Fludarabine in comparison to alkylator-based regimen as induction therapy for chronic lymphocytic leukemia: a systematic review and meta-analysis

Infections in patients with chronic lymphocytic leukemia

INTRODUCTION

Infection is a major complication in patients with chronic lymphocytic leukemia (CLL). Newly diagnosed patients are at high risk of developing infection caused by encapsulated bacteria, such as Streptococcus pneumoniae and Haemophylus influenzae.

METHOD AND RESULTS

However, once treatment is initiated, the spectrum of pathogens causing infection broadens, depending on the treatment regimens. With disease progression, cumulative immunosuppression occurs as a consequence of multiple treatment lines and the risk of infection further increases. On the other hand, the use of targeted therapies in the treatment of CLL have brought new risks of infection, with an increased incidence of invasive fungal diseases, particularly aspergillosis, in patients receiving Bruton kinase inhibitors.

CONCLUSION

In this article, we review the epidemiology of infection in patients with CLL, taking into account the treatment regimen, and briefly discuss the management of infection.

Trends of chronic lymphocytic leukemia incidence and mortality in the United States: a population-based study over the last four decades

BACKGROUND

Chronic lymphocytic leukemia (CLL) is the most common leukemia among adults, and its incidence is higher in elderly individuals. This study aims to examine the burden of CLL in the United States (US) by exploring the incidence-based rates (IBR) and incidence-based mortality (IBMR) across four decades.

RESEARCH DESIGN AND METHODS

CLL incidence data were obtained from the SEER-8 registry, covering 8.3% of the US population. Cases were identified using specific diagnostic codes and excluded if diagnosed on autopsy or death certificate. Age-standardized IBR and IBMR were calculated based on age, sex, and ethnicity/race. Joinpoint Regression Program was used to analyze changing trends in incidence and mortality.

RESULTS

Since 2011, males' and females' IBRs declined by -1.72%/year (p = 0.028) and -1.07%/year (p = 0.222), respectively. IBR of patients > 75 years increased by 4.01%/year (p < 0.001) form 1998-2010, then declined by 2.02%/year (p = 0.011). IBR of Blacks increased by 0.96%/year (p < 0.001) throughout the study period. CLL IBMR stabilized at -0.38%/year (p = 0.457) since 2012. Whites' IBMR plateaued at a rate of -0.10%/year (p = 0.857) form 2012-2019, while blacks' IBMR increased by 1.40%/year (p = 0.056) between 2000-2019.

CONCLUSIONS

The analysis revealed a decline in CLL incidence since 2013, with stable mortality rates since 2012, indicating advancements in CLL management.

Survival trends in chronic lymphocytic leukemia across treatment eras: US SEER database analysis (1985-2017)

In this population-based study, we used the SEER database (1985-2015) to examine survival outcomes in chronic lymphocytic leukemia (CLL) patients followed up to the era of advanced treatments including targeted therapies. Data were extracted for patients 15 years or older with a primary diagnosis of CLL. A period analysis was performed to estimate 5- and 10-year relative survival rates for patients diagnosed during different calendar periods from 1985 to 2015. A mixture cure model was used to examine long-term survivors' proportions among patients diagnosed in 1985-2015 and for two cohorts diagnosed in 2000-2003, followed up to 2012 and 2004-2007, and followed up to 2015. Cox proportional hazard modeling was used for the two cohorts to estimate hazard ratios (HRs) of death adjusted for gender and age. The 5-year and 10-year age-adjusted relative survival rate ranged between 73.7 and 89.4% and from 51.6% to "not reached," respectively, for calendar periods of 1985-1989 to 2010-2014. The long-term survivor proportions varied by age and gender from 0 to 59%. The HRs (95%CI) for the 2004-2007 cohort in comparison to the 2000-2003 cohort were 0.58 (0.43-0.78), 0.58 (0.48-0.70), 0.57 (0.49-0.0.67), 0.68 (0.54-0.85), and 0.83 (0.68-1.02) for the age categories of 45-54, 55-64, 65-74, 75-84, and ≥ 85 years, respectively. Overall, relative survival improved significantly for CLL patients diagnosed between 1985 and 2015. These improvements were markedly better following the introduction of targeted therapies.

