Comparison of cetuximab to bevacizumab as the first-line bio-chemotherapy for patients with metastatic colorectal cancer: superior progression-free survival is restricted to patients with measurable tumors and objective tumor response--a retrospective study

The effectiveness and safety of bevacizumab versus cetuximab in the treatment of colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Despite available meta-analyses, comparative efficacy and safety between bevacizumab and cetuximab-containing therapies in treating advanced colorectal cancer (CRC) still need to be elucidated.

AIM

This meta-analysis aimed to investigate the efficacy and grade 3-5 treatment-related adverse events (TARE3-5) of bevacizumab versus cetuximab in treating advanced CRC.

METHOD

A random sample of 400 patients aged 65 years or older from a clinical trial in four Swedish hospitals was selected. All patients' emergency department visits within 12 months after discharge were assessed with AT-HARM10. The main outcome measures were the percentage of successfully assessed visits for applicability and the interrater reliability (Cohen's kappa).

RESULTS

Five RCTs and four observational cohort studies (2970 patients) were included. The bevacizumab-containing group was associated with a significantly lower ORR (risk ratio RR 0.91, 95% confidence interval CI 0.85-0.97, P = 0.006) than the cetuximab group. Bevacizumab was associated with significant superior DCR (RR 1.05, 95% CI 1.01 to 1.10, P = 0.02) and prolonged OS (hazard ratio HR 0.81, 95% CI 0.74-0.90, P < 0.0001) than cetuximab. No significant differences were observed for PFS (HR 0.97, 95% CI 0.92-1.03, P = 0.33) between the groups. Bevacizumab showed a lower rate of skin disorders (RR 0.10, 95% CI 0.02-0.43, P = 0.002) than cetuximab. There were no significant differences between the groups in the overall rate of TRAE3-5 (RR 0.92, 95% CI 0.84-1.01, P = 0.08). Subgroup analysis found a lower TARE3-5 rate in the bevacizumab group in RCTs (RR 0.91, 95% CI 0.83-1.00, P = 0.04).

CONCLUSION

Bevacizumab could increase DCR, prolong OS, and lower the skin disorder rate to treat patients with advanced CRC.

Tolerability on Serious Adverse Events of First-Line Bevacizumab and Cetuximab for RAS Wild-Type Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis

Proper medication management is crucial in metastatic colorectal cancer because of its substantially low survival rate. There has been advancing evidence on the efficacy of the two most prescribed targeted agents (bevacizumab and cetuximab); however, comprehensive analyses on their safety are limited. This study aims to comprehensively assess the clinical safety of first-line bevacizumab and cetuximab-based chemotherapy in unresectable RAS wild-type metastatic colorectal cancer patients and to provide guidance on the selection of appropriate targeted therapeutic agents. Keyword searches of MEDLINE, Cochrane Library, and ClinicalKey were conducted per PRISMA guidelines. We performed pooled analysis on safety outcomes from six studies which administered FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) or FOLFIRI (5-fluorouracil, leucovorin, irinotecan) as backbone chemotherapy. Thirty different adverse events from six categories were compared. First-line bevacizumab-based chemotherapy substantially lowered the risks of adverse events related to the dermatological (RR 0.24, 95% CI: 0.11–0.53, p < 0.00001) and renal systems (RR 0.57, 95% CI: 0.37–0.86, p = 0.007), while significantly increasing the incidence of cardiovascular adverse events (RR 4.65, 95% CI: 1.83–11.78, p = 0.001). Thus, first-line cetuximab-based chemotherapy increases patient susceptibility to dermatological and renal adverse events, especially with rash and electrolyte disorders, whereas bevacizumab-based chemotherapy increases cardiovascular risks such as hypertension and arrhythmia.

The efficacy of anti-EGFR therapy in treating metastatic colorectal cancer differs between the middle/low rectum and the left-sided colon

BACKGROUND

Clinically, metastatic rectal cancer has been considered a subset of left-sided colon cancer. However, heterogeneity has been proposed to exist between high and middle/low rectal cancers. We aimed to examine the efficacy of anti-epidermal growth factor receptor (EGFR) treatment for middle/low rectal and left-sided colon cancers.

