Model-based estimates of tumor growth inhibition (TGI) metrics to predict for overall survival (OS) in first-line non-small cell lung cancer (NSCLC).

e19049 Background: A survival model using change in tumor size at week 8 from baseline (CTS) (Clin Pharmacol Ther 86:167-174, 2009) was used to predict OS of the motesanib phase III study in NSCLC (Clin Pharmacol Ther 92:631-634, 2012). However CTS may not fully capture treatment effect on OS. We investigated other TGI metrics to predict OS using historical phase III data. Methods: Various TGI metrics, CTS, time to growth (TTG), and tumor growth rate (G), were estimated using two longitudinal tumor size models (Clin Cancer Res 17:907-917, 2011, PAGE 21 [www.page-meeting.org/?abstract=2328], 2012, JCO in press, 2013) developed from phase III data (1218 1st-line patients with NSCLC treated with doxetaxel (D) plus cisplatin (Cs) or carboplatin (Cb) or vinorelbine (V) plus Cs) (J Clin Oncol, 21:2016-3024, 2003). TGI metrics and baseline prognostic factors were assessed in univariate Cox and multivariate parametric survival models. Alternative models were qualified by simulating OS distributions in 1000 replic...