Trends in survival of chronic lymphocytic leukemia patients in Germany and the USA in the first decade of the twenty-first century

Background

Recent population-based studies in the United States of America (USA) and other countries have shown improvements in survival for patients with chronic lymphocytic leukemia (CLL) diagnosed in the early twenty-first century. Here, we examine the survival for patients diagnosed with CLL in Germany in 1997–2011.

Methods

Data were extracted from 12 cancer registries in Germany and compared to the data from the USA. Period analysis was used to estimate 5- and 10-year relative survival (RS).

Results

Five- and 10-year RS estimates in 2009–2011 of 80.2 and 59.5 %, respectively, in Germany and 82.4 and 64.7 %, respectively, in the USA were observed. Overall, 5-year RS increased significantly in Germany and the difference compared to the survival in the USA which slightly decreased between 2003–2005 and 2009–2011. However, age-specific analyses showed persistently higher survival for all ages except for 15–44 in the USA. In general, survival decreased with age, but the age-related disparity was small for patients younger than 75. In both countries, 5-year RS was >80 % for patients less than 75 years of age but <70 % for those age 75+.

Conclusions

Overall, 5-year survival for patients with CLL is good, but 10-year survival is significantly lower, and survival was much lower for those age 75+. Major differences in survival between countries were not observed. Further research into ways to increase survival for older CLL patients are needed to reduce the persistent large age-related survival disparity.

Relationship between progression-free survival and overall survival in chronic lymphocytic leukemia: a literature-based analysis

BACKGROUND

The endpoints of progression-free survival (pfs) and time-to-progression (ttp) are frequently used to evaluate the clinical benefit of anticancer drugs. However, the surrogacy of those endpoints for overall survival (os) is not validated in all cancer settings. In the present study, we used a trial-based approach to assess the relationship between median pfs or ttp and median os in chronic lymphocytic leukemia (cll).

METHODS

The pico (population, interventions, comparators, outcomes) method was used to conduct a systematic review of the literature. The population consisted of patients with cll; the interventions and comparators were standard therapies for cll; and the outcomes were median pfs, ttp, and os. Two independent reviewers screened titles, abstracts, and full papers for eligibility and then extracted data from selected studies. Correlation coefficients were calculated to assess the relationship between median pfs or ttp and median os. Subgroup correlation analyses were also conducted according to the characteristics of the selected studies (such as line of treatment and type of treatment under investigation).

RESULTS

Of the 1263 potentially relevant articles identified during the literature search, twenty-three were included. On average, median pfs or ttp was 16.0 months (standard deviation: 12.4 months) and median os was 43.5 months (standard deviation: 31.2 months). Results of the correlation analysis indicated that median pfs or ttp is highly correlated with median os (Spearman correlation coefficient: 0.813; p ≤ 0.001). A significant correlation between median pfs or ttp and median os was observed in second- and subsequent-line therapies, but not in the first-line setting.

CONCLUSIONS

Our study demonstrates a strong correlation between median pfs or ttp and median os in previously treated cll, which reinforce the hypothesis that pfs and ttp could be adequate surrogate endpoints for os in this cancer setting.

Management of HIV infection in patients with cancer receiving chemotherapy

The optimal antiretroviral therapy (ART) regimen for human immunodeficiency virus (HIV)-infected patients with cancer remains unknown, as clinical trials are lacking and published data are insufficient to guide recommendations. When concomitant use of chemotherapy and ART is anticipated, overlap of toxic effects and drug-drug interactions between chemotherapy and ART may alter the optimal choice of ART. Prospective studies are urgently needed to further define the toxic effects of combined chemotherapy and ART in HIV-positive cancer patients. Such studies should aid the development of guidelines for treatment of this population. For now, clinicians should individualize decisions regarding treatment of HIV according to clinical and laboratory findings, cancer treatment plan (chemotherapy, radiotherapy, or surgery), liver or renal disease, potential adverse drug effects (eg, rash, gastrointestinal intolerance, bone marrow suppression), and patient preference. This review focuses on what infectious disease specialists need to know to select the most appropriate ART regimens for patients receiving chemotherapy.