METHODS

This study enrolled 609 patients with metastatic colorectal cancer who were treated with anti-EGFR therapy. They were divided into groups based on primary tumour locations: the right-sided colon, the left-sided colon or the middle/low rectum. The efficacy of first-line and non-first-line anti-EGFR treatment was analysed. Genomic differences in colorectal cancer data from The Cancer Genome Atlas (TCGA) were investigated and visualised with OncoPrint and a clustered heatmap.

RESULTS

On first-line anti-EGFR treatment, patients with middle/low rectal tumours had significantly lower progression-free survival, overall survival, and overall response rates (6.8 months, 27.8 months and 43%, respectively) than those with left-sided colon cancer (10.1 months, 38.3 months and 66%, respectively). Similar outcomes were also identified on non-first-line anti-EGFR treatment. In TCGA analysis, rectal tumours displayed genetic heterogeneity and shared features with both left- and right-sided colon cancer.

CONCLUSIONS

Anti-EGFR treatment has lower efficacy in metastatic middle/low rectal cancer than in left-sided colon cancer.

Preference criteria for regorafenib in treating refractory metastatic colorectal cancer are the small tumor burden, slow growth and poor/scanty spread

Given the unclear preference criteria for regorafenib in treating refractory metastatic colorectal cancer (mCRC), this study aimed to construct an algorithm in selecting right patients for regorafenib. This was a multicenter retrospective cohort study. Patients with pathology confirmed mCRC and administered with regorafenib for > 3 weeks were enrolled. Patients with good response were defined to have progression-free survival (PFS) of ≥ 4 months. The Kaplan–Meier plot was used to analyze survival. A Cox proportional hazards model was used to analyze univariate and multivariate prognostic factors and was visualized using forest plot. A clustering heatmap was used to classify patients according to responses. The decision tree and nomogram were used to construct the approaching algorithm. A total of 613 patients was analyzed. The median PFS and overall survival (OS) were 2.7 and 10.6 months, respectively. The partial response and stable disease rate are 2.4% and 36.4%. The interval between metastasis (M1) and regorafenib, metastatic status (number, liver, and brain), and CEA level were independent prognostics factors of PFS that classifies patients into three groups: good, bad and modest-1/modest-2 group with PFS >  = 4 months rates of 51%, 20%, 39% and 30%, respectively. Results were used to develop the decision tree and nomogram for approaching patients indicated with regorafenib. The preference criteria for regorafenib in treating patients with refractory mCRC are small tumor burden (CEA), slow growth (interval between metastasis and regorafenib) and poor/scanty spread (metastatic status: number and sites of metastasis): The 3S rules.

TRIAL registration ClinicalTrials.gov Identifier: NCT03829852; Date of first registration (February 11, 2019).

A molecular subtype of colorectal cancers initiates independently of epidermal growth factor receptor and has an accelerated growth rate mediated by IL10-dependent anergy

Although epidermal growth factor receptor (EGFR)-targeted therapies are approved for colorectal cancer (CRC) treatment, only 15% of CRC patients respond to EGFR inhibition. Here, we show that colorectal cancers (CRC) can initiate and grow faster through an EGFR-independent mechanism, irrespective of the presence of EGFR, in two different mouse models using tissue-specific ablation of Egfr. The growth benefit in the absence of EGFR is also independent of Kras status. An EGFR-independent gene expression signature, also observed in human CRCs, revealed that anergy-inducing genes are overexpressed in EGFR-independent polyps, suggesting increased infiltration of anergic lymphocytes promotes an accelerated growth rate that is partially caused by escape from cell-mediated immune responses. Many genes in the EGFR-independent gene expression signature are downstream targets of interleukin 10 receptor alpha (IL10RA). We further show that IL10 is detectable in serum from mice with EGFR-independent colon polyps. Using organoids in vitro and Src ablation in vivo, we show that IL10 contributes to growth of EGFR-independent CRCs, potentially mediated by the well-documented role of SRC in IL10 signaling. Based on these data, we show that the combination of an EGFR inhibitor with an anti-IL10 neutralizing antibody results in decreased cell proliferation in organoids and in decreased polyp size in pre-clinical models harboring EGFR-independent CRCs, providing a new therapeutic intervention for CRCs resistant to EGFR inhibitor therapies.

