Treatment with bevacizumab plus carboplatin for recurrent malignant glioma

Reduced-dose bevacizumab vs. standard-dose bevacizumab in recurrent high-grade glioma: Which one is better? A meta-analysis

BACKGROUND

Based on the effective radiological responses, bevacizumab (BEV) has been widely used in the treatment of recurrent high-grade glioma. Although the current standard dose is 5 mg/kg/week, the optimal dosage of BEV is controversial, as few dose-response studies have been performed in recent years. Therefore, we conducted a meta-analysis to explore the value of reduced-dose bevacizumab versus standard-dose bevacizumab in recurrent high-grade glioma treatment.

METHODS

Three major electronic databases (PubMed, EMBASE and the Cochrane Library) were searched for eligible documents published before February 2020. Literature on low-dose bevacizumab versus conventional dose in progressive high-grade glioma was included, and the endpoints of eligible researches should be progression-free survival (PFS) and overall survival (OS). All available data were collected and then analyzed with Stata software.

RESULTS

Four cohort studies were evaluated, including 552 patients (reduced-dose BEV group: 257, standard-dose BEV group: 295). Low dose BEV seems to slightly improve survival compared to conventional dose as HR < 1 indicates a protective effect, but no significant differences in OS (HR 0.77; 95 % CI 0.53-1.10; P = 0.151) and PFS (HR 0.66; 95 % CI 0.37-1.20; P = 0.175) were found between the two groups in this study.

CONCLUSION

Reduced-dose bevacizumab schedule resulted in similar OS and PFS to standard-dose bevacizumab in recurrent high-grade glioma, with less side effects and less cost of treatment. Therefore, low-dose bevacizumab represents a promising therapeutic option for recurrent high-grade glioma patients. Further prospective randomized trials are needed to confirm our results.

Hypomethylation of 111 Probes Predicts Poor Prognosis for Glioblastoma

Glioblastoma (GBM) is a complicated brain tumor with heterogeneous outcome. Identification of effective biomarkers is an urgent need for the treatment decision-making and precise evaluation of prognosis. Based on a relatively large dataset of genome-wide methylation (138 glioblastoma patients), a joint-score of 111 methyl-probes was found to be of statistical significance for prognostic evaluation. Low joint-score were significantly associated with adverse outcomes (OS: P < 0.001, PFS: P = 0.03). Multivariable analyses adjusted for known risk factors confirmed the low joint-score of 111 methyl-probes as a high risk factor. The prognostic value of the methylated joint-score was further validated in another dataset of glioblastoma patients (OS: P = 0.006). Additionally, variance analysis revealed that aberrant genetic and epigenetic alterations were significantly associated with the joint-score of those methyl-probes. In conclusion, our results supported the joint-score of 111 methyl-probes as a potential prognosticator for the precision treatment of glioblastoma.

Bevacizumab in Recurrent Glioma: Patterns of Treatment Failure and Implications

Glioblastoma, the most common primary malignant brain tumor in adults, is highly aggressive and associated with a poor prognosis. Bevacizumab, a monoclonal antibody against the vascular endothelial growth factor receptor, has increasingly been used in the treatment of recurrent glioblastoma. It has achieved excellent rates of radiographic response, but most patients will progress after only a few months. Upon recurrence, tumors may not enhance, secondary to vascular normalization. We describe four patterns of radiographic progression commonly associated with Bevacizumab failure: 1) Distant enhancing tumor, 2) Local tumor progression without enhancement, 3) Diffuse gliomatosis-like infiltration, and 4) Local or multifocal progression, with enhancement. Some have noted an increased incidence of distant or diffuse disease upon recurrence, suggestive of a transition to a more aggressive phenotype, but a review of the literature suggests there is no conclusive evidence that Bevacizumab treatment is associated with an increased rate of distant or diffuse recurrence.

Vascular Reactivity Maps in Patients with Gliomas Using Breath-Holding BOLD fMRI

BACKGROUND AND PURPOSE

To evaluate whether breath-holding (BH) blood oxygenation level-dependent (BOLD) fMRI can quantify differences in vascular reactivity (VR), as there is a need for improved contrast mechanisms in gliomas.

