Efficacy of rituximab in combination with steroids in refractory chronic lymphocytic leukemia

Rituximab, Cyclophosphamide and Dexamethasone (RCD) Chemoimmunotherapy for Relapsed Chronic Lymphocytic Leukaemia

High doses of corticosteroids in combination with rituximab remain an alternative in the treatment in relapsed or refractory chronic lymphocytic leukaemia (CLL) in the current era of targeted therapies. This study retrospectively evaluates the efficacy of an RCD (rituximab, cyclophosphamide and dexamethasone) regimen in the treatment of 51 patients with relapsed CLL (median age, 72 years). Unfavourable prognostic features, such as Rai stage III/IV, unmutated IGHV, del11q, TP53 mutation/deletion, complex karyotype and bulky lymphadenopathy, were frequent. The overall response or complete remission was of 57% and 7%, respectively, and the median progression-free survival (PFS) was of 12.3 months, median time to next treatment 23.1 months and median overall survival 39.2 months. Significant independent predictors of shorter PFS were TP53 deletion/mutation, advanced Rai stage and ≥2 previous lines of treatment. The incidence of neutropenia grade ≥ 3 was of 13%. Serious (CTCAE grade 3-5) infections were found in 20% of patients. Steroid-induced diabetes or diabetes decompensation occurred in 20% patients. Treatment-related adverse events resulted in RCD dose reduction in 35% of patients. In comparison with a historical R-Dex patient group, the treatment response and/or toxicity in our group was largely similar. However, the substantial differences in the baseline clinical characteristics of the groups may affect this comparison. In conclusion, the RCD regimen is an active, time-limited therapeutic strategy for elderly patients with relapsed CLL. Further, the results of our analysis indicate that the addition of cyclophosphamide to the R-Dex regimen maintains a similar efficacy, even after 50% reduction in the dexamethasone dose.

Five years of experience with rituximab plus high-dose dexamethasone for relapsed/refractory chronic lymphocytic leukemia

INTRODUCTION

High-dose methylprednisolone (HDMP) in combination with rituximab is active in the treatment of relapsed/refractory chronic lymphocytic leukemia (CLL), but serious infections are frequent. Recently published data suggested that high-dose dexamethasone might be equally effective as HDMP despite a lower cumulative dose.

MATERIAL AND METHODS

We performed retrospective analysis of 60 patients with relapsed/refractory CLL (median age: 66 years; range: 37-86) treated with rituximab plus dexamethasone (R-dex) at a single tertiary center between September 2008 and October 2012. The schedule of R-dex consisted of rituximab 500 mg/m(2) i.v. day 1 (375 mg/m(2) in cycle 1) and dexamethasone 40 mg orally on days 1-4 and 10-13 repeated every 3 weeks for a maximum of 8 cycles. Unfavorable prognostic features were frequent (Rai stages III/IV in 67%, unmutated IgVH 82%, del 11q 43%, TP53 mutation/deletion 23%, bulky lymphadenopathy 58% of patients).

RESULTS

Overall response (OR)/complete remission (CR) was achieved in 75/3%. At the median follow-up of 21 months, median progression-free survival (PFS) was 8 months, median time to next treatment 12.9 months and median overall survival 25.5 months. Refractoriness to fludarabine (p = 0.04) and age ≥ 65 years (p = 0.03) were significant predictors of shorter PFS. R-dex was successfully used for debulking before allogenic stem cell transplantation in 7 patients (12%). Serious (CTCAE grade III/IV) infections occurred in 27% of patients; 20% of patients developed steroid diabetes requiring temporary short-acting insulin.

CONCLUSIONS

Our results show that R-dex is an active and well-tolerated regimen for patients with relapsed/refractory CLL; however, major infections remain frequent despite combined antimicrobial prophylaxis.

Practical approach to management of chronic lymphocytic leukemia

Revolutionary progress has recently changed the landscape of chronic lymphocytic leukemia (CLL). Powerful prognostic factors, especially p53 mutation and/or deletion and IGHV mutation status, have refined individual patient prognosis. Purine analogs and monoclonal antibodies paved the way from palliative treatment to chemoimmunotherapy capable of eradication of minimal residual disease and prolongation of survival. Obinutuzumab (GA-101) and ofatumumab have been recently approved for the treatment of comorbid patients. Bendamustine is available for first-line treatment of patients ineligible for fludarabine, cyclophosphamide, and rituximab (FCR). High-dose glucocorticoids combined with rituximab represent a promising option for refractory CLL; ofatumumab is approved for fludarabine- and alemtuzumab-refractory patients. Allogeneic stem cell transplantation is the only curative option but is feasible in a highly selected group of patients only. The novel small molecule inhibitors ibrutinib and idelalisib have been recently approved for relapsed/refractory CLL. This review provides practical advice for diagnosis, prognostication and treatment of CLL.