First-line cetuximab versus bevacizumab for RAS and BRAF wild-type metastatic colorectal cancer: a systematic review and meta-analysis

BACKGROUND

A first-line biologic treatment for metastatic colorectal cancer (mCRC) is still controversial. We, therefore, performed a meta-analysis to determine the efficacy of first-line cetuximab versus bevacizumab for RAS and BRAF wild-type mCRC.

METHODS

In March 2018, an electronic search of the following biomedical databases was performed: PubMed, EMBASE, Cochrane Library, ClinicalTrials.gov and Web of Knowledge. Randomized controlled trials (RCTs) and prospective or observational cohort studies (OCSs) were included. Subgroup analyses of all RCTs were performed in all outcomes. All statistical analyses were performed using RevMan software 5.3.

RESULTS

Two RCTs and three OCSs, involving a total 2576 patients, were included. The meta-analysis reported that cetuximab was associated with a longer overall survival (OS) [HR 0.89, 95% CI (0.81-0.98); p = 0.02], a higher ORR [RR 1.11, 95% CI (1.03-1.19); p = 0.006], higher complete response [RR 3.21, 95% CI (1.27-8.12); p = 0.01] and a greater median depth of response than bevacizumab. However, no significant difference was observed between cetuximab and bevacizumab groups for PFS, DCR, partial response, progressive disease, curative intent metastasectomy, EORR and incidence of grade 3 or higher adverse events. In the subgroup meta-analyses of the RCTs, inconsistent results compared to the main analysis, however, were found, in the ORR, DCR and curative intent metastasectomy.

CONCLUSIONS

The current evidence indicates that compared to bevacizumab treatment, cetuximab provides a clinically relevant effect in first-line treatment against mCRC, at the cost of having lower stable disease.

Comparative Effectiveness and Safety of Monoclonal Antibodies (Bevacizumab, Cetuximab, and Panitumumab) in Combination with Chemotherapy for Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

The last decade has seen the increasing use of biological medicines in combination with chemotherapy containing 5-fluorouracil/oxaliplatin or irinotecan for the treatment of metastatic colorectal cancer (mCRC). These combinations have resulted in increased progression-free survival (PFS) in patients with mCRC; however, there are remaining concerns over the extent of their effect on overall survival (OS). Published studies to date suggest no major differences between the three currently available monoclonal antibodies (MoAbs); however, there are differences in costs. In addition, there is rising litigation in Brazil in order to access these medicines as they are currently not reimbursed.

OBJECTIVE

The aim was to investigate the comparative effectiveness and safety of three MoAbs (bevacizumab, cetuximab and panitumumab) associated with fluoropyrimidine-based chemotherapy regimens and compared to fluoropyrimidine-based chemotherapy alone in patients with mCRC, through an updated systematic review and meta-analysis of concurrent or non-concurrent observational cohort studies, to guide authorities and the judiciary.

METHOD

A systematic review and meta-analysis was performed based on cohort studies published in databases up to November 2017. Effectiveness measures included OS, PFS, post-progression survival (PPS), Response Evaluation Criteria In Solid Tumors (RECIST), response rate, metastasectomy and safety. The methodological quality of the studies was also evaluated.

RESULTS

A total of 21 observational cohort studies were included. There were statistically significant and clinically relevant benefits in patients treated with bevacizumab versus no bevacizumab mainly around OS, PFS, PPS and the metastasectomy rate, but not for the disease control rates. However, there was an increase in treatment-related toxicities and concerns with the heterogeneity of the studies.

CONCLUSION

The results pointed to an advantage in favor of bevacizumab for OS, PFS, PPS, and metastasectomy. Although this advantage may be considered clinically modest, bevacizumab represents a hope for increased survival and a chance of metastasectomy for patients with mCRC. However, there are serious adverse events associated with its use, especially severe hypertension and gastrointestinal perforation, that need to be considered.