METHODS

16 patients (gliomas, grade II = 5, III = 2, IV = 9) were evaluated using the BH paradigm: 4-second single deep breath followed by 16 seconds of BH and 40 seconds of regular breathing for five cycles. VR was defined as the difference in BOLD signal between the minimal signal seen at the end of the deep breath and maximal signal seen at the end of BH (peak-to-trough). VR was measured for every voxel and compared for gray versus white matter and tumor versus normal contralateral brain. VR maps were compared to the areas of enhancement and FLAIR/T2 abnormality.

RESULTS

VR was significantly lower in normal white matter than gray matter (P < .05) and in tumors compared to the normal, contralateral brain (P < 0.002). The area of abnormal VR (1103 ± 659 mm²) was significantly greater (P = .019) than the enhancement (543 ± 530 mm²), but significantly smaller (P = .0011) than the FLAIR abnormality (2363 ± 1232 mm²). However, the variability in the areas of gadolinium contrast enhancement versus VR abnormality indicates that the contrast mechanism elicited by BH (caused by abnormal arteriolar smooth muscles) appears to be fundamentally different from the contrast mechanism of gadolinium enhancement (caused by the presence of "leaky" gap junctions).

CONCLUSIONS

BH maps based on peak-to-trough can be used to characterize VR in brain tumors. VR maps in brain tumor patients appear to be caused by a different mechanism than gadolinium enhancement.

Randomized phase 2 study of carboplatin and bevacizumab in recurrent glioblastoma

BACKGROUND

The optimal use of bevacizumab in recurrent glioblastoma (GBM), including the choice of monotherapy or combination therapy, remains uncertain. The purpose of this study was to compare combination therapy with bevacizumab monotherapy.

METHODS

This was a 2-part randomized phase 2 study. Eligibility criteria included recurrent GBM after radiotherapy and temozolomide, no other chemotherapy for GBM, and Eastern Cooperative Oncology Group performance status 0-2. The primary objective (Part 1) was to determine the effect of bevacizumab plus carboplatin versus bevacizumab monotherapy on progression-free survival (PFS) using modified Response Assessment in Neuro-Oncology criteria. Bevacizumab was given every 2 weeks, 10 mg/kg; and carboplatin every 4 weeks, (AUC 5). On progression, patients able to continue were randomized to continue or cease bevacizumab (Part 2). Secondary endpoints included objective radiological response rate (ORR), quality of life, toxicity, and overall survival (OS).

RESULTS

One hundred twenty-two patients (median age, 55y) were enrolled to Part 1 from 18 Australian sites. Median follow-up was 32 months, and median on-treatment time was 3.3 months. Median PFS was 3.5 months for each arm (hazard ratio [HR]: 0.92, 95% CI: 0.64-1.33, P = .66). ORR was 14% (combination) versus 6% (monotherapy) (P = .18). Median OS was 6.9 (combination) versus 7.5 months (monotherapy) (HR: 1.18, 95% CI: 0.82-1.69, P = .38). The incidence of bevacizumab-related adverse events was similar to prior literature, with no new toxicity signals. Toxicities were higher in the combination arm. Part 2 data (n = 48) will be reported separately.

CONCLUSIONS

Adding carboplatin resulted in more toxicity without additional clinical benefit. Clinical outcomes in patients with recurrent GBM treated with bevacizumab were inferior to those in previously reported studies.

CLINICAL TRIALS REGISTRATION NR

ACTRN12610000915055.

The added value of bevacizumab concomitantly administered with carboplatin versus carboplatin alone in patients with recurrent glioblastomas

AIMS AND BACKGROUND

Carboplatin (CBDCA) and bevacizumab (BEV) are active in glioblastoma (GBM) with different profiles of toxicity. To date, no study has compared the value of the addition of BEV to historical or traditional cytotoxic chemotherapy. We sought to determine the relative value of BEV in combination with CBDCA versus CBDCA alone in patients with recurrent GBM.

METHODS AND STUDY DESIGN

Eligible patients with progressive GBM following surgery, radiotherapy and temozolomide received CBDCA either alone (group 1, n = 25) or in combination with BEV (group 2, n = 23) at 5 mg/kg once every 3 weeks between June 2010 and December 2013. Baseline characteristics and outcomes after treatment were recorded. The primary end points of this retrospective analysis were progression-free survival (PFS) and objective response rate. Secondary end points included safety and overall survival (OS).

