Fludarabine, Cyclophosphamide and Mitoxantrone in Relapsed or Refractory Chronic Lymphocytic Leukemia and Low Grade Non-Hodgkin's Lymphoma

Results of the randomized phase IIB ADMIRE trial of FCR with or without mitoxantrone in previously untreated CLL

ADMIRE was a multicenter, randomized-controlled, open, phase IIB superiority trial in previously untreated chronic lymphocytic leukemia. Conventional front-line therapy in fit patients is fludarabine, cyclophosphamide and rituximab (FCR). Initial evidence from non-randomized phase II trials suggested that the addition of mitoxantrone to FCR (FCM-R) improved remission rates. Two hundred and fifteen patients were recruited to assess the primary end point of complete remission (CR) rates according to International Workshop on Chronic Lymphocytic Leukemia criteria. Secondary end points were progression-free survival (PFS), overall survival (OS), overall response rate, minimal residual disease (MRD) negativity and safety. At final analysis, CR rates were 69.8 FCR vs 69.3% FCM-R (adjusted odds ratio (OR): 0.97; 95% confidence interval (CI): (0.53-1.79), P=0.932). MRD-negativity rates were 59.3 FCR vs 50.5% FCM-R (adjusted OR: 0.70; 95% CI: (0.39-1.26), P=0.231). During treatment, 60.0% (n=129) of participants received granulocyte colony-stimulating factor as secondary prophylaxis for neutropenia, a lower proportion on FCR compared with FCM-R (56.1 vs 63.9%). The toxicity of both regimens was acceptable. There are no significant differences between the treatment groups for PFS and OS. The trial demonstrated that the addition of mitoxantrone to FCR did not increase the depth of response. Oral FCR was well tolerated and resulted in impressive responses in terms of CR rates and MRD negativity compared with historical series with intravenous chemotherapy.

Rituximab maintenance after first-line therapy with rituximab, fludarabine, cyclophosphamide, and mitoxantrone (R-FCM) for chronic lymphocytic leukemia

The effectiveness of rituximab maintenance therapy in the treatment of chronic lymphocytic leukemia has been investigated in a phase 2 clinical trial that included an initial treatment with rituximab 500 mg/m2 on day 1 (375 mg/m2 the first cycle), fludarabine 25 mg/m2 on days 1 to 3, cyclophosphamide 200 mg/m2 on days 1 to 3, and mitoxantrone 6 mg/m2 on day 1 (R-FCM), for 6 cycles, followed by a maintenance phase with rituximab 375 mg/m2 every 3 months for 2 years. Sixty-seven patients having achieved complete response (CR) or partial response (PR) with R-FCM were given maintenance therapy. At the end of maintenance, 40.6% of patients were in CR with negative minimal residual disease (MRD), 40.6% were in CR MRD-positive, 4.8% remained in PR, and 14% were considered failures. Six of 29 patients (21%) who were in CR MRD-positive or in PR after R-FCM improved their response upon rituximab maintenance. The 4-year progression-free survival (PFS) and overall survival rates were 74.8% and 93.7%, respectively. MRD status after R-FCM induction was the strongest predictor of PFS. Maintenance with rituximab after R-FCM improved the quality of the response, particularly in patients MRD-positive after initial treatment, and obtained a prolonged PFS. This trial was registered at www.clinicaltrialsregister.eu as identifier #2005-001569-33.

cMyc/miR-125b-5p signalling determines sensitivity to bortezomib in preclinical model of cutaneous T-cell lymphomas

Successful/effective cancer therapy in low grade lymphoma is often hampered by cell resistance to anti-neoplastic agents. The crucial mechanisms responsible for this phenomenon are poorly understood. Overcoming resistance of tumor cells to anticancer agents, such as proteasome inhibitors, could improve their clinical efficacy. Using cutaneous T-cell lymphoma (CTCL) as a model of the chemotherapy-resistant peripheral lymphoid malignancy, we demonstrated that resistance to proteasome inhibition involved a signaling between the oncogene cMyc and miR-125b-5p. Bortezomib repressed cMyc and simultaneously induced miR-125b-5p that exerted a cytoprotective effect through the downmodulation of MAD4. Overexpression of cMyc repressed miR-125b-5p transcription and sensitized lymphoma cells to bortezomib. The central role of miR-125b-5p was further confirmed in a mouse model of T-cell lymphoma, where xenotransplantation of human CTCL cells overexpressing miR-125b-5p resulted in enhanced tumor growth and a shorter median survival. Our findings describe a novel mechanism through which miR-125b-5p not only regulates tumor growth in vivo, but also increases cellular resistance to proteasome inhibitors via modulation of MAD4.

