Long-term treatment results of pembrolizumab monotherapy: reconsideration of immune checkpoint inhibitor monotherapy.

Objective: The extended outcomes of the KEYNOTE-024 study demonstrated a favorable 5-year overall survival (OS) rate of 31.9%. The present study investigated the outcomes of pembrolizumab monotherapy for advanced or recurrent non-small cell lung cancer (NSCLC) at our institution.

Patient: The long-term outcomes of 102 patients with advanced or recurrent NSCLC treated with pembrolizumab monotherapy between March 2017 and December 2022 were retrospectively assessed.

Results: This study included a total of 102 patients [mean age: 72 ± 9.6 years (range: 41-91 years), male/female=77/25; performance status (PS; 0, 1, 2, 3, 4)=49/38/15/0/0; smokers=91 (89%), non-squamous cell carcinoma/squamous cell carcinoma=66/36, PD-L1 tumor proportion score (TPS) ≥50%/1-49%=80/22, positive for EGFR mutation=5, advanced/postoperative recurrence=51/51, treatment line: first/second or later=81/21, treatment courses: median 8 (range: 1-39), objective response rate/disease control rate=44%/55%, immune-related adverse events (irAEs): 47, 5-year OS=34%]. On univariate analysis, PS, PD-L1 TPS, and irAEs were significant prognostic factors. On multivariate analysis, histology, PD-L1 TPS, and irAEs were significant prognostic factors.

Conclusion: Pembrolizumab monotherapy demonstrated promising treatment outcomes for advanced or recurrent NSCLC, as evidenced by the significant association of PD-L1 TPS with irAEs and prognosis, suggesting its potential as a beneficial therapeutic option.