Real-world use of bevacizumab in metastatic colorectal, metastatic breast, advanced ovarian and cervical cancer: a systematic literature review

AIM

This review aims to assist physicians and payers in assessing the efficacy and safety of bevacizumab in real-world clinical practice by identifying evidence on the comparative effectiveness and safety of bevacizumab in its most frequent indications. Materials & methods: In a systematic review of the published literature, electronic databases (Embase^®, MEDLINE^® and the Cochrane Library) were searched in May 2016 and updated in January 2017; 20 scientific congresses were searched in 2014-2017.

RESULTS

Of 61 included publications, 49, eight, four and 0 concerned metastatic colorectal cancer, metastatic breast cancer, advanced ovarian cancer and cervical cancer, respectively. Fifteen publications (metastatic colorectal cancer) reported on factors predictive of response to therapy.

CONCLUSION

Effectiveness findings from real-world studies broadly supported results from registration studies.

Role of Anti-Epidermal Growth Factor Receptor Therapy Compared with Anti-Vascular Endothelial Growth Factor Therapy for Metastatic Colorectal Cancer: an Update Meta-Analysis of Randomized Clinical Trials

Monoclonal antibodies targeting epidermal growth factor receptor (EGFR) or vascular endothelial growth factor (VEGF) have showed clinical benefit in combination with chemotherapeutic cytotoxic drugs in the first-line therapy of metastatic colorectal cancer (mCRC). Data from randomized studies comparing these monoclonal antibodies as initial therapy is conflicting, and their comparative efficacy remains unknown. This study aimed to evaluate the impact of the combination of anti-epidermal growth factor receptor (anti-EGFR) therapy and anti-vascular endothelial growth factor therapy on mCRC patient outcomes by combining the data from randomized clinical trials. Three trials meeting the eligibility criteria, and four randomized studies were included in the meta-analysis. For MCRC patients with KRAS wild type (KRAS-WT), the ORR was superior in patients treated with anti-EGFR compared with those who treated with anti-VEGF therapy. This effect was even better for all RAS-WT patients. Progression-free survival (PFS) rates were not significantly different for KRAS-WT mCRC and all RAS-WT mCRC between the two groups. The overall survival (OS) was higher for RAS wild-type (RAS-WT) mCRC patients who received anti-EGFR, but the KRAS-WT patients compared to the anti-VEGF therapy. The results of our research indicate that superior ORR and OS between the addition of anti-EGFR therapy VS anti-VEGF therapy in all RAS-WT patients with MCRC. There was no significant difference in OS and PFS between the two groups for KRAS-WT mCRC. These results suggest that anti- EGFR monoclonal antibodies can achieve an equivalent efficacy when compared with anti-VEGF therapy of all RAS-WT mCRC patients.

Effectiveness of Cetuximab as First-Line Therapy for Patients With Wild-Type KRAS and Unresectable Metastatic Colorectal Cancer in Real-Life Practice: Results of the EREBUS Cohort

INTRODUCTION

Few real-life data are available on cetuximab benefit. The EREBUS cohort was performed to assess metastases resection rate, use, safety, and survival outcomes in wild-type KRAS (Kirsten rat sarcoma viral oncogene) patients with initially unresectable metastatic colorectal cancer (mCRC) treated by cetuximab in real practice.

PATIENTS AND METHODS

The study cohort comprised patients initiating cetuximab between January 2009 and December 2010 in 65 French centers, with initially unresectable mCRC and wild-type KRAS. Kaplan-Meier analysis estimated 24-month probability of metastases resection and progression-free survival, and 36-month overall survival (OS). Cox proportional hazards models investigated factors associated with survival outcomes.

RESULTS

Among the 389 patients included, median age was 64 years, 67.4% were male, 77.9% had Eastern Cooperative Oncology Group performance status ≤ 1, and hepatic metastases were most frequent at baseline (n = 146 exclusively, n = 149 not exclusively, n = 94 nonliver only). Median duration of cetuximab use was 4.8 months. Metastases resection was performed in 106 patients (27.2%) (n = 60 liver exclusively, n = 33 not exclusively, n = 13 nonliver only). The 24-month probability (95% confidence interval) of metastases resection occurrence was 33.6% (28.5-39.3). Median progression-free survival was 9.2 (8.5-9.8) months for the total cohort and 13.0 (11.6-15.1) for those resected; median OS was 23.0 (20.6-26.3) months for the total cohort and was not reached after 36 months for those who were resected. The strongest factor associated with higher OS was metastases resection with complete remission (hazard ratio, 0.41; 95% confidence interval, 0.19-0.88).

