Utility of early circulating tumour DNA dynamics as a surrogate for progression free survival in the BEECH phase I/II trial in metastatic breast cancer
S Hrebien; V Citi; I Garcia-Murillas; R Cutts; I Kozarewa ...
Annals of Oncology, Volume 30, Issue Supplement_3, May 2019, mdz095.005, https://doi.org/10.1093/annonc/mdz095.005
Extract
Background: Dynamic changes in circulating tumour DNA (ctDNA) levels may predict long-term outcome of therapy. We utilised samples from a phase I/II randomised trial (BEECH) to assess ctDNA dynamics as a surrogate for progression free survival (PFS) and early predictor of drug efficacy.

Methods: Patients with oestrogen receptor positive advanced metastatic breast cancer (ER+ mBC) in the BEECH study were randomised to paclitaxel plus placebo versus paclitaxel plus AKT inhibitor capivasertib. Plasma samples were collected for ctDNA analysis at baseline and at multiple timepoints in the development cohort (safety run-in, part A) and validation cohort (randomised, part B). Baseline sample...