Figure 1.

The observed (KM) and predicted (Cox Model) of overall survival of patients with squamous and nonsquamous NSCLC with high (≥50%) and low (<50%) PD-L1 tumor proportion score

Red lines indicate high PD-L1 TPS (≥50%); black lines indicate low PD-L1 TPS (<50%). Overall survival is measured from the start date of first-line pembrolizumab. Solid lines represent estimates from the Kaplan-Meier (KM) analysis; dashed lines are estimates from a generalized gamma regression model adjusting for gender and stage of diagnosis. A generalized gamma model adjusting for gender and stage at diagnosis found that for patients with nonsquamous histology, high PD-L1 TPS was significantly associated with improved overall survival by a median OS difference of 8.4 months (p <0.001). In contrast, for patients with squamous histology, there was no evidence of association between PD-L1 expression level and overall survival (p = 0.283). PD-L1-related incremental differences in median OS between the patients with squamous and nonsquamous tumors were significantly different (p = 0.034).

Abbreviations: KM, Kaplan-Meier; TPS, tumor proportion score