4-year overall survival for patients with advanced NSCLC treated with pembrolizumab: Results from KEYNOTE-001.

9030 Background: Pembrolizumab (pembro) has shown antitumor activity in patients (pts) with advanced NSCLC and is standard-of-care therapy for pts with PD-L1‒expressing tumors (first-line, TPS ≥50%; previously treated, TPS ≥1%). KEYNOTE-001, an open-label phase 1b study, evaluated pembro monotherapy in treatment-naive or previously treated pts with advanced NSCLC (NCT01295827). We report a 4-y update of KEYNOTE-001. Methods: Pts had confirmed locally advanced/metastatic NSCLC and provided a contemporaneous tumor tissue sample for evaluation of PD-L1 levels by IHC using the 22C3 antibody. Pts received pembro 2 mg/kg Q3W or 10 mg/kg Q2W or Q3W. Primary efficacy endpoint was ORR. OS was a secondary endpoint. Results: As of data cutoff (Sep 1, 2017), among 550 pts enrolled (treatment-naive, n = 101; previously treated, n = 449), median (range) follow-up was 46.5 (37.7–63.8) mo. ORR (by investigator per irRC) was 41.6 % (95% CI, 31.9–51.8) for treatment-naive pts and 22.9% (95% CI, 19.1–27.1) for previously treated pts. Median OS was 22.3 mo (95% CI, 17.1–32.3) for treatment-naive pts and 10.5 mo (95% CI, 8.6–13.2) for previously treated pts; estimated 4-y OS rates were 27.2% and 16.4 %, respectively. Kaplan-Meier curves for OS appeared to plateau after 42 mo for treatment-naive pts and 36 mo for previously treated pts. Increased PD-L1 expression was associated with improved OS (Table). Immune-mediated AEs occurred in 24.8% of treatment-naive and 17.4% of previously treated pts. No additional grade 5 treatment-related AEs occurred (compared with 3-y follow-up; data cutoff Sep 1, 2016). Conclusions: Pembro provides long-term OS benefit for both treatment-naive and previously treated advanced NSCLC that expresses PD-L1. These data represent the longest efficacy and safety follow-up for pts with advanced NSCLC treated with pembro. Clinical trial information: NCT01295827.OS in subgroups defined by PD-L1 TPS. Treatment-Naive (N = 101) Previously Treated (N = 449) n Median (95% CI), mo Est. 4-y rate n Median (95% CI), mo Est. 4-y rate TPS ≥50% 27 35.4 (20.3‒NE) 48.1% 138 15.4 (10.6‒18.8) 24.8% TPS 1%–49% 52 19.5 (10.7‒26.3) NE 168 8.5 (6.0‒12.6) 15.6% TPS ≤1% Not reported* 90 8.6 (5.5‒10.6) 6.5% NE = not estimable. *Due to small pt numbers (n = 12).