Camrelizumab Plus Carboplatin and Paclitaxel as First-Line Treatment for Advanced Squamous NSCLC (CameL-Sq): A Phase 3 Trial

Camrelizumab, a humanized immunoglobulin G4-κ monoclonal antibody against programmed cell death protein 1, has exhibited antitumor activity and tolerability across various tumors, including lung cancers. We conducted this double-blind, randomized phase 3 trial to investigate the efficacy and safety of camrelizumab or placebo plus chemotherapy as first-line treatment for patients with advanced squamous NSCLC. The predictive value of circulating tumor DNA (ctDNA) dynamics was also analyzed.CameL-sq, a double-blind, randomized phase 3 trial (NCT03668496), was conducted in 53 centers in the People's Republic of China. A total of 389 patients with stage IIIB-IV squamous NSCLC were randomized (1:1) to receive 4 to 6 cycles of carboplatin plus paclitaxel with camrelizumab or placebo (every 3 wk), followed by maintenance therapy with camrelizumab or placebo. Peripheral blood ctDNA samples were collected at baseline and the time after two cycles of treatment.Of 389 eligible patients, 193 patients allocated camrelizumab plus chemotherapy and 196 patients allocated placebo plus chemotherapy were included in the efficacy and safety analysis. The results revealed significantly prolonged progression-free survival (median, 8.5 vs. 4.9 mo; p <0.0001) and overall survival (median, not reached vs. 14.5 mo; p <0.0001) with camrelizumab-chemotherapy versus placebo-chemotherapy. No unexpected treatment immune-related adverse events were observed in both groups. Biomarker analysis revealed that ctDNA clearance after two cycles of treatment was independently associated with dramatically longer progression-free survival (p <0.0001) and overall survival (p <0.0001) in camrelizumab plus chemotherapy group.Our findings support camrelizumab plus chemotherapy as a first-line treatment option in advanced squamous NSCLC. On-treatment ctDNA dynamics exhibited the potency to predict the efficacy of camrelizumab plus chemotherapy.