Predictive markers of response to immune checkpoint inhibitor rechallenge in metastatic non-small cell lung cancer

Aim: The present study aims to evaluate the efficacy of rechallenge with immune checkpoint inhibitors (ICIs) compared to chemotherapy and the predictive role of clinical parameters in non-small cell lung cancer (NSCLC) patients who were rechallenged. Methods: The study included 113 metastatic NSCLC patients who had initially responded to ICIs and platinum-based chemotherapy, either in combination in the first line or sequentially in the first and second line, but later experienced disease progression. Of those patients, 52 later received ICI rechallenge and 61 were exposed to chemotherapy. Results: In the rechallenge cohort, the median age was 67 years, 38 patients were men (73.1%), 26 (50.0%) had squamous cell carcinoma. Patients who underwent ICI rechallenge had longer overall survival (OS) compared to those who received chemotherapy (12.9 months vs. 9.6 months, P = 0.008). Multivariate analysis for progression-free survival (PFS) and OS revealed that poor Eastern Cooperative Oncology Group Performance Status (ECOG PS; PFS: P = 0.013 and OS: P = 0.037), absence of objective response during initial ICI therapy (PFS: P = 0.014 and OS: P = 0.028), and baseline neutrophil-to-lymphocyte ratio (NLR) ≥ 3.8 (PFS: P = 0.001 and OS: P = 0.003) were negative predictive factors of ICI rechallenge. The three parameters were included in a risk model named as the NEO score, which stratified patients who received ICI rechallenge into two predictive groups. Patients with ECOG PS 0-1, objective response during initial ICI treatment, and NLR < 3.8 (favorable group) had longer PFS (8.6 months vs. 3.0 months, P < 0.001) and OS (16.6 months vs. 5.5 months, P < 0.001) compared to those with absence of all three markers (poor group). There was no association between the NEO score and survival outcomes in patients who did not undergo rechallenge. Conclusions: ICI rechallenge showed a survival benefit, particularly in NSCLC patients with NLR < 3.8, good ECOG PS, and objective response.