Fludarabine and bendamustine in refractory and relapsed indolent lymphoma--a multicenter phase I/II Trial of the east german society of hematology and oncology (OSHO)

Real-World Evidence of Relapsed/Refractory Mantle Cell Lymphoma Patients and Treatments: A Systematic Review

Introduction

Mantle cell lymphoma (MCL) is an incurable disease with an aggressive clinical course, and most patients eventually relapse after chemotherapy. Targeted therapies developed for relapsed/refractory MCL have been approved based on clinical trial data. However, real-world setting data are scarce and scattered.

Areas Covered

This systematic review aimed to collect, synthesize, and describe the characteristics and treatment outcomes of patients with relapsed/refractory MCL after receiving a second or subsequent line of therapy in the real-world setting.

Expert Opinion

R/R MCL is clinically and biologically heterogeneous and still represents a therapeutic challenge, with high-risk and early relapsed patients remaining an unmet medical need. This systematic review is limited by the quality of the available data and the difficulty of comparing outcomes in R/R MCL due to the heterogeneity of the disease, but the results suggest that covalent BTKis should be positioned as second-line therapy, followed by CAR T-cells in BTK-i-relapsed patients. Chemo-free and combination therapies with established chemoimmunotherapy backbones in the relapsed and front-line settings have been recently developed, and front-line options are being improved to move targeted and cellular therapies to earlier lines, including front-line therapy, in elderly and younger fit patients. In the upcoming years, many new targeted agents will play an important role and will be incorporated to the routine practice as their sequence, and outcomes in unselected patients are determined.

Evaluation of bendamustine in combination with fludarabine in primary chronic lymphocytic leukemia cells

The fludarabine and cyclophosphamide couplet has become the backbone of the chronic lymphocytic leukemia (CLL) standard of care. Although this is an effective treatment, it results in untoward toxicity. Bendamustine is a newly approved and better-tolerated alkylating agent. We hypothesized that similar to cyclophosphamide, bendamustine-induced DNA damage will be inhibited by fludarabine, resulting in increased cytotoxicity. To test this hypothesis and the role of the stromal microenvironment in this process, we treated CLL lymphocytes in vitro with each drug alone and in combination. Simultaneous or prior addition of fludarabine to bendamustine resulted in maximum cytotoxicity assayed by 3,3'-dihexyloxacarbocyanine iodine negativity, annexin positivity, and poly (adenosine 5'-diphosphate-ribose) polymerase cleavage. Cytotoxicity elicited by combination of both agents was similar in these malignant B cells cultured either in suspension or on marrow stroma cells. Cell death was associated with DNA damage response, which was determined by phosphorylation of H2AX and unscheduled DNA synthesis. H2AX activation was maximum with the drug combination, and unscheduled DNA synthesis induced by bendamustine was blocked by fludarabine. In parallel, ATM, Chk2, and p53 were phosphorylated and PUMA was induced. Cell death was caspase independent; however, caspases did decrease levels of Mcl-1 survival protein. These data provide a rationale for combining fludarabine with bendamustine for patients with CLL.

Purine analog-like properties of bendamustine underlie rapid activation of DNA damage response and synergistic effects with pyrimidine analogues in lymphoid malignancies

