68O EFFICACY, SAFETY AND TOLERABILITY RESULTS FROM A PHASE IV, OPEN-LABEL, SINGLE ARM STUDY OF 1ST-LINE GEFITINIB IN CAUCASIAN PATIENTS (PTS) WITH EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) MUTATION-POSITIVE NON-SMALL-CELL LUNG CANCER (NSCLC)

What is the best strategy for targeting EGF receptors in non-small-cell lung cancer?

EGF receptors (EGFRs) are often overexpressed or constitutively activated in non-small-cell lung cancer, and are an important therapeutic target. EGFR signaling can be blocked with tyrosine kinase inhibitors (TKIs) and anti-EGFR antibodies. Three EGFR-TKIs are approved as initial monotherapies in patients with EGFR-activating mutations, and erlotinib has a role as maintenance and second-line therapy. Investigational anti-EGFR monoclonal antibodies plus standard first-line therapy improve survival in patients with advanced non-small-cell lung cancer, especially in tumors with high EGFR expression. Anti-EGFR antibodies inhibit EGFR signaling and have the potential to stimulate antibody-dependent cell-mediated cytotoxicity. Multikinase TKIs are investigational as first- and second-line therapies, as monotherapies and in combination with chemotherapy. This article summarizes the available clinical data for EGFR-targeted therapies.

Pooled analysis of clinical outcome for EGFR TKI-treated patients with EGFR mutation-positive NSCLC

Patients with non-small-cell lung cancer (NSCLC) appear to gain particular benefit from treatment with epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKI) if their disease tests positive for EGFR activating mutations. Recently, several large, controlled, phase III studies have been published in NSCLC patients with EGFR mutation-positive tumours. Given the increased patient dataset now available, a comprehensive literature search for EGFR TKIs or chemotherapy in EGFR mutation-positive NSCLC was undertaken to update the results of a previously published pooled analysis. Pooling eligible progression-free survival (PFS) data from 27 erlotinib studies (n = 731), 54 gefitinib studies (n = 1802) and 20 chemotherapy studies (n = 984) provided median PFS values for each treatment. The pooled median PFS was: 12.4 months (95% accuracy intervals [AI] 11.6-13.4) for erlotinib-treated patients; 9.4 months (95% AI 9.0-9.8) for gefitinib-treated patients; and 5.6 months (95% AI 5.3-6.0) for chemotherapy. Both erlotinib and gefitinib resulted in significantly longer PFS than chemotherapy (permutation testing; P = 0.000 and P = 0.000, respectively). Data on more recent TKIs (afatinib, dacomitinib and icotinib) were insufficient at this time-point to carry out a pooled PFS analysis on these compounds. The results of this updated pooled analysis suggest a substantial clear PFS benefit of treating patients with EGFR mutation-positive NSCLC with erlotinib or gefitinib compared with chemotherapy.

Advanced non-small-cell lung cancer with epidermal growth factor receptor mutations: current evidence and future perspectives

The identification of activating mutations in the tyrosine kinase domain of the EGF receptor (EGFR) predictive of response to tyrosine kinase inhibitors (TKIs) led to a therapeutic revolution in the treatment of patients with metastatic non-small-cell lung cancer (NSCLC). To date, eight randomized clinical trials have demonstrated that first-line treatment with TKIs in advanced NSCLC patients harboring activating EGFR mutations is associated with significant improvement in response rate, progression-free survival, quality of life and tolerability, compared with platinum-based chemotherapy. These results prompted the EGFR TKIs as the current standard first-line treatment of patients with advanced NSCLC harboring activating EGFR mutations. However, there are several questions that need to be addressed, including the best choice among different EGFR TKIs, the treatment of resistant disease and of patients with specific clinical conditions. Ongoing and future, well-designed trials should answer all these questions.

