatment. The median progression-free survival (PFS) was 16 months (range 3-39) for the first treatment and 9.5 months (range 3-18) for re-treatment (P=0.34). Grade III or IV neutropenia was observed in 20% patients during the first treatment and in 35% patients during re-treatment (P=0.1). 2-CdA-induced thrombocytopenia occurred in 20% and 42% of the patients, respectively (P=0.05). Anemia was also more frequent during re-treatment (35%) than during the first treatment (7%) (P=0.007). Autoimmune hemolytic anemia developed in four (10%) of the patients during or after re-treatment. Severe infections, including pneumonia and herpes reactivation, occurred in 11 patients during the first treatment and in 10 patients during re-treatment. Twelve (30%) patients died during the study. Infections were the cause of death in six and AIHA in two patients. In conclusion, 2-CdA applied in monotherapy or in combination with prednisone or cyclophosphamide and mitoxantrone has therapeutic activity in some B-CLL patients in whom these drugs induced earlier complete or partial remission. However, since the second response is usually shorter and myelotoxicity more pronounced than during the first therapy, more clinical trials to find other therapeutical approaches are necessary.

B-chronic lymphocytic leukemia: practical aspects

B-CLL is the most common adult leukemia in the Western world. It is a neoplasia of mature looking B-monoclonal lymphocytes co-expressing the CD5 antigen (involving the blood, the bone marrow, the lymph nodes and related organs). Much new information about the nature of the neoplastic cells, including chromosomal and molecular changes as well as mechanisms participating in the survival of the leukemic clone have been published recently, in an attempt to elucidate the biology of the disease and identify prognostic subgroups. For the time being, clinical stage based on Rai and Binet staging systems remains the strongest predictor of prognosis and patients' survival, and therefore it affects treatment decisions. In the early stages treatment may be delayed until progression. When treatment is necessary according to well-established criteria, there are nowadays many different options. Chlorambucil has been the standard regimen for many years. During the last decade novel modalities have been tried with the emphasis on fludarabine and 2-chlorodeoxyadenosine and their combinations with other drugs. Such an approach offers greater probability of a durable complete remission but no effect on overall survival has been clearly proven so far. Other modalities, included in the therapeutic armamentarium, are monoclonal antibodies, stem cell transplantation (autologous or allogeneic) and new experimental drugs. Supportive care is an important part of patient management and it involves restoring hypogammaglobulinemia and disease-related anemia by polyvalent immunoglobulin administration and erythropoietin respectively.

Results of first salvage therapy for patients refractory to a fludarabine regimen in chronic lymphocytic leukemia

Resistance to purine analogs is emerging as a major problem in the management of patients with chronic lymphocytic leukemia (CLL). Most of these patients have already been exposed to and have become refractory to alkylating agents. To define the natural history of fludarabine (Fludara) refractory patients with CLL, we reviewed the response to first salvage therapy of 147 patients who were refractory to Fludara or had a remission less than six months in duration after a Fludara-containing regimen. Thirty-three (22%) patients responded to their first salvage attempt. However, the median survival was only 10 months. Responders survived significantly longer than non-responders. The most effective salvage regimens were combinations of purine analogs and cyclophosphamide. Patients still possibly sensitive to alkylating agents had a superior response than alkylating agent resistant or naive patients. Subsequent salvage therapy was administered to 61 patients. The most promising results noted in the group were transplantation and the use of Campath-1H antibody. The major morbidity and cause of death were associated with infections. The probability of infection was most strongly associated with the response to salvage therapy. Gram-positive organisms were most commonly associated with infection. However, gram-negative bacilli or opportunistic infection such as fungi, Pneumocystis carinii, acid-fast bacilli and legionella were prominent causes of infection. Fludara-refractory patients are a poor prognosis group and need more effective therapeutic regimens and well-designed infection prophylactic regimens.

