Abstract 1263P
Background
Tislelizumab + chemotherapy has shown antitumor activity with a favorable tolerability profile in patients (pts) with histologically confirmed nsq-NSCLC.
Methods
In this open-label phase 3 study (NCT03663205), Chinese pts were randomized 2:1 to receive tislelizumab 200 mg + platinum (carboplatin AUC 5 or cisplatin 75 mg/m2) + pemetrexed 500 mg/m2, followed by maintenance tislelizumab + pemetrexed (Arm A); pts in Arm B received platinum + pemetrexed and maintenance pemetrexed. Patients with known EGFR mutations or ALK rearrangement were ineligible. Patients were stratified by disease stage (IIIB vs IV) and tumor cell PD-L1 expression (<1% vs 1-49% vs ≥50%) assessed using the Ventana PD-L1 (SP263) Assay. Platinum was administered for 4-6 cycles at investigator’s discretion; crossover to tislelizumab was allowed. Treatment beyond progression was allowed for tislelizumab. The primary endpoint, progression-free survival per RECIST v1.1, was assessed by Independent Review Committee (PFSIRC); key secondary endpoints included overall survival (OS), objective response rate (ORRIRC), duration of response (DoRIRC), and safety/tolerability.
Results
As of 23 Jan 2020, 334 pts with nsq-NSCLC (A, n=223; B, n=111) were randomized; median study follow-up was 9.8 mo (95% CI: 9.23,10.38). PFSIRC was significantly longer with tislelizumab combination therapy than chemotherapy alone (P=0.0044; HR=0.645 [95% CI: 0.462, 0.902]; median PFSIRC, 9.7 mo vs 7.6 mo). ORRIRC was 57% (95% CI: 50.6, 64.0) and 37% (95% CI: 28.0, 46.6) in Arms A and B, respectively. Median DoR in Arm A was 8.5 mo (95% CI: 6.80, 10.58) and 6.0 mo (95% CI: 4.99, NE) in Arm B. A total of 221 pts (99.5%) had a treatment-related AE (TRAE) in Arm A; 185 pts (83%) had AEs related to tislelizumab. Of 140 pts (63%) with grade ≥3 TRAEs, 69 (31%) were considered related to tislelizumab by the investigator. In Arm B, 107 pts (97%) experienced ≥1 TRAE, of which 50 (46%) were grade ≥3. Across the entire study, four pts (1%) had fatal pneumonitis; 3 of which were considered possibly related to tislelizumab.
Conclusions
Tislelizumab plus chemotherapy was generally well tolerated and demonstrated antitumor activity in pts with nsq-NSCLC.
Clinical trial identification
NCT03663205.
Editorial acknowledgement
Writing and editorial assistance was provided by Stephan Lindsey, PhD, and Elizabeth Hermans, PhD (OPEN Health Medical Communications, Chicago. IL), and funded by the study sponsor.
Legal entity responsible for the study
This study was sponsored by BeiGene, Ltd.
Funding
BeiGene, Ltd.
Disclosure
S. Lu: Research grant/Funding (institution): AstraZeneca BMS, Hutchison, BMS, Heng Rui, and Roche; Speaker Bureau/Expert testimony: AstraZeneca, Roche, Hanseng; Advisory/Consultancy: AstraZeneca, Boehringer Ingelheim, Hutchison Medipharma, Simcere, and Roche. Y. Sun: Speaker Bureau/Expert testimony: AstraZeneca, Roche. Y. Bao, L. Liang: Full/Part-time employment: BeiGene, Ltd. All other authors have declared no conflicts of interest.