Cyclophosphamide followed by fludarabine for untreated chronic lymphocytic leukemia: a phase II SWOG TRIAL 9706

Transcription

1 (2005) 19, & 2005 Nature Publishing Group All rights reserved /05 $ Cyclophosphamide followed by fludarabine for untreated chronic lymphocytic leukemia: a phase II SWOG TRIAL 9706 MA Hussein 1, H Gundacker 2, DR Head 3, L Elias 4, KA Foon 5, DH Boldt 6, SM Dobin 7, SR Dakhil 8, GT Budd 1 and FR Appelbaum 9 1 Cleveland Clinic Foundation, Myeloma Program, Cleveland, OH, USA; 2 Department of Pathology, Southwest Oncology Group Statistical Center, Seattle, WA, USA; 3 Department of Internal Medicine, Division of Hematology/Oncology, St Jude Children s Research Hospital, Memphis, TN, USA; 4 Department of Internal Medicine, Division of Hematology and Oncology, University of New Mexico, Albuquerque, NM, USA; 5 Department of Medicine, Division of Hematology, University of Cincinnati, Cincinnati, OH, USA; 6 Department of Pathology, University of Texas Health Science Center, San Antonio, TX, USA; 7 Scott & White Hospital, Temple, TX, USA; 8 Taussig Cancer Center, Wichita Community Clinical Oncology Program, Wichita, KS, USA; and 9 Puget Sound Oncology Consortium, Seattle, WA, USA B-cell chronic lymphocytic leukemia (CLL) accounts for 95% of chronic leukemia cases and 25% of all leukemia. Despite the prevalence of CLL, progress in its treatment has been only modest over the past three decades. Based upon the ability of fludarabine to produce high-grade remissions especially among patients with low initial tumor mass, and the ability of alkylators to reduce tumor mass, we hypothesized that sequential administration of a limited number of cycles of intermediate-dose cyclophosphamide followed by fludarabine could result in a larger percentage of patients with complete remissions (CRs). In all, 27 of the 49 eligible patients achieved overall responses of CR, unconfirmed complete remission (UCR), or PR, for a total response rate of 55% (95% confidence interval (CI) 40 69%). Considering the confounding medical issues of this patient population with advanced aggressive disease, the regimen was generally well tolerated. This study demonstrates that high-dose cyclophosphamide followed by fludarabine was relatively well tolerated in this group of advanced CLL patients. The study s criterion for testing whether the regimen is sufficiently effective to warrant further investigation was met: 14 (32%) of the first 44 eligible patients achieved CR or UCR. (2005) 19, doi: /sj.leu ; published online 29 September 2005 Keywords: chronic lymphocytic leukemia; cyclophosphamide; fludarabine Introduction B-cell chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia in Western countries. It accounts for 95% of chronic leukemia cases and 25% of all leukemia. Despite the prevalence of CLL, progress in its treatment has been only modest over the past three decades. 1 This may relate to the older age of patients and the indolent nature of the disease, which limits application of aggressive approaches. Current therapies have failed to substantially influence survival and are associated with significant toxicity. Consequently, treatment of the disease is generally with palliative intent only. The majority of patients with CLL present with early disease and most often they do not require immediate therapy. 2,3 The median survival is in excess of 10 years. Occasionally, earlystage patients show a rapidly progressive course and require cytotoxic intervention. Unfortunately, there are no consistent reliable clinical or laboratory features that prospectively identify Correspondence: Dr MA Hussein, Southwest Oncology Group (S9706), Operations Office, Omicron Drive, San Antonio, Texas , USA; Fax: þ ; pubs@swog.org Received 2 August 2004; accepted 12 July 2005; published online 29 September 2005 these patients. 4,5 Several variables, that have been reported to influence the clinical course in CLL include age, sex, clinical stage, and response to therapy. Lymphocyte doubling time in the peripheral blood, histological pattern of lymphocytic infiltration in the bone marrow biopsy specimen, cytogenetics, and more recently CD38 expression are known to assist in predicting the clinical course and duration of survival Patients with CLL who are asymptomatic and do not have evidence of progression can be safely watched to assess their disease s clinical behavior. 