Management of indolent lymphoma: where are we now and where are we going

Indolent lymphoma comprises a unique and challenging subset of non-Hodgkin lymphoma (NHL). While definitions of indolence will vary, the most common indolent NHL subtypes include follicular lymphoma, marginal zone lymphoma, and small lymphocytic lymphoma. Patients with indolent NHL (iNHL) excluding those with rare localized presentations are often met with an incurable but highly treatable NHL. In the rituximab era, response rates are approaching 90% with rituximab plus chemotherapy and time to next treatment are beginning to be measured in years. As a result of a prolonged natural history, we are encountering a gridlock of novel regimens and agents that appropriately fill peer-reviewed journals. In this review, we tackle a spectrum of topics in the management of indolent lymphoma including the initial approach to the newly diagnosed patient, approaches to first cytotoxic chemotherapy, maintenance and consolidation techniques, as well as highlight promising treatments on the horizon in iNHL. Clinicians continue to face tough choices in the management of iNHL. Through well-thought out clinical trials and peer-reviewed vetting of data we will continue to determine how to best manage the clinical continuum that is iNHL.

Treatment of relapsed or refractory chronic lymphocytic leukemia

BACKGROUND

Recent advances in the treatment of chronic lymphocytic leukemia (CLL) have moved beyond the traditional use of alkylating agents and purine analogs into regimens combining these two chemotherapy classes with monoclonal antibodies.

METHODS

This article reviews treatments options for patients with relapsed or refractory CLL.

RESULTS

Several studies have investigated novel agents in treating patients with 17p deletion, TP53 mutation, and fludarabine-refractory CLL, as well as patients with suboptimal response to intense treatment. These investigational agents include rituximab, alemtuzumab, ofatumumab, bendamustine, high-dose methylprednisolone, lenalidomide, lumiliximab, cyclin-dependent kinase inhibitors, small modular immunopharmaceuticals, Bcl-2 inhibitors, and histone deacetylase inhibitors. While these newer drugs and combination therapies have shown promise as treatment options for CLL, additional studies are needed to determine the immunosuppression, toxicities, and infections associated with their use.

CONCLUSIONS

Despite improvement in initial overall response rates, most patients relapse and require further treatment. CLL remains incurable with standard therapies due to development of disease refractoriness. As such, novel approaches such as those noted above warrant continued research to improve outcomes for patients with CLL.

Salvage therapy for relapsed chronic lymphocytic leukemia

Chronic lymphocytic leukemia is a common hematologic malignancy with a highly variable clinical course. While the median age at diagnosis is 72 years of age and fewer than 10% of patients are diagnosed before the age of 60 years, the majority of patients who require therapy will ultimately relapse. Advances in upfront therapy and supportive care have dramatically improved initial responses compared with traditional akylator-based chemotherapy. However, comparable results are not generally observed in the salvage setting. Careful planning that takes into account the duration of the initial response, patient age and/or comorbidities, and cytogenetic and molecular profiles are critical for the successful management of patients with relapsed chronic lymphocytic leukemia.

Role of rituximab in first-line treatment of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a biologically heterogeneous illness that primarily afflicts the elderly. For many decades, the initial therapy for most patients requiring treatment was limited to single-agent alkylator therapy. Within the last two decades, we have seen remarkable progress in understanding the biology of CLL and the development of more effective treatment strategies that have employed monoclonal antibodies, such as rituximab (anti-CD20). Furthermore, recognition of the synergy between fludarabine, cyclophosphamide, and rituximab (FCR) prompted investigators to explore the clinical activity of FCR in Phase II and III trials in patients with relapsed/refractory or previously untreated CLL. On the basis of these findings, the US Food and Drug Administration (FDA) recently approved rituximab in combination with fludarabine and cyclophosphamide for the treatment of patients with relapsed/refractory or previously untreated CD20-postive CLL. Recent data from a randomized Phase III trial has confirmed improved overall survival with FCR in patients with previously untreated CLL. However, FCR is not for everyone. More tolerable regimens using rituximab for the elderly and less fit patients are being pursued in clinical trials. Recent Phase II trials have explored potentially less myelosuppressive approaches by using lower doses of fludarabine and cyclophosphamide, replacing fludarabine with pentostatin, and combining rituximab with chlorambucil. Furthermore new biomarkers predictive of early disease progression have prompted investigators to explore the benefits of early treatment with rituximab combined with other agents. In addition to the proven utility of rituximab as a frontline agent for CLL, rituximab has a favorable toxicity profile both as a single agent and in combination with chemotherapy. The majority of adverse events are Grade 1 and 2 infusion-related reactions (fevers, chills, and rigors) and occur with the first dose of rituximab. The improved tolerability observed with second and subsequent infusions allows for shorter infusion times. Rituximab's proven activity and favorable toxicity profile has made it an ideal agent for expanding treatment options for patients with CLL, the majority of whom are elderly.

