High efficacy with five days schedule of oral fludarabine phosphate and cyclophosphamide in patients with previously untreated chronic lymphocytic leukaemia

Rituximab maintenance versus observation following abbreviated induction with chemoimmunotherapy in elderly patients with previously untreated chronic lymphocytic leukaemia (CLL 2007 SA): an open-label, randomised phase 3 study

BACKGROUND

Most patients with chronic lymphocytic leukaemia relapse after initial therapy combining chemotherapy with rituximab. We assessed the efficacy and safety of rituximab maintenance treatment versus observation for elderly patients in remission after front-line abbreviated induction by fludarabine, cyclophosphamide, and rituximab (FCR).

METHODS

This randomised, open-label, multicentre phase 3 trial at 89 centres in France enrolled treatment-naive and fit patients aged 65 years or older with chronic lymphocytic leukaemia without del(17p). Eligible patients had an Eastern Cooperative Oncology Group performance status of 0-1 and adequate renal and hepatic function. Patients in response to complete induction treatment with four monthly courses of full-dose FCR with two interim rituximab doses on day 14 of cycles 1 and 2 (oral fludarabine [40 mg/m² per day] and oral cyclophosphamide [250 mg/m² per day] for the first 3 days of each cycle, rituximab at 375 mg/m² intravenously on day 0 of cycle 1 and subsequently at 500 mg/m² on day 14 of cycle 1, days 1 and 14 of cycle 2, and day 1 of cycles 3 and 4) were eligible for randomisation. Recovery from FCR toxicity and patient willingness to continue the trial were mandatory. We randomly assigned (1:1) patients to either receive intravenous rituximab (500 mg/m²) every 8 weeks for up to 2 years or undergo observation, with a central computer-generated randomisation list using randomly permuted blocks of variable sizes. Randomisation was stratified by IGHV mutational status, the presence or absence of del(11q), and response level to induction treatment. The primary endpoint was progression-free survival, with the objective to assess the superiority of rituximab maintenance relative to observation. The final analysis was done in the intention-to-treat population. Safety was analysed in all patients who received at least one dose of study drug in the rituximab group and in all patients in the observation group. This trial is closed to accrual whilst continuing patient follow-up. The study is registered with ClinicalTrials.gov, number NCT00645606.

FINDINGS

Between Dec 14, 2007, and Feb 18, 2014, 542 patients were enrolled, of whom 525 started FCR induction. Between June 10, 2008, and Aug 14, 2014, 409 (78%) patients were randomly assigned to rituximab maintenance (n=202) or observation (n=207). Four (2%) patients in the rituximab group did not receive the allocated treatment (progressive disease [n=1], adverse events [n=3]). After a median follow-up of 47·7 months (IQR 30·4-65·8), median progression-free survival in the rituximab group (59·3 months, 95% CI 49·6-not estimable) was improved compared with the observation group (49·0 months, 39·9-60·5; hazard ratio 0·55, 95% CI 0·40-0·75; p=0·0002). Neutropenia and grade 3-4 infections were more common with rituximab maintenance (105 [53%] of 198 patients vs 74 [36%] of 207 patients and 38 [19%] vs 21 [10%], respectively) during the study. The most common grade 3-4 infection was lower respiratory tract infection (24 [12%] vs eight [4%]). The incidence of second cancers, except basal cell carcinoma, was similar in both groups (29 [15%] vs 23 [11%]). Deaths were related to adverse events for 23 (11%) patients in the rituximab group and 16 (8%) in the observation group.

INTERPRETATION

2-year maintenance rituximab in selected elderly patients improves progression-free survival and shows an acceptable safety profile. Immunotherapy maintenance strategy is a relevant option in front-line treatment of chronic lymphocytic leukaemia, even in the age of targeted therapy.

FUNDING

French National Cancer Institute (INCa), Roche, Chugai.

Obinutuzumab for the treatment of chronic lymphocytic leukemia and other B-cell lymphoproliferative disorders