Afatinib versus cisplatin plus gemcitabine for first-line treatment of Asian patients with advanced non-small-cell lung cancer harbouring EGFR mutations (LUX-Lung 6): an open-label, randomised phase 3 trial

BACKGROUND

Afatinib-an oral irreversible ErbB family blocker-improves progression-free survival compared with pemetrexed and cisplatin for first-line treatment of patients with EGFR mutation-positive advanced non-small-cell lung cancer (NSCLC). We compared afatinib with gemcitabine and cisplatin-a chemotherapy regimen widely used in Asia-for first-line treatment of Asian patients with EGFR mutation-positive advanced NSCLC.

METHODS

This open-label, randomised phase 3 trial was done at 36 centres in China, Thailand, and South Korea. After central testing for EGFR mutations, treatment-naive patients (stage IIIB or IV cancer [American Joint Committee on Cancer version 6], performance status 0-1) were randomly assigned (2:1) to receive either oral afatinib (40 mg per day) or intravenous gemcitabine 1000 mg/m(2) on day 1 and day 8 plus cisplatin 75 mg/m(2) on day 1 of a 3-week schedule for up to six cycles. Randomisation was done centrally with a random number-generating system and an interactive internet and voice-response system. Randomisation was stratified by EGFR mutation (Leu858Arg, exon 19 deletions, or other; block size three). Clinicians and patients were not masked to treatment assignment, but the independent central imaging review group were. Treatment continued until disease progression, intolerable toxic effects, or withdrawal of consent. The primary endpoint was progression-free survival assessed by independent central review (intention-to-treat population). This study is registered with ClinicalTrials.gov, NCT01121393.

FINDINGS

910 patients were screened and 364 were randomly assigned (242 to afatinib, 122 to gemcitabine and cisplatin). Median progression-free survival was significantly longer in the afatinib group (11·0 months, 95% CI 9·7-13·7) than in the gemcitabine and cisplatin group (5·6 months, 5·1-6·7; hazard ratio 0·28, 95% CI 0·20-0·39; p<0·0001). The most common treatment-related grade 3 or 4 adverse events in the afatinib group were rash or acne (35 [14·6%] of 239 patients), diarrhoea (13 [5·4%]), and stomatitis or mucositis (13 [5·4%]), compared with neutropenia (30 [26·5%] of 113 patients), vomiting (22 [19·5%]), and leucopenia (17 [15·0%]) in the gemcitabine and cisplatin group. Treatment-related serious adverse events occurred in 15 (6·3%) patients in the afatinib group and nine (8·0%) patients in the gemcitabine and cisplatin group.

INTERPRETATION

First-line afatinib significantly improves progression-free survival with a tolerable and manageable safety profile in Asian patients with EGFR mutation-positive advanced lung NSCLC. Afatinib should be considered as a first-line treatment option for this patient population.

FUNDING

Boehringer Ingelheim.

Predictors of outcome for patients with lung adenocarcinoma carrying the epidermal growth factor receptor mutation receiving 1st-line tyrosine kinase inhibitors: Sensitivity and meta-regression analysis of randomized trials

PURPOSE

We performed a sensitivity and meta-regression analysis, cumulating all randomized trials exploring the benefit of afatinib, erlotinib and gefitinib versus chemotherapy in advanced EGFR mutant NSCLC, to investigate the potential role of additional clinico-pathological predictors of TKIs efficacy.

RESULTS

With regard to progression-free survival (PFS), a significant interaction according to ethnicity (Asian versus Caucasian versus mixed) and to trial design (retrospective versus prospective EGFR analysis), was found; a trend toward significance with regard to type of drug (gefitinib versus erlotinib versus afatinib) was determined. No statistically significant differences in survival were observed. With regard to response, a significant interaction according to ethnicity, trial design and type of drug, was found.

CONCLUSION

These data, together with a deeper characterization of the molecular background sustaining the oncogenic process, may contribute to create a clinico-pathologic predictive model, aimed to improve the magnitude of benefit expected from the use of targeted agents.