12,13 Treatment is eventually required for most patients with CLL because of progressive disease (PD) or disease-related morbidity from infection, hemorrhage, constitutional symptoms, and/or problems resulting from lymphadenopathy and hepatosplenomegaly. Since there is no curative therapy for CLL, a number of clinical considerations usually enter into the decision of when to treat. These factors have been detailed in a report prepared by the National Cancer Institute Working Group on CLL. 14 Fludarabine is an effective treatment option for CLL, currently approved for second-line treatment after alkylator failures. The U. S. CALGB/Inter-group study of Rai et al 15 compared the efficacy of fludarabine with that of chlorambucil in the primary treatment of CLL. The complete response rate in the intermediate group appeared to be higher than in the advanced group of patients with the use of fludarabine. In addition to advanced stage, other factors have been associated with highresponse rates, including a low white blood count, limited lymph node involvement, normal hemoglobin and platelet levels, and normal serum albumin and alkaline phosphatase levels. Similar patterns, including higher objective response rates with fludarabine compared to cyclophosphamide/doxorubicin-based combinations, were noted in the large Phase II trial reported by the French Cooperative Group. 16 Based upon the ability of fludarabine to produce high-grade remissions especially among patients with low initial tumor mass, and the ability of alkylators to reduce tumor mass, we hypothesized that sequential administration of a limited number of cycles of intermediate-dose cyclophosphamide followed by fludarabine could result in a larger percentage of patients with complete remissions (CRs). Improved outcomes could also be expected to result from such coordinated use of these agents with differing mechanisms of resistance. We expected this strategy to circumvent the potential for increased toxicity noted with some combination approaches, while allowing fludarabine to be administered at full dosages. We have elected to use GM-CSF as the preferred growth factor because of its possible immunologic role in the management of lymphoproliferative disorders. In a report by Bernell et al, 17 the increased level of IL-2R in response to GM-CSF

2 therapy was paralleled by an increased percentage of a subset of T-lymphocytes with an activated phenotype (CD3 þ, HLA Dr þ ). This was associated with regression of the patients multiple myeloma. Ho et al 18 have conveyed a similar observation in a group of patients with nonhodgkin s lymphoma receiving intensive chemotherapy and GM-CSF. Ho and his coworkers failed to notice these biologic effects in the group who did not receive GM-CSF. Moreover, the non-hodgkin s lymphoma patients that received GM-CSF seemed to have higher CR rates and longer survival (Ho AD et al. Blood (1989) 74 (Suppl 1):7 abstract 604). These observations could be explained by the positive effect of GM-CSF within the different immunologic parameters. 19 Methods and patient population Eligibility criteria The diagnosis of B-cell CLL was based on criteria recommended in 1988 by the Working Group on CLL sponsored by the National Cancer Institute (NCI). 14 The stage of disease was assessed according to the guidelines of the NCI Working Group and the modified Rai staging system. All newly diagnosed untreated CLL patients were considered for the study if they fulfilled the following parameters. All patients in the high-risk category (Rai stage III or IV) were eligible. Intermediate-risk patients (Rai stage I or II) were also eligible if they had at least one of the following signs of active disease: any disease-related symptom such as weight loss, extreme fatigue, night sweats, or fever without evidence of infection; massive or progressive splenomegaly and/or lymphadenopathy; or more than a 50% increase in the number of peripheral-blood lymphocytes over a 2-month period or an anticipated doubling of these cells within less than 6 months. Patients who had previously received any cytotoxic therapy were not eligible. Additional eligibility requirements were age of at least 18 years and Southwest Oncology Group performance status of 0, 1, or 2. Patients with active infection requiring antibiotic or antifungal therapy and patients known to be HIV-positive were not eligible. Table 1 summarizes the patient characteristics. Each patient signed an informed-consent form approved by a local institutional review board. Submission of blood smears, bone marrow aspirates, and biopsy slides for central pathological review was required. Treatment plan Cyclophosphamide at a dose of 1.5 gm/m 2 was given every 3 weeks for a total of four cycles before proceeding to fludarabine. GM-CSF was started on day 2 after cyclophosphamide of therapy for a total of 10 days or longer if the neutrophil count was o1500/ml. GM-CSF was discontinued at least 48 h before initiating a new cycle of therapy. Patients exhibiting PD while on cyclophosphamide proceeded directly to fludarabine 4 weeks after the last dose of