INTRODUCTION

Chemoimmunotherapeutic regimens using the anti-CD20 antibody rituximab improved significantly the survival rates in various B-cell lymphoproliferative disorders (LPDs), including chronic lymphocytic leukemia (CLL). The next-generation CD20 antibody obinutuzumab represents an addition to the drug armamentarium used for the therapeutic management of patients with LPDs. Areas covered: Herein, the authors discuss the biochemical and conformational engineering of obinutuzumab to increase antibody-dependent cell-mediated cytotoxicity and direct cell death. They also describe the available preclinical data on obinutuzumab's role in B-cell LPDs. Furthermore, the authors summarize the Phase I and II clinical trials of obinutuzumab, focusing on the main pharmacokinetic/pharmacodynamic characteristics, the most common clinically significant adverse events, dose optimization, and clinical outcomes of patients with CLL and other B-cell LPDs treated with obinutuzumab as monotherapy or in combination with other agents. To put these data in perspective, the use of obinutuzumab is compared with that of rituximab in CLL and other B-cell LPDs. Expert opinion: Clinical trials have demonstrated that obinutuzumab is well tolerated. The novel mechanism of action of obinutuzumab is associated with significant efficacy in CLL and other B-cell LPDs. Ongoing clinical trials are expected to determine the optimal use of obinutuzumab in these diseases.

Evaluating abbreviated induction with fludarabine, cyclophosphamide, and dose-dense rituximab in elderly patients with chronic lymphocytic leukemia

Elderly patients with chronic lymphocytic leukemia (CLL) are underrepresented in trials evaluating fludarabine, cyclophosphamide, and rituximab (FCR). We assessed four cycles of FCR with two additional rituximab doses on day 14 of cycles 1 and 2 in 194 untreated CLL patients > 65 years (median age 71.2) without del17p. Four FCR cycles were administered to 90.7% (176/194), with (n = 74) or without (n = 102) dose-delay and/or dose-reduction. A total of 50% grade 3/4 neutropenia occurred after each cycle. Only 6.2% cycles were associated with severe infection. Complete remission (CR) was achieved in 19.7%, and partial remission (PR) in 73.9% of patients. Minimal residual disease (MRD) was negative in 36.7%. Overall survival at 36 months was estimated at 87.4%. Oral FC and dose-dense rituximab is feasible and active in fit elderly CLL patients. However, myelosuppression is significant and frequent dose adaptations are required implying that these results cannot be generalized to unfit or frail elderly CLL.

Chemoimmunotherapy with oral low-dose fludarabine, cyclophosphamide and rituximab (old-FCR) as treatment for elderly patients with chronic lymphocytic leukaemia

Median age at diagnosis for chronic lymphocytic leukaemia (CLL) patients is now 72 years, thus a consistent number of patients may not tolerate standard doses i.v. of fludarabine, cyclophosphamide and rituximab (FCR), the best available therapy, due to unacceptable myelotoxicity and risk of severe infections. We studied safety and efficacy of the addition of rituximab to the oral low-dose FC regimen (old-FCR) in a selected population of 30 elderly (median age 75, 15 untreated, 15 treated with 1 prior therapy) CLL patients. Complete remission (CR) rate was 80% in the untreated patients (overall response rate, ORR 93%), and 30% in pretreated patients (ORR 74%). Progression free survivals (PFS) were 45 months and 30 months in the untreated and treated patients, respectively. In patients achieving CR, old-FCR led to PFS of 67 months. Moreover, haematological toxicity was mild (grade 3-4: 15%) and patients were treated mostly in outpatient clinic. Old-FCR could be a good therapy option for elderly CLL patients outside clinical trials, larger studies are needed to confirm our findings.

Frontline low-dose alemtuzumab with fludarabine and cyclophosphamide prolongs progression-free survival in high-risk CLL

Frontline FCA increases progression-free survival in CLL and, in a post hoc analysis, also survival in younger patients. With the low-dose approach, no increase in treatment related mortality is seen.

Novel agents for chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a heterogeneous group of B-cell neoplasm. CLL is typically sensitive to a variety of cytotoxic agents, but relapse frequently occurs with conventional approaches. The treatment of CLL is evolving rapidly with the introduction of novel drugs, such as bendamustine, ofatumumab, lenalidomide, ibrutinib, idelalisib, veltuzumab, XmAb5574, navitoclax, dasatinib, alvespimycin, and TRU-016. This review summarizes the most current clinical experiences with these agents in the treatment of CLL.

Impact of dose intensity on outcome of fludarabine, cyclophosphamide, and rituximab regimen given in the first-line therapy for chronic lymphocytic leukemia

