Bendamustine hydrochloride in patients with refractory soft tissue sarcoma: a noncomparative multicenter phase 2 study of the German sarcoma group (AIO-001)

Feasibility and Efficacy of Partially Replacing Post-Transplantation Cyclophosphamide with Bendamustine in Pediatric and Young Adult Patients Undergoing Haploidentical Bone Marrow Transplantation

Post-transplantation cyclophosphamide (PT-CY) is the most widely applied graft-versus-host disease (GVHD) prophylaxis regimen in T-cell replete haploidentical bone marrow transplantation (haplo-BMT). Although PT-CY has met with great success in the haplo-BMT arena by suppressing GVHD, patients without acute GVHD have high relapse rates. One strategy to reduce relapse rates being explored by others is a dosage reduction of PT-CY. We have taken a different approach in evaluating whether partially replacing PT-CY with post-transplantation bendamustine (PT-BEN) would be advantageous, an idea based on our preclinical research identifying several beneficial immunomodulatory properties of BEN. We therefore initiated and completed a Phase Ia trial to evaluate the progressive substitution of PT-CY with PT-BEN (ClinicalTrials.gov identifier NCT02996773). We compared outcomes between 13 patients with high-risk hematologic malignancies who received PT-CY/BEN and 31 contemporaneous haplo-BMT recipients treated with the same myeloablative conditioning regimens but receiving only PT-CY. We found that partial replacement of PT-CY with PT-BEN (PT-CY/BEN) on day +4 was well tolerated and associated with significantly earlier trilineage engraftment. We also report favorable trends toward significant improvements on univariate and multivariate analyses with PT-CY/BEN compared with PT-CY with respect to rates of chronic GVHD (hazard ratio [HR], .08; 95% confidence interval [CI], .005 to 1.11; P = .06), and GVHD-free relapse-free survival (GRFS) (HR, .22; 95% CI, .05 to .86; P = .039). Our human trial has now transitioned to Phase Ib, which will further evaluate the safety and potential benefits of PT-CY/BEN. Herein we also expand our pediatric, adolescent, and young adult experience to 31 patients, demonstrating overall survival, progression-free survival, and GRFS at 3 years of 85.6%, 76.1%, and 58.2%, respectively, in a largely racial/ethnic minority cohort. PT-CY/BEN appears to be a promising treatment option that requires further evaluation.

Bendamustine: A review of pharmacology, clinical use and immunological effects (Review)

Bendamustine is an alkylating agent classified into the group of nitrogen mustard analogues, synthesized almost sixty years ago. It was registered in former East Germany in 1971 and approved by the US Food and Drug Administration in 2008 for treatment of chronic lymphocytic leukemia and indolent B-cell non-Hodgkin lymphoma. Considering its beneficial properties in the therapy of relapsed or refractory hematological malignancies, synergistic effects with other antineoplastic agents and increasing recent reports on its immunomodulatory effects, bendamustine has once again gained its justified attention. The uniqueness of bendamustine-mediated effects should be observed keeping in mind its distinctive structure with structural similarities to both alkylating agents and purine analogs. In the present review, the current knowledge on the use of bendamustine in oncology, its pharmacokinetics, mechanism of action and toxicity was summarized. In addition, its immune-modulating effects that have not been fully elucidated so far are emphasized, hoping to encourage further investigations of this unique drug.

The first-in-class alkylating deacetylase inhibitor molecule tinostamustine shows antitumor effects and is synergistic with radiotherapy in preclinical models of glioblastoma

Background

The use of alkylating agents such as temozolomide in association with radiotherapy (RT) is the therapeutic standard of glioblastoma (GBM). This regimen modestly prolongs overall survival, also if, in light of the still dismal prognosis, further improvements are desperately needed, especially in the patients with O6-methylguanine-DNA-methyltransferase (MGMT) unmethylated tumors, in which the benefit of standard treatment is less. Tinostamustine (EDO-S101) is a first-in-class alkylating deacetylase inhibitor (AK-DACi) molecule that fuses the DNA damaging effect of bendamustine with the fully functional pan-histone deacetylase (HDAC) inhibitor, vorinostat, in a completely new chemical entity.