cyclophosphamide. Fludarabine was given days 1 5 at 25 mg/m 2 every 4 weeks or later, depending on the counts, for a total of six cycles or until disease progression. GM-CSF was administered as detailed above after the completion of fludarabine. Patients continued study treatment until completion, disease progression, relapse, or more than a 2-week delay due to toxicity. Dose reductions were required in the event of hematologic toxicity. Evaluation of hematological toxicity in patients with CLL must consider the high frequency of hematological Table 1 S9706 patient characteristics (N ¼ 49 eligible patients) Age: median (range) 58 (35 80) Sex: males (%) 42 (86%) Race (%): White subjects 44 (90%) Black subjects 5 (10%) Performance status (%): 0 or 1 48 (98%) 2 1 (2%) RAI risk stage (%): 0 low 0 (0%) I intermediate 6 (12%) II intermediate 16 (33%) III high 11 (22%) IV high 16 (33%) Lymphocyte count 10 3 : median (range) 73 (7 564) Hemoglobin g %: median (range) 12 (6 16) Platelet count 10 3 : median (range) 141 (12 782) b2 microglobulin mg/l, N ¼ 41: median (range) 3.5 (0.2, 14.0) Cytogenetics, N ¼ 33 eligible patient cases Normal karyotype (%) 22 (67%) Abnormal karyotype (%) a : 11 (33%) Trisomy 12 4 (36%) del(13q) 2 (18%) del(6q) 2 (18%) 14q32 rearrangement 2 (18%) del(11q) 1 (9%) Complex karyotype b 4 (36%) a Each abnormal karyotype have more than one type of abnormality. b Three or more chromosome abnormalities. compromise at the initiation of therapy. Therefore, the standard criteria used for solid tumors were not applied directly; many patients would be considered to have Grade 2 4 hematological toxicity at presentation. The parameters for dose reductions listed below apply for both cyclophosphamide and fludarabine. Based on day-1 count value, patients who experienced Grade 3 or 4 neutropenia were to resume therapy at 50% dose after the granulocyte count has increased to 4500/ml or recovery of the granulocyte count to at least 75% of pretreatment baseline. Dose reductions for decreased platelet count were also required by the protocol. GM-CSF was discontinued for patients who experienced acute anaphylactic reactions. The replacement of the growth factor with G-CSF in such patients was allowed. Evaluation of response to therapy Each patient s responses to each agent and overall response to the entire treatment regimen were evaluated according to criteria recommended by the NCI-sponsored Working Group on CLL to evaluate responses. 14,20 A CR was defined as the absence of constitutional symptoms and of lymphadenopathy, splenomegaly, and hepatomegaly on physical examination; an absolute neutrophil count of at least 1500/mm 3, a platelet count of at least /mm 3, a hemoglobin level higher than 11 g/dl (without transfusion), an absolute lymphocyte count of less than 4000/mm 3 ; and bone marrow of normal cellularity, with less than 30% lymphocytes and no lymphoid nodules. The Working Group criteria for CR also recommends performance of bone marrow biopsy and aspiration 2 months after the criteria above are met, in order to confirm that a CR was achieved. Therefore, 1881

3 1882 if a patient met the clinical and laboratory criteria for CR and did not relapse within 60 days, but did not have the confirmatory marrow examination after at least 60 days, then the overall response was coded as an unconfirmed CR (UCR). This additional criterion was applied to the patient s overall response, but not to responses to each agent since the patient would be treated as if in clinical remission and the patient would be onto the next phase of treatment before completing the 60-day marrow exam. Partial remission (PR) was defined as a reduction of at least 50% in the size of the lymph nodes, spleen, and liver on physical examination, if they were enlarged before therapy; a decrease of at least 50% in the number of peripheral blood lymphocytes from the value before treatment; and one of the following: an absolute neutrophil count of at least 1500/ mm 3 or an increase of at least 50% over the baseline value; a platelet count of at least /mm 3 or an increase of at least 50% over the base line value, and a hemoglobin level of at least 11 g/dl or an increase of at least 50% over the base line value (without transfusion). PD was defined as an increase of at least 50% in the size of the lymph nodes, spleen, or liver if they were previously enlarged, or the detection of enlargement if they were not previously enlarged; an increase of at least 50% in the number of peripheral blood lymphocytes; or both. Patients whose responses were adequately assessed and who did not meet any of these criteria, and who received at least two cycles of cyclophosphamide and three cycles of fludarabine, were considered to have stable disease (SD). Cytogenetic analysis Cytogenetic studies were performed in SWOG-approved cytogenetics laboratories. Bone marrow and/or blood specimens were cultured and harvested according to the protocols of the individual institutions. Analysis was performed using standard G-banding techniques and karyotypes were interpreted using the International System for Cytogenetic Nomenclature (ISCN) criteria. 