Ofatumumab added to dexamethasone in patients with relapsed or refractory chronic lymphocytic leukemia: Results from a phase II study

The treatment of relapsed/refractory chronic lymphocytic leukemia (CLL) remains a challenging clinical issue. An important treatment option is the use of high-dose corticosteroids. The purpose of this clinical trial was to determine the efficacy and toxicity of an ofatumumab-dexamethasone (O-Dex) combination in relapsed or refractory CLL. The trial was an open-label, multicenter, nonrandomized, Phase II study. The O-Dex regimen consisted of intravenous ofatumumab (Cycle 1: 300 mg on day 1, 2,000 mg on days 8, 15, and 22; Cycles 2-6: 1,000 mg on days 1, 8, 15, and 22) and oral dexamethasone (40 mg on days 1-4 and 15-18; Cycles 1-6). The O-Dex regimen was given until best response, or a maximum of six cycles. Thirty-three patients (pts) were recruited. Twenty-four (73%) pts completed at least three cycles of therapy. The remaining nine pts were prematurely discontinued owing to Grade 3/4 infections (seven pts), disease progression (one pt), or uncontrollable diabetes mellitus (one pt). Overall response rates/complete remissions (ORR/CR) were achieved in 22/5 pts (67/15%). The median progression-free survival (PFS) was 10 months. In pts with p53 defects (n = 8), ORR/CR were achieved in 5/2 pts (63/25%) with a median PFS of 10.5 months. The median overall survival (OS) was 34 months. The Grades 3-5 infectious toxicity in 33% of pts represented the most frequent side effect during the treatment period. In conclusion, the O-Dex regimen shows a relatively high ORR and CR with promising findings for PFS and OS. The study was registered at www.clinicaltrials.gov (NCT01310101).

Rituximab, ofatumumab and other monoclonal anti-CD20 antibodies for chronic lymphocytic leukaemia

BACKGROUND

Chronic lymphocytic leukaemia (CLL) accounts for 25% of all leukaemias and is the most common lymphoid malignancy in western countries. Standard treatments include mono- or polychemotherapies, usually combined with monoclonal antibodies such as rituximab or alemtuzumab. However, the impact of these agents remains unclear, as there are hints for increased risk of severe infections.

OBJECTIVES

The objectives of this review are to provide an evidence-based answer regarding the clinical benefits and harms of monoclonal anti-CD20 antibodies (such as rituximab, ofatumumab, GA101) compared to no further therapy or to other anti-leukaemic therapies in patients with CLL, irrespective of disease status.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 12, 2011), MEDLINE (from January 1990 to 4 January 2012), and EMBASE (from 1990 to 20 March 2009) as well as conference proceedings (American Society of Hematology, American Society of Clinical Oncology, European Hematology Association and European Society of Medical Oncology) for randomised controlled trials (RCTs).

SELECTION CRITERIA

We included RCTs examining monoclonal anti-CD20 antibodies compared to no further therapy or to anti-leukaemic therapy such as chemotherapy or monoclonal antibodies in patients with newly diagnosed or relapsed CLL.

DATA COLLECTION AND ANALYSIS

We used hazard ratios (HR) as effect measures for overall survival (OS), progression-free survival (PFS) and time to next treatment, and risk ratios (RR) for response rates, treatment-related mortality (TRM) and adverse events (AEs). Two review authors independently extracted data and assessed quality of trials.