Methods

Tinostamustine has been tested in models of GBM by using 13 GBM cell lines and seven patient-derived GBM proliferating/stem cell lines in vitro. U87MG and U251MG (MGMT negative), as well as T98G (MGMT positive), were subcutaneously injected in nude mice, whereas luciferase positive U251MG cells and patient-derived GBM stem cell line (CSCs-5) were evaluated the orthotopic intra-brain in vivo experiments.

Results

We demonstrated that tinostamustine possesses stronger antiproliferative and pro-apoptotic effects than those observed for vorinostat and bendamustine alone and similar to their combination and irrespective of MGMT expression. In addition, we observed a stronger radio-sensitization of single treatment and temozolomide used as control due to reduced expression and increased time of disappearance of γH2AX indicative of reduced signal and DNA repair. This was associated with higher caspase-3 activation and reduction of RT-mediated autophagy. In vivo, tinostamustine increased time-to-progression (TTP) and this was additive/synergistic to RT. Tinostamustine had significant therapeutic activity with suppression of tumor growth and prolongation of DFS (disease-free survival) and OS (overall survival) in orthotopic intra-brain models that was superior to bendamustine, RT and temozolomide and showing stronger radio sensitivity.

Conclusions

Our data suggest that tinostamustine deserves further investigation in patients with glioblastoma.

Electronic supplementary material

The online version of this article (10.1186/s13045-018-0576-6) contains supplementary material, which is available to authorized users.

The PARP Inhibitor Veliparib Can Be Safely Added to Bendamustine and Rituximab and Has Preliminary Evidence of Activity in B-Cell Lymphoma

Purpose: The PARP inhibitor veliparib enhances the cytotoxicity of alkylating agents. This phase I study evaluated veliparib with the bifunctional alkylator bendamustine (VB) in patients with relapsed/refractory lymphoma, multiple myeloma, and solid malignancies, with a cohort expansion of VB with rituximab (VBR) in patients with B-cell lymphomas.Experimental Design: This dose-escalation study evaluated safety, pharmacokinetics, and preliminary efficacy of veliparib (20-400 mg twice a day, days 1-7 of 28-day cycle) and bendamustine (70 and 90 mg/m² intravenously, days 1 and 2). A cohort expansion was conducted, which combined veliparib and bendamustine at the maximum tolerated dose (MTD) with rituximab (375 mg/m², day 1) in patients with B-cell lymphomas. Thirty-four patients were treated in seven dose-escalation cohorts and seven patients in the dose-expansion cohort.Results: The MTD was veliparib 300 mg twice daily plus bendamustine 90 mg/m² Dose-limiting toxicities (DLT) were anemia, nausea, hypertension, and hyperhidrosis. Grade ≥3 toxicities included lymphopenia (87.8%), anemia (19.5%), neutropenia (12.2%), thrombocytopenia (9.8%), leukopenia (9.8%), nausea (7.3%), and hypophosphatemia (7.3%). Apparent veliparib clearance was slightly lower than previously reported. Of 14 patients with lymphoma evaluable for response, five of seven (71%) on VB and six of seven (86%) on VBR achieved objective response. One patient with multiple myeloma achieved partial response.Conclusions: VB and VBR were generally well-tolerated. VBR had preliminary clinical activity in patients with B-cell lymphoma, which warrants further investigation in a phase II trial. This trial was registered at www.clinicaltrials.gov as NCT01326702 Clin Cancer Res; 23(15); 4119-26. ©2017 AACR.

Follicular dendritic cell sarcoma treated with a variety of chemotherapy

Follicular dendritic cell sarcoma (FDCS) is a very rare malignant tumor derived from follicular dendritic cells. Radical resection is the standard therapy for patients with local disease, but an optimal chemotherapy regimen has not been determined for unresectable disease. We report our experience of an FDCS patient with multiorgan involvement. In the present case, disease was only located in the pancreas initially and radical resection was performed. Multiple metastasis developed after the treatment and several factors that indicated a poor prognosis were observed. The present case had a very poor prognostic disease but survived for a long time with a good performance status because of the multiple chemotherapy regimens, which follow therapeutic strategies for malignant lymphoma and soft tissue sarcoma. As far as we know, this is the first study reporting the indication of bendamustine for FDCS patients.

Determination of Bendamustine in Human Plasma and Urine by LC-FL Methods: Application in a Drug Monitoring

Simple and sensitive liquid chromatography (LC) methods with fluorescence (FL) detection for the determination of bendamustine (BM) in human plasma and urine were developed and validated. The procedure of BM extraction from a plasma sample involved solid-phase extraction with a C18 SPE column, while liquid–liquid extraction with dichloromethane was applied for a urine sample. In both methods, cinoxacin was used as the internal standard. Chromatographic separations were performed on a Synergi Max-RP column, while FL detector was set at the excitation wavelength of 328 nm and the emission wavelength of 420 nm. The LC-FL methods were validated for accuracy, precision, selectivity, linearity, recovery, and stability. The detection limits for BM were 0.5 and 2.5 ng mL⁻¹ in plasma and urine, respectively. The intra-day and inter-day precisions were less than 9.86 %, while the accuracies were higher than 92.63 and 94.29 % for BM in plasma and urine, respectively. The proposed LC-FL methods were sensitive, robust, and specific, allowing reliable drug quantification in plasma and urine samples. The methodologies were successfully applied to monitoring of BM in a child with cancer treated with BM.

Topotecan plus cyclophosphamide in adults with relapsed or refractory pediatric-type sarcoma: a retrospective analysis from the German Sarcoma Medical Oncology Group (AIO)

BACKGROUND

To assess the efficacy and safety of topotecan and cyclophosphamide (TC) in adult patients with pediatric-type sarcoma subtypes who failed induction chemotherapy.

PATIENTS AND METHODS

Patients with pediatric sarcoma subtypes, refractory to or relapsed after at least one prior induction chemotherapy, inoperable, ECOG PS 0-2, with measurable, progressive disease (PD), adequate organ functions, who have been treated with TC combination were retrospectively analysed within the AIO and SAREZ/BMBF network.

RESULTS

Thirty-nine patients, median age 28 years (18-58), 14 females, 25 males, have been identified. All patients had received induction treatment according to (inter)national study protocols. Second-line TC was applied in 33 patients (≥3rd-line in 6 patients). Twenty-three patients had refractory disease (evidence of PD during induction chemotherapy); 8 patients experienced an early relapse within 6 months as well as 8 patients after more than 24 months (late relapse). A median of 3 cycles (range, 1-6) had been applied and antitumor activity was: CR 2.6 %, PR 7.9 %, and disease stabilisation (SD) 26.3 %. PR lasted 32.8 months and median duration in patients with SD was 5 months (range, 2.0-14.7). The 3/6-months progression-free rates were 43.2 and 18.9 %.

CONCLUSIONS

Limited activity was seen in adult pts with refractory or relapsed pediatric-type sarcomas with the regimen which has proven activity in pediatric patients. Adults with refractory small cell sarcoma appear to have a similar dismal outcome as seen in pts with common adult-type histologies; however, a subset of patients has achieved long-lasting remissions on TC resulting in long-term survival.

An old drug with a new future: bendamustine in multiple myeloma

INTRODUCTION

Bendamustine is a unique bifunctional alkylating agent with promising activity in multiple myeloma (MM). It is currently licensed in Europe for use as frontline treatment with prednisolone for patients with MM who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib therapy.

AREAS COVERED

Studies evaluating the safety and efficacy of bendamustine administered alone or in combination in both the upfront and relapse settings of MM patients, including those with renal insufficiency, were reviewed. The use of bendamustine as conditioning for autologous stem-cell transplantation and the possibility of stem-cell mobilization after bendamustine therapy are discussed.