21 Karyotypes were considered normal diploid if no clonal abnormalities were detected in a minimum of 20 metaphases examined and if two growth/harvesting methods were used. Each karyotype was independently reviewed by at least two members of the SWOG Cytogenetics Committee. Statistical considerations The study design called for a total of 44 eligible patients, registered without interruption for interim analyses since there was widespread experience with these agents and sufficient evidence of their safety. The CR rate for the entire treatment regimen included both CR and UCR since the patients achieving UCR are treated clinically as if they achieved CR. If 14 or more of the 44 patients achieved CR or UCR, then further investigation of the regimen would be warranted. This study design and test criterion would provide statistical power of 90% to correctly reject the null hypothesis of a 20% CR rate, if the true CR rate was in fact 40%. Demographic and clinical data were collected and evaluated using standard procedures of the Southwest Oncology Group. Toxicities were defined and graded according to the NCI Common Toxicity Criteria; version 2.X. Overall survival was measured from the date of study entry until death from any cause, with observation censored on the last date the patient was known to be alive. Disease-free survival (DFS) was measured from the date the complete response was established until the relapse of leukemia or death from any cause, with observations censored for patients last known to be alive without report of relapse. Results Patient characteristics and delivery of treatment A total of 51 patients entered the study, slightly in excess of the planned accrual. Two patients who did not have B-CLL were ineligible and are excluded from the results reported below. The 49 eligible patients (42 male patients, seven female patients) had median age 58 years (range years). In all, 27 patients (55%) had high-risk disease, and all but one had SWOG performance status 0 or 1. The median absolute peripheral lymphocyte count was /mm 3 (range /mm 3 ). Table 2 summarizes the numbers of cycles of cyclophosphamide and fludarabine given to the 49 eligible patients. In all, 27 (55%) received all four cycles of cyclophosphamide and all six cycles of fludarabine. Two others received all six cycles of fludarabine but only three of cyclophosphamide. In all, 18 patients were permanently removed from protocol treatment before completing six cycles of fludarabine: six per protocol due to low blood counts leading to delay of treatment greater than 2 weeks, three due to other toxicities, four due to PD (including one not based on protocol criteria), four due to refusal to continue therapy (including one who moved with no forwarding address), and one due to a physician s error. The two remaining patients died while on treatment. Both deaths were likely related to comorbidity conditions and possibly disease progression. One of the two patients was a 53-year-old male who, 21 days after cycle 2 of cyclophosphamide, underwent multiple dental extractions with cell component and antibiotic support. After 9 days, he was admitted with fevers, diarrhea, increased WBC with a neutrophil count 41000/ml, and a peripheral smear suggestive of CLL transformation to a more aggressive form, either prolymphocytic leukemia or Richter s syndrome. He developed multiorgan system failure and succumbed within 24 h of admission, on day 60. The second patient was a 56-yearold male with a history of coronary artery disease, hypertension, diabetes mellitus, and significant end organ damage secondary to these medical problems. At 5 days after the first cycle of cyclophosphamide, he presented with complaints of dyspnea and nausea. Initial evaluation showed the patient to have myocardial infarction. His course was further complicated by multiple pulmonary problems culminating in adult respiratory distress syndrome and death on day 24. On admission the patient was noted to have adequate neutrophil counts. Table 2 Cycles of fludarabine Summary of protocol treatment given to 49 CLL patients Cycles of cyclophosphamide Total Total

