Camrelizumab, a humanised immunoglobulin G4-κ monoclonal antibody against PD-1 previously exhibited antitumour activity and tolerability in advanced squamous non-small cell lung cancer. Updated results from the CameL-sq trial now continued to demonstrate survival benefits and further support camrelizumab plus carboplatin-paclitaxel as a new first-line treatment option in this patient population.
CameL-sq is a randomised, phase III trial conducted in China to compare first-line camrelizumab plus chemotherapy versus placebo plus chemotherapy in patients with advanced squamous non-small cell lung cancer (NSCLC). At the primary analysis, camrelizumab plus chemotherapy significantly prolonged blinded-independent review committee-assessed progression-free survival (PFS) vs. placebo plus chemotherapy. At that time, overall survival (OS) data were not mature. At ELCC 2022, an updated analysis of OS and safety after more than one year of additional follow-up was presented.
CameL-sq study design
Patients with pathologically confirmed stage IIIB-IV squamous NSCLC who did not receive prior systemic treatment and had an ECOG performance status of 0 or 1 were eligible for the Camel-sq trial. Patients were randomised (1:1) to receive 4–6 cycles of carboplatin (AUC 5) plus paclitaxel (175 mg/m2) with camrelizumab (200 mg) or placebo every 3 weeks, followed by maintenance therapy with camrelizumab or placebo. Maintenance camrelizumab was given until disease progression, unacceptable toxicity or a maximum of two years. Cross-over to second-line camrelizumab after disease progression was allowed for patients in the placebo arm.
At the data cut-off on January 31, 2022, median follow-up was 23.7 months in the camrelizumab plus chemotherapy group (N= 193) and 15.2 months in the placebo plus chemotherapy group (N= 196). At that time, six patients in the camrelizumab arm and one in the placebo arm were still receiving their assigned treatment. Baseline patient characteristics were well balanced between the two arms, with the majority of patients being male (92.7%), having an ECOG performance status of 1 (80.3%) and stage IV disease (72.0%).
Camrelizumab plus chemo significantly improved the OS vs. placebo plus chemo with approximately one year (median 27.4 months vs. 15.5 months, HR[95%CI]: 0.57[0.44-0.75]; 1-sided log-rank p< 0.0001). Survival rates were 75.0% vs. 62.0%, 53.4% vs. 35.0% and 42.8% vs. 23.7% at 12, 24 and 36 months, respectively. In total, 106 patients (55.8%) in the placebo plus chemotherapy arm crossed over to receive second-line camrelizumab. However, the OS benefit was persistent when the cross-over effect was adjusted using the Rank Preserving Structural Failure Time model (HR[95%CI]: 0.41[0.30-0.56], p< 0.0001). The combination of camrelizumab plus chemotherapy was well tolerated, with the majority of adverse events due to chemotherapy. Patients received a median of 12 cycles of camrelizumab or 7 cycles of placebo. Treatment-related adverse events (TRAEs) of grade 3-4 were reported in 74.1% of patients in the camrelizumab arm and in 71.4% of patients treated in the placebo arm. The most common treatment-related adverse events of all grades included decreased white blood cell count, decreased neutrophil count, anaemia, decreased platelet count, reactive capillary endothelial proliferation and alopecia.
The addition of camrelizumab to chemotherapy continued to demonstrate survival benefits and an acceptable safety profile after prolonged follow-up, further supporting camrelizumab plus carboplatin and paclitaxel as a standard first-line treatment option for advanced squamous NSCLC.
Zhou C, et al. First-line camrelizumab plus carboplatin and paclitaxel for advanced squamous non-small-cell lung cancer: Updated overall survival results from the phase 3 CameL-sq trial. Presented at ELCC 2022; Abstract 3MO.