RESULTS

Forty-eight patients were enrolled. The median number of cycles was 4 in group 1 and 6 in group 2. No toxicities or intracerebral bleeding were observed. The objective response rate was higher in group 2 than group 1, 66% vs 24% (p = 0.003). The estimated median PFS and OS were 3.1 vs 6.7 months (p&lt;0.0001) and 6.1 vs 8.6 months (p = 0.09) in group 1 vs group 2, respectively.

CONCLUSIONS

The combination of BEV and CBDCA is associated with improved response rates and survival compared with CBDCA alone. These results highlight the value of BEV in recurrent GBM. However, the clinical benefit of this interesting approach needs validation in a larger patient cohort.

Current and investigational drug strategies for glioblastoma

Medical treatments for glioblastoma face several challenges. Lipophilic alkylators remain the mainstay of treatment, emphasising the primacy of good blood-brain barrier penetration. Temozolomide has emerged as a major contributor to improved patient survival. The roles of procarbazine and vincristine in the procarbazine, lomustine and vincristine (PCV) schedule have attracted scrutiny and several lines of evidence now support the use of lomustine as effective single-agent therapy. Bevacizumab has had a convoluted development history, but clearly now has no major role in first-line treatment, and may even be detrimental to quality of life in this setting. In later disease, clinically meaningful benefits are achievable in some patients, but more impressively the combination of bevacizumab and lomustine shows early promise. Over the last decade, investigational strategies in glioblastoma have largely subscribed to the targeted kinase inhibitor paradigm and have mostly failed. Low prevalence dominant driver lesions such as the FGFR-TACC fusion may represent a niche role for this agent class. Immunological, metabolic and radiosensitising approaches are being pursued and offer more generalised efficacy. Finally, trial design is a crucial consideration. Progress in clinical glioblastoma research would be greatly facilitated by improved methodologies incorporating: (i) routine pharmacokinetic and pharmacodynamic assessments by preoperative dosing; and (ii) multi-stage, multi-arm protocols incorporating new therapy approaches and high-resolution biology in order to guide necessary improvements in science.

Inhibition of SUR1 decreases the vascular permeability of cerebral metastases

Inhibition of sulfonylurea receptor 1 (SUR1) by glyburide has been shown to decrease edema after subarachnoid hemorrhage. We investigated if inhibiting SUR1 reduces cerebral edema due to metastases, the most common brain tumor, and explored the putative association of SUR1 and the endothelial tight junction protein, zona occludens-1 (ZO-1). Nude rats were intracerebrally implanted with small cell lung carcinoma (SCLC) LX1 or A2058 melanoma cells (n = 36). Rats were administered vehicle, glyburide (4.8 µg twice, orally), or dexamethasone (0.35 mg, intravenous). Blood-tumor barrier (BTB) permeability (K (trans)) was evaluated before and after treatment using dynamic contrast-enhanced magnetic resonance imaging. SUR1 and ZO-1 expression was evaluated using immunofluorescence and Western blots. In both models, SUR1 expression was significantly increased (P < .05) in tumors. In animals with SCLC, control mean K (trans) (percent change ± standard error) was 101.8 ± 36.6%, and both glyburide (-21.4 ± 14.2%, P < .01) and dexamethasone (-14.2 ± 13.1%, P < .01) decreased BTB permeability. In animals with melanoma, compared to controls (117.1 ± 43.4%), glyburide lowered BTB permeability increase (3.2 ± 15.4%, P < .05), while dexamethasone modestly lowered BTB permeability increase (63.1 ± 22.1%, P > .05). Both glyburide (P < .001) and dexamethasone (P < .01) decreased ZO-1 gap formation. By decreasing ZO-1 gaps, glyburide was at least as effective as dexamethasone at halting increased BTB permeability caused by SCLC and melanoma. Glyburide is a safe, inexpensive, and efficacious alternative to dexamethasone for the treatment of cerebral metastasis-related vasogenic edema.