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.

Chronic lymphocytic leukemia: treatment options for patients with refractory disease

Patients with purine analogue-refractory chronic lymphocytic leukemia (CLL) have short survival and limited treatment options. Defining the best salvage strategies for this population is challenging, because limited data are available from clinical trials, and because studies have enrolled mixed populations (patients with recurrent and refractory disease or patients with refractory disease and Richter transformation). Moreover, patients with refractory CLL have a high incidence of unfavorable molecular and clinical features, such as high-risk genomic profiles, unmutated immunoglobulin heavy-chain genes, expression of zeta-chain-associated protein kinase 70, and bulky lymphadenopathies. These patients are also severely immunosuppressed because of the underlying disease and the treatments received, and experience a high rate of infectious complications that pose an additional difficulty in selecting treatment. Despite these challenges, in parallel with better characterizations of the biologic features of refractory CLL, the number of available treatment modalities for this population has increased. Several chemoimmunotherapy combinations have been developed, and novel agents with a different mechanism of action are being investigated in clinical trials. Furthermore, allogeneic stem cell transplantation with nonmyeloablative conditioning regimens is a therapeutic strategy that is increasingly offered to patients with refractory CLL.

Rituximab, fludarabine, cyclophosphamide, and mitoxantrone: a new, highly active chemoimmunotherapy regimen for chronic lymphocytic leukemia

PURPOSE

The addition of monoclonal antibodies to chemotherapy has significantly improved treatment of chronic lymphocytic leukemia (CLL). Based on excellent results with the chemotherapy-only regimen fludarabine, cyclophosphamide, and mitoxantrone (FCM), we built a new chemoimmunotherapy combination--rituximab plus FCM (R-FCM). We report a phase II clinical trial consisting of an initial treatment with R-FCM followed by rituximab maintenance.

PATIENTS AND METHODS

Seventy-two untreated CLL patients age 70 years or younger received rituximab 500 mg/m(2) on day 1 (375 mg/m(2) the first cycle), fludarabine 25 mg/m(2) IV on days 1 to 3, cyclophosphamide 200 mg/m(2) on days 1 to 3, and mitoxantrone 6 mg/m(2) IV on day 1, given at 4-week intervals with up to six cycles supported with colony-stimulating factor. Patients achieving response received maintenance with rituximab 375 mg/m(2) every 3 months for 2 years.

RESULTS

The overall response, minimal residual disease (MRD) -negative complete response (CR), MRD-positive CR, and partial response rates were 93%, 46%, 36%, and 11%, respectively. Severe neutropenia developed in 13% of patients. Major and minor infections were reported in 8% and 5% of cycles, respectively. Advanced clinical stage, del(17p), or increased serum beta2-microglobulin levels correlated with a lower CR rate.

CONCLUSION

R-FCM is highly effective in previously untreated CLL, with an 82% CR rate and a high proportion of MRD-negative CRs (46%). Treatment toxicity is acceptable. Parameters correlating with a lower response rate were advanced clinical stage, high serum beta2-microglobulin levels, and del(17p). Based on these results, R-FCM warrants further investigation in randomized clinical trials.

Chronic lymphocytic leukemia: new concepts and emerging therapies

OPINION STATEMENT

Remarkable progress in elucidating the biology of chronic lymphocytic leukemia (CLL) has been made over the last two decades. Improved understanding of CLL has lead to new prognostic tools and therapeutic options, and holds promise for eventually finding a cure for this disease. Challenges lie in incorporating the various treatment modalities, including chemotherapy, monoclonal antibodies, immunotherapeutic strategies and novel small molecules, into a comprehensive treatment strategy guided by the biological complexity of CLL.