4 Table 3 Response of 49 patients with CLL to the treatment regimen of cyclophosphamide followed by fludarabine 1883 Response to cyclophosphamide Response to fludarabine Overall response Response a No. % Response a No. % Response a No. % CR 4 8% CR 4 8% CR 2 4% UCR 2 b 4% PR 16 33% CR 10 20% CR 5 10% UCR 3 6% PR 2 c 4% PR 3 6% PR 3 6% PD 2 4% PD 2 4% NASS 1 2% NASS 1 2% SD 15 31% CR 5 10% UCR 3 6% PR 2 d 4% PR 4 8% PR 4 8% SD 1 2% SD 1 2% PD 1 2% PD 1 2% NASS 4 8% NASS 4 8% PD 4 8% SD 2 4% SD 2 4% PD 2 4% PD 2 4% NASS 8 16% PR 1 2% PR 1 2% PD 1 2% PD 1 2% PR 1 2% PR 1 2% NASS 5 10% NASS 5 10% ED 2 4% NA 2 4% ED 2 4% a CR ¼ complete response with confirmatory marrow after X60 days; UCR ¼ complete response without confirmatory marrow after X60 days; ED ¼ early death; NASS ¼ not adequately assessed; PD ¼ progressive disease; PR ¼ partial response; SD ¼ stable disease. b Both of these patients met the criteria for CR except for a confirmatory marrow done after 60 days. c Both of these patients developed marrow disease within 60 days of CR. d Both of these patients developed splenomegaly within 60 days of CR. Response to cyclophosphamide and fludarabine In all, 27 of the 49 eligible patients achieved overall responses of CR, UCR, or PR, for a total response rate of 55% (95% confidence interval (CI) 40 69%). These included 15 with CR or UCR (31%, CI 18 45%) and 12 with PR (24%, CI 13 39%). Table 3 summarizes the separate responses to cyclophosphamide and fludarabine, as well as the overall responses to the entire regimen. Four patients (8%) achieved CR with cyclophosphamide, and all of these were maintained during the fludarabine portion of the treatment regimen. Two of the four patients had UCR for their overall response since the CR was not confirmed with a marrow exam on or after 60 days from the date of CR. One of these patients did not have a confirmatory marrow was performed after 60 days. A marrow was performed for this patient more than 6 months after the date of CR, which showed lymphocytic infiltrates in the marrow. The other patient with an overall response of UCR had a confirmatory marrow but before 60 days from the date of CR. Of 16 patients (33%) who achieved PR on cyclophosphamide, 10 achieved CR criteria with fludarabine although two of the 10 developed marrow disease within 60 days of CR. Three of the 16 maintained PR, while two had PD and one patient s response to fludarabine was not assessed. Of the 15 patients (31%) with stable disease after cyclophosphamide, five achieved CR criteria with fludarabine although two of the five developed splenomegaly within 60 days of CR. Four of the 15 achieved PR, while one maintained stable disease status and another had PD on fludarabine. None of the four patients (8%) with PD on cyclophosphamide responded to fludarabine. Among eight patients whose responses to cyclophosphamide were not adequately assessed, one achieved PR on fludarabine. In summary, 17 of the 27 total responses (11 CR/ UCR and six PR) were achieved on fludarabine after lesser responses (PR or SD) to cyclophosphamide. Adequate information to assess the overall response to the entire treatment regimen was not available for 10 patients. This was due in large part to the complexity of the response criteria of NCI-sponsored Working Group guidelines, which required consistent assessment of several clinical and laboratory values at multiple time points during this study s prolonged treatment regimen. Four of the 10 had SD on cyclophosphamide, but were removed from study treatment due to toxicity without meeting the criteria for CR, PR, or PD after fewer than three or no cycles of fludarabine required to establish an overall response of SD Three others, whose responses to cyclophosphamide were not adequately assessed, were removed from protocol treatment due to toxicity, refusal, or physician s nonprotocol diagnosis of PD without receiving fludarabine. The remaining three patients overall responses could not be assessed because the required examinations of lymph node, liver, and/or spleen examinations were not performed or not adequately documented. One of these three achieved PR on cyclophosphamide and met all peripheral blood criteria for CR after the second cycle of cyclophosphamide. A second patient met the peripheral blood criteria for CR after two cycles of cyclophosphamide (except for slight anemia after the first course of fludarabine). The third patient met the peripheral blood criteria for PR after four cycles of cyclophosphamide, but this was not sustained during

