Abstract
BACKGROUND: Limited data are available for the combination regimen of anti-programmed cell death protein 1 (PD-1) inhibitor and anti-angiogenic agents as second-line therapy for the treatment of patients with advanced non-small cell lung cancer (NSCLC), especially in patients with squamous NSCLC. This study assessed the efficacy and safety of camrelizumab plus apatinib (a vascular endothelial growth factor receptor 2 inhibitor) as second-line treatment in patients with advanced squamous NSCLC. METHODS: In the Cohort 3 from a phase II dose-expansion trial, patients with advanced non-central squamous NSCLC who were immunotherapy naïve and had failed prior first-line platinum-based chemotherapy received 200 mg of camrelizumab intravenously every 2 weeks plus oral apatinib at the recommended dose of 250 mg once daily. The primary endpoint was objective response rate (ORR) assessed by the investigators as per the Response Evaluation Criteria in Solid Tumors (RECIST) v 1.1. RESULTS: Cohort 3 was prematurely terminated because of slow accrual after 25 patients with advanced squamous NSCLC had been enrolled between 10 October 2018, and 3 March 2019. At the data cutoff date of 12 June 2020, the median follow-up was 13.3 (range, 1.6 to 19.2) months. Among all 25 participants, the ORR was 32.0% (95% CI: 14.9% to 53.5%), the clinical benefit rate was 44.0% (95% CI: 24.4% to 65.1%), and the disease control rate (DCR) was 84.0% (95% CI: 63.9% to 95.5%). Median progression-free survival (PFS) was 6.0 (95% CI: 3.5 to 8.1) months, and median overall survival (OS) was 13.3 (95% CI: 6.4 to 18.8) months. Furthermore, clinical benefits from this combination regimen were evident across all tumor PD ligand 1 (PD-L1) expression subgroups. The most common treatment-related adverse events (TRAEs) of grade 3 or higher were hypertension (44.0%) and palmar-plantar erythrodysesthesia (16.0%). As reported by the investigators, 3 participants (12.0%) died due to TRAEs (interstitial pneumonia, hemorrhage, and unknown reason; n=1 each, 4%). CONCLUSIONS: Camrelizumab plus apatinib as second-line therapy showed satisfactory antitumor activity in patients with non-central squamous NSCLC, regardless of tumor PD-L1 expression. Camrelizumab plus apatinib had a manageable safety profile in this patient population, and the toxic reactions observed were generally consistent with those in previously reported studies. Interstitial pneumonia and hemorrhage are important risks requiring careful monitoring and prompt intervention.