Fludarabine-cyclophosphamide-rituximab is the most efficient first-line treatment for chronic lymphocytic leukemia patients. Many dose adjustments of the original MD Anderson Cancer Center regimen have been proposed. However, whether fludarabine-cyclophosphamide-rituximab relative dose intensity may have an impact on outcome has not yet been investigated. We retrospectively assessed relative dose intensity in 106 community-based patients included in our regional healthcare network from 2004-11, all receiving fludarabine-cyclophosphamide-rituximab as first-line treatment outside clinical trials. Dose reductions were observed in 51.4% of patients, mainly decided by the individual physician and not based on recommendations (52.7%), while there were fewer reports of toxicity or dose reduction because of impaired renal function. Progression-free survival was significantly reduced in patients who had a reduction in dose intensity of more than 20% in fludarabine-cyclophosphamide and/or rituximab. Multivariate analysis showed dose of rituximab had a significant impact on minimal residual disease and progression-free survival. Although prophylactic granulocyte-colony stimulating factor significantly reduced the rate of grade 3-4 neutropenia and febrile neutropenia, it had no impact on relative dose intensity and outcome. This study shows that, in routine clinical practice, there is low adherence to the original MD Anderson Cancer Center fludarabine-cyclophosphamide-rituximab schedule, and that the decision to modify dosage was mostly taken by the individual physician and was based on anticipated toxicity. This study shows that reduction of fludarabine-cyclophosphamide and, more importantly, of rituximab doses seriously interferes with progression-free survival.

Excess mortality after treatment with fludarabine and cyclophosphamide in combination with alemtuzumab in previously untreated patients with chronic lymphocytic leukemia in a randomized phase 3 trial

A French and Belgian multicenter phase 3 trial was conducted in medically fit patients with untreated chronic lymphocytic leukemia. Of 178 patients enrolled in the study, 165 were randomly assigned to receive 6 courses of oral fludarabine and cyclophosphamide (FC) in combination with rituximab (FCR; 375 mg/m2 in cycle one, 500 mg/m2 in all subsequent cycles) or alemtuzumab (FCCam; 30 mg subcutaneously injected on cycle days 1-3); each cycle was 28 days. Recruitment was halted prematurely because of excess toxicity; 8 patients died in the FCCam group, 3 from lymphoma and 5 from in-fection. Overall response rates were 91% with FCR and 90% with FCCam (P = .79). Complete remission rates were 33.75% with FCR and 19.2% with FCCam (P = .04). Three-year progression-free survival was 82.6% with FCR and 72.5% with FCCam (P = .21). Three-year overall survival was similar between the 2 arms at 90.1% in the FCR arm and 86.4% in the FCCam arm (P = .27). These results indicate that the FCCam regimen for the treatment of advanced chronic lymphocytic leukemia was not more effective than the FCR regimen and was associated with an unfavorable safety profile, representing a significant limitation of its use. This study is registered with www.clinicaltrials.gov as number NCT00564512.

Minimal Residual Disease Quantification Is an Independent Predictor of Progression-Free and Overall Survival in Chronic Lymphocytic Leukemia: A Multivariate Analysis From the Randomized GCLLSG CLL8 Trial

Purpose

To determine the clinical significance of flow cytometric minimal residual disease (MRD) quantification in chronic lymphocytic leukemia (CLL) in addition to pretherapeutic risk factors and to compare the prognostic impact of MRD between the arms of the German CLL Study Group CLL8 trial.

Patients and Methods

MRD levels were prospectively quantified in 1,775 blood and bone marrow samples from 493 patients randomly assigned to receive fludarabine and cyclophosphamide (FC) or FC plus rituximab (FCR). Patients were categorized by MRD into low- (< 10−4), intermediate- (≥ 10−4 to <10−2), and high-level (≥ 10−2) groups.

Results

Low MRD levels during and after therapy were associated with longer progression-free survival (PFS) and overall survival (OS; P < .0001). Median PFS is estimated at 68.7, 40.5, and 15.4 months for low, intermediate, and high MRD levels, respectively, when assessed 2 months after therapy. Compared with patients with low MRD, greater risks of disease progression were associated with intermediate and high MRD levels (hazard ratios, 2.49 and 14.7, respectively; both P < .0001). Median OS was 48.4 months in patients with high MRD and was not reached for lower MRD levels. MRD remained predictive for OS and PFS in multivariate analyses that included the most important pretherapeutic risk markers in CLL. PFS and OS did not differ between treatment arms within each MRD category. However, FCR induced low MRD levels more frequently than FC.

Conclusion

MRD levels independently predict OS and PFS in CLL. Therefore, MRD quantification might serve as a surrogate marker to assess treatment efficacy in randomized trials before clinical end points can be evaluated.

SIE, SIES, GITMO updated clinical recommendations for the management of chronic lymphocytic leukemia

By using GRADE system we updated the guidelines for management of CLL issued in 2006 from SIE, SIES and GITMO group. We recommended fludarabine, cyclophosphamide, rituximab (FCR) in younger and selected older patients with a good fitness status, no unfavourable genetics (deletion 17p and/or p53 mutations), and a less toxic treatment in nonfit and elderly patients. In patients without unfavourable genetics, relapsed after 24 months the same initial treatment including rituximab can be considered. In patients with unfavourable genetics, refractory or relapsed within 24 months from a prior fludarabine-based treatment, allogeneic SCT or experimental treatments should be given.