5 1884 Figure 1 Kaplan Meier estimate of the distribution of overall survival of the 49 eligible patients. Tick marks indicate censored observations. cultures grew Gram-positive cocci. His pulmonary status continued to deteriorate with death occurring on day 17, post cycle 6. Five other patients experienced Grade 4 nonhematologic toxicities in the form of deep venous thrombosis and pneumonia (one patient), febrile neutropenia (two patients), arrhythmia (one patient), and Guillain Barre syndrome (one patient). Grade 3 nonhematologic toxicities were reported for an additional 14 patients (Table 4). As expected, neutropenia and thrombocytopenia were common side effects. Of the 49 eligible patients, 19 patients had reports of Grade 4 neutropenia and nine additional patients had reports of Grade 3 neutropenia. Three patients had reports of Grade 4 thrombocytopenia and 14 additional patients had reports of Grade 3 thrombocytopenia. One patient reported Richter s transformation. In addition, one patient reported hemolytic anemia. The following toxicities were reported for this patient: nonhematologic Grade 3 included nausea, fever without neutropenia (during cyclophosphamide) and febrile neutropenia (during fludarabine); Hematologic Grade 3 anemia and PRBC transfusion during cyclophosphamide; Grade 4 leukopenia and neutropenia and Grade 3 anemia during fludarabine. Chromosomal aberrations Of a total of 33 cases evaluated by chromosome analysis, 22 cases had normal karyotypes and 11 cases had clonal chromosome abnormalities (Table 1). Among the 11 abnormal cases, the most common chromosome aberration was trisomy 12 (observed in four cases). Eight of the 11 abnormal cases contained one or more of these chromosome abnormalities, all of which have been previously reported to be common abnormalities observed in CLL. 22 Analysis of the cytogenetic data was inconclusive due to the small sample size. Figure 2 Kaplan Meier estimate of the distribution of DFS of the 15 patients to achieve remission. Tick marks indicate censored observations. fludarabine treatment. Thus, two additional patients may have actually had overall responses of CR, although these could not be documented. In all, 27 of the 49 eligible patients have died, and the remaining 22 were last known to be alive between 55 and 79 months after entering the study (median 69 months). The estimated probability of surviving at least 5 years is 55% (CI 41 69%). Of the 15 patients who achieved CR or UCR, the 5-year estimate of DFS (Figure 2) is 33% (CI 9 57%) (Figures 1 and 2). Toxicities Considering the comorbidities of this group of patients with advanced aggressive disease, the regimen was generally well tolerated. Two early deaths that occurred 24 and 60 days after registration onto the study are described above. A third patient died from a possibly treatment-related infection. This was a 73-year-old male who completed the full course of the cyclophosphamide and four cycles of fludarabine at full dose. The final two cycles of fludarabine were administered with 50% dose reduction because of delayed count recovery. On day 11 of cycle 6, this patient presented with non-neutropenic fever. Chest X-ray showed a right lower lobe infiltrate, and blood Discussion This study demonstrates that high-dose cyclophosphamide followed by fludarabine was relatively well tolerated in this group of advanced CLL patients. The study s criterion for testing whether the regimen is sufficiently effective to warrant further investigation was met: 14 (32%) of the first 44 eligible patients achieved CR or UCR. Among all 49 eligible patients on the study, 15 achieved CR or UCR, for a rate of 31% (CI 18 45%). Treatment with cyclophosphamide alone resulted in significant reduction of the disease volume, with 20 (41%) of the 49 patients achieving CR or PR. Subsequent treatment with fludarabine resulted in improvement of the quality of response: 15 patients with PR or SD after cyclophosphamide met the criteria for CR with fludarabine treatment, although four of these were not sustained for at least 60 days as required by the NCIsponsored Working Group guidelines. 14 Overall, 15 patients (31%) on the study achieved CR þ UCR (four following cyclophosphamide and 11 following fludarabine). Notably, the CR rate on this study was higher than that of patients treated with fludarabine only on the recent intergroup study (20%), even though the proportion of patients with high-risk disease (Rai stage III or IV) was higher in this study (55 vs 39%). 15 Of the 27 patients with high-risk disease on this study, five (19%) and eight (30%) had overall responses of CR or PR, respectively. This study suggests that there may be a benefit from reducing the volume of disease and an absence of cross resistance when cyclophosphamide is followed by fludarabine. This hypothesis is extrapolated from the intergroup trial, which demonstrated that

