Maintenance single-agent bevacizumab or observation after first-line chemotherapy in patients with metastatic colorectal cancer: a multicenter retrospective study

Optimizing the first-line treatment for metastatic colorectal cancer

Colorectal cancer represents an important oncological challenge both for its incidence, which makes it an important health problem, and for its biological complexity, which has made clinical results very difficult in terms of outcome for this category of patients. To date these diseases should not be treated as a single entity but it is necessary to distinguish colorectal cancers based on characteristics that nowadays are essential to have greater therapeutic benefits. These include the sideness of the disease, the state of microsatellites, the presence of prognostic and predictive mutations of response to treatments currently available in clinical practice, which are associated with new therapeutic targets. The greatest challenge in the future will be to circumvent the resistance mechanisms that make this disease very difficult to treat with good long-term results by studying effective combination treatments with a good toxicity profile. Once such combinations or targeted treatments are consolidated, it will be desirable to shift the best therapies to the first line treatment to make them immediately accessible to the patient. It will also be essential to refine the selection of patients who can benefit from these treatments.

A Retrospective Exploration of Targeted Maintenance Therapy in Advanced Colorectal Cancer: Based on the Background of Chinese Patient Assistance Program

Background: Maintenance therapy with bevacizumab (Bev) in patients with colorectal cancer (CRC) provides progression-free survival (PFS) benefits. However, the role of maintenance therapy with an anti-EGFR monoclonal antibody has not been established.

Methods: Eligible CRC patients were assigned to maintenance therapy with cetuximab (Cet; Cet group) or Bev (Bev group). PFS, the duration of maintenance therapy, and safety were analyzed. Cox multivariate regression analyses were performed to determine independent prognostic factors.

Results: A total of 143 eligible patients were assigned to the Cet (n = 79) or Bev (n = 64) groups. In the Cet group, all patients had KRAS wild-type. The baseline characteristics were well-balanced between the two groups, except for a higher percentage of patients with a left-sided primary tumor in the Cet group than in the Bev group (86.1 vs. 62.5%, P < 0.0001). The median PFS was not significantly different between the Cet group and the Bev group: 5.9 months (95% CI 2.30–9.50) vs. 7.0 months (95% CI 3.69–10.31) (HR 1.17, 95% CI 0.77–1.79, P = 0.45). The median duration of maintenance therapy in the Cet group was shorter than that in the Bev group: 4.0 months (95% CI 1.94–5.99) vs. 4.8 months (95% CI 2.68–6.98) (HR 0.90, 95% CI 0.61–1.33; P = 0.59). The subgroup analyses showed that the median PFS for the first maintenance therapy and the second maintenance therapy were 3.2 months (95% CI 1.69–4.78) and 5.2 months (95% CI 1.58–8.83), respectively (HR 0.89, 95% CI 0.44–1.81; P = 0.75).

Conclusions: This study suggests that maintenance therapy with Cet or Bev can be considered an appropriate option following induction chemotherapy for selected patients with advanced CRC. Multiple maintenance therapy seems to confer survival benefits in advanced CRC. Maintenance therapy with Cet after first-line induction chemotherapy seems to be associated with greater survival benefits.

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.

Survival Benefit and Safety of Bevacizumab in Combination with Erlotinib as Maintenance Therapy in Patients with Metastatic Colorectal Cancer: A Meta-Analysis

BACKGROUND

Recently, the need for maintenance chemotherapy arose as a result of the significantly improved survival of patients with metastatic colorectal cancer (mCRC) without increasing adverse events. Currently used maintenance regimens are fluoropyrimidines, bevacizumab, and the combination of fluoropyrimidine with bevacizumab. A new combination with bevacizumab and erlotinib, a tyrosine kinase inhibitor of the epithelial growth factor receptor, has shown synergistic effects in preclinical tests and promising results in some clinical trials. Whether bevacizumab combined with erlotinib vs. bevacizumab alone as maintenance therapy will further improve the clinical outcomes in patients with mCRC is controversial. We conducted this meta-analysis to compare the survival benefit and safety of these two regimens in patients with mCRC.

METHODS

We searched PubMed, EMBASE, and the Central Registry of Controlled Trials of the Cochrane Library up to August 2016. We also searched the Proceedings of the American Society of Clinical Oncology (1986 to August 2016). Abstracts were manually searched to identify relevant trials. A total of three randomized controlled trials with 682 patients met the inclusion criteria.

RESULTS

Our results demonstrated that bevacizumab combined with erlotinib significantly improved overall survival (hazard ratio 0.78; 95 % confidence interval 0.66-0.93; p = 0.006) and progression-free survival (hazard ratio 0.79; 95 % confidence interval 0.68-0.92; p = 0.002). Significantly more grade 3 rash, diarrhea, infection total, and fatigue were observed in the bevacizumab combined with erlotinib arm, which were controllable and reversible.

CONCLUSIONS

Based on current evidence, the addition of erlotinib to bevacizumab as maintenance therapy significantly increases overall survival and progression-free survival with an increased but manageable toxicity in patients with mCRC. It should be considered as a treatment option for these patients under the premise of a reasonable selection of the target population.