A comparison of the efficacy and safety of oral and intravenous fludarabine in chronic lymphocytic leukemia in the LRF CLL4 trial

BACKGROUND

An oral formulation of fludarabine was introduced for use in chronic lymphocytic leukemia in 2001 following studies demonstrating the bioequivalence of a 40 mg/m(2) oral dose with a 25 mg/m(2) intravenous dose. We assessed retrospectively the efficacy of these two routes of administration in the LRF CLL4 trial.

METHODS

A total of 777 patients were randomized from 1999-2004 to receive fludarabine, alone or with cyclophosphamide, or chlorambucil. In 2001, a protocol amendment allowed the oral formulation. There were 117 assessable patients who received fludarabine intravenously and 252 who received it orally. A total of 387 patients given chlorambucil acted as a control group.

RESULTS

Patients given oral fludarabine were less likely to receive the full dose (P = .0004) and experienced more, predominantly gastrointestinal, toxicity. Progression-free survival (PFS) and overall survival were not affected by the route of administration (PFS hazard ratio, 1.10; 95% confidence interval, 0.87-1.40), but the overall rate of response to treatment appeared to be lower with the oral formulation (P = .003). However, patients recruited since 2001 were older (P = .03) and were more likely to have TP53 deletion, and response rates after 2001 were also lower in the chlorambucil group. After excluding patients with TP53 deletion, no significant difference in outcome was attributable to the route of administration.

CONCLUSIONS

Although the LRF CLL4 data suggest no important difference in the effectiveness of oral compared with intravenous fludarabine, randomized trials are needed to reliably evaluate this comparison, particularly in combination with rituximab. Meanwhile, it is important to monitor compliance and gastrointestinal side effects with the oral route and to switch to intravenous therapy if a reduced dose is being received.

Development of fludarabine formulations in the treatment of chronic lymphocytic leukemia

Fludarabine is an antineoplastic agent used in the treatment of hematological malignancies, particularly chronic lymphocytic leukemia (CLL) and indolent B-cell lymphoma. Because of its immunosuppressive effects, fludarabine has been added to reduced intensity conditioning regimens. The oral formulation of fludarabine has become widely available. Pharmacokinetic studies have shown that an oral dose of 40 mg/m²/d would provide systemic drug exposure similar to the standard intravenous (IV) dose of 25 mg/m²/d. The oral dose can be taken once daily without any dietary restrictions. Dose adjustments are mandatory in patients with renal impairment to avoid increased toxicity. Several noncomparative trials in previously untreated and treated patients with CLL have shown that treatment with the oral formulation demonstrates similar efficacy compared to historical control groups treated with the IV formulation. The tolerability profile of oral fludarabine seems similar to that of the IV formulation. Myelosuppression and infectious complications are the most frequently reported adverse events. Gastrointestinal toxicity is more frequent with the oral formulation, but is usually of mild or moderate severity. Although oral fludarabine makes treatment more convenient, health care workers must be aware of the compliance behavior of each patient.

Fludarabine in the treatment of chronic lymphocytic leukemia: a review

Fludarabine (FAMP) is the most effective and most extensively studied purine analog in indolent B-cell malignancies. Its use is indicated for first-and second-line treatment of B-cell chronic lymphocytic leukemia (B-CLL). FAMP as a single agent has produced superior response rates and progression-free survival than standard therapy with chlorambucil and alkylator-based regimen. Efficacy of FAMP may be increased by combining this purine analog with other chemotherapeutic and non-chemotherapeutic agents. FAMP and cyclophosphamide combination (FC) has shown promising results with higher overall response and complete response rates than FAMP in monotherapy, although no difference has been detected in survival. Quality of response and eradication of minimal residual disease (MRD) have been reported to be associated with prolonged survival. Eradication of MRD has been achieved by combining FC with mitoxantrone or monoclonal antibody including alemtuzumab or rituximab or both. FAMP has been widely used in non-myeloablative conditioning regimens, often combined with a variety of other cytotoxic agents, with the aim of inducing enough immunosuppression to allow successful engraftment and to exert some pretransplant anti-tumor activity. The current paper provides an overview of use of FAMP as a single agent or as a cornerstone of different therapeutic strategies for treatment of B-CLL patients.