Bendamustine has shown considerable clinical activity against indolent lymphoid malignancies as a single agent or in combination with rituximab, but combination with additional anti-cancer drugs may be required for refractory and/or relapsed cases as well as other intractable tumors. In this study, we attempted to determine suitable anti-cancer drugs to be combined with bendamustine for the treatment of mantle cell lymphoma, diffuse large B-cell lymphoma, aggressive lymphomas and multiple myeloma, all of which are relatively resistant to this drug, and investigated the mechanisms underlying synergism. Isobologram analysis revealed that bendamustine had synergistic effects with alkylating agents (4-hydroperoxy-cyclophosphamide, chlorambucil and melphalan) and pyrimidine analogues (cytosine arabinoside, gemcitabine and decitabine) in HBL-2, B104, Namalwa and U266 cell lines, which represent the above entities respectively. In cell cycle analysis, bendamustine induced late S-phase arrest, which was enhanced by 4-hydroperoxy-cyclophosphamide, and potentiated early S-phase arrest by cytosine arabinoside (Ara-C), followed by a robust increase in the size of sub-G1 fractions. Bendamustine was able to elicit DNA damage response and subsequent apoptosis faster and with shorter exposure than other alkylating agents due to rapid intracellular incorporation via equilibrative nucleoside transporters (ENTs). Furthermore, bendamustine increased the expression of ENT1 at both mRNA and protein levels and enhanced the uptake of Ara-C and subsequent increase in Ara-C triphosphate (Ara-CTP) in HBL-2 cells to an extent comparable with the purine analog fludarabine. These purine analog-like properties of bendamustine may underlie favorable combinations with other alkylators and pyrimidine analogues. Our findings may provide a theoretical basis for the development of more effective bendamustine-based combination therapies.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Bendamustine for treatment of chronic lymphocytic leukemia

INTRODUCTION

Chronic lymphocytic leukemia (CLL) often has an extended disease course. With a median age at diagnosis of 72 years, newer treatment options with less toxicity than standard nucleoside analogue-based regimens are needed. Historically, few therapy options are available once CLL has become refractory to nucleoside analogues. Bendamustine has emerged as a feasible therapy for older and less fit CLL patients, with clinical efficacy in previously untreated and refractory CLL.

AREAS COVERED

This paper reviews several of the pivotal clinical trials that established the clinical activity of bendamustine in previously untreated and relapsed/refractory CLL. The toxicity profile of bendamustine, primarily myelosuppression and infections, is reviewed and compared across different CLL populations. A review of the clinical data focuses on potential explanations for differences in response rates and duration of remission reported across studies and how this may impact the development of therapies for CLL.

EXPERT OPINION

Bendamustine is a valuable new agent for the management of CLL. Ongoing clinical trials are comparing bendamustine with standard CLL regimens in untreated disease, and investigating bendamustine combinations with novel targeted therapies and monoclonal antibodies. These studies will help to define the optimal role for bendamustine in CLL management.

Bendamustine HCL for the treatment of relapsed indolent non-Hodgkin's lymphoma

Bendamustine is an alkylating agent which also shows properties of a purine analog. Because of its unique mechanism of action it shows activity in relapsed indolent lymphomas which are resistant to alkylating agents, purine analogs, and rituximab. Bendamustine has a favorable toxicity profile causing no alopecia and only a moderate hematotoxicity and gastrointestinal toxicity. Combinations of bendamustine with mitoxantrone and rituximab and with rituximab alone have been shown to be highly active in relapsed/refractory indolent lymphomas and mantle cell lymphomas achieving long lasting complete remissions. Because of only moderate toxicity these combinations can be applied safely in elderly patients who can be treated in an outpatient setting.

Bendamustine: safety and efficacy in the management of indolent non-hodgkins lymphoma

Bendamustine (Treanda, Ribomustin) was recently approved by the US Food and Drug Administration (FDA) for treatment of patients with rituximab refractory indolent lymphoma and is expected to turn into a frontline therapy option for indolent lymphoma. This compound with amphoteric properties was designed in the former Germany Democratic Republic in 1960s and re-discovered in 1990s with multiple successive well-designed studies. Bendamustine possesses a unique mechanism of action with potential antimetabolite properties, and only partial cross-resistance with other alkylators. Used in combination with rituximab in vitro, bendamustine shows synergistic effects against various leukemia and lymphoma cell lines. In clinical studies, bendamustine plus rituximab is highly effective in patients with relapsed-refractory indolent lymphoma, inducing remissions in 90% or more and a median progression-free survival of 23-24 months. The optimal dosing and schedule of bendamustine administration is largely undecided and varies among studies. Results of ongoing trials and dose-finding studies will help to further help ascertain the optimal place of bendamustine in the management of indolent NHL.

