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

Use of Bevacizumab in recurrent glioblastoma: a scoping review and evidence map

BACKGROUND

Glioblastoma (GBM) is the most malignant primary tumor in the brain, with poor prognosis and limited effective therapies. Although Bevacizumab (BEV) has shown promise in extending progression-free survival (PFS) treating GBM, there is no evidence for its ability to prolong overall survival (OS). Given the uncertainty surrounding BEV treatment strategies, we aimed to provide an evidence map associated with BEV therapy for recurrent GBM (rGBM).

METHODS

PubMed, Embase, and the Cochrane Library were searched for the period from January 1, 1970, to March 1, 2022, for studies reporting the prognoses of patients with rGBM receiving BEV. The primary endpoints were overall survival (OS) and quality of life (QoL). The secondary endpoints were PFS, steroid use reduction, and risk of adverse effects. A scoping review and an evidence map were conducted to explore the optimal BEV treatment (including combination regimen, dosage, and window of opportunity).

RESULTS

Patients with rGBM could gain benefits in PFS, palliative, and cognitive advantages from BEV treatment, although the OS benefits could not be verified with high-quality evidence. Furthermore, BEV combined therapy (especially with lomustine and radiotherapy) showed higher efficacy than BEV monotherapy in the survival of patients with rGBM. Specific molecular alterations (IDH mutation status) and clinical features (large tumor burden and double-positive sign) could predict better responses to BEV administration. A low dosage of BEV showed equal efficacy to the recommended dose, but the optimal opportunity window for BEV administration remains unclear.

CONCLUSIONS

Although OS benefits from BEV-containing regimens could not be verified in this scoping review, the PFS benefits and side effects control supported BEV application in rGBM. Combining BEV with novel treatments like tumor-treating field (TTF) and administration at first recurrence may optimize the therapeutic efficacy. rGBM with a low apparent diffusion coefficient (ADCL), large tumor burden, or IDH mutation is more likely to benefit from BEV treatment. High-quality studies are warranted to explore the combination modality and identify BEV-response subpopulations to maximize benefits.

Treatment options for progression or recurrence of glioblastoma: a network meta-analysis

BACKGROUND

Glioblastoma (GBM) is a highly malignant brain tumour that almost inevitably progresses or recurs after first line standard of care. There is no consensus regarding the best treatment/s to offer people upon disease progression or recurrence. For the purposes of this review, progression and recurrence are considered as one entity.

OBJECTIVES

To evaluate the effectiveness of further treatment/s for first and subsequent progression or recurrence of glioblastoma (GBM) among people who have received the standard of care (Stupp protocol) for primary treatment of the disease; and to prepare a brief economic commentary on the available evidence.

SEARCH METHODS

We searched MEDLINE and Embase electronic databases from 2005 to December 2019 and the Cochrane Central Register of Controlled Trials (CENTRAL, in the Cochrane Library; Issue 12, 2019). Economic searches included the National Health Service Economic Evaluation Database (NHS EED) up to 2015 (database closure) and MEDLINE and Embase from 2015 to December 2019.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and comparative non-randomised studies (NRSs) evaluating effectiveness of treatments for progressive/recurrent GBM. Eligible studies included people with progressive or recurrent GBM who had received first line radiotherapy with concomitant and adjuvant temozolomide (TMZ).

