Impact of Delayed Addition of Anti-EGFR Monoclonal Antibodies on the Outcome of First-Line Therapy in Metastatic Colorectal Cancer Patients: a Retrospective Registry-Based Analysis

Impact of Delaying the Addition of Anti-EGFR in First Line of RAS Wild-Type Metastatic Colorectal Cancer: A Propensity-Weighted Pooled Data Analysis

Simple Summary

The first-line therapy of patients with RAS wild-type (WT) non-resectable metastatic colorectal cancer (mCRC) is usually 5-fluorouracil-based chemotherapy with either bevacizumab or an anti-epidermal growth factor receptor (EGFR). The introduction of anti-epidermal growth factor antibodies is commonly delayed because of late RAS testing results. Our objective was to evaluate the impact on the overall survival of delayed anti-EGFR introduction strategy. This study compared 305 patients with delayed anti-EGFR introductions, 401 with immediate anti-EGFRs, and 129 with immediate anti-VEGFs. The study suggests that delayed introduction has no deleterious impact on survival compared to the immediate introduction of an anti-EGFR or of an anti-VEGF.

Abstract

The first-line therapy of patients with RAS wild-type (WT) non-resectable metastatic colorectal cancer (mCRC) is usually 5-fluorouracil-based chemotherapy with either bevacizumab or an anti-epidermal growth factor receptor (EGFR). The addition of anti-EGFR antibodies is commonly delayed in clinical practice because of late RAS testing results. Our objective was to evaluate the impact on overall survival (OS) of a delayed anti-EGFR introduction strategy. This study pooled the data of two large retrospective studies. Patients with RAS WT non-resectable mCRC, treated in first line by a doublet chemotherapy with an anti-EGFR introduced with a delay of 2 to 4 cycles, were compared to an anti-EGFR and to an anti-VEGF that was introduced immediately. Patients numbering 305 in the delayed anti-EGFR group, 401 in the immediate anti-EGFR group, and 129 in the immediate anti-VEGF group were analyzed. After propensity scoring, there was no difference between the characteristics of the three groups. Median OS was 28.6 months (95% CI: 23.5–34.1) in the immediate anti-EGFR group, 35.1 (95% CI: 29.9–43.5) in the delayed anti-EGFR group, and 32.4 (95% CI: 25.4–44.8) in the immediate anti-VEGF group. There was no significant difference concerning median OS (p = 0.24) or progression-free survival (p = 0.56). This study suggests that delaying the introduction of an anti-EGFR has no deleterious impact on survival compared to the immediate introduction of an anti-VEGF or of an anti-EGFR.

Characteristics and Absolute Survival of Metastatic Colorectal Cancer Patients Treated With Biologics: A Real-World Data Analysis From Three European Countries

Introduction: Biologics were approved for the treatment of advanced colorectal cancer (CRC) based on favorable benefit-risk-assessments from randomized controlled trials (RCTs), but evidence on their use in the real-world setting is scarce. Based on descriptive analyses we therefore aimed to assess characteristics and survival of CRC patients treated with biologics using large healthcare databases from three European countries (Netherlands, Italy, Germany).

Methods: We included CRC patients treated with a biologic in 2010 or 2014 and characterized them regarding age, sex, comorbidities, and absolute survival.

Results: Among 4,758 patients, the mean age ranged from 64.8 to 66.8 years, the majority was male, and comorbidities used as exclusion criteria in RCTs were coded in up to 30% of these patients. The proportion of bevacizumab users decreased between 2010 (72–93%) and 2014 (63–85%). In 2014, the absolute 12-month survival in new users was 64% (95% CI 51–77%), 56% (30–80%), and 61% (58–63%) in the Dutch, Italian, and German database, respectively, varying by age and comorbidity.

Conclusions: Our study suggests that in the real-world setting, CRC patients treated with biologics are older and less selected regarding comorbidities compared to patients in RCTs, potentially explaining the relatively low 12-month survival we found. Treatment decisions in the real-world setting may require careful evaluation given that the risk-benefit ratio may vary depending on age and co-existing conditions.

Sequential Treatment with Bevacizumab and Aflibercept for Metastatic Colorectal Cancer in Real-World Clinical Practice

BACKGROUND

Bevacizumab and aflibercept are currently the mainstay of antiangiogenic therapy for metastatic colorectal carcinoma (mCRC). They are often used in sequence with first- and second-line chemotherapy, especially in patients with RAS-mutated tumours.

OBJECTIVE

The aim of the present study was to investigate the outcomes of patients with mCRC treated with the bevacizumab-aflibercept sequence in real-world clinical practice.

PATIENTS AND METHODS

Data from a national clinical registry of targeted therapies for mCRC were analysed retrospectively. Overall, there were 366 patients with valid data who received first-line treatment with bevacizumab and chemotherapy followed by aflibercept with chemotherapy. The majority of the patients (n = 296, 80.8%) had RAS mutated tumours.

