[Atezolizumab therapy in Chinese patients with locally advanced or metastatic solid tumors: An open-label, phase Ⅰ study].

OBJECTIVE: To evaluate pharmacokinetics (PK), efficacy, and safety of atezolizumab (anti-PD-L1) in high interest cancers in China, including esophageal cancer (EC), gastric cancer (GC), hepatocellular carcinoma (HCC), nasopharyngeal cancer (NPC), and non-small cell lung can-cer (NSCLC). METHODS: This phase I, open-label study was conducted at 6 Chinese sites from August 4, 2016 to April 15, 2019. The patients were >/=18 years old with a histologically documented incurable or metastatic solid tumor that was advanced or recurrent and had progressed since the last anti-tumor the-rapy. The PK phase characterized PK and safety of atezolizumab following multiple-dose administration when atezolizumab was administered as a single agent. The extension phase studied safety and efficacy of atezolizumab, as monotherapy (EC, GC, HCC, NPC) and with chemotherapy (NSCLC). RESULTS: This study enrolled 120 patients (PK phase: n=20; extension phase: n=20/cohort). Fourty-two patients (42.0%) were PD-L1 positive in atezolizumab monotherapy group (100 patients), of the 9 patients (9.0%) with microsatellite instability-high (MSI-H) tumors. Atezolizumab clearance was 0.219 L/d, and steady state was reached after 6 to 9 weeks (2-3 cycles) of repeated dosing. Objective response rates (ORRs) in EC, GC, HCC, NPC, and NSCLC were 10.0%, 15.0%, 10.0%, 5.0%, and 40.0%, respectively. In the patients with PD-L1 positive tumors, ORR was 11.9% with atezolizumab and 46.2% with atezolizumab plus gemcitabine and cisplatin. Two GC patients achieved durable response after pseudo-progression. The most common treatment-related adverse events in the atezolizumab monotherapy group were fatigue, anemia, fever, and decreased white blood cell count. The most common treatment-related adverse events in the combination group were anemia, decreased white blood cell count, and decreased appetite. No new safety signals were identified. CONCLUSION: Atezolizumab's PK, efficacy, and safety were similar in Chinese patients vs. global patients in previous studies.