Retrospective analysis of bevacizumab in combination with ifosfamide, carboplatin, and etoposide in patients with second recurrence of glioblastoma

Bevacizumab has been reported to be effective for recurrent glioblastoma. In our hospital, ifosfamide, carboplatin, etoposide (ICE) is the second-line chemotherapy for first recurrence of glioblastoma after temozolomide failure. In the present analysis, we retrospectively investigated the feasibility and effectiveness of bevacizumab combined with ICE in patients with glioblastoma at second relapse during ICE treatment. Between 2010 and 2012, tumor progressions were diagnosed in consecutive 8 patients who were treated with ICE for the first recurrence of glioblastoma. These patients were administered 3 cycles of 10 mg/kg bevacizumab every two weeks in combination with ICE treatment. The objective response rate of bevacizumab combination was 75% in Neuro-Oncology Working Group (RANO criteria), including complete response and partial response. Median progression free survival (PFS) and median overall survival (OS) after second relapse were 3.7 months (95% confidence interval [CI], 2.5–18.5 months) and 6.0 months (95% CI, 3.2–19.7 months), respectively. The 6-month PFS rates were 25% (95% CI, 0–55.0%). The median OS after initial diagnosis was 23.3 months (95% CI, 16.2–55.8 months). The grade 2 or 3 hematologic adverse events were identified in 7 of 8 patients, most of which might be due to ICE chemotherapy. The results of our retrospective analysis suggest that combination treatment with bevacizumab and ICE may be safe and beneficial in patients with recurrent glioblastoma.

Drug review: Safety and efficacy of bevacizumab for glioblastoma and other brain tumors

Glioblastoma is a highly vascular tumor that expresses vascular endothelial growth factor, a key regulator of angiogenesis and tumor blood vessel permeability. Bevacizumab is a monoclonal antibody that inhibits vascular endothelial growth factor and the growth of gliomas. Bevacizumab monotherapy has proven effective for recurrent glioblastoma, and it extended progression-free survival and improved patient quality of life in various clinical trials. Some patients who receive bevacizumab experience improvements in neurological symptoms and steroid dose reductions. Bevacizumab induces a dramatic and rapid radiological response, but non-enhancing lesions are often detected on magnetic resonance imaging without enhancing lesions. Rebound phenomena such as rapid tumor regrowth are occasionally observed after the discontinuation of bevacizumab therapy. Therefore, Response Assessment in Neuro-Oncology criteria were recently devised to evaluate the efficacy and radiological response of bevacizumab treatment. Hypertension and proteinuria are characteristic adverse events associated with bevacizumab therapy. In addition, many fatal adverse events such as intracranial hemorrhage and venous thromboembolism are reported in patients treated with bevacizumab. However, these events are also associated with glioma itself, and careful attention needs to be paid to these events. Bevacizumab is used to treat various diseases including radiation necrosis and recurrent brain tumors such as brain metastases, schwannoma and meningioma, but additional clinical trials are necessary. The efficacy and current problems associated with bevacizumab in the treatment of glioblastoma and other brain tumors are reviewed.

Using susceptibility-weighted imaging to determine response to combined anti-angiogenic, cytotoxic, and radiation therapy in patients with glioblastoma multiforme

BACKGROUND

The goal of this study was to investigate whether the amount of hypointense signal on susceptibility-weighted imaging within the contrast-enhancing lesion (%SWI-h) on the pretreatment scan could determine response in patients with newly diagnosed glioblastoma multiforme who received external beam radiation therapy with concomitant anti-angiogenic therapy (enzastaurin) and cytotoxic chemotherapy (temozolomide).

METHODS

Twenty-five patients were imaged before therapy (postsurgical resection) and scanned serially every 2 months until progression. Standard clinical MR imaging and SWI were performed on a 3T scanner. %SWI-h was quantified for each patient's pretreatment scan. Time to progression and death were used to characterize patients into non-, immediate-, and sustained-response groups for both events. Cox proportional hazards models were used to assess the association between %SWI-h and both progression-free survival (PFS) and overall survival (OS). Classification and regression tree analysis were used to determine optimal cutoffs on which to split %SWI-h.