Bendamustine in chronic lymphocytic leukemia and non-Hodgkin's lymphoma

Bendamustine (Treanda(®); Pharmachemie BV, The Netherlands for Cephalon, Inc., PA, USA) is a unique cytotoxic agent with both alkylating and antimetabolite properties. A growing body of evidence demonstrates its efficacy in a number of hematologic malignancies, and as such, it has been US FDA approved for the treatment of chronic lymphocytic leukemia and non-Hodgkin's lymphoma that has not responded to, or progressed within 6 months of, a rituximab-based regimen. Bendamustine has efficacy both as a single agent as well as in combination with other chemotherapeutics and immunotherapeutics. Here, we will discuss in the detail the molecular properties, clinical efficacy and safety profile of bendamustine.

Bendamustine: a review of its use in the management of indolent non-Hodgkin's lymphoma and mantle cell lymphoma

Bendamustine (bendamustine hydrochloride) is an alkylating agent indicated in several countries for the treatment of indolent non-Hodgkin's lymphoma (NHL) and mantle cell lymphoma (MCL). While the precise mechanism of action of bendamustine is as yet unknown, it has limited cross resistance to other alkylating agents and appears to exert its antineoplastic effects via a different mechanism to that of other alkylating agents. Bendamustine monotherapy was effective in treatment-refractory (including rituximab-refractory) indolent NHL or MCL. Moreover, bendamustine-based combination treatment was at least as effective as cyclophosphamide-based treatment, and bendamustine plus rituximab was at least as effective as cyclophosphamide, doxorubicin, vincristine plus prednisone (CHOP) plus rituximab, as first-line therapy in patients with indolent NHL or MCL. Treatment-refractory disease also appeared to respond favourably to bendamustine-containing combination treatment. In general, bendamustine was associated with a high overall response rate and a durable response. The most common adverse events associated with bendamustine were haematological or gastrointestinal in nature, and most were of mild to moderate severity. Regimens that included bendamustine were also associated with a very low rate of alopecia compared with regimens that included other antineoplastic drugs. In conclusion, bendamustine is a unique alkylating agent, which in clinical trials has demonstrated consistent efficacy and acceptable tolerability in patients with indolent NHL or MCL. It may be a particularly useful treatment option in patients with rituximab-refractory disease, but has also demonstrated efficacy as part of a first-line combination treatment. While further research is necessary to firmly establish the best place for bendamustine in the management of indolent NHL and MCL, it is a valuable addition to the pool of available treatments for these diseases.

Temsirolimus in the treatment of relapsed or refractory mantle cell lymphoma

Mantle cell lymphoma (MCL) is a rare and aggressive subtype of lymphoma associated with a poor prognosis. Chemotherapy is the mainstay of frontline treatment for patients with this disease. Despite high response rates to combination chemotherapy regimens, the majority of patients relapse within a few years of treatment. Therefore, finding efficacious treatments for relapsed or refractory disease has become a growing area of clinical research. The mammalian target of rapamycin (mTOR) is responsible for integrating cell signals from growth factors, hormones, and nutrients and communicating energy status. Scientific research on aberrant molecular pathways in cancer has revealed that several proteins along the mTOR pathway may be upregulated in this and other types of lymphoma. Temsirolimus is the first mTOR inhibitor that has shown clinical efficacy in treating MCL that has relapsed after frontline treatments.

Bendamustine: something old, something new

BACKGROUND

Bendamustine (Treanda, Ribomustin) is a water-soluble, bifunctional chemotherapeutic agent that also has potential antimetabolite properties and only partial cross-resistance with other alkylators. Designed in 1963 and re-discovered in 1990s, this drug's unique mechanism of action and favorable side-effect profile promise a major role in the management of lymphoproliferative disorders. Bendamustine has been designated as an orphan drug in the United States, conferring prolonged market exclusivity.