Liposomal Coencapsulated Fludarabine and Mitoxantrone for Lymphoproliferative Disorder Treatment**Xiaobin Zhao and Jianmei Wu contributed equally to this study

Fludarabine (FLU)-based combination therapies are commonly used to treat low-grade lymphoma and chronic lymphocytic leukemia (CLL) patients. In vitro and clinical studies have indicated advantages when FLU and mitoxantrone (MTO) are applied in combination. To further enhance this effect, these two agents were coencapsulated in liposomes. FLU was passively encapsulated during liposome formation, and MTO was loaded with a transmembrane pH gradient. Entrapment efficiency, particle size, stability, and drug release kinetics were characterized. In vitro cytotoxicity study was carried out in two representative B-cell lines: Wac3CD5 and Raji. Synergism as measured by combination index (CI) was observed in cells treated with liposomes coencapsulating FLU and MTO. Annexin V/propidium iodide (PI) analysis further confirmed that coencapsulated FLU and MTO improved the percentage of apoptosis among primary CLL cells. These data suggest that adopting liposomes containing coencapsulated drug combinations constitutes a potential strategy to promote drug synergism and may have utility in the treatment of leukemia and lymphoma.

Fludarabine, cyclophosphamide, and mitoxantrone as initial therapy of chronic lymphocytic leukemia: high response rate and disease eradication

PURPOSE

Fludarabine, cyclophosphamide, and mitoxantrone (FCM) results in a high response rate in previously treated patients with chronic lymphocytic leukemia (CLL). The aim of this study was to investigate FCM as frontline therapy in CLL.

EXPERIMENTAL DESIGN

Sixty-nine patients under the age of 65 years with active CLL were treated. Patients received six cycles of fludarabine 25 mg/m(2) i.v. x 3 days, cyclophosphamide 200 mg/m(2) i.v. x 3 days, and mitoxantrone 6 mg/m(2) i.v. x 1 day. Treatment outcome was correlated with clinical and biological variables. The clinical significance of eradicating minimal residual disease (MRD) was also analyzed.

RESULTS

The overall response, MRD-negative complete response (CR), MRD-positive CR, nodular partial response (PR), and PR rates were 90%, 26%, 38%, 14%, and 12%, respectively. Severe (grades 3 or 4) neutropenia developed in 10% of the patients. Major and minor infections were reported in 1% and 8% of cases, respectively. Median response duration was 37 months. Patients with del(17p) failed to attain CR. Patients achieving MRD-negative CR had a longer response duration and overall survival than patients with an inferior response. Low serum lactate dehydrogenase levels, low ZAP-70 expression, and mutated IgV(H) genes predicted longer response duration. Finally, both low ZAP-70 and CD38 expression in leukemic cells correlated with MRD-negativity achievement.

CONCLUSION

FCM induces a high response rate, including MRD-negative CRs in untreated patients with active CLL. Treatment toxicity is acceptable. Both high ZAP-70 and increased CD38 expression predict failure to obtain MRD-negative response. Patients in whom MRD can be eradicated have longer response duration and overall survival than those with inferior response. These results indicate that FCM can be an ideal companion for chemoimmunotherapy of patients with CLL.

Emerging therapy for chronic lymphocytic leukaemia

The presentation, clinical course and prognosis for chronic lymphocytic leukaemia (CLL) is diverse and strategies for therapy reflect this variability. Staging of the disease has assisted in deciding treatment options and more recently the cytogenetic, molecular and surrogate markers of the immunoglobulin heavy chain mutational status, CD38 and ZAP-70, have assisted in further risk stratification. Chemotherapy has been the mainstay of interventional therapy when required and the two most important classes of agents in the treatment of CLL are nucleoside analogues and alkylating agents. Combining these two groups of agents has significantly improved prognosis in this disease. More recently a number of novel agents have been applied to patients with CLL to determine if they represent better therapy. However, allogeneic stem cell transplantation offers perhaps the only realistic chance of a cure in this disease. Clinical trials are still needed to determine the timing and role of this promising treatment modality in the treatment of CLL and, where possible, combined with the emerging awareness of the disease biology, related biological markers and prognostic indicators.

Chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western world and is due to the accumulation of mature B lymphocytes in the peripheral blood, bone marrow and secondary lymphoid organs. The leukemic cells show a distinct phenotype, which is essential to reach the correct diagnosis. Despite the phenotypic homogeneity, the clinical outcome may be significantly different. Some patients have an indolent leukemia, with long survival while others experience an aggressive disease, with early and frequent need of treatment. At present, no chemotherapeutic regimens can be considered curative and all patients will die with (or because of) their disease. In recent years, research on CLL has led to important discoveries that help defining patients' prognosis at the moment of diagnosis. These prognostic factors, which are derived from the biological features of the leukemic lymphocytes, are now rapidly moved into the clinical arena. They are used to stratify patients in selected clinical trials to assess the value of early and more modern treatments, which are becoming available to hematologists.

Phase II study of single-agent bortezomib for the treatment of patients with fludarabine-refractory B-cell chronic lymphocytic leukemia

Therapeutic options are limited and the prognosis is poor for patients with fludarabine-refractory B-cell chronic lymphocytic leukemia (CLL). Bortezomib induces apoptosis in vitro in CLL cells, both alone and in combination, including in cells resistant to fludarabine or other agents. The aim of the current randomized, open-label, Phase II study was to investigate the clinical activity of bortezomib in patients with fludarabine-refractory B-cell CLL. Twenty-two patients with histologically confirmed B-cell CLL were treated with bortezomib at doses of 1.0 mg/m2, 1.3 mg/m2, or 1.5 mg/m2 on Days 1, 4, 8, and 11 of a 21-day treatment cycle for a maximum of 9 cycles. None of 19 patients evaluable for response achieved complete remission or partial response; however, signs of biologic activity based on disease site responses (e.g., reduction in lymphocytosis, splenomegaly, and lymphadenopathy) were observed. In the 1.5 mg/m2 dose group, a higher proportion of patients had stable disease, and a lower proportion had progressive disease compared with the 2 lower-dose groups. Eleven patients, all in the 2 higher dose groups, experienced Grade 3/4 adverse events (AEs) (according to National Cancer Institute Common Toxicity Criteria [version 2.0]); 2 patients experienced Grade 4 neutropenia. Grade 3 hematologic AEs included anemia, neutropenia, thrombocytopenia, and hemolytic anemia; Grade 3 nervous system AEs included aphasia; peripheral neuropathy, not otherwise specified; and peripheral sensory neuropathy. Although no objective responses were achieved in patients with fludarabine-refractory B-cell CLL, single-agent bortezomib demonstrated biologic activity. In view of the evidence for its activity, further exploration of bortezomib in combination with other agents is warranted.

Potentiation of the activity of cisplatin and cyclophosphamide by trimidox, a novel ribonucleotide reductase inhibitor, in leukemia-bearing mice

We describe the use of the new ribonucleotide reductase inhibitor, trimidox (TDX), in combination chemotherapy under in vitro and in vivo conditions with cisplatin and cyclophosphamide. In vitro, the combination of TDX and cisplatin was tested in L1210 cells. The combination caused concentration dependent antagonistic or additive effects. However, the combination of TDX-cisplatin-cyclophosphamide in vivo is highly synergistic in both, the L1210 and P388D1 leukemia mouse models. Both combinations, TDX with cisplatin or TDX with cyclophosphamide were also synergistic in the L1210 and P388D1 leukemia animal models.

Purine Analogue Combinations for Indolent Lymphomas

Indolent lymphomas are a group of lymphoid malignancies with differing patterns of behavior and responses to treatment. The progress in treating patients with hairy cell leukemia (HCL) using nucleoside analogues can be used as a model for other indolent B-lymphoproliferative disorders, such as follicular lymphoma. Recent advancements in therapeutic options available for these patients include combination therapy with agents that have differing mechanisms of action and non-overlapping toxicity. It has been shown that patients who are candidates for aggressive therapy might receive benefit, including disease-free survival and overall survival, from combination purine analogue therapy. Using these more aggressive therapeutic approaches earlier in the disease course and as maintenance therapy may further enhance outcomes. With the advent of these new therapies along with the molecular evaluation of these regimens, we may be nearing the time where the goal for more advanced indolent lymphoma will be to achieve a cure.