Quality of life assessment in patients with metastatic colorectal cancer receiving maintenance therapy after first-line induction treatment: a preplanned analysis of the phase III AIO KRK 0207 trial

BACKGROUND

First-line maintenance strategies are a current matter of debate in the management of mCRC. Their impact on patient's health-related quality of life (HRQOL) has not yet been evaluated. The objective of this study was to assess whether differences in HRQOL during any active maintenance treatment compared with no maintenance treatment exist.

PATIENT AND METHODS

Eight hundred and thirty-seven patients were enrolled in the AIO KRK 0207 trial. Four hundred and seventy-two underwent randomization (after 24 weeks of induction treatment) into one of the maintenance arms: FP plus Bev (arm A), Bev alone (arm B), or no active treatment (arm C). HRQOL were assessed every 6 weeks during induction and maintenance treatment independent from treatment stop, delay, or modification, and also continued after progression, using the EORTC QLQ-C30, QLQ-CR29. The mean value of the global quality of life dimension (GHS/QoL) of the EORTC QLQ-C30, calculated as the average of all available time points after randomization was considered as pre-specified main endpoint. Additionally, EORTC QLQ-C30 response scores were analyzed.

RESULTS

For HRQOL analysis, 413 patients were eligible (arm A: 136; arm B: 142, arm C: 135). Compliance rate with the HRQOL questionnaires was 95% at time of randomization and remained high during maintenance (98%, 99%, 97% and 97% at week 6, 12, 18 and 24). No significant differences between treatment arms in the mean GHS/QoL scores were observed at any time point. Also, rates of GHS/QoL score deterioration were similar (20.5%; 17.2% and 20.7% of patients), whereas a score improvement occurred in 36.1%; 43.8% and 42.1% (arms A, B and C).

CONCLUSION

Continuation of an active maintenance treatment with FP/Bev after induction treatment was neither associated with a detrimental effect on GHS/QoL scores when compared with both, less active treatment with Bev alone or no active treatment.

CLINICAL TRIALS NUMBER

NCT00973609 (ClinicalTrials.gov).

Bevacizumab in combination with fluoropyrimidine-irinotecan- or fluoropyrimidine-oxaliplatin-based chemotherapy for first-line and maintenance treatment of metastatic colorectal cancer

Despite a slight decrease in mortality rates, recent advances in screening methods, diagnosis and overall improved therapeutic options, colorectal cancer (CRC) remains among the leading causes of cancer-related death worldwide. The major cause is the mortality related to metastatic status of CRC. Increasing clinical evidence derived from randomized trials strongly suggests that the efficacy of standard cytotoxic agents, including various combinations of 5-fluoouracil (5-FU)/leucovorin (LV), capecitabine, irinotecan and oxaliplatin, may be significantly augmented with concomitant administration of molecular agents targeting the vascular endothelial growth factor (VEGF) signaling pathways, such as bevacizumab. Herein, we critically discuss the current data on the efficacy and safety profile of bevacizumab in combination with fluoropyrimidine-based chemotherapy for first-line and maintenance treatment of metastatic CRC and briefly comment on existing controversies and future perspectives.

Anti-angiogenic agents in metastatic colorectal cancer

Colorectal cancer (CRC) is a major public health concern being the third leading cause of cancer mortality in the United States. The availability of better therapeutic options has led to a decline in cancer mortality in these patients. Surgical resection should be considered in all stages of the disease. The use of conversion therapy has made surgery a potentially curative option even in patients with initially unresectable metastatic disease. In this review we discuss the role of various anti-angiogenic agents in patients with metastatic CRC (mCRC). We describe the mechanism of action of these agents, and the rationale for their use in combination with chemotherapy. We also review important clinical studies that have evaluated the safety and efficacy of these agents in mCRC patients. Despite the discovery of several promising anti-angiogenic agents, mCRC remains an incurable disease with a median overall survival of just over 2 years in patients exposed to all available treatment regimens. Further insights into tumor biology and tumor microenvironment may help improve outcomes in these patients.

Molecularly targeted drugs for metastatic colorectal cancer

The survival rate of patients with metastatic colorectal cancer (mCRC) has significantly improved with applications of molecularly targeted drugs, such as bevacizumab, and led to a substantial improvement in the overall survival rate. These drugs are capable of specifically targeting the inherent abnormal pathways in cancer cells, which are potentially less toxic than traditional nonselective chemotherapeutics. In this review, the recent clinical information about molecularly targeted therapy for mCRC is summarized, with specific focus on several of the US Food and Drug Administration-approved molecularly targeted drugs for the treatment of mCRC in the clinic. Progression-free and overall survival in patients with mCRC was improved greatly by the addition of bevacizumab and/or cetuximab to standard chemotherapy, in either first- or second-line treatment. Aflibercept has been used in combination with folinic acid (leucovorin)-fluorouracil-irinotecan (FOLFIRI) chemotherapy in mCRC patients and among patients with mCRC with wild-type KRAS, the outcomes were significantly improved by panitumumab in combination with folinic acid (leucovorin)-fluorouracil-oxaliplatin (FOLFOX) or FOLFIRI. Because of the new preliminary studies, it has been recommended that regorafenib be used with FOLFOX or FOLFIRI as first- or second-line treatment of mCRC chemotherapy. In summary, an era of new opportunities has been opened for treatment of mCRC and/or other malignancies, resulting from the discovery of new selective targeting drugs.