Beyond a negative trial: timing, molecular residual disease, and antibody biology in adjuvant immunotherapy for resected NSCLC.

The phase 3 EA5142/ALCHEMIST study of adjuvant nivolumab for completely resected EGFR/ALK-negative non-small cell lung cancer (NSCLC) is being widely interpreted as a negative trial. Its immediate clinical significance is that nivolumab monotherapy, given after the completion of standard postoperative treatment, did not offer a disease-free survival advantage in this population. However, inconsistent results from adjuvant, neoadjuvant, and perioperative trials raise unanswered questions about treatment sequencing, residual disease burden, biomarker selection, and trial design. We propose a hypothesis-generating timing × molecular residual disease (MRD) framework to organize these questions, while recognizing that cross-trial comparisons cannot establish either treatment timing or MRD status as a causal determinant of efficacy. NADIM-Adjuvant is the first trial to demonstrate that postoperative circulating tumor DNA positivity can serve as a prognostic marker; however, these data do not confirm MRD as a predictive biomarker for response to chemoimmunotherapy. We also assess an antibody-biology hypothesis mediated by the interplay between immunoglobulin G subclasses and Fcγ receptors that may drive inter-agent heterogeneity, although this has not been clinically established in resected NSCLC. These considerations collectively identify several testable hypotheses for future adjuvant trials, without diminishing the negative clinical outcome of EA5142.