Li X, Zhang D, Li B, et al. - Among pretreated non-small-cell lung cancer (NSCLC) patients, this inquiry was performed to examine the link between B-cell lymphoma 2-like 11 (BCL-2-like 11, BCL2L11, also known as BIM) deletion polymorphism (BIM-del) and therapeutic effectiveness of osimertinib. The clinical results of patients with and without BIM-del were assessed using Cox proportional hazards models. This analysis involved 152 Chinese Han patients with NSCLC, including 143 T790M-positive and 9 T790M-negative patients. In only 17.5% of T790M-positive patients (25/143) the presence of BIM-del was identified. A poorer objective response rate was reported in patients with BIM-del vs those without, as was a significantly shorter progression-free survival (PFS) and moderately shorter overall survival (OS). In multivariate analysis, BIM-del was revealed as an independent prognostic factor for PFS in EGFR T790 M NSCLC patients, but not for OS. Overall, findings demonstrated an association of BIM-del with poor clinical responses and results, and BIM-del might represent a negative predictive and prognostic biomarker in EGFR T790 M NSCLC patients with osimertinib therapy.