Treatment of older patients with chronic lymphocytic leukemia: key questions and current answers

Despite the advanced age at onset, chronic lymphocytic leukemia (CLL) shortens the life expectancy of the majority of newly diagnosed patients. The management of elderly patients with CLL is more complex than that of younger patients due to the greater frequency of comorbidities and functional impairment as well as reduced organ function. Many of the recent advances in the care of CLL patients (prognostication, more intense combination therapy regimens) are of unclear relevance for elderly patients. This review addresses 5 key questions in the management of elderly patients with CLL: (1) why is classifying the “fitness” of CLL patients necessary; (2) what criteria should be used to classify patient fitness; (3) when should elderly patients be treated; (4) how should therapy be selected for elderly patients; and (5) which therapy is best (for this patient)?

Bendamustine for patients with indolent B cell lymphoid malignancies including chronic lymphocytic leukaemia

BACKGROUND

Indolent B cell lymphoid malignancies include follicular lymphoma, small lymphocytic lymphoma, mantle cell lymphoma, lymphoplasmacytic lymphoma and marginal zone lymphomas. Chronic lymphocytic leukaemia (CLL) is a lymphoid malignancy similar to small lymphocytic lymphoma (SLL) in its leukaemic phase.Indolent lymphoid malignancies including CLL are characterised by slow growth, a high initial response rate and a relapsing and progressive disease course. Advanced-stage indolent B cell lymphoid malignancies are often incurable. If symptoms or progressive disease occur, chemotherapy plus rituximab is indicated. No chemotherapy regimen has been shown to improve overall survival compared to a different regimen.Bendamustine is efficacious in the treatment of patients with indolent B cell lymphoid malignancies. A number of randomised controlled trials have examined the effect of bendamustine compared to other chemotherapy regimens in these patients. Improved disease control with no survival benefit is shown.

OBJECTIVES

To evaluate the efficacy of bendamustine therapy for patients with indolent B cell lymphoid malignancies including CLL.

SEARCH METHODS

We electronically searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 2), MEDLINE (1966 to May 2012), EMBASE (1974 to November 2011), LILACS (1982 to May 2012), databases of ongoing trials (accessed 30 April 2012) and relevant conference proceedings. We searched references of identified trials and contacted the first author of each included trial.

SELECTION CRITERIA

Randomised controlled trials that compared a bendamustine-containing regimen to other chemotherapy with or without immunotherapy.

DATA COLLECTION AND ANALYSIS

Two authors independently appraised the quality of each trial and extracted data from included trials. We estimated and pooled hazard ratios (HR) and risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included five trials randomising 1343 adult patients in the systematic review. Allocation and blinding were unclear in three trials and adequate in two. Incomplete outcome data and selective reporting were adequate in all trials. Trials varied in the type of lymphoid malignancy, bendamustine regimen and the comparator regimen. In the three trials that included patients with follicular lymphoma, mantle cell lymphoma and other indolent lymphomas the comparator treatment was cyclophosphamide, a combination of cyclophosphamide, vincristine, doxorubicin and prednisone, and fludarabine. Two trials included only patients with CLL and compared bendamustine to chlorambucil, and to fludarabine. We did not conduct a meta-analysis due to the clinical heterogeneity among trials. Bendamustine had no statistically significant effect on the overall survival of patients with indolent B cell lymphoid malignancies in any of the included trials (trials of moderate quality). Progression-free survival was statistically significantly improved with bendamustine treatment compared to other chemotherapy in three of the four trials that reported on it. One trial demonstrated a non statistically significant improvement of PFS. The risk of grade 3 or 4 adverse events was similar when bendamustine was compared to CHOP and fludarabine, and higher when compared to chlorambucil. Compared to chlorambucil quality of life was unaffected by bendamustine treatment (one trial, no meta-analysis).

AUTHORS' CONCLUSIONS

As none of the currently available chemotherapeutic protocols for induction therapy in indolent B cell lymphoid malignancies confer a survival benefit and due to the improved progression-free survival in each of the included trials, and a similar rate of grade 3 or 4 adverse events, bendamustine may be considered for the treatment of patients with indolent B cell lymphoid malignancies. However, the unclear effect on survival and the higher rate of adverse events compared to chlorambucil in patients with CLL/SLL does not support the use of bendamustine for these patients.The effect of bendamustine combined with rituximab should be evaluated in randomised clinical trials with more homogenous populations and outcomes for specific subgroups of patients by type of lymphoma should be reported. Any future trial should evaluate the effect of bendamustine on quality of life.

