Phase Ib study of sintilimab in combination with chemotherapy for 1L advanced or metastatic non-small cell lung cancer (NSCLC).

e20546 Background: Anti-programmed death-1 antibodies (PD-1 Abs) have shown benefits in advanced NSCLC. The efficacy and safety of sintilimab, a PD-1 Ab, in combination with chemotherapy for 1L NSCLC is evaluated in this phase Ib study (NCT02937116). Methods: The study enrolled treatment-naïve unresectable locally advanced or metastatic non-squamous (nsq-) and squamous (sq-) NSCLC patients with neither EGFR mutations nor ALK rearrangements in cohort D and E respectively. Patients received sintilimab 200mg IV q3w in combination with pemetrexed 500mg/m2 and cisplatin 75mg/m2 IV q3w (4 cycles) in cohort D, or gemcitabine 1250mg/m2 D1,8 and cisplatin 75mg/m2 D1 IV q3W (6 cycles) in cohort E until disease progression, unacceptable toxicity or death. The primary objective was to evaluate the efficacy and safety of the combination. Results: As data cutoff (15 Jan 2019), 21 and 20 patients were enrolled in cohort D and E respectively. ORR in nsq- and sq-NSCLC were 68.4% (95%CI, 43.4 to 87.4) and 64.7% (95%CI, 38.3 to 85.8) respectively based on data of 19 and 17 patients with at least one radiological assessment. Median PFS was 11.4 months (95%CI, 3.1 to NA) and 6.5 months (95%CI, 5.3 to 8.0) respectively (Table). Totally 38 (92.7%) patients experienced at least one treatment emergent adverse event (TEAE). Treatment-related AEs (TRAEs) occurred in 28 (68.3%) patients. TRAE ≥grade 3 occurred in 4 (9.8%) patients. Immune related AEs occurred in 10 patients (24.4%), the most common of which were skin rash (N = 5), pneumonitis (N = 3) and hypothyroidism (N = 2). There was no AEs leading to death. The biomarker analysis was ongoing. Conclusions: The combination of sintilimab and chemotherapy showed efficacy with an acceptable safety profile in 1L nsq- and sq-NSCLC. Two phase III trials are ongoing to evaluate the combination in 1L nsq- (NCT03607539) and sq-NSCLC (NCT03629925) respectively. Clinical trial information: NCT02937116. [Table: see text]