6 Table 4 Non-hematologic and hematologic Grade 3 5 toxicities by treatment and overall N ¼ 49 eligible S9706 patients 1885 Grade Cyclophosphamide cycles (N ¼ 49) Fludarabine cycles (N ¼ 42) Overall treatments (N ¼ 49) Nonhematologic toxicities ARDS Arrhythmia Arthralgia Blurred vision Cardiac ischemia/infarction Catheter related infection Dehydration Diarrhea without colostomy Dizziness/light headedness Dyspnea Edema Epistaxis Fatigue/malaise/lethargy Febrile neutropenia Fever without neutropenia GU-other Headache Hematuria Hemorrhage w/ 3 4 thrombocytopenia Hypotension Infection w/o 3 4 neutropenia Infection with 3 4 neutropenia Infection, unknown ANC Lung-other Myalgia Nausea Peri-cardial effusion/pericarditis Respiratory infect w/o neutropenia Sensory neuropathy Thrombosis/embolism Weakness (motor neuropathy) Maximum Grade for any Grade 3 or higher nonhematologic toxicity per patient Hematologic toxicities Anemia Hemolysis Leukopenia Lymphopenia Neutropenia/granulocytopenia PRBC transfusion Platelet transfusion Thrombocytopenia Maximum Grade for any Grade 3 or higher hematologic toxicity per patient patients with lower disease stage achieved a better response to fludarabine. We therefore contemplated that the use of what would be considered average-dose cyclophosphamide might allow for a significant reduction in the stage of the disease thus the theoretic improvement in response to fludarabine as compared to fludarabine initially to advanced-disease patients. Despite the discouraging experience with concurrent administration of chlorambucil and fludarabine in the recent intergroup study, 15 encouraging results with acceptable toxicity have been described with cyclophosphamide/fludarabine combinations in different schedules and dose levels. In a phase II trial, Flinn et al evaluated the response rate and toxicities of fludarabine and cyclophosphamide with filgrastim support in patients with previously untreated low-grade and select intermediate-grade lymphoid malignancies. Symptomatic patients with preserved end organ function received cyclophosphamide 600 mg/m 2 intravenous (iv) day 1 and fludarabine 20 mg/m 2 i.v. days 1 5, followed by filgrastim 5 mg/kg subcutaneous starting on day 8. Treatment was repeated every 28 days until maximum response or a maximum of six cycles. In all, 60 patients with nonhodgkin s lymphoma or CLL, median age 53.5 years, were enrolled. Six of 17 patients with CLL had high-risk disease. Of the patients with CLL, 47% achieved a CR and the remaining 53% achieved a PR. Similar to our regimen the toxicity was mainly hematologic, although significant nonhematologic toxicities, including infections, were seen in 10% of all patients. In all, 24 patients subsequently received an autologous or allogeneic stem cell transplant. The authors concluded that fludarabine, cyclophosphamide, and filgrastim form a highly active and well-tolerated regimen in

7 1886 CLL. 23 In a larger study (128 patients), O Brien et al 24 studied a 3-day concurrent combination, which included cohorts at different doses of cyclophosphamide in both previously treated and untreated CLL patients. They have reported a CR rate of 35% among the previously untreated patients. Finally, Weiss et al 25 have used cyclophosphamide following fludarabine in a sequential plan that was the reverse of that reported in this paper. This group reported an 8% CR rate with fludarabine, which increased to 32% with cyclophosphamide. The toxicity rate in Weiss et al s 25 study was less than in the current study, possibly because our population had a higher prevalence of comorbidity. Thus, it appears likely to be true that sequencing or combining fludarabine with cyclophosphamide can increase the CR rate achieved among previously untreated patients with CLL. More recently, Hallek et al 26 reported on the efficacy and toxicity of a combination of fludarabine and cyclophosphamide given to 36 patients with relapsed B-cell CLL,. Both drugs were given simultaneously and repeated every 4 weeks. In all, 24 partial remissions and five CRs were observed. Two patients showed no change and one patient showed disease progression. These results compare favorably to our study. The optimal treatment plan with regard to impact upon survival of such approach is yet to be defined in phase III studies. Acknowledgements This investigation was supported in part by the following PHS Cooperative Agreement grant numbers awarded by the National Cancer Institute, DHHS: CA38926, CA32102, CA35431, CA04919, CA35176, CA37981, CA46441, CA46282, CA58861, CA45450, CA45807, CA76429, CA35261, CA42777, CA45377, CA35178, CA67663, CA12644, CA27057, CA67575, CA20319, CA63850, CA76462, CA58415, CA35119, CA76447, CA35996, CA References 1 Dighiero G, Maloum K, Desablens B, Cazin B, Navarro M, Leblay R et al. The French Cooperative Group on Chronic Lymphocytic. N Engl J Med 1998; 338: Rai KR, Sawitsky A, Cronkite EP, Chanana AD, Levy RN, Pastermack BS et al. Clinical staging of chronic lymphocytic leukemia. Blood 1975; 46: Binet JL, Auquier A, Dighiero G, Chastang