Treatment and management of chronic lymphocytic leukemia in the elderly: what the pharmacist clinician should know

OBJECTIVE

To review the literature for current treatment options and supportive care management for elderly patients with chronic lymphocytic leukemia (CLL).

DATA SOURCES

PubMed searches using the terms chronic lymphocytic leukemia, elderly, practice guidelines, and controlled clinical trials were performed from 1949 through August 2011. Reference lists from relevant articles were examined for additional studies, review articles, and guidelines.

STUDY SELECTION AND DATA EXTRACTION

Eighty-three articles were generated and abstracted articles were chosen based on trial results that changed clinical practice, resulted in approval of new drugs for CLL by the Food and Drug Administration and/or had clinical relevance to the elderly population.

DATA SYNTHESIS

Fit elderly CLL patients have more treatment options than frail elderly. Most studies include patients younger than 65 years of age, and recent advances in treatment may not prove beneficial for all ages. Clinicians should use available evidence and clinical judgment when treating and monitoring elderly CLL patients.

CONCLUSION

Treatment armamentarium has improved over the last decade, yet clinical trials research should include more elderly cohorts as new agents are developed. Increased awareness of supportive care issues improves quality of life for a population with multiple disease complications.

Enhancement of fludarabine sensitivity by all-trans-retinoic acid in chronic lymphocytic leukemia cells

BACKGROUND

A subset of patients with fludarabine-resistant chronic lymphocytic leukemia has previously been shown to express elevated intracellular levels of the concentrative high-affinity fludarabine transporter hCNT3, without any detectable related activity. We have recently shown that all-trans-retinoic acid is capable of inducing hCNT3 trafficking to plasma membrane in the MEC1 cell line. We, therefore, evaluated the effect of all-trans-retinoic acid on hCNT3 in primary chronic lymphocytic leukemia cells as a suitable mechanism to improve fludarabine-based therapy of chronic lymphocytic leukemia.

DESIGN AND METHODS

Cells from 23 chronic lymphocytic leukemia patients wild-type for P53 were analyzed for ex vivo sensitivity to fludarabine. hCNT3 activity in chronic lymphocytic leukemia cell samples was evaluated by measuring the uptake of [8-(3)H]-fludarabine. The amounts of transforming growth factor-β1 and hCNT3 messenger RNA were analyzed by real-time polymerase chain reaction. The effect of all-trans-retinoic acid on hCNT3 subcellular localization was analyzed by confocal microscopy and its effect on fludarabine-induced apoptosis was evaluated by flow cytometry analysis using annexin V staining.

RESULTS

Chronic lymphocytic leukemia cases showing higher ex vivo basal sensitivity to fludarabine also had a greater basal hCNT3-associated fludarabine uptake capacity compared to the subset of patients showing ex vivo resistance to the drug. hCNT3 transporter activity in chronic lymphocytic leukemia cells from the latter patients was either negligible or absent. Treatment of the fludarabine-resistant subset of chronic lymphocytic leukemia cells with all-trans-retinoic acid induced increased fludarabine transport via hCNT3 which was associated with a significant increase in fludarabine sensitivity.

CONCLUSIONS

Improvement of ex vivo fludarabine sensitivity in chronic lymphocytic leukemia cells is associated with increased hCNT3 activity after all-trans-retinoic acid treatment.

Pharmacokinetics, bioavailability and effects on electrocardiographic parameters of oral fludarabine phosphate

The pharmacokinetics, bioavailability and effects on electrocardiographic (ECG) parameters of fludarabine phosphate (2F-ara-AMP) were evaluated in adult patients with B-cell chronic lymphocytic leukemia. Patients received single doses of intravenous (IV) (25 mg/m(2), n=14) or oral (40 mg/m(2), n=42) 2F-ara-AMP. Plasma concentrations of drug and metabolites and digital 12-lead ECGs were monitored for 23 h after dosing. The dephosphorylated product fludarabine (2F-ara-A) was the principal metabolite present in the systemic circulation. Mean (+/-SD) elimination half-life did not differ significantly between IV and oral dosage groups (11.3+/-4.0 vs 9.7+/-2.0 h, p=0.053). Renal excretion was a major clearance pathway, along with transformation to a hypoxanthine metabolite 2F-ara-Hx. Estimated mean oral bioavailability of 2F-ara-A was 58%. Compared to the time-matched drug-free baseline Fridericia correction of the QT interval (QTcF), the mean QTcF change following 2F-ara-AMP did not differ from zero, and a treatment effect of >+10 and >+15 ms could be excluded following oral and IV 2F-ara-AMP, respectively. Similarly, heart rate, PR interval and QRS duration did not change following 2F-ara-AMP treatment. Thus the 25 mg/m(2) IV and 40 mg/m(2) oral doses of 2F-ara-AMP produce similar systemic exposure, and do not prolong QTcF, indicating low risk of drug induced Torsades de Pointes.