OBJECTIVE

This article provides a comprehensive review of the data on efficacy and toxicity from trials investigating the use of bendamustine for the treatment of lymphoproliferative neoplasms. The pharmacology, pharmacokinetics, and pre-clinical studies with bendamustine are also reviewed.

METHODS

MEDLINE and Pubmed databases (1970-2010) were searched using the terms bendamustine, bendamustin, Treanda, Ribomustin, SDX-105, IMET-3393, and Cytostasan. All relevant articles were reviewed and references screened for additional articles. The databases of the American Society of Hematology (2004-2009) and the American Society of Clinical Oncology (1995-2009) were also searched for relevant abstracts.

RESULTS

Bendamustine induces a remission in more than three-fourths of patients with rituximab-refractory indolent B cell non-Hodgkin lymphoma (NHL). Combined with rituximab in vitro, bendamustine shows synergistic effects against various leukemia and lymphoma cell lines. Clinical trials supporting these results show that bendamustine plus rituximab is highly effective in patients with relapsed-refractory indolent lymphoma, inducing remissions in 90% or more and a median progression-free survival of 23-24 months. Bendamustine has been reasonably well tolerated in clinical trials with low propensity to induce alopecia.

CONCLUSIONS

Combination of bendamustine and rituximab has the potential to become a new standard first-line treatment option for patients with FL, MCL, and indolent lymphomas. Results of ongoing trials will help to further elucidate the optimal role of bendamustine in indolent NHL.

Bendamustine is effective therapy in patients with rituximab-refractory, indolent B-cell non-Hodgkin lymphoma: results from a Multicenter Study

BACKGROUND

Bendamustine hydrochloride is a novel alkylating agent. In this multicenter study, the authors evaluated the efficacy and toxicity of single-agent bendamustine in patients with rituximab-refractory, indolent B-cell lymphoma.

METHODS

Eligible patients (N = 100, ages 31-84 years) received bendamustine at a dose of 120 mg/m(2) by intravenous infusion on Days 1 and 2 every 21 days for 6 to 8 cycles. Histologies included follicular (62%), small lymphocytic (21%), and marginal zone (16%) lymphomas. Patients had received a median of 2 previous regimens (range, 0-6 previous regimens), and 36%were refractory to their most recent chemotherapy regimen. Primary endpoints included overall response rate (ORR) and duration of response (DOR). Secondary endpoints were safety and progression-free survival (PFS).

RESULTS

An ORR of 75% (a 14% complete response rate, a 3% unconfirmed complete response rate, and a 58% partial response rate) was observed. The median DOR was 9.2 months, and median PFS was 9.3 months. Six deaths were considered to be possibly treatment related. Grade 3 or 4 (determined using National Cancer Institute Common Toxicity Criteria [version 3.0.19]. reversible hematologic toxicities included neutropenia (61%), thrombocytopenia (25%), and anemia (10%). The most frequent nonhematologic adverse events (any grade) included nausea (77%), infection (69%), fatigue (64%), diarrhea (42%), vomiting (40%), pyrexia (36%), constipation (31%), and anorexia (24%).

CONCLUSIONS

Single-agent bendamustine produced a high rate of objective responses with acceptable toxicity in patients with recurrent, rituximab-refractory indolent B-cell lymphoma.

Bendamustine for the treatment of chronic lymphocytic leukemia and rituximab-refractory, indolent B-cell non-Hodgkin lymphoma

BACKGROUND

Bendamustine is a mechlorethamine derivative with a purine-like benzimidazole ring, which may enhance its clinical efficacy. Bendamustine was approved by the US Food and Drug Administration (FDA) for the treatment of chronic lymphocytic leukemia (CLL) in March 2008 and for the treatment of rituximab-refractory, indolent B-cell non-Hodgkin lymphoma (NHL) in October 2008.

OBJECTIVE

This article reviews the pharmacologic and pharmacodynamic properties of bendamustine, together with data on efficacy and toxicity from trials investigating the use of bendamustine for the treatment of various hematologic malignancies, including CLL, NHL, and multiple myeloma (MM).

