EGFR expression as a predictor of survival for first-line chemotherapy plus cetuximab in patients with advanced non-small-cell lung cancer: analysis of data from the phase 3 FLEX study.

BACKGROUND: Findings from the phase 3 First-Line ErbituX in lung cancer (FLEX) study showed that the addition of cetuximab to first-line chemotherapy significantly improved overall survival compared with chemotherapy alone (hazard ratio [HR] 0·871, 95% CI 0·762-0·996; p=0·044) in patients with advanced non-small-cell lung cancer (NSCLC). To define patients benefiting most from cetuximab, we studied the association of tumour EGFR expression level with clinical outcome in FLEX study patients. METHODS: We used prospectively collected tumour EGFR expression data to generate an immunohistochemistry score for FLEX study patients on a continuous scale of 0-300. We used response data to select an outcome-based discriminatory threshold immunohistochemistry score for EGFR expression of 200. Treatment outcome was analysed in patients with low (immunohistochemistry score <200) and high (≥200) tumour EGFR expression. The primary endpoint in the FLEX study was overall survival. We analysed patients from the FLEX intention-to-treat (ITT) population. The FLEX study is registered with ClinicalTrials.gov, number NCT00148798. FINDINGS: Tumour EGFR immunohistochemistry data were available for 1121 of 1125 (99·6%) patients from the FLEX study ITT population. High EGFR expression was scored for 345 (31%) evaluable patients and low for 776 (69%) patients. For patients in the high EGFR expression group, overall survival was longer in the chemotherapy plus cetuximab group than in the chemotherapy alone group (median 12·0 months [95% CI 10·2-15·2] vs 9·6 months [7·6-10·6]; HR 0·73, 0·58-0·93; p=0·011), with no meaningful increase in side-effects. We recorded no corresponding survival benefit for patients in the low EGFR expression group (median 9·8 months [8·9-12·2] vs 10·3 months [9·2-11·5]; HR 0·99, 0·84-1·16; p=0·88). A treatment interaction test assessing the difference in the HRs for overall survival between the EGFR expression groups suggested a predictive value for EGFR expression (p=0·044). INTERPRETATION: High EGFR expression is a tumour biomarker that can predict survival benefit from the addition of cetuximab to first-line chemotherapy in patients with advanced NSCLC. Assessment of EGFR expression could offer a personalised treatment approach in this setting. FUNDING: Merck KGaA.

Gemcitabine administered as a short infusion versus a fixed dose rate in combination with cisplatin for the treatment of patients with advanced non-small cell lung cancer.

Previous studies have indicated that, in combination with cisplatin, fixed dose rate gemcitabine may be more efficacious than standard infusion gemcitabine. This open-label, randomised phase II study was aimed to compare the efficacy and safety of these regimens as treatment for advanced non-small cell lung cancer (NSCLC) in Latin American patients. Sixty-four patients were randomised to receive up to six cycles of treatment with cisplatin 75 mg/m(2) on Day 1 plus either gemcitabine 1000 mg/m(2) over 30 min on Days 1 and 8 of a 21-day cycle (standard arm, N=33) or gemcitabine 1000 mg/m(2) at a fixed dose rate of 10 mg/m(2)/min on Days 1 and 8 of a 21-day cycle (FDR arm, N=31). In the standard arm, 9 of 33 (27%) patients responded compared with 6 of 30 (20%) patients in the FDR arm (odds ratio: 0.67, 95% CI, 0.21-2.2; p=0.56). Median overall survival was 7.5 months in the standard arm and 9.9 months in the FDR arm. One-year survival rates were 35% and 37% in the standard arm and the FDR arm, respectively. Patients in the FDR arm experienced more grade 3/4 haematological toxicity than those in the standard arm (48% versus 21%). The results of this trial do not support FDR administration of gemcitabine in preference to the standard administration in Latin American patients with NSCLC.