RNA sequencing of the phase II PERFECT trial combining a PD-L1 inhibitor (atezolizumab) with neoadjuvant chemoradiotherapy in resectable esophageal adenocarcinoma patients.

We performed bulk RNA sequencing of tumor biopsies from patients before treatment, on-treatment and in case a poor response was suspected from the resection specimen. At baseline we found in responding patients a higher six-gene IFNy score compared to non-responders. On-treatment non-responders showed either high expression of co-inhibitory checkpoints with a high number of cytotoxic lymphocytes or low expression and a low number of cytotoxic lymphocytes. Overall design: RNA sequencing of esophageal tumor biopsies at baseline from patients, on-treatment (3rd week) and at resection.