METHODS

MEDLINE and International Pharmaceutical Abstracts (1970-April 15, 2009) were searched using the terms bendamustine, bendamustin, Treanda, Ribomustin, SDX-105, IMET-3393, and Cytostasan. References from relevant articles were also reviewed for additional sources and material. The databases of the American Society of Hematology (2004-2008) and the American Society of Clinical Oncology (1995-2008) were searched for relevant abstracts.

RESULTS

Bendamustine is a mechlorethamine derivative with structural similarity to chlorambucil and other drugs from the nitrogen mustard class, as well as a benzimidazole ring, which may act as an antagonist to purines and amino acids. It has good oral bioavailability but has been studied almost exclusively in the intravenous formulation. It undergoes extensive first-pass metabolism by cytochrome P450 1A2 to active metabolites gamma-hydroxy bendamustine and N-desmethyl-bendamustine, but clinical activity appears to be associated primarily with the parent compound. The t(1/2) of bendamustine is approximately 40 minutes. While bendamustine has 2 moieties with possible antitumor effect, it is unclear to what extent the benzimidazole ring enhances the efficacy of the drug. Numerous studies including in vitro assays have reported, however, that bendamustine has little cross-resistance with other alkylating agents and remains active even in extensively pretreated patients. FDA approval for use in CLL was based on findings from a randomized, open-label, Phase III study comparing bendamustine with chlorambucil as single-agent therapy in treatmentnaive patients with CLL (Binet stage B or C). Bendamustine was administered intravenously at a dose of 100 mg/m2 on days 1 and 2, while chlorambucil was administered orally at 0.8 mg/kg daily, both over 4-week cycles for up to 6 cycles. At interim analysis (the data used for FDA approval), bendamustine was associated with a greater overall response (68% vs 39%; P < 0.001), median progression-free survival (21.7 vs 9.3 months; P < 0.001) and median duration of remission (18.9 vs 6.1 months; P < 0.001) compared with chlorambucil. FDA approval for rituximabrefractory, indolent B-cell NHL followed a Phase III, open-label, single-arm study evaluating bendamustine monotherapy in patients who did not respond to rituximab or had progressive disease within 6 months of rituximab therapy. Bendamustine 120 mg/m(2) was administered intravenously on days 1 and 2 of a 21-day cycle for up to 8 cycles. At interim analysis, the overall response rate was 84%, including 29% complete response. The median progression-free survival was 9.7 months. The efficacy of bendamustine has also been reported in the treatment of MM in clinical studies, and bendamustine has been approved in Europe for treating MM, NHL, CLL, breast cancer, and Hodgkin lymphoma. Dose-limiting toxicity is primarily hematologic. Treatment-associated infections have been reported in some studies; however, nonhematologic adverse events have rarely been dose limiting. The most common nonhematologic adverse events include fatigue, nausea, xerostomia, and pyrexia.

CONCLUSIONS

Bendamustine is a mechlorethamine derivative with a purine-like benzimidazole ring, which may enhance its clinical efficacy. It has been approved in the United States for the treatment of CLL and rituximab-refractory, indolent B-cell NHL. It has been approved in Europe for use in other malignancies, and clinical studies have reported activity in MM.

The role of bendamustine in the treatment of indolent non-Hodgkin lymphoma

There is no consensus on recommendations for the treatment of relapsed and refractory indolent non-Hodgkin lymphoma (NHL). Bendamustine hydrochloride (bendamustine) has recently been approved for treatment of these patients. Bendamustine is a uniquely structured alkylating agent that lacks cross-resistance with other alkylators. This agent has a high degree of activity against a variety of tumor cell lines. Clinically, bendamustine has demonstrated activity against indolent NHL, chronic lymphocytic lymphoma, multiple myeloma and mantle cell lymphoma. Moreover, studies have validated its activity in patients with indolent NHL who are resistant to purine analogs and rituximab. The cytotoxic activity of bendamustine has been shown to be synergistic with rituximab in hematological malignancies. The incidence of alopecia is significantly less than with other alkylating agents. Myelosuppression is the major toxicity associated with bendamustine.