EXPERT OPINION

Bendamustine seems to be efficacious either in monotherapy or in combination with other drugs in previously treated or untreated patients. This is due to its unique mechanism of action including its ability to activate apoptosis and inhibit mitotic checkpoints, making it potentially more effective than other alkylating agents. Moreover, it has an acceptable toxicity profile and is suitable for patients with renal impairment. Finally, this drug does not seem to compromise the possibility of achieving a stem-cell mobilization. Nonetheless, data from Phase III studies demonstrating its effectiveness in terms of overall survival are not yet available.

Bendamustine overcomes resistance to melphalan in myeloma cell lines by inducing cell death through mitotic catastrophe

Melphalan has been a mainstay of multiple myeloma (MM) therapy for many years. However, following treatment with this alkylator, malignant plasma cells usually escape both apoptosis and cell cycle control, and acquire drug-resistance resulting in tumor progression. Bendamustine is being used in MM patients refractory to conventional DNA-damaging agents, although the mechanisms driving this lack of cross-resistance are still undefined. Here, we investigated the molecular pathway of bendamustine-induced cell death in melphalan-sensitive and melphalan-resistant MM cell lines. Bendamustine affected cell survival resulting in secondary necrosis, and prompted cell death primarily through caspase-2 activation. Also, bendamustine blocked the cell cycle in the G2/M phase and induced micronucleation, erratic chromosome spreading and mitotic spindle perturbations in melphalan-resistant MM cells. In these cells, both Aurora kinase A (AURKA) and Polo-like kinase-1 (PLK-1), key components of the spindle-assembly checkpoint, were down-regulated following incubation with bendamustine, whereas levels of Cyclin B1 increased as a consequence of the prolonged mitotic arrest induced by the drug. These findings indicate that, at least in vitro, bendamustine drives cell death by promoting mitotic catastrophe in melphalan-resistant MM cells. Hence, activation of this alternative pathway of cell death may be a novel approach to the treatment of apoptosis-resistant myelomas.

Pemetrexed in patients with refractory soft tissue sarcoma: a non-comparative multicenter phase II study of the German Sarcoma Group AIO-STS 005

BACKGROUND

This study evaluated efficacy and safety of pemetrexed in patients with refractory soft tissue sarcoma.

METHODS

Patients received pemetrexed intravenously at a dose of 500 mg/m² every 21 days until progression or unacceptable toxicity. The primary endpoint was objective tumor response.

RESULTS

Fourty-eight of 53 screened patients were included and received a total of 200 cycles (median 2; range 1-30). Median age was 53 years (range, 20-81). The observed toxicity profile was favorable. NCI-CTC hematologic grade 3/4 toxicity consisted of neutropenia in 13 %, anemia in 15 %, and febrile neutropenia in 4 % of patients of patients, respectively. Non-hematologic CTC grade 3/4 toxicity consisted of elevated ASAT/ALAT in 10 %, hyperglycemia in 6 %, infection with or without neutropenia in 6 %, nausea in 2 % and stomatitis in 2 % of patients. No other grade 3 toxicities and no treatment-related toxic deaths were observed. Overall response as defined by RECIST was 5 %, 16 patients experienced stable disease (40 %). The estimated 3- and 6-months progression-free rates were 33.3 % and 14.6 %, respectively.

CONCLUSIONS

In patients with refractory STS, pemetrexed is well tolerated and moderately effective. The confirmed objective response rate in STS is low, however, disease stabilizations are seen in a high proportion of patients (ClinicalTrials.gov NCT00427466).

