Abstract
BACKGROUND
The role of gefitinib for the treatment of advanced non-small cell lung cancer (NSCLC) is evolving. We undertook a systematic review to evaluate the available evidence from all randomised trials.
OBJECTIVES
To determine the effectiveness and safety of gefitinib as first-line, second-line or maintenance treatment for advanced NSCLC.
SEARCH METHODS
We performed searches in CENTRAL, MEDLINE and Embase from inception to 17 February 2017. We handsearched relevant conference proceedings, clinical trial registries and references lists of retrieved articles.
SELECTION CRITERIA
We included trials assessing gefitinib, alone or in combination with other treatment, compared to placebo or other treatments in the first- or successive-line treatment of patients with NSCLC, excluding compassionate use.
DATA COLLECTION AND ANALYSIS
We used the standard Cochrane methodology. Two authors independently assessed the search results to select those with sound methodological quality. We carried out all analyses on an intention-to-treat basis. We recorded the following outcome data: overall survival, progression-free survival, toxicity, tumour response and quality of life. We also collected data for the following subgroups: Asian ethnicity and positive epidermal growth factor receptor (EGFR) mutation.
MAIN RESULTS
We included 35 eligible randomised controlled trials (RCTs), which examined 12,089 patients.General populationGefitinib did not statistically improve overall survival when compared with placebo or chemotherapy in either first- or second-line settings. Second-line gefitinib prolonged time to treatment failure (TTF) (hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.75 to 0.90, P < 0.0001) when compared with placebo. Maintenance gefitinib improved progression-free survival (HR 0.70, 95% CI 0.53 to 0.91, P = 0.007) after first-line therapy.Studies in patients of Asian ethnicity or that conducted subgroup analysesSecond-line gefitinib prolonged overall survival over placebo (HR 0.66, 95% CI 0.48 to 0.91, P = 0.01). In the first-line setting, progression-free survival was improved with gefitinib over chemotherapy alone (HR 0.65, 95% CI 0.43 to 0.98, P = 0.04, moderate quality of evidence). Gefitinib given in combination with a chemotherapy regimen improved progression-free survival versus either gefitinib alone or chemotherapy alone (HR 0.69, 95% CI 0.49 to 0.96, P = 0.03; HR 0.69, 95% CI 0.62 to 0.77, P < 0.00001, respectively). In the second-line setting, progression-free survival was superior in patients given gefitinib over placebo or chemotherapy (HR 0.69, 95% CI 0.52 to 0.91, P = 0.009; HR 0.71, 95% CI 0.57 to 0.88, P = 0.002; moderate quality of evidence, respectively). Combining gefitinib with chemotherapy in the second-line setting was superior to gefitinib alone (HR 0.65, 95% CI 0.43 to 0.97, P = 0.04). As maintenance therapy, gefitinib improved progression-free survival when compared with placebo (HR 0.42, 95% CI 0.33 to 0.54, P < 0.00001).Patients with EGFR mutation-positive tumoursStudies in patients with EGFR mutation-positive tumours showed an improvement in progression-free survival in favour of gefitinib over first-line and second-line chemotherapy (HR 0.47, 95% CI 0.36 to 0.61, P < 0.00001; HR 0.24, 95% CI 0.12 to 0.47, P < 0.0001, respectively). Gefitinib as maintenance therapy following chemotherapy improved overall and progression-free survival (HR 0.39, 95% CI 0.15 to 0.98, P = 0.05; HR 0.17, 95% CI 0.07 to 0.41, P < 0.0001, respectively) in one phase III study when compared to placebo.Toxicities from gefitinib included skin rash, diarrhoea and liver transaminase derangements. Toxicities from chemotherapy included anaemia, neutropenia and neurotoxicity.In terms of quality of life, gefitinib improved Functional Assessment of Cancer Therapy-Lung (FACT-L) (standardised mean difference (SMD) 10.50, 95% CI 9.55 to 11.45, P < 0.000001), lung cancer subscale (SMD 3.63, 95% CI 3.08 to 4.19, P < 0.00001) and Trial Outcome Index (SMD 9.87, 95% CI 1.26 to 18.48, P < 0.00001) scores when compared with chemotherapy.
AUTHORS' CONCLUSIONS
This systematic review shows that gefitinib, when compared with standard first- or second-line chemotherapy or maintenance therapy, probably has a beneficial effect on progression-free survival and quality of life in selected patient populations, particularly those with tumours bearing sensitising EGFR mutations.Patients with EGFR mutations lived longer when given maintenance gefitinib than those given placebo.One study conducted subgroup analysis and showed that gefitinib improved overall survival over placebo in the second-line setting in patients of Asian ethnicity. All other studies did not detect any benefit on overall survival. The data analysed in this review were very heterogenous. We were limited in the amount of data that could be pooled, largely due to variations in study design. The risk of bias in most studies was moderate, with some studies not adequately addressing potential selection, attrition and reporting bias. This heterogeneity may have an impact on the applicability of the resultsCombining gefitinib with chemotherapy appears to be superior in improving progression-free survival to either gefitinib or chemotherapy alone, however further data and phase III studies in these settings are required.Gefitinib has a favourable toxicity profile when compared with current chemotherapy regimens. Although there is no improvement in overall survival, gefitinib compares favourably with cytotoxic chemotherapy in patients with EGFR mutations with a prolongation of progression-free survival and a lesser side effect profile.
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