Bendamustine: Rebirth of an Old Drug

Bendamustine is a unique cytotoxic agent with structural similarities to alkylating agents and antimetabolites, but which is non–cross-resistant with alkylating agents and other drugs in vitro and in the clinic. Early clinical studies conducted in the German Democratic Republic more than 30 years ago suggested promising activity in indolent non-Hodgkin's lymphoma (NHL). Two North American trials reported responses in more than 70% of patients with chemotherapy- and rituximab-refractory disease, suggesting that bendamustine may be the most effective drug available for this patient population. Response rates of 90% to 92%, with complete remission in 55% to 60%, have been reported in patients with follicular and mantle-cell lymphoma with the combination of bendamustine and rituximab. Superiority over chlorambucil in previously untreated patients with chronic lymphocytic leukemia (CLL) led to its recent approval for this disease in the United States. Bendamustine is approved in Germany for the treatment of patients with indolent NHL, CLL, and multiple myeloma. Activity has also been noted in patients with breast cancer and small-cell lung cancer. Questions related to the optimization of bendamustine therapy, including dose and schedule, role relative to other available agents, and management of toxicities, are being investigated. However, the availability of bendamustine provides another effective treatment option for patients with lymphoid malignancies.

Bendamustine in the treatment of non-Hodgkin's lymphomas

PURPOSE

To review available data using bendamustine alone and in combination with other chemotherapeutic agents in treatment of patients with non-Hodgkin's lymphomas.

METHODS

Internet database searches and literature review.

RESULTS

Bendamustine was approved in March 2008 by the United States Food and Drug Administration for the treatment of patients with chronic lymphocytic leukemia. Many trials have been performed over the last decade using bendamustine not only as monotherapy, but also in combination with other agents including rituximab, vincristine, mitoxantrone, fludarabine, and other agents as therapy for patients with relapsed non-Hodgkin's lymphomas, and recently was approved for use in therapy of patients with relapsed indolent lymphomas considered refractory to rituximab therapy. As monotherapy, bendamustine induces good responses with only minor side effects. In combination with other agents, efficacy improves, especially when given in combination with rituximab. The drug has also been studied in combination with rituximab as initial therapy for indolent lymphomas, and has excellent activity with less toxicity than R-CHOP (rituximab - cyclophosphamide, hydroxydaunorubicin [Adriamycin], Oncovin [vincristine], and prednisone/prednisolone).

CONCLUSION

Overall, bendamustine has demonstrated promising results as therapy for non-Hodgkin's lymphomas and should be included in the armamentarium of agents used to treat relapsed indolent non-Hodgkin's lymphomas and may prove valuable as initial therapy for these diseases. Further studies are being conducted to demonstrate the efficacy of this drug in combination with other agents.

Low-dose, single-agent temsirolimus for relapsed mantle cell lymphoma: a phase 2 trial in the North Central Cancer Treatment Group

BACKGROUND

The objective of this study was to test a low dose of (25 mg weekly) of the mammalian target of rapamycin kinase inhibitor temsirolimus for patients with relapsed mantle cell lymphoma (MCL).

METHODS

Patients with relapsed or refractory MCL were eligible to receive temsirolimus 25 mg intravenously every week as a single agent. Patients who had a tumor response after 6 cycles were eligible to continue drug for a total of 12 cycles or 2 cycles after complete remission and then were observed without maintenance.

RESULTS

Of 29 enrolled patients, 28 were evaluable for toxicity, and 27 were evaluable for efficacy. The median age was 69 years (range, 51-85 years), 86% of patients had stage IV disease, and 71% had > or = 2 extranodal sites. Patients had received a median of 4 prior therapies (range, 1-9 prior therapies), and 50% were refractory to the last treatment. The overall confirmed response rate was 41% (11 of 27 patients; 90% confidence interval [CI], 22%-61%) with 1 complete response (3.7%) and 10 partial responses (37%). The median time to progression in all eligible patients was 6 months (95% CI, 3-11 months), and the median duration of response for the 11 responders was 6 months (range, 1-26 months). Hematologic toxicities were the most common, with 50% (14 of 28 patients) grade 3 and 4% (1 of 28 patients) grade 4 toxicities observed. Thrombocytopenia was the most frequent cause of dose reduction.

