Comparison of Immune Checkpoint Inhibitor Plus Chemotherapy or Ipilimumab Plus Nivolumab-Based Therapy for NSCLC Patients with PD-L1 TPS (1-49%): TOPGAN2023-01

Introduction: Immune checkpoint inhibitors (ICIs) plus chemotherapy is now a standard treatment for non-small cell lung cancer (NSCLC). Whether ICI plus chemotherapy (ICI-chemo) or ipilimumab plus nivolumab (I-N)-based therapy is superior for patients with NSCLC with a programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) of 1-49 % has not been evaluated. Methods: This multicenter retrospective study included NSCLC patients with a TPS score of 1-49 %, who began first-line chemotherapy. Propensity score matching analysis was used to adjust for various confounders and evaluate treatment efficacy. Results: A total of 401 patients were enrolled, of whom 308 received ICI-chemo and 93 received I-N-based therapy. The median OS was 21.0 months in the ICI-chemo group and 20.0 months in the I-N-based therapy group. After propensity score matching, there was no difference in OS or PFS between the ICI-chemo group and the I-N-based therapy group (OS: hazard ratios (HR), 0.83; 95 % confidence interval [CI], 0.54-1.26, PFS: HR, 0.72; 95 % CI, 0.52-1.00). Among PD-L1 TPS 25-49 %, there was a tendency for OS to be favorable for the ICI-chemo group (OS: HR, 0.30; 95 % CI, 0.09-0.85). Treatment discontinuation occurred for 26.2 % of the patients in the ICI-chemo group and 41.9 % in the I-N-based therapy group. Conclusions: Among PD-L1 TPS 1-49 %, there was no significant difference in survival outcomes between the ICI-chemo group and the I-N-based therapy group. Based on the results of a subgroup analysis, ICI-chemo may be superior for treating NSCLC with a TPS of 25-49 %.