Fludarabine combination therapy for the treatment of chronic lymphocytic leukemia

Fludarabine combination therapies have attained an increased popularity in the treatment of chronic lymphocytic leukemia (CLL). Among them, the combination of fludarabine/cyclophosphamide (FC) is by far the best regimen studied. Patients receiving FC at relapse show response rates (RRs) of 70%-94% with 11%-34% complete remission (CR) rates. In previously untreated patients with CLL, RRs of 64%-88% with 21%-46% CR rates were observed. The main side effects of FC are myelotoxicity and infections; most complications are reported as fever of unknown origin, infections of the upper respiratory tract, or herpes virus infection. There is probably a correlation between the higher dose of cyclophosphamide (> 750 mg/m2 per treatment course) and an increase in the number of severe infectious complications. Similar results were reported regarding the RRs and side effects of the combination of fludarabine/epirubicin. The triple combination of fludarabine/cyclophosphamide/mitoxantrone and fludarabine combinations with anti-CD20 (rituximab) or anti-CD52 (Campath-1H) antibody, might be even be more promising, since a relevant number of complete molecular remissions are achieved with these drugs. The precise role of fludarabine combinations within the overall treatment strategy remains to be determined. Our current recommendation is to use these combinations at relapse, while their use in first-line therapy should be investigated in clinical protocols. It remains to be shown whether patients with CLL achieve improved overall survival with these combination chemotherapies.

Cladribine combined with cyclophosphamide and mitoxantrone as front-line therapy in chronic lymphocytic leukemia

The objective of the study was to determine the effectiveness and the toxicity of a combined chemotherapy consisting of cladribine (2-CdA), mitoxantrone and cyclophosphamide (CMC regimen) in the treatment of previously untreated B cell chronic lymphocytic leukemia (B-CLL). From August 1998 to December 2000 2-CdA was administered at a dosage of 0.12 mg/kg for 3 (CMC3) or 5 (CMC5) consecutive days, mitoxantrone at 10 mg/m2 on day 1 and cyclophosphamide at 650 mg/m2 on day 1 to 62 patients with advanced or progressive B-CLL. The cycles were repeated at 4 week intervals or longer if severe myelosuppression occurred. Twenty patients received CMC5 and 42 patients CMC3. Within the analyzed group an overall response (OR) rate (CR+PR) of 64.5% (95% CI: 52.7-76.3%) was reported, including 29.0% CR. There was no difference in the CR rate between the patients treated with CMC5 (30%) and CMC3 (28.6%) (P = 0.9), nor in the OR rate (55.0% and 69.0%, respectively, P = 0.3). Residual disease was identified in seven out of 18 (38.9%) patients who were in CR, including two treated with CMC5 and five treated with CMC3 protocols. CMC-induced grade III or IV thrombocytopenia occurred in 12 (19.4%) of patients, including four (20%) CMC5-treated and eight (19%) CMC3-treated patients (P= 0.8). Neutropenia grade III or IV was observed in seven (35%) and 11 (26.2%) patients, respectively (P = 0.8). Severe infections, including pneumonia and sepsis, occurred more frequently after CMC5 (11 patients, 55.0%) than CMC3 (10 patients, 28.6%) (P = 0.03) Fourteen patients died, including six treated with CMC5 and eight treated with CMC3 (30% and 19%, respectively). Infections were the cause of death in nine patients, including four in the CMC5 group and five in the CMC3 group. In conclusion, our results indicate that the CMC programme is an active combined regimen in previously untreated B-CLL patients; its efficiency seems to be similar to that observed earlier in B-CLL patients treated with 2-CdA as a single agent. However, toxicity, especially after CMC5 administration, is significant. Therefore, we recommend the CMC3 but not the CMC5 programme for further evaluation.

Fludarabine and mitoxantrone: effective and well-tolerated salvage therapy in relapsed indolent lymphoproliferative disorders

BACKGROUND

Prior studies of the combination of fludarabine, mitoxantrone and dexamethasone have yielded high response rates but are associated with a significant risk of opportunistic infections, predominantly Pneumocystis Carinii pneumonia (PCP) requiring routine prophylaxis.

PATIENTS AND METHODS

We evaluated the combination of fludarabine (25 mg/m2/day x 3) and mitoxantrone (10 mg/m2 x 1) without corticosteroids or PCP prophylaxis in 29 patients with relapsed or refractory indolent lymphoproliferative disorders; median age 56 years, 62% refractory to preceding chemotherapy.

RESULTS

A median of four cycles was administered without cumulative myelosuppression. Neutropenia <0.5 x 10(9/)l was seen in 16% of cycles. Infections complicated 10.4% of cycles. with impaired performance status (> or = ECOG 2) and increased age ( > 56 years) significant risk factors (P < or = 0.01). No cases of PCP were encountered. The response rate was 90%, median remission duration 11.9 months and the median survival 57 months. Peripheral blood progenitor cell mobilization was attempted in 11 patients and yielded > or = 2 x 10(6) CD34+ cells/kg in only 5 cases (45%).