C, Piguet H, Goasguen H et al. A new prognostic classification of chronic lymphocytic leukemia derived from a multivariate survival analysis. Cancer 1981; 48: Lee JS, Dixon DO, Kantarjian HM, Keating MJ, Talpaz M. Prognosis of chronic lymphocytic leukemia: a multivariate regression analysis of 325 untreated patients. Blood 1987; 69: Rozman C, Montserrat E, Feliu E, Granena A, Marin P, Nomdedeu B et al. Prognosis of chronic lymphocytic leukemia: a multivariate survival analysis of 150 cases. Blood 1982; 59: Montserrat E, Sanchez-Bisono J, Vinolas N, Rozman C. Lymphocyte doubling time in chronic lymphocytic leukemia: analysis of prognostic significance. Br J Haematol 1986; 62: Rozman C, Montserrat E, Rodriguez-Fernandez JM, Ayats R, Vallespi T, Parody R et al. Bone marrow histologic pattern the best single prognostic parameter in chronic lymphocytic leukemia: a multivariate survival analysis of 329 cases. Blood 1984; 64: Juliusson G, Oscier DG, Fitchett M, Ross FM, Stockdill G, Mackie MJ et al. Prognostic subgroups in B-cell chronic lymphocytic leukemia defined by specific cytogenetic abnormalities. N Engl J Med 1990; 323: Han T, Henderson ES, Emrich LJ, Sandberg AA. Prognostic significance of karyotypic abnormalities in B-cell chronic lymphocytic leukemia. Semin Oncol 1987; 24: Shustik C, Mick R, Silver R, Sawitsky A, Tai K, Shaprio L. Treatment of early chronic lymphocytic leukemia: intermittent chlorambucil versus observation. Hematol Oncol 1988; 6: Hsi ED, Kopecky KJ, Appelbaum FR, Boldt D, Frey T, Loftus M et al. Prognostic significance of CD38 and CD20 expression as assessed by quantitative flow cytometry in chronic lymphocytic leukaemia. Br J Haematol 2003; 120: Matrai Z, Lin K, Dennis M, Sherrington P, Zuzel M, Pettitt AR et al. CD38 expression and Ig VH gene mutation in B-cell chronic lymphocytic leukemia. Blood 2001; 97: French Cooperative Group on Chronic Lymphocytic. Prognostic and therapeutic advances in CLL management: the experience of the French Cooperative Group. Semin Hematol 1987; 24: Cheson BD, Bennett JM, Rai KR, Grever MR, Kay NE, Schiffer CA et al. Guidelines for clinical protocols for chronic lymphocytic leukemia: report of the NCI-sponsored Working Group. Am J Hematol 1988; 29: Rai KR, Peterson B, Appelbaum F, Kolitz J, Elias L, Shepherd L et al. Fludarabine compared with chlorambucil as primary therapy for chronic lymphocytic leukemia. N Engl J Med 2000; 343: Leporrier M, Chevret S, Boudjerra N, Feugier P, Desablens B, Rapp MJ et al. French Cooperative Group on Chronic Lymphocytic. Randomized comparison of fludarabine, CAP and ChOP in 938 previously untreated stage B and C chronic lymphocytic leukemia patients. Blood 2001; 98: Bernell P, Pisa P, Hast R, Hansson M, Sandstedt B, Stenke L. Increase of serum interleukin-2 and regression of multiple myeloma after rhgm-csf treatment of drug induced bone marrow aplasia. Hematol Oncol 1991; 9: Ho AD, Haas R, Wulf G, Knauf W, Erhardt R, Heilig B et al. Activation of lymphocytes induced by recombinant human granulocyte macrophage colony-stimulating factor in patients with malignant lymphoma. Blood 1990; 75: Baxevanis CN, Tsavaris NB, Papadhimitriou SI, Zarkadis IK. Granulocyte macrophage colony-stimulating factor improves immunological parameters in patients with refractory solid tumors receiving second-line chemotherapy: correlation with clinical responses. Eur J Cancer 1997; 33: Cheson BD, Bennett JM, Grever M, Kay N, Keating MJ, O Brien S et al. National Cancer Institute-Sponsored working group guidelines for chronic lymphocytic leukemia: revised guidelines for diagnosis and treatment. Blood 1996; 87: Mitelman F ed. An International System for Cytogenetic Nomenclature. Basel, Switzerland: Karger, Stilgenbauer S, Lichter P, Dohner H. Genetic features of B-cell chronic lymphocytic leukemia. Rev Clin Exp Hematol 2000; 4: Flinn IW, Byrd JV, Morrison C, Jamison J, Diehl LF, Murphy T et al. Fludarabine and cyclophosphamide with filgrastim support in patients with previously untreated indolent lymphoid malignancies. Blood 2000; 96: O Brien SM, Kantarjian HM, Cortes J, Beran M, Koller CA, Giles FJ et al. Results of the fludarabine and cyclophosphamide combination regimen in chronic lymphocytic leukemia. J Clin Oncol 2001; 19: Weiss MA, Glenn M, Maslak P, Rahman Z, Noy A, Zelents A et al. Consolidation therapy with high-dose cyclophosphamide improves the quality of response in patients with chronic lymphocytic leukemia treated with fludarabine as induction therapy. 2000; 14: Hallek B, Schmitt M, Wilhelm R, Busch A, Krober HP, Fostitsch O et al. Fludarabine plus cyclophosphamide is an efficient treatment for advanced chronic lymphocytic leukemia (CLL): results of a phase II study of the German CLL Study Group. Br J Haematol 2001; 114: