Bevacizumab/Irinotecan. Un nouveau traitement actif dans les gliomes de haut grade récidivants : résultats préliminaires d’une étude multicentrique de l’Anocef

Cost-effectiveness analysis of the bevacizumab-irinotecan regimen in the treatment of primary glioblastoma multiforme recurrences

The purpose of the present study was to calculate the cost-effectiveness of the inclusion of the bevacizumab (BVZ) + irinotecan (CPT-11) regimen in the second-line of treatment for primary glioblastoma multiforme. A retrospective cohort study with a control group was performed in which the cost-effectiveness of a course of chemotherapy was calculated based on survival time and the incremental cost between the two lines of treatment. A total of 77 patients were included, 36 of who formed the BVZ/CPT-11 cohort. The median survival time for the non-BVZ control cohort was 13.23 months [95% confidence interval (CI), 11.79-14.68], while for the BVZ/CPT-11 treatment cohort, the median survival time was 17.63 months (95% CI, 15.38-19.89). Overall, each year of life gained for each patient treated with BVZ/CPT-11 would cost €46,401.99. These results demonstrate the effectiveness of the BVZ/CPT-11 combination, but its incremental cost compared with other lines of treatment or the best care available does not appear to be acceptable for public health systems in the current situation of budgetary adjustments.

Current trends in the management of glioblastoma in a French University Hospital and associated direct costs

WHAT IS NEW AND OBJECTIVES

Trends in the care of glioblastoma in actual practice settings are poorly described. In a previous pharmacoepidemiologic study, we highlighted changes in the management of patients with glioblastoma (GBM) newly diagnosed between 2004 and 2008. Our aim was to complete and to extend the previous report with a study of a cohort of patients diagnosed in 2011 to emphasize the trends in the pharmacotherapy of GBM over the last decade.

METHODS

A single-centre study was undertaken of three historic cohorts of GBM patients newly diagnosed during years 2004, 2008 and 2011 (corresponding to groups 1, 2 and 3, respectively) but limited to patients eligible for radiotherapy after initial diagnosis. The type of medical management was described and compared, as well as overall survival and total cost from diagnosis to death or the last follow-up date. Cost analysis was performed from the French sickness fund perspective using tariffs from 2014.

RESULTS

Two hundred and seventeen patients (49 in Group 1, 73 in Group 2, 95 in Group 3) were selected with similar baseline characteristics. Fluorescence-guided surgery using 5-ALA was increasingly used over the three periods. There was a strong trend towards broader use of temozolomide radiochemotherapy (39%, 73% and 83% of patients, respectively) as first-line treatment as well as bevacizumab regimen at recurrence (6%, 48% and 58% of patients, respectively). The increase in overall survival between Group 2 and Group 1 was confirmed for patients in Group 3 (17·5 months vs. 10 months in Group 1). The mean total cost per patient was 53368 € in Group 1, 70 201 € in Group 2 and 78355 € in Group 3. Hospital care represented the largest expenditure (75%, 59% and 60% in groups 1, 2 and 3, respectively) followed by chemotherapy drug costs (11%, 30% and 29%, respectively).

WHAT IS NEW AND CONCLUSION

This is the first study to report on changes in the management of GBM in real-life practice. The ten-year study indicates an improvement in overall survival but also an increase in total cost of care. The data should be useful for informing the care of GBM patients in settings similar to ours.

Neurocognitive functions and health-related quality of life in glioblastoma patients: a concise review of the literature

The maintenance of quality of life in patients with high-grade glioma is an important endpoint during treatment, particularly in those with glioblastoma multiforme, given its dismal prognosis; thus, the primary aims of treatments are to reduce morbidity, restore or preserve neurological functions, and the capacity to perform daily activities. This review aims to summarise what is currently known about neurocognitive outcome and quality of life in patients with high-grade glioma, particularly in glioblastoma patients. We considered all the variables that can influence neurocognitive functions, the perception of quality of life and their role as predictors for treatment outcomes.

Anti-VEGF Therapy with Bevacizumab--limited cardiovascular toxicity

PURPOSE

This analysis was conducted to evaluate cardiovascular toxicity of commonly used anti-VEGF therapeutic agent, bevacizumab, in treating patients with cancer.

METHODS

Clinical studies evaluating the efficacy and safety of bevacizumab-based regimens on response and safety for patients with cancer were identified using a predefined search strategy, allowing cardiovascular toxicity and other side effects of treatment to be estimated.

RESULTS

In bevacizumab based regimens, 4 clinical studies including 282 patients with advanced cancer (including gliomas, cervical, breast and ovarian cancer) were considered eligible for inclusion. These bevacizumab-based regimens included docetaxel, irinitecan and carboplatin. Systematic analysis suggested that, of 282 patients treated by bevacizumab based regimens, hypertension and thrombo-embolism occurred in 2.5% (7/282), while only 3 patients reported cardiovascular events (1.1%). No treatment related death occurred in bevacizumab based treatment.

CONCLUSION

This systemic analysis suggests that bevacizumab based regimens are associated with reasonable and accepted cardiovascular toxicity when treating patients with gliomas, cervical, breast and ovarian cancer.

Bevacizumab and irinotecan in recurrent malignant glioma, a single institution experience

BACKGROUND

Treatment options of recurrent malignant gliomas are very limited and with a poor survival benefit. The results from phase II trials suggest that the combination of bevacizumab and irinotecan is beneficial.

PATIENTS AND METHODS

The medical documentation of 19 adult patients with recurrent malignant gliomas was retrospectively reviewed. All patients received bevacizumab (10 mg/kg) and irinotecan (340 mg/m(2) or 125 mg/m(2)) every two weeks. Patient clinical characteristics, drug toxicities, response rate, progression free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

Between August 2008 and November 2011, 19 patients with recurrent malignant gliomas (median age 44.7, male 73.7%, WHO performance status 0-2) were treated with bevacizumab/irinotecan regimen. Thirteen patients had glioblastoma, 5 anaplastic astrocytoma and 1 anaplastic oligoastrocytoma. With exception of one patient, all patients had initially a standard therapy with primary resection followed by postoperative chemoradiotherapy. Radiological response was confirmed after 3 months in 9 patients (1 complete response, 8 partial responses), seven patients had stable disease and three patients have progressed. The median PFS was 6.8 months (95% confidence interval [CI]: 5.3-8.3) with six-month PFS rate 52.6%. The median OS was 7.7 months (95% CI: 6.6-8.7), while six-month and twelve-month survival rates were 68.4% and 31.6%, respectively. There were 16 cases of hematopoietic toxicity grade (G) 1-2. Non-hematopoietic toxicity was present in 14 cases, all G1-2, except for one patient with proteinuria G3. No grade 4 toxicities, no thromboembolic event and no intracranial hemorrhage were observed.

CONCLUSIONS

In recurrent malignant gliomas combination of bevacizumab and irinotecan might be an active regimen with acceptable toxicity.

The impact of bevacizumab treatment on survival and quality of life in newly diagnosed glioblastoma patients

Glioblastoma multiforme (GBM) remains one of the most devastating tumors, and patients have a median survival of 15 months despite aggressive local and systemic therapy, including maximal surgical resection, radiation therapy, and concomitant and adjuvant temozolomide. The purpose of antineoplastic treatment is therefore to prolong life, with a maintenance or improvement of quality of life. GBM is a highly vascular tumor and overexpresses the vascular endothelial growth factor A, which promotes angiogenesis. Preclinical data have suggested that anti-angiogenic treatment efficiently inhibits tumor growth. Bevacizumab is a humanized monoclonal antibody against vascular endothelial growth factor A, and treatment has shown impressive response rates in recurrent GBM. In addition, it has been shown that response is correlated to prolonged survival and improved quality of life. Several investigations in newly diagnosed GBM patients have been performed during recent years to test the hypothesis that newly diagnosed GBM patients should be treated with standard multimodality treatment, in combination with bevacizumab, in order to prolong life and maintain or improve quality of life. The results of these studies along with relevant preclinical data will be described, and pitfalls in clinical and paraclinical endpoints will be discussed.

Bevacizumab Use for Recurrent High-Grade Glioma at McGill University Hospital

Background:

Bevacizumab, a humanized recombinant anti-vascular endothelial growth factor antibody, was approved in Canada in 2010 for the treatment of high-grade glioma. We report the effectiveness and safety of bevacizumab in the treatment of patients with recurrent high-grade gliomas at a single institution.

Methods:

Twenty-seven consecutive patients with high-grade glioma (anaplastic glioma and glioblastoma) at first or subsequent relapse were treated with bevacizumab alone or in combination with chemotherapy. The primary endpoint was progression-free survival (PFS) and secondary endpoints were objective response rate, six month PFS, overall survival (OS), and safety profile.

Results:

The clinical benefit rate (complete and partial responses plus stable disease) was 59%. Median PFS was 4.3 (95% CI, 3.0-10.9) months, with a six month PFS rate of 43%. Median OS after current relapse was 8.9 (95% CI, 5.8-not reached) months. Ten episodes of grade 3/4 adverse events were observed in nine patients, including fatigue (n = 3), thrombocytopenia (n = 4), and myelotoxicity, febrile neutropenia, and pulmonary embolism (each n = 1).

Conclusions:

We consider the efficacy and safety profile of bevacizumab is comparable to other cohorts of patients treated for recurrent high-grade glioma at other international institutions.

Management of glioblastoma: comparison of clinical practices and cost-effectiveness in two cohorts of patients (2008 versus 2004) diagnosed in a French university hospital

WHAT IS KNOWN AND OBJECTIVE

Therapeutic options for the management of glioblastoma (GBM) have greatly evolved over the last decade with the emergence of new regimens combining radiotherapy plus temozolomide and the use of bevacizumab at recurrence. Our aim was to assess the clinical and economic impacts of those novel strategies in our center.

METHODS

A single-center retrospective chart review was conducted on patients newly diagnosed with a GBM over two periods (year 2004, group 1 or year 2008, group 2) with limitations to those eligible to radiotherapy after initial diagnosis. The type of medical management was described and compared, as well as overall survival and total costs from diagnosis to death or the last follow-up date. Cost analysis was performed under the French Sickness Fund perspective using tariffs from 2012.

RESULTS

One hundred twenty-two patients were selected (49 in group 1 and 73 in group 2) with similar baseline characteristics within the two groups. Patients from group 2 received more frequently temozolomide radiochemotherapy (71% vs. 39%, P < 0·05) as first-line treatment as well as bevacizumab regimen at recurrence (48% vs. 6%, P < 0·05); the median overall survival was increased between the two periods (respectively 17 vs. 10 months, P < 0·05). The mean total cost per patient was 54,388 € in group 1 and 71,148 € in group 2 (P < 0·05). Hospital care represented the largest expenditure (76% and 58% in groups 1 and 2 respectively) followed by chemotherapy drugs costs (11% and 30% respectively). The total cost difference between the two groups was explained by the increasing use of temozolomide and bevacizumab. The incremental cost-effectiveness ratio was estimated at 54,355 € per life-year gained.

WHAT IS NEW AND CONCLUSION

As far as we know, this is the first study reporting the total cost of GBM management based on the French perspective, as well as the cost-effectiveness of clinical practices in term of cost per life-year gained. Those novel strategies have contributed to improve overall survival while inducing a substantial, but acceptable, increase of total costs.

Circulating fibrocytes stabilize blood vessels during angiogenesis in a paracrine manner

Accumulating evidence supports that circulating fibrocytes play important roles in angiogenesis. However, the specific role of fibrocytes in angiogenesis and the underlying mechanisms remain unclear. In this study, we found that fibrocytes stabilized newly formed blood vessels in a mouse wound-healing model by inhibiting angiogenesis during the proliferative phase and inhibiting blood vessel regression during the remodeling phase. Fibrocytes also inhibited angiogenesis in a Matrigel mouse model. In vitro study showed that fibrocytes inhibited both the apoptosis and proliferation of vascular endothelial cells (VECs) in a permeable support (Transwell) co-culture system. In a three-dimensional collagen gel, fibrocytes stabilized the VEC tubes by decreasing VEC tube density on stimulation with growth factors and preventing VEC tube regression on withdrawal of growth factors. Further mechanistic investigation revealed that fibrocytes expressed many prosurvival factors that are responsible for the prosurvival effect of fibrocytes on VECs and blood vessels. Fibrocytes also expressed angiogenesis inhibitors, including thrombospondin-1 (THBS1). THBS1 knockdown partially blocked the fibrocyte-induced inhibition of VEC proliferation in the Transwell co-culture system and recovered the fibrocyte-induced decrease of VEC tube density in collagen gel. Purified fibrocytes transfected with THBS1 siRNA partially recovered the fibrocyte-induced inhibition of angiogenesis in both the wound-healing and Matrigel models. In conclusion, our findings reveal that fibrocytes stabilize blood vessels via prosurvival factors and anti-angiogenic factors, including THBS1.

Factors influencing quality of life in adult patients with primary brain tumors

We performed a literature review with respect to factors influencing health-related quality of life (QOL) in adults with primary brain tumors. A comprehensive, peer-reviewed literature search was performed including studies examining QOL in adults with high-grade gliomas and low-grade gliomas and in routine neuro-oncology practice. The interpretation and implication of QOL domain scores may be different in high-grade, low-grade, and benign brain tumors. Several patient-related, treatment-related, and sociocultural factors influence QOL scores. Pretreatment baseline QOL domain scores have been shown to be a predictive parameter for survival function. Implementation of QOL scores in routine clinical practice is underused. QOL is an important outcome measure in the treatment of patients with brain tumors and should be incorporated as a surrogate end point along with traditional end points, such as disease-free and overall survival in most current trials.

Limited impact of prognostic factors in patients with recurrent glioblastoma multiforme treated with a bevacizumab-based regimen

Bevacizumab has demonstrated activity in patients with recurrent glioblastoma. However, the impact of prognostic factors associated with recurrent glioblastoma treated with cytotoxic agents has not been determined in patients treated with bevacizumab. To analyze the prognostic factors and clinical benefits of bevacizumab and irinotecan treatment in patients with recurrent glioblastoma. This monocentric study retrospectively analyzed all patients with recurrent glioblastoma who were treated with at least one cycle of bevacizumab and irinotecan at our institution from April 2007 to May 2010. Multivariate analysis was used to analyze prognostic factors for overall survival (OS) from the initiation of bevacizumab administration. Among the 100 patients that were identified (M/F: 65/35), the median age was 57.9 years (range: 18-76). Karnofsky Performance Status (KPS) was <70 in 44 patients and ≥ 70 in 56 patients; 83 % of the patients were on steroids. The median tumor area was 2012 mm². The median progression free survival was 3.9 months (CI 95 %: 3.4-4.3). The median OS was 6.5 months (CI 95 %: 5.6-7.4). Multivariate analysis revealed that OS was affected by KPS (p = 0.024), but not by gender, age, steroid treatment, number of previous lines of treatment, tumor size, or time from initial diagnosis. KPS was improved in 30 patients, including 14/44 patients with an initial KPS <70. The median duration of maintained functional independence (KPS ≥ 70) was 3.75 months (CI 95 %: 2.9-4.6). The median OS from initial diagnosis was 18.9 months (CI 95 %: 17.5-20.3). In patients with recurrent glioblastoma treated with bevacizumab, KPS was revealed as the only factor to impact OS. The clinical benefits associated with this regimen appear valuable. A positive impact of bevacizumab administration on OS of patients with glioblastoma multiforme is suggested.

Bevacizumab for the treatment of glioblastoma

Glioblastoma (GBM) or grade IV glioma is the most common primary brain tumor in adults. Standard treatment median overall survival (OS) is only 14–15 months and less than 10% of patients will survive 5 years after diagnosis. There is no standard treatment in recurrent GBM and OS ranges from 3 to 9 months. GBM is 1 of the most vascularized human tumors and GBM cells produce vascular endothelial growth factor (VEGF). Bevacizumab, a humanized monoclonal antibody against VEGF, has demonstrated activity in vitro and in phase II trials in relapse, as well as in 1 phase III trial as first line therapy. Bevacizumab also improves quality of life for patients suffering GBM. This paper reviews the mechanism of action of bevacizumab, its metabolism and pharmacokinetic profile. It summarizes the clinical studies in recurrent and newly diagnosed GBM, its potential side effects and complications and its place in therapy.

Reversible posterior leukoencephalopathy syndrome associated with concurrent bevacizumab, gemcitabine, and oxaliplatin for cholangiocarcinoma

INTRODUCTION

Reversible posterior leukoencephalopathy syndrome (RPLS) is a rare disorder characterized by altered mental status, seizure, hypertension, and symmetrical white matter edema (leukoencephalopathy) typically in the posterior cerebral hemispheres on brain imaging. It is often linked to certain medication use, in particular, chemotherapeutic agents. Here, we present a case of chemotherapy-related RPLS and review the current literature on this topic.

CASE REPORT

We report a case of RPLS associated with concurrent bevacizumab (Avastin), gemcitabine, and oxaliplatin use for unresectable intrahepatic cholangiocarcinoma.

CONCLUSION

This is the first reported case of RPLS associated with bevacizumab, gemcitabine, and oxaliplatin combination chemotherapy. Concurrent use of multiple agents could significantly increase the risk of RPLS, a potentially fatal disease. Our case suggests that gradual progression of hypertension and proteinuria may be early warning signs before the onset of RPLS that should alarm clinicians.

Effectiveness of the bevacizumab-irinotecan regimen in the treatment of recurrent glioblastoma multiforme: Comparison with other second-line treatments without this regimen

A retrospective cohort study was conducted to analyse the effectiveness of bevacizumab and irinotecan (BVZ/CPT-11) as a second-line treatment in patients with primary glioblastoma multiforme (GBM) in comparison with a control group that were not administered BVZ/CPT-11 at the first recurrence. The difference in overall survival (OS) between the two groups was used as a predictor of effectiveness. OS was calculated according to prognostic factors and gender. A total of 28 and 32 patients were enrolled in the BVZ/CPT-11 cohort and control group, respectively. The median OS was 17.94 months (95% CI, 14.91-20.96) in the BVZ/CPT-11 treatment cohort and 10.97 months (95% CI, 7.65-14.30) in the control cohort. The results obtained on the effectiveness of BVZ/CPT-11 treatment in patients with primary GBM are consistent with data from previous studies. No significant differences were identified in OS based on prognostic factors; therefore, the latter cannot be used to select patients who would incur the greatest benefits from BVZ/CPT-11 treatment.

Discontinuing bevacizumab in patients with glioblastoma: an ethical analysis

Glioblastoma (GBM) is a highly lethal malignant brain tumor that expresses proangiogenic factors, including vascular endothelial growth factor (VEGF). Bevacizumab (Avastin®; Genentech, Inc., South San Francisco, CA), a monoclonal antibody against VEGF, is routinely used in the U.S. to treat GBM patients whose tumors have progressed following initial therapy. The Ethics Advisory Committee at the Dana-Farber Cancer Institute was asked to provide consultation on two cases involving patients with recurrent GBM who were receiving bevacizumab. Despite evidence of disease progression, family members advocated for the continued use of bevacizumab because of its mild toxicity profile and concern that discontinuation would impair quality of life. However, continuing bevacizumab in this setting posed physical and financial risks to the patients and raised ethical concerns about resource allocation and justice. We analyze the ethical questions regarding bevacizumab discontinuation in the setting of progressive GBM. We articulate the potential benefits and harms of continuing the drug and identify guiding principles for drug discontinuation that should be made transparent to patients and families. With the increasing availability of new, modestly toxic, expensive drugs for patients with advanced cancer, questions of when to stop these drugs will become increasingly relevant.

[Anti-angiogenic strategies in glioblastoma]

INTRODUCTION

Glioblastoma, a highly angiogenic tumor, has poor prognosis despite aggressive conventional therapies combining surgery, chemotherapy and radiotherapy. Anti-angiogenic strategies that have recently come to the clinic, are the most promising therapeutic approaches for these tumors.

STATE OF ART

Tumor hypoxia is the main trigger of angiogenesis processes driven primarily by vascular endothelial growth factor (VEGF). Clinical data indicate that inhibitors of VEGF such as bevacizumab or VEGF receptors such as tyrosine kinase inhibitors are of potential interest in the treatment of recurrent glioblastoma, with an acceptable toxicity. However, despite high rate of initial radiological response and rapid clinical improvement in about half of patients, therapeutic failure is the rule. Mechanisms of resistance remain poorly understood but an invasive phenotype and alternative angiogenesis factors may contribute to tumor escape.

CONCLUSIONS AND PERSPECTIVES

Anti-angiogenic strategies already play an important role in the management of recurrent glioblastoma. However, optimal combination and schedules of angiogenic inhibitors with radiotherapy and chemotherapy remain to be established. Important randomized clinical trials currently investigate therapeutic combinations for newly diagnosed glioblastoma.

Impact of therapy on quality of life, neurocognitive function and their correlates in glioblastoma multiforme: a review

The maintenance of quality of life (QoL) in patients with high-grade glioma is an important endpoint during treatment, particularly in those with glioblastoma multiforme (GBM) given its dismal prognosis despite limited advances in standard therapy. It has proven difficult to identify new therapies that extend survival in patients with recurrent GBM, so one of the primary aims of new therapies is to reduce morbidity, restore or preserve neurologic functions, and the capacity to perform daily activities. Apart from temozolomide, cytotoxic chemotherapeutic agents do not appear to significantly impact response or survival, but produce toxicity that is likely to negatively impact QoL. New biological agents, such as bevacizumab, can induce a clinically meaningful proportion of durable responses among patients with recurrent GBM with an acceptable safety profile. Emerging evidence suggests that bevacizumab produces an improvement or preservation of neurocognitive function in GBM patients, suggestive of QoL improvement, in most poor-prognosis patients who would otherwise be expected to show a sudden and rapid deterioration in QoL.

Vascular endothelial growth factor inhibitors in malignant gliomas

Glioblastomas are highly vascularized tumors. Treatment strategies targeting angiogenesis have demonstrated promising results in preclinical studies and clinical trials in patients with malignant gliomas. Anti-VEGF agents, either alone or in combination with chemotherapy, have been associated with reduction in vasogenic brain edema, and prolonged progression-free survival. Larger prospective clinical trials are needed to validate these results, and to assess the impact of these agents on overall survival. Unfortunately, antiangiogenic treatment inevitably fails in most patients. Further studies are needed to understand the molecular pathways that enable a tumor to evade antiangiogenic therapy.

[Systematic review of stereotactic radiotherapy for high-grade gliomas]

The purpose of this literature systematic review was the use of stereotactic radiotherapy in glioma. Research was performed in Medline/PubMed and associated references found in published articles without publication date limit. The quality of series is variable and many biases can be evidenced. Only two randomized trials have been published using stereotactic radiotherapy for up-front treatment. There is a lack of evidence of survival advantages to use this treatment at the time of diagnosis or relapse. There is also insufficient evidence regarding the benefice/harms in the use of stereotactic fractionated radiation therapy for patients with glioma. No recommendations can be enounced. Stereotactic irradiation as boost in primary diagnosed glioma or relapsed tumour is not associated with survival improvement. For relapsed patients, treatment needs to be discussed according to the other treatment options.

Effects of bevacizumab plus irinotecan on response and survival in patients with recurrent malignant glioma: a systematic review and survival-gain analysis

Background

The combination of bevacizumab and irinotecan is a new chemotherapy protocol increasingly used for recurrent malignant glioma. Results from phase II trials suggest this drug combination is beneficial to patients, but no conclusive comparisons between this and other treatment protocols have been published.

Methods

We performed a systematic review and survival gain analysis of phase II studies to evaluate the efficacy and safety of bevacizumab plus irinotecan treatment. To do this, we utilized a preexisting database from which the mean overall survival and response rate of patients could be predicted. Survival gain, which characterized the influence of treatment, was defined as the difference between observed and predicted mean overall survival. Response gain was calculated similarly.

Results

741 cohorts were enrolled in the database. Among them, 282 cohorts were based on recurrent adult HGG, mean reported median overall survival was 10.96 ± 8.4 months, and mean response rate was 18.9% ± 20.5. We found that compared with other treatment protocols, bevacizumab plus irinotecan largely improved response rates (P = 0.00002) and had a possible moderate effect on overall survival time (P = 0.024). Hemorrhage, thromboembolic complications, and gastrointestinal toxicities were the most frequently reported side effects.

Conclusion

The combination of bevacizumab and irinotecan might improve outcome in patients with recurrent malignant glioma. Randomized controlled trials are recommended to evaluate this treatment protocol and the additional value of irinotecan.

Cetuximab, bevacizumab, and irinotecan for patients with primary glioblastoma and progression after radiation therapy and temozolomide: a phase II trial

The aim of this clinical trial was to investigate safety and efficacy when combining cetuximab with bevacizumab and irinotecan in patients with recurrent primary glioblastoma multiforme (GBM). Patients were included with recurrent primary GBM and progression within 6 months of ending standard treatment (radiotherapy and temozolomide). Bevacizumab and irinotecan were administered IV every 2 weeks. The first 10 patients received bevacizumab 5 mg/kg, but this was increased to 10 mg/kg after interim safety analysis. Irinotecan dose was based on whether patients were taking enzyme-inducing antiepileptic drugs or not: 340 and 125 mg/m(2), respectively. Cetuximab 400 mg/m(2) as loading dose followed by 250 mg/m(2) weekly was administered IV. Forty-three patients were enrolled in the trial, of which 32 were available for response. Radiographic responses were noted in 34%, of which 2 patients had complete responses and 9 patients had partial responses. The 6-month progression-free survival probability was 30% and median overall survival was 29 weeks (95% CI: 23-37 weeks). One patient had lacunar infarction, 1 patient had multiple pulmonary embolisms, and 3 patients had grade 3 skin toxicity, for which 1 patient needed plastic surgery. One patient was excluded due to suspicion of interstitial lung disease. Three patients had deep-vein thrombosis; all continued on study after adequate treatment. Cetuximab in combination with bevacizumab and irinotecan in recurrent GBM is well tolerated except for skin toxicity, with an encouraging response rate. However, the efficacy data do not seem to be superior compared with results with bevacizumab and irinotecan alone.

Exciting new advances in neuro-oncology: the avenue to a cure for malignant glioma

Malignant gliomas are the most common and deadly brain tumors. Nevertheless, survival for patients with glioblastoma, the most aggressive glioma, although individually variable, has improved from an average of 10 months to 14 months after diagnosis in the last 5 years due to improvements in the standard of care. Radiotherapy has been of key importance to the treatment of these lesions for decades, and the ability to focus the beam and tailor it to the irregular contours of brain tumors and minimize the dose to nearby critical structures with intensity-modulated or image-guided techniques has improved greatly. Temozolomide, an alkylating agent with simple oral administration and a favorable toxicity profile, is used in conjunction with and after radiotherapy. Newer surgical techniques, such as fluorescence-guided resection and neuroendoscopic approaches, have become important in the management of malignant gliomas. Furthermore, new discoveries are being made in basic and translational research, which are likely to improve this situation further in the next 10 years. These include agents that block 1 or more of the disordered tumor proliferation signaling pathways, and that overcome resistance to already existing treatments. Targeted therapies such as antiangiogenic therapy with antivascular endothelial growth factor antibodies (bevacizumab) are finding their way into clinical practice. Large-scale research efforts are ongoing to provide a comprehensive understanding of all the genetic alterations and gene expression changes underlying glioma formation. These have already refined the classification of glioblastoma into 4 distinct molecular entities that may lead to different treatment regimens. The role of cancer stem-like cells is another area of active investigation. There is definite hope that by 2020, new cocktails of drugs will be available to target the key molecular pathways involved in gliomas and reduce their mortality and morbidity, a positive development for patients, their families, and medical professionals alike.

Progress on antiangiogenic therapy for patients with malignant glioma

Glioblastoma (GBM) is the most common primary brain tumor occurring in America. Despite recent advances in therapeutics, the prognosis for patients with newly diagnosed GBM remains dismal. As these tumors characteristically show evidence of angiogenesis (neovascularization) there has been great interest in developing anti-angiogenic therapeutic strategies for the treatment of patients with this disease and some anti-angiogenic agents have now been used for the treatment of patients with malignant glioma tumors. Although the results of these clinical trials are promising in that they indicate an initial therapeutic response, the anti-angiogenic therapies tested to date have not changed the overall survival of patients with malignant glioma tumors. This is due, in large part, to the development of resistance to these therapies. Ongoing research into key features of the neovasculature in malignant glioma tumors, as well as the general angiogenesis process, is suggesting additional molecules that may be targeted and an improved response when both the neovasculature and the tumor cells are targeted. Prevention of the development of resistance may require the development of anti-angiogenic strategies that induce apoptosis or cell death of the neovasculature, as well as an improved understanding of the potential roles of circulating endothelial progenitor cells and vascular co-option by tumor cells, in the development of resistance.

Bevacizumab and dose-intense temozolomide in recurrent high-grade glioma

BACKGROUND

Angiogenesis inhibition is a rational treatment strategy for high-grade glioma (HGG). Combined antiangiogenic therapy and chemotherapy could be beneficial, taking advantage of different mechanisms of antitumour activity of both therapies. We carried out a phase I-II clinical trial with the combination of bevacizumab and continuous dose-intense temozolomide (TMZ) for patients with a recurrent HGG after first- or second-line treatment.

PATIENTS AND METHODS

Twenty-three HGG patients were treated with bevacizumab (10 mg/kg i.v. every 3 weeks) and TMZ (daily 50 mg/m(2)), until clinical or radiological progression. Conventional and dynamic magnetic resonance imaging (MRI) were carried out on days -4, 3 and 21 and until clinical or radiological progression.

RESULTS

Overall response rate (20%), 6-month progression-free survival (PFS6) (17.4%), median progression-free survival (13.9 weeks) and median overall survival (OS) (17.1 weeks) were considerably lower compared with most other studies with bevacizumab-containing regimens. The dynamic MRI parameters contrast transfer coefficient and relative cerebral blood volume decreased rapidly during the early phases of treatment, reflecting changes in vascularisation and vessel permeability but not in tumour activity. In addition, >50% of patients showed oedema reduction and a reduced shift on T1 images.

CONCLUSION

Treatment with bevacizumab and TMZ is feasible and well tolerated but did not improve PFS6 and median OS.

Antiangiogenic therapies for high-grade glioma

High-grade gliomas (HGGs) are vascular tumors that represent attractive targets for antiangiogenic therapies. In this Review, we present the rationale and clinical trial evidence for targeting angiogenesis in HGGs, focusing predominantly on agents that target vascular endothelial growth factor (VEGF) and its receptors. Bevacizumab, a humanized monoclonal antibody against VEGF, was recently approved by the FDA for treatment of recurrent glioblastoma. Bevacizumab prolongs progression-free survival and controls peritumoral edema, but its effects on overall survival remain to be determined. Other inhibitors of VEGF, VEGF receptors and other proangiogenic signaling pathways are being evaluated. Antiangiogenic therapies are well tolerated, although potentially serious adverse events can occasionally occur, and resistance to antiangiogenic therapy inevitably develops. Mechanisms of resistance include upregulation of alternative proangiogenic pathways, and increased perivascular tumor growth. Tumor progression on antiangiogenic agents is a challenging problem for which no effective salvage therapy has been identified. Combining these agents with radiation therapy, cytotoxic chemotherapy, other targeted molecular agents, or anti-invasion therapies could be helpful. The international Response Assessment in Neuro-Oncology Working Group has developed consensus treatment response criteria for HGG that account for the complex effects of antiangiogenic drugs.

Bevacizumab plus irinotecan in the treatment patients with progressive recurrent malignant brain tumours

MATERIAL AND METHODS

We retrospectively determined the efficacy and safety of a combination of bevacizumab and irinotecan in a consecutive series of 52 heavily pre-treated patients with recurrent high-grade brain tumours. Patients received bevacizumab (10 mg/kg) and irinotecan [340 mg/m(2) for those receiving enzyme-inducing antiepileptic drugs (EIAEDs) and 125 mg/m(2) for those not receiving EIAEDs] every 2 weeks. Fifty-two patients were included and 47 were evaluable for response.

RESULTS

Complete or partial response was observed in 25% of all cases (30% response in grade IV glioma and 15% in grade III glioma). Estimated median progression-free survival (PFS) for both grade IV and grade III glioma was 22 weeks. The 6-month PFS was 32% for all patients, 40% for grade IV glioma and 33% for grade III glioma. Estimated median overall survival was 30 weeks for all patients, 28 weeks for grade IV glioma and 32 weeks for grade III glioma. Four patients discontinued treatment because of unmanageable toxicity: cerebral haemorrhage, cardiac arrhythmia, intestinal perforation and diarrhoea, the latter resulting in death.

DISCUSSION

We conclude that the combination of bevacizumab and irinotecan shows acceptable safety and is a clinically relevant choice of therapy in heavily pre-treated patients with recurrent high-grade brain tumours.

