Long-term OS for patients with advanced NSCLC enrolled in the KEYNOTE-001 study of pembrolizumab (pembro).

9026 Background: The anti–PD-1 antibody pembro (MK-3475) is approved in the US for treating PD-L1–positive NSCLC that progressed after platinum-containing chemotherapy. This approval was based on data from the large, phase 1b KEYNOTE-001 study (NCT01295827). We present updated, long-term OS data for treatment-naive and previously treated patients (pts) enrolled in KEYNOTE-001. Methods: 550 pts received pembro 2 or 10 mg/kg Q3W or 10 mg/kg Q2W until intolerable toxicity, progression, or investigator decision. PD-L1 was assessed by IHC using the 22C3 antibody, with positivity defined as PD-L1 expression on ≥1% of tumor cells (tumor proportion score [TPS] ≥1%). Response was assessed by RECIST v1.1 every 9 wk. Survival was assessed every 2 mo after discontinuation. Results: As of Sep 18, 2015, median follow-up duration was 23.1 mo. Median OS (95% CI) was 22.1 mo (17.1-27.2) for treatment-naive pts and 10.6 mo (8.6-13.3) for previously treated pts. 18-mo OS rates were 58.2% and 37.0% respectively; 24-mo rates were 44.5% and 31.3%. OS increased with increasing PD-L1 TPS (Table). OS by smoking history, histology, and EGFR status is shown (Table). Conclusions: Pembrolizumab provides long-term OS benefit for PD-L1–positive treatment-naive and previously treated NSCLC. Along with data from KEYNOTE-010, these data support both PD-L1 as a predictive biomarker for pembro and the benefit of pembro in pts with PD-L1–positive (TPS ≥1%) NSCLC. The 22.1-mo median OS in treatment-naive pts with PD-L1–positive tumors is very promising and compares favorably with that of standard-of-care chemotherapy. Clinical trial information: NCT01295827.Median OS (95% CI), mo Treatment Naive N = 101 Previously Treated N = 449 PD-L1 TPS ≥1% n = 79 22.1 (16.7-27.2) n = 306 11.3 (8.3-14.0) ≥50% n = 27 NR (22.1-NR) n = 138 15.4 (10.6-18.5) 1%-49% n = 52 19.5 (10.7-22.2) n = 168 8.2 (6.0-12.7) PD-L1 TPS <1% n = 12 14.7 (3.4-NR) n = 90 8.6 (5.5-12.0) Squamous n = 19 15.6 (6.0-21.0) n = 76 14.7 (10.4-18.4) Nonsquamous n = 79 26.3 (22.0-NR) n = 367 9.4 (7.3-12.6) Current/former smoker n = 90 22.0 (16.7-27.2) n = 324 12.2 (9.2-14.3) Never smoker n = 11 NR (16.2-NR) n = 125 7.6 (5.9-12.1) EGFR wild type * n = 335 12.1 (9.1-14.3) EGFR mutant * n = 74 6.0 (4.6-9.9) *Pts with EGFR-mutant, treatment-naive NSCLC were ineligible.