RESULTS

For both death- and progression-based response categories, %SWI-h was significantly higher in sustained responders than in nonresponders. Cox model coefficients showed an association between %SWI-h and PFS and OS, both in univariate analysis (PFS: hazard ratio [HR] = 0.966, 95% confidence interval [CI] = 0.942-0.988; and OS: HR = 0.945, 95% CI = 0.915-0.976) and when adjusting for baseline KPS, age, sex, and resection extent (PFS: HR = 0.968, 95% CI = 0.940 -0.994; and OS: HR = 0.943, 95% CI = 0.908 -0.976). A cutoff value of 38.1% significantly differentiated patients into 2 groups based on censored OS and into non- and intermediate-response categories based on time to progression.

CONCLUSIONS

These early differences suggest that SWI may be able to predict which patients would benefit most from similar combination therapies and may assist clinicians in making important decisions about patient care.

Carboplatin and bevacizumab for recurrent malignant glioma

Over 65,000 primary brain tumors are diagnosed annually in the US alone. Malignant gliomas represent more than one-third of such cases. Despite advances in neuroimaging, surgical techniques, radiotherapy and chemotherapy, the survival rate of this disease remains poor. The introduction of agents which disrupt the function of vascular endothelial growth factor (VEGF) and its receptors to glioma therapy has resulted in an unusually high percentage of patients experiencing radiographic responses. Bevacizumab, approved by the Food and Drug Administration for the treatment of recurrent glioblastoma in 2009, has changed the field of neuro-oncology. The drug has been utilized as a single agent and in combination with the classic cytotoxic agents typically applied in this setting. Numerous studies have reported high response rates and encouraging extensions of time-to-progression. The optimal schedule and combination of bevacizumab with alternative drugs has not been identified. The current study presents the results of a retrospective analysis of the combination therapy utilizing bevacizumab with the alkylating agent carboplatin in patients with recurrent malignant glioma.

The paradoxical effect of bevacizumab in the therapy of malignant gliomas

One rationale behind the use of agents that inhibit vascular endothelial growth factor in the therapy of primary CNS malignancies is based upon the concept that normalization of tumor vasculature with a decrease in tumor interstitial pressure will improve access of cytoreductive drugs and improve radiotherapy efficacy due to increased oxygen delivery. However, several studies have raised the concern that these agents may both rapidly restore the low permeability characteristics of the blood-brain barrier and counteract the beneficial effect of pseudoprogression. The result may be decreased therapeutic efficacy while increasing infiltration by co-opting normal vessels. In this discussion, we examine both histologic and radiographic tumor progression in the context of antiangiogenic agents. Issues dealing with the safety of bevacizumab (Avastin®, Genentech, South San Francisco, CA) and its potential to decrease efficacy of standard radiochemotherapy when used to treat patients with newly diagnosed malignant glioma are emphasized.

Correlation of MRI sequences to assess progressive glioblastoma multiforme treated with bevacizumab

In the context of bevacizumab therapy for the treatment of progressive malignant gliomas, it is currently unclear how different magnetic resonance imaging (MRI) sequences correlate with each other over time. The objective of this study was to determine if a reliable and predictable relationship over time exists between post-gadolinium based contrast agent T1-weighted (T1 + GBCA), T2-weighted, and FLAIR MRI in patients with progressive glioblastoma multiforme (GBM) receiving bevacizumab and chemotherapy. The MRI lesion volumes of 10 patients with progressive GBM that received bevacizumab plus chemotherapy were manually calculated by two independent reviewers. T2 and FLAIR volumes were analyzed by analysis of covariance (ANCOVA) as a function of T1 + GBCA lesion enhancement volume, reviewer, and time interval between MRI acquisitions. Pearson product moment correlation (r) was used to compare pre and post treatment volumes for the group of 10 patients and for each individual patient over their treatment course. ANCOVA demonstrated a significant association between T1 + GBCA and T2-weighted volumes (P = 0.0006) and between T1 + GBCA and FLAIR volumes (P < 0.0001). These associations remained constant over time. The correlation between T1 + GBCA and both T2-weighted and FLAIR volumes improved after bevacizumab treatment. Individual correlations between T1 + GBCA and FLAIR were strong (r ≥ 0.63) with one exception, while correlations between T1 + GBCA and T2 were more variable (r = 0.18-0.99). These findings suggest that FLAIR MRI should be evaluated in addition to T1 + GBCA MRI when evaluating GBM responses.