RESULTS

Median cumulative progression-free survival (PFS) from the start of the bevacizumab-containing regimen to progression on aflibercept was 18.2 months (95% CI 16.8-19.5). Median PFS for bevacizumab and aflibercept was 10.6 months (95% CI 9.5-11.7) and 5.6 months (95% CI 5.1-6.1), respectively. Longer PFS on aflibercept was associated with metachronous metastatic disease and longer PFS on bevacizumab. Median overall survival (OS) from the start of first-line bevacizumab was 32.0 months (95% CI 26.6-37.5). The presence of metastatic disease at diagnosis was associated with worse OS.

CONCLUSIONS

Patients treated with aflibercept in real-world clinical practice achieved similar survival outcomes as those treated within randomised trials. Cumulative survival data provide a benchmark for future studies and enable indirect comparisons with other treatment sequences used in mCRC.

Withholding the Introduction of Anti-Epidermal Growth Factor Receptor: Impact on Outcomes in RAS Wild-Type Metastatic Colorectal Tumors: A Multicenter AGEO Study (the WAIT or ACT Study)

BACKGROUND

Patients with RAS wild-type (WT) nonresectable metastatic colorectal cancer (mCRC) may receive either bevacizumab or an anti-epidermal growth factor receptor (EGFR) combined with first-line, 5-fluorouracil-based chemotherapy. Without the RAS status information, the oncologist can either start chemotherapy with bevacizumab or wait for the introduction of the anti-EGFR. Our objective was to compare both strategies in a routine practice setting.

MATERIALS AND METHODS

This multicenter, retrospective, propensity score-weighted study included patients with a RAS WT nonresectable mCRC, treated between 2013 and 2016 by a 5-FU-based chemotherapy, with either delayed anti-EGFR or immediate anti-vascular endothelial growth factor (VEGF). Primary criterion was overall survival (OS). Secondary criteria were progression-free survival (PFS) and objective response rate (ORR).

RESULTS

A total of 262 patients (129 in the anti-VEGF group and 133 in the anti-EGFR group) were included. Patients receiving an anti-VEGF were more often men (68% vs. 56%), with more metastatic sites (>2 sites: 15% vs. 9%). The median delay to obtain the RAS status was 19 days (interquartile range: 13-26). Median OS was not significantly different in the two groups (29 vs. 30.5 months, p = .299), even after weighting on the propensity score (hazard ratio [HR] = 0.86, 95% confidence interval [CI], 0.69-1.08, p = .2024). The delayed introduction of anti-EGFR was associated with better median PFS (13.8 vs. 11.0 months, p = .0244), even after weighting on the propensity score (HR = 0.74, 95% CI, 0.61-0.90, p = .0024). ORR was significantly higher in the anti-EGFR group (66.7% vs. 45.6%, p = .0007).

CONCLUSION

Delayed introduction of anti-EGFR had no deleterious effect on OS, PFS, and ORR, compared with doublet chemotherapy with anti-VEGF.

IMPLICATIONS FOR PRACTICE

For RAS/RAF wild-type metastatic colorectal cancer, patients may receive 5-fluorouracil-based chemotherapy plus either bevacizumab or an anti-epidermal growth factor receptor (EGFR). In daily practice, the time to obtain the RAS status might be long enough to consider two options: to start the chemotherapy with bevacizumab, or to start without a targeted therapy and to add the anti-EGFR at reception of the RAS status. This study found no deleterious effect of the delayed introduction of an anti-EGFR on survival, compared with the introduction of an anti-vascular endothelial growth factor from cycle 1. It is possible to wait one or two cycles to introduce the anti-EGFR while waiting for RAS status.

Sequential therapy with bevacizumab and EGFR inhibitors for metastatic colorectal carcinoma: a national registry-based analysis

Purpose

Although inhibitors of vascular endothelial growth factor and inhibitors of epidermal growth factor receptor (EGFRi) are commonly used for the treatment of metastatic colorectal cancer (mCRC), the optimal sequencing of these agents is currently unclear.

Methods

A national registry of targeted therapies was used to analyze baseline characteristics and outcomes of patients with mCRC and wild-type KRAS exon 2 status who received bevacizumab and EGFRi (cetuximab or panitumumab) as a part of first- and second-line treatment in either sequence.

Results

The cohort included 490 patients (181 patients treated with first-line EGFRi and second-line bevacizumab and 309 patients treated with first-line bevacizumab and second-line EGFRi). Median overall survival (OS) from the initiation on first-line therapy was similar for patients treated with either sequence, reaching 31.8 (95% CI 27.5-36.1) vs 31.4 months (95% CI 27.8-35.0) for EGFRi → bevacizumab vs bevacizumab → EGFRi cohort, respectively. Time from first-line initiation to progression on the second-line therapy [progression-free survival (PFS)] was 21.1 (95% CI 19.3-23.0) vs 19.3 months (95% CI 17.3-21.3) for bevacizumab → EGFRi vs EGFRi → bevacizumab cohort, respectively (P=0.016).

Conclusion

This retrospective analysis of real-world data of patients with wild-type KRAS exon 2 mCRC showed no differences in OS between cohorts treated with bevacizumab → EGFRi vs the reverse sequence while combined PFS favored the bevacizumab → EGFRi sequence.