OSE2101 Versus Chemotherapy in HLA-A2 Positive Patients With Advanced NSCLC After Immune Checkpoint Inhibitor Failure

The study was a two-step randomized (2:1) study. Patients were stratified by histology (non-squamous versus squamous), best response to first-line treatment \[complete response or partial response versus stable disease or progressive disease\] and line of treatment with prior ICI (first-line ICI when combined with platinum-based chemotherapy versus second-line ICI when administered as sequential treatment). Primary endpoint was overall survival (OS). Interim OS futility analysis was planned as per Fleming design. In April 2020 at the time of the interim analysis, a decision was taken to early stop the accrual due to COVID-19 after 219 out of 363 patients were randomized. It led to a decrease of the study power from 80% to 62%. At the time of the interim analysis, a subgroup of patients was identified from stratification factor based on a clinical and biological rationale: those who received ICI second line and having received at least 12 weeks ICI. This subgroup was defined as ICI secondary resistance. The final analysis was carried out in the subgroup of patients with ICI secondary resistance and in all patients (ICI primary and secondary resistance).