Cetuximab: a guide to its use in combination with FOLFIRI in the first-line treatment of metastatic colorectal cancer in the USA

Efficacy of apatinib combined with FOLFIRI in the first-line treatment of patients with metastatic colorectal cancer

Objective. To evaluate the efficacy and safety of apatinib combined with FOLFIRI in the first-line treatment of advanced metastatic colorectal cancer (mCRC) and explore potential factors of efficacy. Methods. Twenty mCRC patients treated at Affiliated Cancer Hospital of Shanxi Medical University from March 2017 to March 2019 were included according to the enrolment criteria. They provided informed consent and were treated with apatinib combined with FOLFIRI according to the scheduled regimen until disease progression or unacceptable toxicity occurred. The primary endpoint was OS. The secondary endpoints included PFS, ORR, DCRand safety. OS and PFS were calculated using Kaplan–Meier curves. Univariate and multivariate Cox regression analyses were used to evaluate independent prognostic factors of OS and PFS. R was used to determine cut-off values for biochemical indicators. Forest maps were drawn for Cox univariate results and the relationships between NLR and ECOG, which were significant in univariate analysis, and OS were represented by Kaplan–Meier curves. Results. The median OS and PFS were 16.135 months (95% CI: 9.211–22.929) and 6 months (95% CI: 5.425–6.525). Multivariate Cox analysis showed that NLR and CEA were independent prognostic factors. The most common grade 3–4 adverse events were hypertension, diarrhoea, increased alkaline phosphatase, decreased leukocytes and decreased neutrophils. Conclusion. Apatinib combined with FOLFIRI for the first-line treatment of advanced unresectable mCRC showed good efficacy and safety. The baseline NLR was predictive of efficacy, and a low baseline NLR (HR: 0.2895, P = 0.0084) was associated with improved OS.

Clinical Research Registration Number: ChiCTR1800015308.

Overall survival of patients with KRAS wild-type tumor treated with FOLFOX/FORFIRI±cetuximab as the first-line treatment for metastatic colorectal cancer: A meta-analysis

The addition of cetuximab to FOLFIRI or FOLFOX as the first-line treatment for metastatic colorectal cancer (mCRC) was shown to reduce the risk of disease progression and increase the chance of response in patients with KRAS wild-type disease. An updated systematic meta-analysis was undertaken to determine the efficacy of cetuximab plus FOLFIRI or FOLFOX.Major databases were searched to identify RCTs investigating wild-type KRAS mCRC after the first-line treatment, and treatment with FOLFOX/FORFIRI ± cetuximab was compared. Data on clinical efficacy and safety were pooled and compared by ORs, HRs, and 95% CIs.Five eligible trials with 1464 patients were included in the meta-analysis. Compared to FOLFOX/FORFIRI, cetuximab as the first-line therapy has improved overall survival (OS) (hazard ratio [HR] = 0.82, 95% confidence interval [CI]: 0.72-0.93, P = 0.003), progression-free survival (PFS) (HR = 0.66, 95% CI: 0.56 -0.77, P < 0.00001), and overall response rate (ORR) (odds ratio [OR] = 2.12, 95% CI: 1.70-2.65, P < 0.00001). However, Grade 3/4 AE was increased with the OR of 2.76 (95%CI: 2.01-3.78, P < 0.00001). The most common grade 3/4 toxicity in the wild-type KRAS population was neutropenia and diarrhea. For cetuximab plus FOLFIRI, there was a higher incidence of grade 3 or 4 diarrhea (OR = 1.76, 95% CI: 1.15-2.70, P = 0.01), but there was no significant difference for neutropenia (OR = 1.35, 95% CI: 1.00-1.83, P = 0.05).The addition of cetuximab in mCRC as the first-line treatment is a potential effective approach in the improved outcomes but associated with increased toxicity.

FCGR2A, FCGR3A polymorphisms and therapeutic efficacy of anti-EGFR monoclonal antibody in metastatic colorectal cancer

Anti-EGFR monoclonal antibodies (mAb) such as cetuximab, panitumumab are one kind of efficacious targeted drugs in treatment of metastatic colorectal cancer (mCRC). However, only a small proportion of patients harbored wild-KRAS genotype can benefit from it. We hypothesized that personal genetic heterogeneity might be the main cause leading to obvious difference in its clinical efficacy. A retrospective study including 82 mCRC patients treated with chemotherapy plus cetuximab and a comprehensive meta-analysis containing 2831 cases within sixteen eligible studies were conducted to investigate the possible association between FCGR2A H131R and FCGR3A V158F and clinical outcome of mCRC patients treated with anti-EGFR mAb based therapy. Results of the retrospective study showed that H131R within FCGR2A or V158F within FCGR3A were not associated with clinical outcome in 82 KRAS wild chemorefractory mCRC patients in co-dominant, dominant, recessive, over-dominant, allele genetic models. However, the comprehensive meta-analysis with the largest of sample size obtained the significant result between FCGR3A V158F and PFS (FV/VV vs. FF: P_h = 0.027, MSR = 0.680, 95%CI = 0.549−0.842 in overall population; P_h = 0.12, MSR = 0.728, 95%CI = 0.648–0.818 in KRAS wild population) and OS (VV vs. FF: P_h < 0.001, MSR = 0.733, 95%CI = 0.578−0.930 in overall population). These findings indicate that KRAS wild chemorefractory mCRC individual harbored genotype FF of V158Fcan benefit from anti-EGFR mAb adjuvant therapy in terms of PFS and OS, and it may be useful genetic biomarker to predict clinical survival of mCRC individuals with anti-EGFR mAb based therapy.

Clinical application of genetics in management of colorectal cancer

The extensive study of genetic alterations in colorectal cancer (CRC) has led to molecular diagnostics playing an increasingly important role in CRC diagnosis and treatment. Currently, it is believed that CRC is a consequence of the accumulation of both genetic and epigenetic genomic alterations. It is known that there are at least 3 major pathways that lead to colorectal carcinogenesis: (1) the chromosomal instability pathway, (2) the microsatellite instability pathway, and (3) the cytosine-phospho-guanine island methylator phenotype pathway. With recent advances in CRC genetics, the identification of specific molecular alterations responsible for CRC pathogenesis has directly influences clinical care. Patients at high risk for developing CRC can be identified by genetic testing for specific molecular alterations, and the use of molecular biomarkers for predictive and prognostic purposes is also increasing. This is clearly supported by the recent advances in genetic testing for CRC whereby specific molecular alterations are identified for the purpose of guiding treatment with targeting therapies such as anti-endothelial growth factor receptor monoclonal antibodies.