114P Changes in serum choline (Ch) levels to predict treatment outcomes in advanced cancer patients (pts) treated with immunotherapy (IO)

Abstract

T cell-derived acetylcholine (Ach) induces vasodilation and increases T cell migration to infected tissues in response to viral infection. We previously reported that an increase from baseline in Ch (a stable Ach precursor) at week 7 after pembrolizumab was associated with improved PFS (NCT02644369; Watson et al, ASCO 2020). Our aim is to validate these findings in an independent cohort.