CONCLUSIONS

High response rates can be attained with fludarabine and mitoxantrone in combination without corticosteroids, and routine PCP prophylaxis can safely be omitted. Peripheral blood progenitor collections are problematic in these heavily pretreated patients.

Infectious complications of purine analog therapy

Patients with lymphoid malignancies such as chronic lymphocytic leukemia, particularly those who receive the newer purine analogs, are at increased risk for infectious morbidity and mortality. Defects in cell-mediated immunity appear to be a major predisposing factor in these patients. An expanding spectrum of pathogens associated with lymphocytopenia and depletion of CD4 has been described in the setting of therapy with purine analogs. During the past 2 years new knowledge about the immunosuppression related to that treatment has continued to accumulate.

Infectious complications in chronic lymphoid malignancy

Taking steps to minimize, prevent, and treat infection in patients with chronic lymphoid malignancies, especially chronic lymphocytic leukemia, has always been a challenge. As more patients with these diseases live longer and lead productive lives upon successful initial treatment, strategies for preventing infections have become more important. Distinguishing patients at low risk for infection from those at high risk is a crucial but challenging issue. Unfortunately, there are hardly any data on the use of prophylactic antibiotics for patients with chronic lymphoid malignancy (CLL). If patients cannot be enrolled in a clinical trial, antibiotics with co-trimoxazole should be administered when steroids are warranted. They should also be administered in patients who have had a documented infection early in the treatment course and during neutropenia. Viral infections remain another controversial issue in patients with CLL receiving treatment, especially a purine analogue. Very low CD4 counts (less than 50 cells/mL) might predict for reactivation for herpes zoster. Outside of depleted CD4 counts, there are no other means of identifying a high-risk group. Based on limited data, it would be reasonable to administer herpes zoster prophylaxis to patients with CD4 counts that are severely depleted or to patients with a prior episode of zoster. Controversial issues still remain regarding immunoglobulin treatment, specifically cost, scarcity of the product, and adequate dose, which has not yet been established. We would consider intravenous immunoglobulin (Ig) replacement in patients with marked hypogammaglobulinemia (IgG less than 400 mg/dL) with more than two recent severe infections [1]. Lower Ig doses (240 mg/kg) have been shown to be equivalent to higher ones in this trial [1].

Does intensive treatment with high dose chlorambucil and prednisone as first line and cladribine as second line influence the survival of the patients with chronic lymphocytic leukemia?

Cladribine (2-CdA) and fludarabine are the new purine analogs introduced in the treatment of chronic lymphocytic leukemia (CLL). Despite the high response rate, their influence on survival is still uncertain. The aim of this study was a retrospective analysis and comparison of the response rate and survival of CLL patients treated with high dose chlorambucil (HDChl) as first and 2-CdA as second line, with an historical group of patients never treated with purine analogs who received standard doses of chlorambucil (SDChl). We analyzed 347 patients with CLL treated between January 1985 and January 2000. Group A (190 patients) received HDChl (12 mg/m(2) ) with prednisone (P) 30 mg/m(2) daily for 7 days monthly as first line and in refractory or early relapsed patients 2-CdA (0.12 mg/kg/day) for 5 days with or without P (30mg/m(2) ) as second line. Group B (157 patients) received continuous SDChl (4-8 mg/m(2) /day) and P as first line and COP or CHOP as second line. The overall response rate (OR) for the first line was 48,4% in group A and 38,9% in group B (p=0.09). 148 patients in group A and 52 in group B received the second line treatment and the second OR was 19.6% and 13.5%, respectively (p=0.4). At the time of analysis, 124 patients died in group A and 139 in group B. Median survival was 65 months and 50 months, respectively. In group A, survival was longer in advanced Rai stage patients (p=0.001) but in early Rai stage was similar for both groups (p=0.4). We suggest that intensive treatment with HDChl as first line and 2-CdA as second line should be applied in more advanced rather than in less advanced stages of CLL until the final results of randomized clinical trials are available.