Comparison of cladribine plus cyclophosphamide with fludarabine plus cyclophosphamide as first-line therapy for chronic lymphocytic leukemia: a phase III randomized study by the Polish Adult Leukemia Group (PALG-CLL3 Study)

PURPOSE Little is known about comparison of the activity of different purine nucleoside analogs in chronic lymphocytic leukemia (CLL). We conducted a randomized phase III trial to compare efficacy and safety of cladribine and fludarabine, each combined with cyclophosphamide, in previously untreated progressive CLL. PATIENTS AND METHODS Patients received cladribine at 0.12 mg/kg combined with cyclophosphamide at 250 mg/m(2) for 3 days intravenously (CC regimen) or fludarabine at 25 mg/m(2) combined with cyclophosphamide at 250 mg/m(2) for 3 days intravenously (FC regimen), every 28 days for up to six cycles. The primary end point was complete response (CR) rate. Secondary end points included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and treatment-related toxicity. RESULTS Of 423 randomly assigned patients (211 to CC and 212 to FC), 395 were evaluated in the final analysis. The CR and ORR reached 47% and 88% in the CC arm and 46% and 82% in the FC arm (P = .25 and P = .11, respectively). The median PFS was 2.34 years with CC and 2.27 years with FC (P = .51). OS and grade 3/4 treatment-related toxicity were also comparable. Moreover, we did not observe any significant differences in CC and FC efficacy across different patient prognostic subgroups that included patients with 17p13 (TP53 gene) deletion who had poor survival in both study arms. CONCLUSION Cladribine and fludarabine in combination with cyclophosphamide are equally effective and safe first-line regimens for progressive CLL. Both combinations have unsatisfactory activity in patients with 17p13 (TP53 gene) deletion.

A review of pharmacologic options for previously untreated chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia and has a heterogeneous clinical course. Some patients experience an indolent disease course, which does not require treatment or affect their overall quality of life. Other patients present with symptomatic advanced disease that rapidly progresses and requires therapy. For these patients, chemotherapy is the mainstay of treatment and has undergone significant evolution in the past few decades. From alkylating agents to purine analogs, response rates have greatly improved with new chemotherapy regimens. The development of chemoimmunotherapy regimens has also transformed the treatment of CLL. This article will review front-line treatment options for CLL and discuss the updated National Comprehensive Cancer Network guidelines.

First-line therapy with fludarabine compared with chlorambucil does not result in a major benefit for elderly patients with advanced chronic lymphocytic leukemia

Although chronic lymphocytic leukemia (CLL) is a disease of elderly patients, subjects older than 65 years are heavily underrepresented in clinical trials. The German CLL study group (GCLLSG) initiated a multicenter phase III trial for CLL patients older than 65 years comparing first-line therapy with fludarabine with chlorambucil. A total of 193 patients with a median age of 70 years were randomized to receive fludarabine (25 mg/m2 for 5 days intravenously, every 28 days, for 6 courses) or chlorambucil (0.4 mg/kg body weight [BW] with an increase to 0.8 mg/kg, every 15 days, for 12 months). Fludarabine resulted in a significantly higher overall and complete remission rate (72% vs 51%, P = .003; 7% vs 0%, P = .011). Time to treatment failure was significantly shorter in the chlorambucil arm (11 vs 18 months; P = .004), but no difference in progression-free survival time was observed (19 months with fludarabine, 18 months with chlorambucil; P = .7). Moreover, fludarabine did not increase the overall survival time (46 months in the fludarabine vs 64 months in the chlorambucil arm; P = .15). Taken together, the results suggest that in elderly CLL patients the first-line therapy with fludarabine alone does not result in a major clinical benefit compared with chlorambucil. This trial is registered with www.isrctn.org under identifier ISRCTN 36294212.