MAIN RESULTS

We screened a total of 1150 records. Seven RCTs involving 1763 patients were identified, but only five could be included in the two separate meta-analyses we performed. We judged the overall the quality of these trials as moderate to high. All trials were randomised and open-label studies. However, two trials were published as abstracts only, therefore we were unable to assess the potential risk of bias for these trials in detail.Three RCTs (N = 1421) assessed the efficacy of monoclonal anti-CD20 antibodies (i.e. rituximab) plus chemotherapy compared to chemotherapy alone. The meta-analyses showed a statistically significant OS (HR 0.78, 95% confidence interval (CI) 0.62 to 0.98, P = 0.03, the number needed to treat for an additional beneficial effect (NNTB) was 12) and PFS (HR 0.64, 95% CI 0.55 to 0.74, P < 0.00001) advantage for patients receiving rituximab. In the rituximab-arm occurred more AEs, World Health Organization (WHO) grade 3 or 4 (3 trials, N = 1398, RR 1.15, 95% CI 1.08 to 1.23, P < 0.0001; the number needed to harm for an additional harmful outcome (NNTH) was 9), but that did not lead to a statistically significant difference regarding TRM (3 trials, N = 1415, RR 1.19, 95% CI 0.70 to 2.01, P = 0.52).Two trials (N = 177) evaluated rituximab versus alemtuzumab. Neither study reported OS or PFS. There was no statistically significant difference between arms regarding complete response rate (CRR) (RR 1.21, 95% CI 0.94 to 1.58, P = 0.14) or TRM (RR 0.31, 95% CI 0.06 to 1.51, P = 0.15). However, the CLL2007FMP trial was stopped early owing to an increase in mortality in the alemtuzumab arm. More serious AEs occurred in this arm (43% with alemtuzumab versus 22% with rituximab; P = 0.006).Two trials assessed different dosages or time schedules of monoclonal anti-CD20 antibodies. One trial (N = 104) evaluated two different rituximab schedules (concurrent arm: fludarabine plus rituximab (Flu-R) plus rituximab consolidation versus sequential arm: fludarabine alone plus rituximab consolidation). The comparison of the concurrent versus sequential regimen of rituximab showed a statistically significant difference of the CRR with 33% in the concurrent-arm and 15% in the sequential-arm (P = 0.04), that did not lead to statistically significant differences regarding OS (HR 1.14, 95% CI 0.20 to 6.65, P = 0.30) or PFS (HR 0.96, 95% CI 0.43 to 2.15, P = 0.11). Furthermore results showed no differences in occurring AEs, except for neutropenia, which was more often observed in patients of the concurrent arm. The other trial (N = 61) investigated two different dosages (500 mg and 1000 mg) of ofatumumab in addition to FluC. The arm investigating ofatumumab did not assess OS and a median PFS had not been reached owing to the short median follow-up of eight months. It showed no statistically significant differences between arms regarding CRR (32% in the FCO500 arm versus 50% in the FCO1000 arm; P = 0.10) or AEs (anaemia, neutropenia, thrombocytopenia).

AUTHORS' CONCLUSIONS

This meta-analysis showed that patients receiving chemotherapy plus rituximab benefit in terms of OS as well as PFS compared to those with chemotherapy alone. Therefore, it supports the recommendation of rituximab in combination with FluC as an option for the first-line treatment as well as for the people with relapsed or refractory CLL. The available evidence regarding the other assessed comparisons was not sufficient to deduct final conclusions.

Rituximab in combination with high-dose dexamethasone for the treatment of relapsed/refractory chronic lymphocytic leukemia

BACKGROUND

High-dose methylprednisolone is active in treatment of relapsed/refractory chronic lymphocytic leukemia (CLL) but infectious toxicity is serious. The aim of this project was to retrospectively assess efficacy and safety of high-dose dexamethasone combined with rituximab (R-dex) in this setting.

PATIENTS AND METHODS

We treated 54 patients (pts) with relapsed/refractory CLL using R-dex regimen at two tertiary centers. Two schedules of rituximab were used (not randomized - based on the choice of the center): group 1, rituximab 500 mg/m(2)day 1, 8, 15, 22 (375 mg/m(2) in 1st dose) every 4 weeks (n=29); group 2, 500 mg/m(2)day 1 (375 mg/m(2) in 1st cycle) repeated every 3 weeks (n=25). The target dose of dexamethasone was 40 mg on days 1-4 and 10-13 or 15-18. Rai III/IV stages were present in 82%, unmutated IgVH genes in 82%, del 11q in 38% and del 17p in 19% pts; 46% had bulky lymph nodes; 82% were pretreated with fludarabine and 29% with alemtuzumab.

RESULTS

Overall response rate/complete remissions were 62/21% (Group 1) and 72/4% (Group 2). In three patients, R-dex was successfully used for debulking before nonmyeloablative allogeneic stem cell transplantation. R-dex was particularly effective in improvement of anemia and thrombocytopenia (p=0.0055 and p=0.0036); B-symptoms resolved after treatment in 11/17 pts. Hematological toxicity was mild. Serious infections occurred in 32% pts. At the median follow-up of 9 and 10 months, median progression-free survival was 6 months in Group 1 and 6.9 months in Group 2 (p=ns); median overall survival was 14.1 months in Group 1 vs. not reached in Group 2 (p=ns).