Cladribine in the treatment of chronic lymphocytic leukemia

Cladribine (2-chlorodeoxyadenosine, 2-CdA) is a nucleoside analog with substituted halogen atom at position 2 in its purine ring that makes it resistant to deamination by adenosine deaminase (ADA). 2-CdA is the drug of choice in the treatment of hairy cell leukemia, but it is also highly active in other low grade lymphoid malignancies including chronic lymphocytic leukemia (CLL). The results of the studies presented so far have shown that 2-CdA gives similar complete response (CR) rate and overall response (OR) rate to fludarabine but the influence of both agents on survival times of the patients with CLL is still uncertain. CR rate induced with 2-CdA is significantly higher than in the patients treated with conventional chemotherapy. In refractory or relapsed patients 2-CdA induces 31 to 68% of overall responses including CR in 4 to 31%. In previously untreated patients overall remission rates of about 56-82% have been achieved with 2-CdA alone. When 2-CdA was used as primary therapy the CR rate was also significantly higher and ranged from 10% to 47%. Patients who received 2-CdA as their initial therapy and experienced a response lasting at least a year may be successfully treated subsequently with the same agent. A second response has been achieved in 35 to 100% patients treated with this agent for the second time. Despite the fact that 2-CdA gives higher CR and OR rates than conventional chemotherapy, it has not been established whether it has any influence on survival time. However, cross resistance between 2-CdA and FAMP in CLL patients is evident in the majority of studies. Bone marrow suppression with anemia neutropenia and thrombocytopenia are the dose limiting factors for 2-CdA use. These side effects are pronounced in heavily pretreated patients and after multiple courses of therapy. Treatment with this agent also leads to the decrease of the CD4+/CD8+ ratio for an extensive period of time exceeding 12, even up to 24 months. In consequence, infections including opportunistic type, are frequently observed. We suggest, that in patients with CLL, 2-CdA should be used as second line treatment rather than the first line therapy until the final results of ongoing randomized clinical trials are available.

Infection and immunity in chronic lymphocytic leukemia

Patients having chronic lymphocytic leukemia (CLL) are at increased risk for infectious morbidity and mortality. The predisposition to infections in CLL patients has many components, including both immunodeficiency related to the leukemia itself (humoral and cellular immune dysfunction) and the results of cumulative immunosuppression related to CLL treatment. The risk of infectious complications increases with the duration of CLL, reflecting the natural history of the disease and the cumulative immunosuppression related to its treatment. Hence, in early, untreated CLL, the infectious risk is mainly related to hypogammaglobulinemia, and infections by encapsulated bacteria are common. However, in patients having advanced CLL, particularly those who receive the newer purine analogues, neutropenia and defects in cell-mediated immunity appear to be the major predisposing factors. An expanded spectrum of pathogens, including opportunistic fungi, Pneumocystis carinii, Listeria monocytogenes, mycobacteria, and herpesviruses, are seen in that setting. The changing spectrum of infections in this latter group of patients mandates a newer approach to prophylaxis and therapy.

Inhibition of RNA transcription: a biochemical mechanism of action against chronic lymphocytic leukemia cells by fludarabine

Fludarabine is a nucleotide analog effective in the clinical treatment of chronic lymphocytic leukemia (CLL) and other indolent lymphocytic malignancies. Although the incorporation of fludarabine into DNA is a key event in causing cytotoxicity in proliferating leukemia cells, the precise mechanisms by which fludarabine kills CLL cells remain unclear because of the quiescent nature of this malignancy. The present study demonstrated that inhibition of RNA transcription correlated significantly with the cytotoxic action of fludarabine in CLL cells. In contrast, suppression of the low level of DNA synthesis did not affect the survival of the leukemia cells. In addition, inhibition of fludarabine incorporation into cellular DNA through repair synthesis in CLL cells did not alter the cytotoxicity of this drug. Rather, inhibition of RNA synthesis by fludarabine led to a specific diminishment of certain cellular proteins from CLL cells. The combination of fludarabine with another RNA synthesis inhibitor, actinomycin D, or with the protein synthesis inhibitor, puromycin, substantially enhanced the cytotoxic activity against CLL cells. These results suggest that termination of mRNA transcription and the consequent depletion of proteins required for cell survival may be a novel biochemical mechanism of action of fludarabine in CLL cells. Thus, inhibition of RNA/protein synthesis may provide a new therapeutic strategy for the treatment of CLL patients.

Chronic lymphocytic leukemia

Chronic lymphocytic leukemia continues to attract much basic and clinical research interest. Despite recent advances, the disease still has no established cure. Nonetheless, significant strides have been made in our understanding of the genetics, biology, and clinical staging of this disease. This understanding may improve our ability to segregate patients into subtypes that differ in their cytogenesis, propensity toward disease progression, or response to standard or innovative forms of therapy. Finally, several promising new modalities of treatment are being evaluated in clinical trials, involving novel drugs or drug-combinations, monoclonal antibodies, stem cell transplantation, or gene therapy.