CONCLUSION

This cohort study highlights in French real-life practice the benefit of cetuximab in first-line mCRC therapy, notably in case of metastases resection with complete remission.

Efficacy and safety of anti-epidermal growth factor receptor therapy compared with anti-vascular endothelial growth factor therapy for metastatic colorectal cancer in first-line and second-line therapies: a meta-analysis

Aim

This study aimed to compare anti-epidermal growth factor receptor (anti-EGFR) therapy and anti-vascular endothelial growth factor therapy as first-line and second-line therapies in patients with KRAS exon 2 codon 12/13 wild-type (KRAS-WT) metastatic colorectal cancer (mCRC).

Methods

Major databases were systematically searched. The hazard ratio (HR), odds ratio (OR), and 95% confidence intervals (95% CIs) were used to estimate the effect measures. Review Manager software version 5.3 was used for statistical analysis.

Results

Seven trials including ten articles were eligible in the meta-analysis. The patients treated with anti-EGFR as first-line therapy showed a longer overall survival (OS) for KRAS-WT and all RAS wild-type (RAS-WT) mCRC (HR =0.81, 95% CI: 0.72–0.92, P<0.01, n=5; HR =0.78, 95% CI: 0.66–0.93, P<0.01, n=3, respectively). The objective response rate (ORR) was better with the anti-EGFR therapy for KRAS-WT and all RAS-WT mCRC (OR =1.32, 95% CI: 1.11–1.56, P<0.01, n=5; OR =1.55, 95% CI: 1.21–2.00, P<0.01, n=3, respectively). There was no difference in progression-free survival (PFS) for KRAS-WT mCRC and all RAS-WT mCRC between the two groups (HR =1.00; 95% CI: 0.92–1.09, P=0.99, n=4; HR =0.92, 95% CI: 0.71–1.19, P=0.52, n=3, respectively). In addition, two trials provided data on the second-line therapy; there was no significant difference in OS and PFS for the second-line therapy, but a significant improvement in ORR was found in the anti-EGFR group (OR =1.91, 95% CI: 1.16–3.16, P=0.01, n=2). No difference in the conversion therapy (OR =1.34; 95% CI: 0.91–1.99; P=0.14, n=4) was observed between the two therapies.

Conclusion

Our results indicate that anti-EGFR therapy is superior to anti-vascular endothelial growth factor therapy for OS and ORR as a first-line therapy for KRAS-WT mCRC. In the second-line therapy, there was no significant difference in the survival outcomes on the basis of OS and PFS between the two groups. However, ORR improved significantly in the anti-EGFR group.

Primary tumor location is an important predictive factor for wild-type KRAS metastatic colon cancer treated with cetuximab as front-line bio-therapy

INTRODUCTION

Left- and right-sided colon cancers were significantly different in epidemiologic, clinical and histological parameters. However, the impact of primary tumor location in metastatic colon cancer treated with front-line targeted triplet regimens is unclear, particularly in Asian populations.

METHODS

A total of 121 patients with KRAS exon 2 codon 12/13 wild-type metastatic colon cancer were enrolled between January 2007 and December 2013. All patients received one target agent, such as cetuximab or bevacizumab, as a front-line targeted triplet regimen. The impact of primary tumor location for cetuximab and bevacizumab groups was analyzed, respectively.

RESULTS

In cetuximab group, left-sided metastatic colon cancer was superior to right-sided metastatic colon cancer in objective response rate (70.1% vs 33.3%, P = 0.024), progression-free survival (15.0 vs 5.3 months, P < 0.001) and overall survival (35.8 vs 14.4 months, P = 0.031). Primary tumor location was an independent prognostic factor for progression-free survival (hazard ratio 0.240, 95% confidence interval 0.114-0.508, P < 0.001). However, in the bevacizumab group, there were no differences in outcomes for either side. Primary tumor location was insignificant for progression-free survival and overall survival in univariate analysis.

CONCLUSION

Left-sided primary tumors were favored in cetuximab-based front-line targeted triplet regimen for metastatic colon cancer.