Bendamustine: a new treatment option for chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a slow-growing hematologic malignancy and the most common type of leukemia in the western world. The lifetime risk for developing CLL is 1 in 216 men and women. Unfortunately, CLL is considered incurable with the chemotherapeutic agents available today. Bendamustine is a new agent that was recently added to the available regimens for the treatment of CLL. It was also recently approved for the treatment of non-Hodgkin's lymphoma. Its mechanism of action is unknown, but it contains an alkylating group similar to that of other bifunctional alkylating agents such as chlorambucil, and it also contains a benzimidazole central ring thought to exhibit antipurine-like properties. The United States Food and Drug Administration approved bendamustine based on results from an international phase III study of CLL in which bendamustine was compared with chlorambucil in treatment-naïve patients. Ongoing clinical trials are assessing the utility of bendamustine in combination with other agents for the treatment of CLL, as well as for other malignancies.

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.

Sarcoma in the young adult population: an international view

The outcomes in young adults aged 20-39 with sarcoma tend to be inferior compared to those in children and adolescents. There are differences in sarcoma histotype distribution with age, such that pediatric-type tumors predominate in the 20- to 25-year-old group while more adult-type sarcomas occur in those aged 35-39 years. Certain occupational exposures, co-infection with human herpes virus 8 (HHV-8) and human immunodeficiency virus (HIV), prior radiation exposure, and genetic syndromes are relevant risk factors. In many of the types of sarcoma encountered in 20 to 39 year olds, there are important biological differences compared to the tumors in younger patients that play a role in the outcomes for these patients. Increased research into these differences and incorporating our knowledge about them into treatments tailored towards this age group is necessary to overcome the relatively poor outcomes in young adult sarcoma patients.

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.

Treatment of soft tissue sarcoma: a European approach

This article discusses the treatment of adult soft tissue sarcoma (excluding gastrointestinal stromal tumor), analyzing the principles underlying treatment and the results of surgery, radiotherapy, and chemotherapy. The focus is on the European approach in particular, and ongoing studies are summarized.

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.

Potential combination chemotherapy approaches for advanced adult-type soft-tissue sarcoma

Soft-tissue sarcomas (STS) include a spectrum of histologically and clinically different tumors. Patients with these tumors are typically relatively young and the course of disease is characterized by early metastasis as well as limited response to chemotherapy. However, a few subtypes, such as small round-cell tumors and rhabdomyosarcoma (other than pleomorphic), are considered chemotherapy sensitive. In addition, reflecting successful translational research of recent years, gastrointestinal stromal tumor and dermatofibrosarcoma protuberans have become model diseases for targeted oncologic therapy. We summarize current treatment options for metastatic STS, including established first-line chemotherapy approaches, mainly with anthracyclines and/or ifosfamide and second-line treatment choices beyond anthracyclines. Until only a few years ago, treatment choices for metastatic STS were easy to review because of the very limited number of active compounds available. However, with the advent of novel therapeutic strategies such as the anti-angiogenic approach and a multitude of novel compounds available both outside and within clinical studies, it has potentially become more difficult to keep track of currently available treatment options for STS and their clinical safety and efficacy. In this practice-oriented article, we therefore review treatment goals in advanced STS and provide an overview of compounds with proven activity in this setting. Anthracyclines with or without ifosfamide are still considered standard of care for most STS subtypes, especially for high-grade tumors. There is no evidence-based recommendation regarding use of second-line treatment options. However, a number of established compounds, including dacarbazine/temozolomide, gemcitabine, taxanes, trofosfamide, DNA topoisomerase I inhibitors, DNA minor groove binders, and bendamustine have shown activity. Recently, trabectedin, a DNA minor groove binder initially isolated from a sea sponge, has proven effective and received European approval for use in treatment-refractory STS. In addition, novel compounds such as bevacizumab, multi-tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, imatinib, and the thrombospondin agonist ABT 510 represent attractive partners for the above-mentioned cytostatic agents, or may even be effective single agents in the clinically advanced setting. Novel combinations are being evaluated in clinical studies. In order to be successful, it may be necessary to combine not only different compounds but also different targets beyond the proliferation machinery of sarcoma cells such as tumor angiogenesis, the tumor stromal compartment, or tumor cell oncogene products.