CONCLUSIONS

Single-agent temsirolimus at a dose of 25 mg weekly is an effective new agent for the treatment of MCL. The 25-mg dose level retained the antitumor activity of the 250-mg dose with less myelosuppression. Further studies of temsirolimus in combination with other active drugs for MCL and other lymphoid malignancies are warranted.

Bendamustine, but not fludarabine, exhibits a low stem cell toxicity in vitro

PURPOSE

We investigated the in vitro toxicity of bendamustine and fludarabine to hematopoietic progenitors and stem cells from healthy donors.

METHODS

Clonogenic agar colony assays, non-clonogenic long-term liquid cultures (LTC) and apoptosis assays were used to assess the cytotoxicity of both the agents.

RESULTS

Total colony-forming units (CFU) were more sensitive to fludarabine than to bendamustine in agar colony assays (IC(50) 0.7 microM/L and 8.5 microM/L, respectively). Using the Bliss independence model and combining the two agents yielded additive inhibition of progenitors. Non-clonogenic assays, including LTC and an apoptosis assay detecting activated caspases showed that stem cells are characterized by low sensitivity to bendamustine. In contrast, fludarabine strongly inhibited the viability and growth of stem cells in LTC.

CONCLUSIONS

Our data show that bendamustine is characterized by lower in vitro toxicity to hematopoietic progenitors and stem cells than fludarabine and might thus be preferable in regimens prior to stem cells apheresis.

Bendamustine as a model for the activity of alkylating agents

Attempts to administer personalized standard cytotoxic chemotherapy based on individual patient characteristics have been disappointing. Alkylating agents are one of the oldest classes of anticancer medicine with a wide variety of molecular actions and thus the potential for broad utility. Bendamustine hydrochloride, a new addition to this class, was previously developed in the 1960s and has now been trialled in hematological malignancies and many solid tumor types as monotherapy or in combination with the known standard of care. It appears to occupy a particular role in resistant or refractory hematological disease and it was approved by the US FDA for the treatment of chronic lymphocytic leukemia in March 2008. Further trials will reveal whether it is likely to become incorporated into front-line regimens in non-Hodgkin's lymphoma and other malignancies.

Bendamustine; Levoleucovorin

The complexity of cancer chemotherapy requires that pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy and the agents, both commercially available and investigational, used to treat malignant diseases.

Bendamustine in non-Hodgkin lymphoma: the double-agent that came from the Cold War

Bendamustine was first synthesized in the early 1960s at the Institute for Microbiology and Experimental Therapy in Jena, East Germany by Ozegowski and Krebs. The molecule, originally termed IMET 3393 (4-[5-(bis[2-chloroethyl]amino)-1-methyl-2-benzimidazolyl] butyric acid), was intended to be a "bi-functional" molecule with alkylator and antimetabolite properties. Extensive studies were conducted using this compound over a 20-year period in East Germany, and it became a highly used chemotherapeutic agent in the eastern block before the fall of the Iron Curtain. After its licensing in Europe in the mid 1990s, more than 18,000 patients were studied using this compound, principally in Germany. Over the past decade, significant interest has been generated as a result of ongoing studies that have demonstrated the unique antitumor properties of this compound as a single agent and in different combinations. This article provides a review of studies using bendamustine in the treatment of non-Hodgkin lymphomas.

Bendamustine in Patients With Rituximab-Refractory Indolent and Transformed Non-Hodgkin's Lymphoma: Results From a Phase II Multicenter, Single-Agent Study

Purpose

Bendamustine hydrochloride is an alkylating agent with novel mechanisms of action. This phase II multicenter study evaluated the efficacy and toxicity of bendamustine in patients with B-cell non-Hodgkin's lymphoma (NHL) refractory to rituximab.