Cladribine with or without prednisone in the treatment of previously treated and untreated B-cell chronic lymphocytic leukaemia - updated results of the multicentre study of 378 patients

Between January 1992 and January 1999, we treated 378 B-chronic lymphocytic leukaemia (CLL) patients with cladribine (2-CdA), and 255 of the patients were also treated with prednisone. A total of 194 patients were previously untreated, and 184 had relapsed or refractory disease after previous other therapy. Complete response (CR) was obtained in 111 (29.4%) and partial response (PR) in 138 (36.5%) patients, giving an overall response (OR) rate of 65.9%. CR and OR were achieved more frequently in patients in whom 2-CdA was a first-line treatment (45.4% and 82.5% respectively) than in the pretreated group (12.5% and 48.4% respectively) (P < 0.0001). The median duration of OR for previously untreated patients was 14.7 months and for pretreated patients 13.5 months (P = 0.09). The median survival evaluated from the beginning of 2-CdA treatment was shorter in the pretreated group (16.3 months) than in the untreated group (19.4 months) (P < 0.0001). A total of 117 (63.9%) patients died in the pretreated group and 63 (32.6%) in the untreated group. In pretreated patients, 2-CdA + prednisone (P) and 2-CdA alone resulted in similar OR (51.0% and 45.0% respectively; P = 0.4). In contrast, in untreated patients, 2-CdA + P produced a higher OR (85.4%) than 2-CdA alone (72.1%) (P = 0.04). Infections and fever of unknown origin, observed in 91 (49.4%) pretreated and 74 (38.1%) untreated patients (P = 0.03), were the most frequent toxic effects. Our results indicate that 2-CdA is an effective, relatively well-tolerated drug, especially in previously untreated CLL.

Management of chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common form of adult leukaemia in Western countries. The diagnosis requires mature-appearing lymphocytes in the peripheral blood to >5 x 10(9)/L. The immunophenotype typically includes B cell antigens CD19, CD20 and CD23, low expression of surface immunoglobulin and CD5+, with other T cell antigens absent. Bone marrow biopsy, although not required for diagnosis, must show at least 30% lymphocytes. Cytogenetic abnormalities are frequent in patients with CLL, and may be associated with poor prognosis. Clinically, most patients are asymptomatic at presentation, with incidental lymphadenopathy and/or hepatosplenomegaly in the routine physical examination. Infections by opportunistic pathogens are the major cause of death. Aggressive transformation occurs in 10% of patients with CLL, most commonly prolymphocytic leukaemia (PLL) and Richter's syndrome. PLL de novo must be differentiated from PLL of an aggressive transformation. The incidences of autoimmune diseases and solid or haemopoietic secondary malignancies are increased in patients with CLL. Clinical stage is the strongest prognostic factor in CLL. There is no indication for early intervention. The current recommendation to start treatment includes disease-related symptoms, massive and/or progressive hepatosplenomegaly or lymphadenopathy, increasing bone marrow failure, autoimmune disease, and recurrent infections. Alkylating agents (e.g. chlorambucil) and nucleoside analogues (e.g. fludarabine) are the most active agents for CLL. Fludarabine induces higher response rates, but no improvement in overall survival has been observed. Fludarabine is the drug of choice for the majority of patients with CLL. Chlorambucil may be helpful for elderly patients with poor performance, and for patients who do not tolerate fludarabine. No drug combination is better than single agents. For patients refractory to initial treatment, referral to a clinical trial is the best choice. Other salvage therapy includes retreatment with the same initial agent (chlorambucil or fludarabine) if initial response was observed, or fludarabine for patients refractory to chlorambucil. Promising new approaches include cycle-active agents, nelarabine, biological therapy such as anti-CD52 monoclonal antibody, bone marrow transplantation, including the use of submyeloablative preparative regimens ('minitransplant') to induce graft-versus-leukaemia effect, and gene therapy. Prophylactic antibacterials and intravenous immunoglobulin should not be used routinely during supportive care. Epoetin may be helpful for patients who have anaemia without obvious cause. Assessment of response to therapy in CLL has been updated by the National Cancer Institute Working Group, and these guidelines are used worldwide for clinical trials.