Deciphering antitumour response and resistance with intratumour heterogeneity (DARWIN II).

TPS9099Background: The importance of intratumour heterogeneity (ITH) is increasingly recognised as a driver of cancer progression and survival outcome. However understanding how tumour clonal heterogeneity impacts upon therapeutic outcome is still an area of unmet clinical and scientific need. The TRACERx trial (NCT01888601), a prospective study of patients with radically resected primary non-small cell lung cancer (NSCLC), aims to define the evolutionary trajectories of lung cancer in both space and time through genetic analysis of multi-region and longitudinal tumour sampling. DARWIN II is an investigator initiated study for patients who are enrolled within the TRACERx trial, or who have multi-region sequencing of their primary disease, but subsequently relapse with metastatic disease. This study will examine the role of intra- tumour heterogeneityand predicted neo-antigens on the anti-tumour activity of anti-PDL1 immunotherapy. Methods: This multicentre non-randomised phase II molecularly stratified um...