Patients and Methods

Patients received bendamustine 120 mg/m2intravenously on days 1 and 2 of each 21-day cycle. Outcomes included response, duration of response, progression-free survival, and safety.

Results

Seventy-six patients, ages 38 to 84 years, with predominantly stage III/IV indolent (80%) or transformed (20%) disease were treated; 74 were assessable for response. Twenty-four (32%) were refractory to chemotherapy. Patients received a median of two prior unique regimens. An overall response rate of 77% (15% complete response, 19% unconfirmed complete response, and 43% partial) was observed. The median duration of response was 6.7 months (95% CI, 5.1 to 9.9 months), 9.0 months (95% CI, 5.8 to 16.7) for patients with indolent disease, and 2.3 months (95% CI, 1.7 to 5.1) for those with transformed disease. Thirty-six percent of these responses exceeded 1 year. The most frequent nonhematologic adverse events included nausea and vomiting, fatigue, constipation, anorexia, fever, cough, and diarrhea. Grade 3 or 4 reversible hematologic toxicities included neutropenia (54%), thrombocytopenia (25%), and anemia (12%).

Conclusion

Single-agent bendamustine produced durable objective responses with acceptable toxicity in heavily pretreated patients with rituximab-refractory, indolent NHL. These findings are promising and will serve as a benchmark for future clinical trials in this novel patient population.

Biology and therapy of mantle cell lymphoma

PURPOSE OF REVIEW

Mantle cell lymphoma is an aggressive non-Hodgkin's lymphoma characterized by the t(11;14) chromosomal translocation and overexpression of cyclin D1. Constituting approximately 5 to 8% of all non-Hodgkin's lymphomas, it carries the poorest prognosis among non-Hodgkin's lymphoma subtypes. Standard and effective treatment approaches have yet to be established.

RECENT FINDINGS

Several recent insights regarding the molecular pathogenesis and prognostic biomarkers have been realized by way of comparative genomic hybridization, cDNA microarray, and proteomic analysis. Clinical trials using chemotherapy plus rituximab have shown improved response rates, including complete remissions, but without cure in most cases, indicating a clear need for new treatment approaches. Novel therapies for relapsed disease using the proteasome inhibitor bortezomib, thalidomide plus rituximab, the cyclin inhibitor flavopiridol, or inhibitors of the mammalian target of rapamycin (mTOR) have shown encouraging clinical responses. Stem cell transplantation, including nonmyeloablative approaches, are being incorporated into therapeutic regimens and show promise in both the front-line and relapsed/refractory settings.

SUMMARY

This review summarizes recent advances in the biology, pathogenesis, and therapy of mantle cell lymphoma and identifies ongoing areas of clinical investigation and new treatment approaches.

Relapse in common lymphoma subtypes: salvage treatment options for follicular lymphoma, diffuse large cell lymphoma and Hodgkin disease

Over the last decade diagnostic techniques such as immunophenotyping as well as cytogenetic and molecular profiling gave new insights into the pathogenesis of malignant lymphoma and helped to establish the WHO classification. The recognition of well-defined biological entities with distinct response and relapse patterns led to the development of more specific treatment strategies for individual lymphoma subtypes. New treatment modalities such as the monoclonal antibody rituximab have improved the results of first-line treatment of patients with certain B-cell lymphoma subtypes substantially. Furthermore, new prognostic factors were described for different lymphoma entities leading to further differentiation of treatment. As a consequence, the quality of relapse after first-line therapy has changed and treatment strategies for relapsed disease need to be redefined. This review summarises current salvage treatment options for common lymphoma subtypes taking into account variables which should be considered before an individual patient is treated. We focus on follicular lymphoma, diffuse large B-cell lymphoma and Hodgkin disease since these are most frequent and evidence-based salvage strategies are beginning to emerge.