Antiangiogenic strategies for treatment of malignant gliomas

Numerous antiangiogenic agents with diverse mechanisms of action are currently under investigation for the treatment of patients with glioblastoma (GBM), a diagnosis that continues to carry a poor prognosis despite maximal conventional therapy. Early clinical trials suggest that antiangiogenic drugs, which target the blood vessels of these highly angiogenic tumors, may have clinical benefit in GBM patients. Antiangiogenic agents have potent antiedema and steroid-sparing effects in patients, and emerging data suggest that these drugs may modestly improve progression-free survival. Although these early results are encouraging, several issues arise regarding the use and efficacy of these agents. Interpretation of the radiographic changes that occur after treatment with antiangiogenic agents presents a major challenge. Still lacking are reliable radiographic and biologic markers that can predict which patients will benefit from treatment and that accurately indicate response and progression during therapy. In addition, most patients treated with antiangiogenic drugs eventually progress, and the mechanisms by which tumors escape from therapy are only beginning to be understood. Larger prospective trials that incorporate correlative biomarker studies will be required to address these challenges. Here, we summarize the clinical experience with antiangiogenic therapy in patients with malignant gliomas (MG), review the major issues concerning the use and development of these agents, and discuss strategies that may build upon the initial gains observed with antiangiogenic agents.

Angiogenesis as a therapeutic target in malignant gliomas

Currently, adult glioblastoma (GBM) patients have poor outcomes with conventional cytotoxic treatments. Because GBMs are highly angiogenic tumors, inhibitors that target tumor vasculature are considered promising therapeutic agents in these patients. Encouraging efficacy and tolerability in preliminary clinical trials suggest that targeting angiogenesis may be an effective therapeutic strategy in GBM patients. However, the survival benefits observed to date in uncontrolled trials of antiangiogenic agents have been modest, and several obstacles have limited their effectiveness. This article reviews the rationale for antiangiogenic agents in GBM, their potential mechanisms of action, and their clinical development in GBM patients. Although challenges remain with this approach, ongoing studies may improve upon the promising initial benefits already observed in GBM patients.

Reversible posterior leukoencephalopathy syndrome in a child treated with bevacizumab

Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor (VEGF). Hypertension is a well-recognized, common side effect of VEGF blocking agents. The reversible posterior leukoencephalopathy syndrome (RPLS) has been described as a rare but serious consequence of bevacizumab administration. We present a case of a 6-year-old child with refractory hepatoblastoma who developed hypertensive crisis, seizures and MRI changes consistent with RPLS while receiving bevacizumab with gemcitabine and oxaliplatin. Findings completely resolved without neurologic sequelae with stringent blood-pressure control. Better understanding of risk for RPLS, prompt recognition and aggressive management will be required as bevacizumab gains wider use in pediatrics.

Antiangiogenic therapy in malignant gliomas

PURPOSE OF REVIEW

Antiangiogenic drugs are increasingly used in malignant glioma therapy. This article reviews the rationale for targeting angiogenesis in malignant gliomas, summarizes relevant clinical trial results, and discusses promising avenues of investigation in antiangiogenic therapy.

RECENT FINDINGS

Combination therapy with bevacizumab, the humanized monoclonal antibody against vascular endothelial growth factor, and irinotecan has emerged as the treatment of choice for recurrent malignant gliomas, prolonging progression-free survival markedly in comparison with historical controls. Several small molecule tyrosine kinase inhibitors of the vascular endothelial growth factor receptor are under investigation and show promise as well.

SUMMARY

Antiangiogenic treatments are effective and well tolerated options for recurrent malignant glioma. Future studies will determine whether these drugs have a role in first line therapy. Studies are in progress to elucidate mechanisms of resistance and suggest approaches to further improve survival in patients with these challenging tumors.

An exploratory survival analysis of anti-angiogenic therapy for recurrent malignant glioma

Recent clinical trial results suggest that anti-angiogenic therapy may be effective against recurrent malignant glioma. Though these treatments prolong progression-free survival, the extent to which they prolong overall survival is unknown. We pooled data from 34 patients treated at a single institution on phase II clinical trials of bevacizumab and cediranib, and we compared these data to 18 patients treated on clinical trials of cytotoxic chemotherapies. In univariate and multivariate analyses, treatment group was a significant predictor of progression-free but not overall survival. Median progression-free survival was 8 vs. 22 weeks in patients treated with cytotoxic as compared to anti-angiogenic therapy (P = 0.01). Median overall survival was nearly identical in the two groups (39 vs. 37 weeks). The results of this exploratory analysis suggest that anti-angiogenic therapy may fail to prolong overall survival in patients with recurrent malignant glioma. If this conclusion proves correct, progression-free survival may be an inappropriate endpoint for phase II trials of anti-angiogenic therapies.