The efficacy and safety of chemo-free therapy in epidermal growth factor receptor tyrosine kinase inhibitor-resistant advanced non-small cell lung cancer: A single-arm, phase II study

Objectives: The purpose of this study was to explore the efficacy and safety of toripalimab combined with anlotinib in patients with advanced non-small cell lung cancer (NSCLC) who acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).Materials and Methods: Patients who developed resistance after using first- or second-generation EGFR-TKIs as their first-line regimen without EGFR T790M mutation or had disease progression after being treated with third-generation EGFR-TKIs as first- or second-line therapy were enrolled. All patients received toripalimab (240 mg/day on Day 1, intravenously) combined with anlotinib (12 mg/day, Days 1-14, orally) once every 3 weeks. Treatment continued until disease progression, or if toxicity was intolerable. The primary endpoint was the objective response rate (ORR) assessed by the investigator. The secondary endpoint was the progression-free survival (PFS).Results: In total, 19 patients were enrolled between May 2020 and October 2021.The ORR was 0%, and a median PFS was 2.1 months (95% CI 0.251-3.949). Grade =3 treatment-related adverse events (AEs) occurred in 11% patients. Common adverse events included hypothyroidism (12/19), fatigue (9/19), and hypertension (8/19). Patients in stable disease (SD) group had lower abundance of EGFR mutation allele frequency (AF) before enrollment than those in progressive disease (PD) group (p = 0.031). Patients without detectable EGFR mutation (EGFR-) had longer PFS compared to the ones with EGFR mutations (p = 0.059). Patients with high levels of soluble programmed cell death ligand 1 (PD-L1) at baseline also tended to have longer PFS (p = 0.160).Conclusion: Toripalimab combined with anlotinib was tolerable in EGFR-TKI-resistant advanced NSCLC patients not previously treated with chemotherapy. Patients without detectable EGFR mutation and high soluble PD-L1 levels may benefit from this chemotherapy-free treatment.