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data to a pre-designed data extraction form. We conducted network meta-analyses (NMA) and ranked treatments according to effectiveness for each outcome using the random-effects model and Stata software (version 15). We rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 42 studies: these comprised 34 randomised controlled trials (RCTs) and 8 non-randomised studies (NRSs) involving 5236 participants. We judged most RCTs to be at a low risk of bias and NRSs at high risk of bias. Interventions included chemotherapy, re-operation, re-irradiation and novel therapies either used alone or in combination. For first recurrence, we included 11 interventions in the network meta-analysis (NMA) for overall survival (OS), and eight in the NMA for progression-free survival (PFS). Lomustine (LOM; also known as CCNU) was the most common comparator and was used as the reference treatment. No studies in the NMA evaluated surgery, re-irradiation, PCV (procarbazine, lomustine, vincristine), TMZ re-challenge or best supportive care. We could not perform NMA for second or later recurrence due to insufficient data. Quality-of-life data were sparse. First recurrence (NMA findings) Median OS across included studies in the NMA ranged from 5.5 to 12.6 months and median progression-free survival (PFS) ranged from 1.5 months to 4.2 months. We found no high-certainty evidence that any treatments tested were better than lomustine. These treatments included the following. Bevacizumab plus lomustine: Evidence suggested probably little or no difference in OS between bevacizumab (BEV) combined with lomustine (LOM) and LOM monotherapy (hazard ratio (HR) 0.91, 0.75 to 1.10; moderate-certainty evidence), although BEV + LOM may improve PFS (HR 0.57, 95% confidence interval (CI) 0.44 to 0.74; low-certainty evidence). Bevacizumab monotherapy: Low-certainty evidence suggested there may be little or no difference in OS (HR 1.22, 95% CI 0.84 to 1.76) and PFS (HR 0.90, 95% CI 0.58 to 1.38; low-certainty evidence) between BEV and LOM monotherapies; more evidence on BEV is needed. Regorafenib (REG): REG may improve OS compared with LOM (HR 0.50, 95% CI 0.33 to 0.76; low-certainty evidence). Evidence on PFS was very low certainty and more evidence on REG is needed. Temozolomide (TMZ) plus Depatux-M (ABT414): For OS, low-certainty evidence suggested that TMZ plus ABT414 may be more effective than LOM (HR 0.66, 95% CI 0.47 to 0.92) and may be more effective than BEV (HR 0.54, 95% CI 0.33 to 0.89; low-certainty evidence). This may be due to the TMZ component only and more evidence is needed. Fotemustine (FOM): FOM and LOM may have similar effects on OS (HR 0.89, 95% CI 0.51 to 1.57, low-certainty evidence). Bevacizumab and irinotecan (IRI): Evidence on BEV + irinotecan (IRI) versus LOM for both OS and PFS is very uncertain and there is probably little or no difference between BEV + IRI versus BEV monotherapy (OS: HR 0.95, 95% CI 0.70 to 1.30; moderate-certainty evidence). When treatments were ranked for OS, FOM ranked first, BEV + LOM second, LOM third, BEV + IRI fourth, and BEV fifth. Ranking does not take into account the certainty of the evidence, which also suggests there may be little or no difference between FOM and LOM. Other treatments Three studies evaluated re-operation versus no re-operation, with or without re-irradiation and chemotherapy, and these suggested possible survival advantages with re-operation within the context of being able to select suitable candidates for re-operation. A cannabinoid treatment in the early stages of evaluation, in combination with TMZ, merits further evaluation. Second or later recurrence Limited evidence from three heterogeneous studies suggested that radiotherapy with or without BEV may have a beneficial effect on survival but more evidence is needed. Evidence was insufficient to draw conclusions about the best radiotherapy dosage. Other evidence suggested that there may be little difference in survival with tumour-treating fields compared with physician's best choice of treatment. We found no reliable evidence on best supportive care. Severe adverse events (SAEs) The BEV+LOM combination was associated with significantly greater risk of SAEs than LOM monotherapy (RR 2.51, 95% CI 1.72 to 3.66, high-certainty evidence), and ranked joint worst with cediranib + LOM (RR 2.51, 95% CI 1.29 to 4.90; high-certainty evidence). LOM ranked best and REG ranked second best. Adding novel treatments to BEV was generally associated with a higher risk of severe adverse events compared with BEV alone.

AUTHORS' CONCLUSIONS

For treatment of first recurrence of GBM, among people previously treated with surgery and standard chemoradiotherapy, the combination treatments evaluated did not improve overall survival compared with LOM monotherapy and were often associated with a higher risk of severe adverse events. Limited evidence suggested that re-operation with or without re-irradiation and chemotherapy may be suitable for selected candidates. Evidence on second recurrence is sparse. Re-irradiation with or without bevacizumab may be of value in selected individuals, but more evidence is needed.

Economic implications of the modern treatment paradigm of glioblastoma: an analysis of global cost estimates and their utility for cost assessment

INTRODUCTION

Glioblastoma is the most common primary brain tumor in adults. Standard of care includes maximal surgical resection of the tumor followed by concurrent chemotherapy and radiation. The treatment of glioblastoma must account for an increased disease severity and treatment intensity compared to other cancers which place a significant cost burden on the patient and health system. Cost assessments of glioblastoma treatment have been sparse in comparison to other solid cancer subtypes. This study evaluates all currently available cost literature with an emphasis on the modern treatment paradigm to properly assess the economic implications of this disease.

