Metastatic colorectal cancer first-line treatment with bevacizumab: the impact of K-ras mutation

Discontinuation of first-line bevacizumab in metastatic colorectal cancer: the BEAWARE Italian Observational Study

AIMS

BEAWARE investigated the pattern of first-line bevacizumab early interruption in the Italian real-world setting of metastatic colorectal cancer.

METHODS

A total of 386 patients were followed for 15 months after first-line chemotherapy + bevacizumab start. The rate of bevacizumab interruption for progression or adverse drug reactions (ADRs) constituted the primary endpoint.

RESULTS

A total of 78.2% of patients interrupted bevacizumab: 56.6% for progression, 7.3% for ADRs, and 36.1% for other reasons. Median treatment duration was 6.7, 2.5, and 4.6 months, respectively. Median progression-free survival was 10.3 months; however, 35.8% of patients were not progressed and were thus censored at the data cutoff of 15 months, while 21.8% were still receiving bevacizumab. Patients discontinuing for progression/ADRs more frequently had metastases in >1 site (p = .0001), and a shorter median progression-free survival (6.9 vs 13.9 months, p < .0001).

CONCLUSIONS

In Italy, first-line bevacizumab is interrupted mainly for progression, only 7.3% due to adverse events, and about one third of cases for other reasons. In clinical practice, the attitude to treat until progression as per guidelines might be implemented. ClinicalTrials.gov Identifier: NCT01609075.

The best strategy for RAS wild-type metastatic colorectal cancer patients in first-line treatment: A classic and Bayesian meta-analysis

BACKGROUND

At present, there is uncertainty on the best systemic treatment in first-line setting for RAS wild-type (WT) metastatic colorectal cancer (mCRC) patients. Indeed, several chemotherapy and biologics combinations showed an improvement on survival. We performed a systematic review with a pair-wise and bayesan meta-analysis to rank the best strategy for these patients.

METHODS

A systematic literature search through March 2017 was performed to evaluate the association between several treatment combinations and overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and toxicity rate (TR) in RAS WT mCRC patients. Data were extracted from studies and pooled using the random-effect model for pair-wise meta-analyses and bayesan model for network meta-analysis (NMA).

RESULTS

Eight studies with a total of 2518 individuals were included in the meta-analyses. Pooled analyses for subgroups stratified by type of schedule and tumor location demonstrated that anti-EGFR + doublet had the best OS when compared to doublet ± bevacizumab (0.767; 95%CI, 0.695-0.846; P < 0.0001). This benefit is limited to LSCC when compared to a doublet-based schedule and doublet + bevacizumab (HRs, 0.692; 95%CI, 0.596-0.804; P < 0.001; 0.706; 95%CI, 0.584-0.854; P < 0.001; respectively). No significant differences are detected in PFS, whereas the cetuximab-based regimens showed the highest ORR and TR. In NMA our ranking showed the best performance for FOLFOX + panitumumab.

CONCLUSIONS

Our study indicates that FOLFOX + panitumumab has the major probability to provide an improvement of survival with a good safety profile in patients with RAS WT mCRC with an added value from selection based on sidedness.

Immunotherapy for the treatment of colorectal tumors: focus on approved and in-clinical-trial monoclonal antibodies

Colorectal cancer is considered a disease of the elderly population. Since the number of geriatric patients continues to rise, monoclonal antibody therapy is the most promising therapy in the recent research. Presently, the monoclonal antibodies most frequently used in the treatment of colorectal tumors are bevacizumab, cetuximab, panitumumab, and ramucirumab. Bevacizumab is a monoclonal antibody that acts on VEGF. Cetuximab and panitumumab act on EGFR. Ramucirumab binds directly to the ligand-binding pocket of VEGFR-2 to block the binding of VEGF-A, VEGF-C, and VEGF-D. These monoclonal antibodies, alone or in association with radiotherapy or chemotherapy, are presenting good results and are increasing patient survival, despite the side effects. Due to the limited number of molecules available, several studies are trying to develop new monoclonal antibodies for the treatment of colorectal tumors. Among those being studied, some recent molecules are in phase I and/or II trials and are yielding advantageous results, such as anti-DR5, anti-Fn14, anti-IGF-1R, anti-EGFR, anti-NRP1, and anti-A33 antibodies. This has been successful in reducing side effects and in treating nonresponsive patients.

Efficacy of bevacizumab and chemotherapy in the first-line treatment of metastatic colorectal cancer: broadening KRAS-focused clinical view

Background

The aim of the present retrospective study was to analyze clinical outcome and risk factors associated with treatment outcomes according to KRAS status in patient with metastatic colorectal cancer (mCRC) treated with bevacizumab (bev) plus chemotherapy in the first-line setting.

Methods

We performed observational study on 1622 patients with mCRC treated with bev plus oxaliplatin- or irinotecan-based chemotherapy, and correlated treatment outcomes with KRAS mutation status. The primary endpoint was progression-free survival (PFS) and additionally overall survival (OS). Adverse events of bevacizumab and risk factors including location of metastases were evaluated.

Results

Mutation in KRAS was present in 40.6% of mCRC cases. The median PFS in patients with wild-type KRAS (wtKRAS) vs mutant KRAS was 11.5 vs 11.4 months, respectively. The median OS was 30.7 vs 28.4 months (p = 0.312). Patients with KRAS mutation had lung metastases more frequently than wtKRAS individuals (32.0% vs 23.8%; p = 0.001). We observed no difference in clinical outcome between hepatic and extrahepatic metastatic disease.

Conclusion

KRAS mutation does not interfere with clinical benefit from first-line treatment with bevacizumab plus chemotherapy in mCRC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0266-6) contains supplementary material, which is available to authorized users.

Combinations of vascular endothelial growth factor pathway inhibitors with metronomic chemotherapy: Rational and current status

Chemotherapy given in a metronomic manner can be administered with less adverse effects which are common with conventional schedules such as myelotoxicity and gastrointestinal toxicity and thus may be appropriate for older patients and patients with decreased performance status. Efficacy has been observed in several settings. An opportunity to improve the efficacy of metronomic schedules without significantly increasing toxicity presents with the addition of anti-angiogenic targeted treatments. These combinations rational stems from the understanding of the importance of angiogenesis in the mechanism of action of metronomic chemotherapy which may be augmented by specific targeting of the vascular endothelial growth factor (VEGF) pathway by antibodies or small tyrosine kinase inhibitors. Combinations of metronomic chemotherapy schedules with VEGF pathway targeting drugs will be discussed in this paper.