CONCLUSIONS

R-dex appears to be an active and feasible treatment for relapsed/refractory CLL. Infectious toxicity remains an important issue. Further investigation of this regimen in larger studies appears fully warranted.

The role of high-dose corticosteroids in the treatment of chronic lymphocytic leukemia

INTRODUCTION

Management of refractory chronic lymphocytic leukemia (CLL) represents a major challenge because of the poor prognosis and limited treatment options. While corticosteroids have been used to treat CLL since 1940s, their benefit has never been conclusively proved. Recently, several groups reported use of high-dose corticosteroids (methylprednisolone or dexamethasone) either alone or combined with chemotherapy and/or monoclonal antibodies in relapsed/refractory CLL.

AREAS COVERED

While efficacy of high-dose corticosteroids is excellent including responses in patients with bulky lymphadenopathy or those considered ultra high-risk CLL because of deletion and/or mutation of p53 gene, the duration of response is still unsatisfactory. Combination with monoclonal antibodies seems to improve therapeutic efficacy but no randomized trials have been conducted. For the purpose of this review, a search for terms, high-dose corticosteroids/methylprednisolone/dexamethasone, and chronic lymphocytic leukemia has been performed in PubMed and database of abstracts from American Society of Hematology Meetings.

EXPERT OPINION

High-dose corticosteroids appear to play an important role in the management of highly pretreated relapsed/refractory CLL including patients with massive lymphadenopathy. Myelosuppression is usually limited but infectious toxicity, including increased risk of invasive fungal infections, represents the most dreaded side effects. This therapeutic approach should be further tested within large prospective trials, to optimize efficacy and safety.

Alemtuzumab in Combination With Methylprednisolone Is a Highly Effective Induction Regimen for Patients With Chronic Lymphocytic Leukemia and Deletion of TP53: Final Results of the National Cancer Research Institute CLL206 Trial

Purpose

In chronic lymphocytic leukemia (CLL), TP53 deletion/mutation is strongly associated with an adverse outcome and resistance to chemotherapy-based treatment. In contrast, TP53 defects are not associated with resistance to the anti-CD52 monoclonal antibody alemtuzumab or methylprednisolone. In an attempt to improve the treatment of TP53-defective CLL, a multicenter phase II study was developed to evaluate alemtuzumab and methylprednisolone in combination.

Patients and Methods

Thirty-nine patients with TP53-deleted CLL (17 untreated and 22 previously treated) received up to 16 weeks of treatment with alemtuzumab 30 mg three times a week and methylprednisolone 1.0 g/m2 for five consecutive days every 4 weeks. Antimicrobial prophylaxis consisted of cotrimoxazole, itraconazole, and aciclovir (or valganciclovir for asymptomatic cytomegalovirus viremia). The primary end point was response as assigned by an end-point review committee. Secondary end points were safety, progression-free survival (PFS) and overall survival (OS).

Results

The overall response rate, complete response rate (including with incomplete marrow recovery), median PFS, and median OS were 85%, 36%, 11.8 months, and 23.5 months, respectively, in the entire cohort and 88%, 65%, 18.3 months, and 38.9 months, respectively, in previously untreated patients. Grade 3 to 4 hematologic and glucocorticoid-associated toxicity occurred in 67% and 23% of patients, respectively. Grade 3 to 4 infection occurred in 51% of the overall cohort and in 29% of patients less than 60 years of age. Treatment-related mortality was 5%.

Conclusion

Alemtuzumab plus methypredisolone is the most effective induction regimen hitherto reported in TP53-deleted CLL. The risk of infection is age related and, in younger patients, seems only marginally higher than that associated with rituximab, fludarabine, and cyclophosphamide.

How I treat elderly or comorbid patients with chronic lymphocytic leukemia

Treatment of chronic lymphocytic leukemia (CLL) has recently undergone several major changes. Most importantly, large randomized trials (CLL-8 in first line and REACH in relapse) clearly demonstrated superiority of chemoimmunotherapy consisting of fludarabine, cyclophosphamide and rituximab (FCR) over fludarabine and cyclophosphamide (FC) alone, thus establishing FCR regimen as the new gold standard in younger and physically fit patients. However, management of elderly and/or comorbid patients is still a challenging task because they cannot be treated with agressive approaches due to high risk of unacceptable toxicity. To date, no randomized trials in this patient population have improved therapeutic results over chlorambucil; therefore, this agent remains the backbone of treatment against which the new protocols should be tested. When deciding about the intensity of treatment, performance status, biological age and number as well as severity of comorbidities should be taken into account. Emerging treatment concepts for elderly/comorbid patients include combination of chlorambucil with monoclonal antibodies (rituximab, ofatumumab, GA-101), fludarabine-based regimens in reduced doses or protocols based on bendamustine and lenalidomide. Combination of high-dose steroids with rituximab represent a promising option in relapsed/refractory CLL; however, infectious toxicity remains a serious issue. Finally, ofatumumab monotherapy appears to be a safe and effective therapy for heavily pretreated patients with CLL. This article reviews the current and future possibilities in the treatment of elderly and comorbid patients with CLL.

