Does disease control rate (DCR) at 9 and 18 weeks predict overall survival (OS) in patients with malignant pleural mesothelioma (MPM)? An individual patient data combined analysis of 10 European Organisation for Research and Treatment of Cancer (EORTC) Lung Cancer Group (LCG) studies.

Abstract

7025 Background: The development of new drugs is urgently needed in MPM to improve the efficacy of first-line therapy and identify effective second-line treatments. In phase II trials, the biological activity of drugs is generally assessed using the response rate (RR) as the primary endpoint. However, response criteria have always been difficult to apply to MPM, due to its unique pattern of growth. We hypothesized that the DCR could be a better predictor of OS than the RR in MPM patients (pts). Methods: Individual patient data from 10 EORTC LCG studies (9 phase II and 1 phase III trials) of first-line chemotherapy in MPM were pooled. Response to therapy was assessed according to WHO criteria in all trials except the 2 most recent trials, which used RECIST. Landmark analyses (LA) were performed to assess the association of the intermediate endpoints (DCR and RR) with OS. Two different time points, namely 9 weeks and 18 weeks after registration or randomization, were considered. All 10 studies (N=523 pts) w...