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

Abstract

Introduction: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

Keywords: Biomarker; Chemotherapy; Immunotherapy; Lung squamous cell carcinoma; PD-1.