The spectrum of use of rituximab in chronic lymphocytic leukemia

The monoclonal chimeric anti-CD20 antibody, rituximab, has considerably improved therapeutic outcome in B-cell chronic lymphocytic leukemia. Rituximab has limited clinical activity when used as a single agent. The combination of the monoclonal antibody with fludarabine-based regimens clearly demonstrated, in Phase II and randomized trials, an increase in clinical efficacy in previously untreated and pretreated patients. Furthermore the addition of rituximab enabled the eradication of minimal residual disease, which is correlated with the prognosis in a high proportion of patients. Although the combination of rituximab with fludarabine-based regimens increased myelosuppression and immunosuppression, incidence of infections did not increase. The benefit of adding rituximab to other purine analogs or other chemotherapeutic combination regimens has also been explored. Moreover there could be a role for achieving better quality of responses with the combination of different monoclonal antibodies, considering that they target different antigens and exert different mechanism of action. Although the role of rituximab as maintenance therapy in low grade non-Hodgkin's lymphomas has been determined, the benefit and optimal schedule in chronic lymphocytic leukemia are still under investigation. This review brings together knowledge of the pharmacokinetics, mechanism of action and clinical use of rituximab in chronic lymphocytic leukemia.

Current and emerging treatments for chronic lymphocytic leukaemia

Chronic lymphocytic leukaemia (CLL) is the most common adult leukaemia in Europe and North America. The disease is characterized by proliferation and accumulation of small CD5+ B cells in blood, lymph nodes, spleen, liver and bone marrow. The natural clinical course of CLL is highly variable, and chemotherapy is usually not indicated in early and stable disease. However, patients with progressive and more advanced CLL require treatment. For many years, chlorambucil with or without corticosteroids was used in previously untreated patients with CLL. More recently, purine nucleoside analogues (PNAs) [fludarabine, cladribine and pentostatin] have been included in treatment approaches for this disease, and chlorambucil is no longer the leading standard everywhere. Currently, this drug is rather recommended for the treatment of older, unfit patients with co-morbidities, especially in European countries. Significantly higher overall response (OR) and complete response (CR) rates in patients treated initially with PNAs than in those treated with chlorambucil or cyclophosphamide-based combination regimens have been confirmed in randomized, prospective, multicentre trials. Moreover, PNAs administered in combination with cyclophosphamide produce higher response rates, including CR and molecular CR, compared with PNA as monotherapy. Recent reports suggest that the administration of monoclonal antibodies (mAbs) can significantly improve the course of CLL. At present, two mAbs have the most important clinical value in patients with CLL. The first is rituximab, a human mouse antibody that targets CD20 antigens, and the second is alemtuzumab, a humanized form of a rat antibody active against CD52. Several recent reports suggest that in patients with CLL, rituximab combined with a PNA can increase the OR and CR rates compared with PNA or rituximab alone, with acceptable toxicity. In randomized trials, the combination of rituximab with fludarabine and cyclophosphamide (FC-R regimen) demonstrated higher rates of OR, CR and progression-free survival in patients with previously untreated and relapsed or refractory CLL than fludarabine plus cyclophosphamide (FC regimen). Several reports have confirmed significant activity with alemtuzumab in relapsed or refractory CLL, as well as in previously untreated patients. Recently, several new agents have been investigated and have shown promise in treating patients with CLL. These treatments include new mAbs, agents targeting the antiapoptotic bcl-2 family of proteins and receptors involved in mediating survival signals from the microenvironment, antisense oligonucleotides and other agents. The most promising are new mAbs directed against the CD20 molecule, lumiliximab and anti-CD40 mAbs. Oblimersen, alvocidib (flavopiridol) and lenalidomide are also being evaluated both in preclinical studies and in early clinical trials. In recent years, a significant improvement in haematopoietic stem cell transplantation (HSCT) procedures in patients with high-risk CLL has been observed. However, the exact role of HSCT, autologous or allogeneic, in the standard management of CLL patients is still undefined.