The humanized CD40 antibody SGN-40 demonstrates pre-clinical activity that is enhanced by lenalidomide in chronic lymphocytic leukaemia

Antibody-based therapies, such as rituximab and alemtuzumab, have contributed significantly to the treatment of Chronic Lymphocytic leukaemia (CLL). The CD40 antigen is expressed predominantly on B-cells and represents a potential target for immune-based therapies. SGN-40 is a humanized IgG1 monoclonal antibody currently in Phase I/II clinical trials for indolent lymphomas, diffuse large B cell lymphomas and Multiple Myeloma. Its biological effect on CLL cells has not been studied. The present study demonstrated that SGN-40 mediated modest apoptosis in a subset of patients with secondary cross-linking but did not mediate complement-dependent cytotoxicity. SGN-40 also mediated antibody-dependent cellular cytotoxicity (ADCC) predominantly through natural killer (NK) cells. Previous studies by our group and others have demonstrated that lenalidomide upregulates CD40 expression on primary B CLL cells and activates NK-cells. We therefore examined for the combinatorial effect of lenalidomide and SGN-40 and demonstrated that both enhanced direct apoptosis and ADCC against primary CLL B cells. These data together provide justification for clinical trials of SGN-40 and lenalidomide in combination for CLL therapy.

Alemtuzumab compared with chlorambucil as first-line therapy for chronic lymphocytic leukemia

PURPOSE

We conducted a randomized trial to evaluate the efficacy and safety of intravenous alemtuzumab compared with chlorambucil in first-line treatment of chronic lymphocytic leukemia (CLL).

PATIENTS AND METHODS

Patients received alemtuzumab (30 mg three times per week, for up to 12 weeks) or chlorambucil (40 mg/m(2) every 28 days, for up to 12 months). The primary end point was progression-free survival (PFS). Secondary end points included overall response rate (ORR), complete response (CR), time to alternative therapy, safety, and overall survival.

RESULTS

We randomly assigned 297 patients, 149 to alemtuzumab and 148 to chlorambucil. Alemtuzumab had superior PFS, with a 42% reduction in risk of progression or death (hazard ratio [HR] = 0.58; P = .0001), and a median time to alternative treatment of 23.3 versus 14.7 months for chlorambucil (HR = 0.54; P = .0001). The ORR was 83% with alemtuzumab (24% CR) versus 55% with chlorambucil (2% CR); differences in ORR and CR were highly statistically significant (P < .0001). Elimination of minimal residual disease occurred in 11 of 36 complete responders to alemtuzumab versus none to chlorambucil. Adverse events profiles were similar, except for more infusion-related and cytomegalovirus (CMV) events with alemtuzumab and more nausea and vomiting with chlorambucil. CMV events had no apparent impact on efficacy.

CONCLUSION

As first-line treatment for patients with CLL, alemtuzumab demonstrated significantly improved PFS, time to alternative treatment, ORR and CR, and minimal residual disease-negative remissions compared with chlorambucil, with predictable and manageable toxicity.

Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial

BACKGROUND

Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine.

METHODS

777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610.

FINDINGS

There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival.

INTERPRETATION

Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.

Fludarabine-mediated suppression of the excision repair enzyme ERCC1 contributes to the cytotoxic synergy with the DNA minor groove crosslinking agent SJG-136 (NSC 694501) in chronic lymphocytic leukaemia cells

In this study, we set out to establish whether fludarabine could enhance the DNA interstrand crosslinking capacity of SJG-136 in primary human chronic lymphocytic leukaemia (CLL) cells and thereby offer a rationale for its clinical use in combination with SJG-136. SJG-136 rapidly induced DNA crosslinking in primary CLL cells which was concentration-dependent. Further, the level of crosslinking correlated with sensitivity to SJG-136-induced apoptosis (P=0.001) and higher levels of crosslinking were induced by the combination of SJG-136 and fludarabine (P=0.002). All of the samples tested (n=40) demonstrated synergy between SJG-136 and fludarabine (mean combination index (CI)=0.54±0.2) and this was even retained in samples derived from patients with fludarabine resistance (mean CI=0.62±0.3). Transcription of the excision repair enzyme, ERCC1, was consistently increased (20/20) in response to SJG-136 (P<0.0001). In contrast, fludarabine suppressed ERCC1 transcription (P=0.04) and inhibited SJG-136-induced ERCC1 transcription when used in combination (P=0.001). Importantly, the ability of fludarabine to suppress ERCC1 transcription correlated with the degree of synergy observed between SJG-136 and fludarabine (r²=0.28; P=0.017) offering a mechanistic rationale for the synergistic interaction. The data presented here provides a clear indication that this combination of drugs may have clinical utility as salvage therapy in drug-resistant CLL.