METHODS

A critical review of 21 studies from 13 different countries measuring direct costs related to glioblastoma management was performed. Evaluated data included itemized costs, total costs of treatment regimens from diagnosis until death, the cost of second-line care after recurrence, and the incremental costs and cost-effectiveness of emerging therapies.

RESULTS

The average cost of a craniotomy was $10,042 across studies. Imaging for the duration of glioblastoma care had a mean cost of $2,788 ± 3,719. Studies examined different combinations of treatment modalities. Utilization of the modern treatment paradigm led to survival of 16.3 months across studies and had a mean cost of $62,602. Surgery for the recurrent disease had an average cost of $27,442 ± 18,992.

LIMITATIONS AND CONCLUSIONS

Direct cost estimates for glioblastoma varied substantially between institutions and countries and often failed to uniformly describe direct cost estimates associated with care for glioblastoma. The limitations of these studies make a true economic assessment of standards of care, costs of recurrence, and incremental costs associated with adjunctive therapy uncertain.

Effect of health disparities on overall survival of patients with glioblastoma

BACKGROUND

Examine the potential effects of health disparities in survival of glioblastoma (GB) patients.

METHODS

We conducted a retrospective chart review of newly diagnosed GB patients from 2000 to 2015 at a free standing dedicated cancer center (MD Anderson Cancer Center-MDACC) and a safety net county hospital (Ben Taub General Hospital-BT) located in Houston, Texas. We obtained demographics, insurance status, extent of resection, treatments, and other known prognostic variables (Karnofsky Score-KPS) to evaluate their role on overall GB survival (OS).

RESULTS

We identified 1073 GB patients consisting of 177 from BT and 896 from MDACC. We found significant differences by ethnicity, insurance status, KPS at diagnosis, extent of resection, and percentage of patients receiving standard of care (SOC) between the two centers. OS was 1.64 years for MDACC patients and 1.24 years for BT patients (p < 0.0176). Only 81 (45.8%) BT patients received SOC compared to 577 (64%) of MDACC patients (p < 0.0001). However, there was no significant difference in OS for patients who received SOC, 1.84 years for MDACC patients and 1.99 years for BT patients (p < 0.4787). Of the 96 BT patients who did not receive SOC, 29 (30%) had KPS less than 70 at time of diagnosis and 77 (80%) lacked insurance.

CONCLUSIONS

GB patients treated at a safety net county hospital had similar OS compared to a free standing comprehensive cancer center when receiving SOC. County hospital patients had poorer KPS at diagnosis and were often lacking health insurance affecting their ability to receive SOC.

Neuro-oncologists have spoken - the role of bevacizumab in the inpatient setting. A clinical and economic conundrum

Background

Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor (VEGF), a key player in tumor angiogenesis. The drug can halt tumor progression, treat radiation necrosis, and reduce peritumoral edema. Although it does not increase overall survival, bevacizumab can improve progression-free survival and quality of life. In many countries, bevacizumab use in the inpatient setting is restricted due to its significant cost. Here, we explore attitudes towards the use of bevacizumab amidst practitioners treating brain tumors and assess ease of accessing the drug in the inpatient setting.

Design/Methods

A 10-question survey querying practitioners' opinions of inpatient bevacizumab utility and its availability was distributed to the membership of the Society of Neuro-Oncology in July 2016.

Results

Eighty-seven percent felt that there was a role for bevacizumab in the inpatient setting, and 69% reported favorable experiences with bevacizumab use. However, 40% encountered difficulty in obtaining approval for inpatient use. We present two contrasting clinical cases that highlight favorable and unfavorable outcomes when bevacizumab use was and was not permitted, respectively.

Conclusions

In this sample of neuro-oncology practitioners, there is general consensus that bevacizumab plays an important role in the inpatient treatment of brain tumors. In light of ongoing barriers to inpatient bevacizumab use due to cost concerns, these data motivate the creation of standardized policies for inpatient bevacizumab use that balances its important role in improving quality of life with financial considerations.