Prognostic impact of baseline circulating extracellular vesicles (BCEVs) in the setting of patients with advanced non-small cell lung cancer (ANSCLC) eligible for first line treatment with osimertinib.

Abstract

e14553 Background: In the liquid biopsy era, the interrogation of extracellular vesicles (EVs) content might be complementary for cancer prognostication and response assessment. In this explorative study, we aimed to describe whether the serial characterization of BCEVs plasma tumor-derived EVs could longitudinally reflect response and resistance to available first-line treatments, investigating the potential to predict clinical outcomes in patients with advanced NSCLC (aNSCLC). Methods: From 2020/02 to 2022/05, 27 treatment-naïve patients with aNSCLC (stageIIIB/IV), eligible for first-line treatment with an EGFRTKI (Osimertinib) or ICIs (e.g. Pembrolizumab ± platinum‐based chemotherapy) based on the predictive molecular pathology, were enrolled. Blood samples (∼5 mL) were collected into K2EDTA tubes early in the morning with fasting condition. We isolated EVs from 2 ml of plasma using exo-Easy Maxi Kit (Qiagen-USA). EVs’s size and distribution was determine by use of Dynamic Light Scattering method (DLS). Besides a Bradford assay (cfEV) for the indirect quantification of EV amount based on EVs proteins content was performed. According to the radiologic response, EV analyses were evaluated in patients with available plasma samples from baseline (T0) to the first radiologic evaluation of disease within 12 weeks (T1). Results: From 2020/02 to 2022/05, 27treatment-naïve patients with aNSCLC (stageIIIB/IV), eligible for first-line treatment with an EGFRTKI (Osimertinib) or ICIs (e.g. Pembrolizumab ± platinum‐based chemotherapy) based on the predictive molecular pathology, were enrolled. Blood samples (∼5 mL) were collected into K2EDTA tubes early in the morning with fasting condition. We isolated EVs from 2 ml of plasma using exo-Easy Maxi Kit (Qiagen-USA). EVs’s size and distribution was determine by use of Dynamic Light Scattering method (DLS). Besides a Bradford assay (cfEV) for the indirect quantification of EV amount based on EVs proteins content was performed. According to the radiologic response, EV analyses were evaluated in patients with available plasma samples from baseline (T0) to the first radiologic evaluation of disease within 12 weeks (T1). Conclusions: This real-world study confirmed the in vivo feasibility of isolating and characterizing BCEVs via DLS and Bradford assay from the plasma of patients with ANSCLC. The quantitative changes of the plasma EVs correlated with survival in the real-time monitoring of such first-line patients, mostly in the oncogene-addicted population receiving osimertinib.