Single-agent purine analogues for the treatment of chronic lymphocytic leukaemia: A systematic review and meta-analysis

BACKGROUND

Recent trials suggest improved response rates for purine analogues compared to alkylator-based regimens in the treatment of B-CLL. However, none was able to show a survival advantage. Thus, a systematic Cochrane review may be able to further define the role of purine analogues in the first-line treatment of B-CLL.

METHODS

Randomized controlled trials comparing single-agent purine analogues with alkylator-based regimens were included. Medical databases (Cochrane Library, MEDLINE, EMBASE), conference proceedings and trial registers were searched. We included full-text and abstract publications as well as unpublished data. Relative risks (RR) and hazard ratios (HR) were calculated under a fixed-effects model, clinical and statistical heterogeneity was examined with sensitivity analyses and meta-regression. If applicable, numbers needed to treat or harm (NNT, NNH) were also determined.

FINDINGS

Five trials with 1838 randomized patients were included. Importantly, four trials had a cross-over design. There was a trend for improved overall survival for patients receiving purine analogues as initial therapy but statistical significance was just not reached (HR 0.89 [95% CI 0.78-1.01]). The RR for achieving an overall (RR 1.22 [95% CI 1.13-1.31]; NNT 8 [95% CI 6-13]) and complete response (RR 1.94 [95% CI 1.65-2.28]; NNT 6 [5-8]) was significantly improved, resulting in a longer progression-free survival (HR 0.70 [95% CI 0.61-0.82]). Incidence of grade III/IV infections (RR 1.83 [95% CI 1.30-2.58]; NNH 20 [95% CI 12.5-50]) and haemolytic anaemia (RR 3.36 [95% CI 1.27-8.91]; NNH 21 [95% CI 6-185]) was significantly higher in patients receiving purine analogues.

INTERPRETATION

Despite significantly increased response rates and longer progression-free survival with purine analogues as first-line therapy, we were not able to detect a statistically significant improvement of overall survival compared to alkylator-based regimens. Furthermore, the use of purine analogues augments the risk for grade III/IV infections and haemolytic anaemia.

Phase II study of oral fludarabine phosphate in relapsed indolent B-Cell non-Hodgkin's lymphoma

PURPOSE

Although intravenous (IV) fludarabine phosphate is effective against indolent B-cell non-Hodgkin's lymphoma (B-NHL), IV administration for 3 to 5 consecutive days is inconvenient in an outpatient setting. To assess the efficacy and toxicity of oral fludarabine phosphate in patients with indolent B-NHL, we conducted a multicenter phase II study.

PATIENTS AND METHODS

Patients with relapsed indolent B-NHL received fludarabine phosphate tablets orally once daily on days 1 through 5 every 28 days for three to six cycles. The efficacy was separately analyzed in a mantle-cell lymphoma (MCL) cohort and indolent B-NHL except for MCL (IL) cohort. The primary end point was the overall response rate (ORR).

RESULTS

Fifty-two patients, including 46 in the IL cohort (41 with follicular lymphoma) and six in the MCL cohort, were registered, and all patients were eligible. Forty-one patients (79%) had received rituximab as prior therapy. In the IL cohort, the ORR and complete response rate were 65% (30 of 46 patients; 95% CI, 50% to 79%) and 30% (14 of 46 patients; 95% CI, 18% to 46%), respectively. One of six patients with MCL achieved a partial response. The median times to treatment failure for the 46 patients in the IL cohort and for the six patients in the MCL cohort were 8.6 and 6.1 months, respectively. Hematologic toxicities, including grade 4 neutropenia (37%), were the most frequent toxicities, and nonhematologic toxicities were mild.

CONCLUSION

Oral fludarabine phosphate is highly effective in patients with relapsed indolent B-NHL who have mostly been pretreated with rituximab and is more convenient than the IV formulation.