ctDNA response after pembrolizumab in non-small cell lung cancer: phase 2 adaptive trial results

Assays monitoring circulating tumor DNA (ctDNA) have the potential to predict early resistance to immunotherapy and allow for early intervention. Results from the first stage of the Phase 2 BR.36 trial found high concordance between ctDNA response and radiographic response among 50 advanced lung cancer patients treated with standard of care pembrolizumab, with a sensitivity of 82% and a specificity of 75%. Furthermore, patients with a ctDNA response had longer progression-free and overall survival. These results will now be used to inform the second stage of the trial, where patients at risk of progression will be randomized to treatment intensification or continuation of current therapy.