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Results of the CAMEL-sq trial showed a progression-free survival (PFS) advantage of 3.6 months with camrelizumab plus chemotherapy, compared with chemotherapy plus placebo (P < .0001). The median overall survival (OS) was not reached in the camrelizumab arm, but it was significantly better than in the placebo arm (P < .0001).
Camrelizumab plus chemotherapy is already a standard of care in China for patients with advanced nonsquamous NSCLC who are negative for EGFR and ALK mutations, study investigator Caicun Zhou, MD, PhD, said when presenting the CAMEL-sq results at the European Lung Cancer Virtual Congress 2021 (Abstract 96O).
The CAMEL-sq findings now support the combination as a “standard first-line treatment for advanced squamous NSCLC,” said Dr. Zhou of Shanghai Pulmonary Hospital and Tongji University.
“The study has kind of changed our daily practice,” he said. “I do think we will have the label, camrelizumab plus chemo as first-line treatment for squamous [NSCLC] in China, maybe in a couple of months.”
“Camrelizumab will most likely be another brick in the wall for our Chinese patients and colleagues to use for patients with squamous histology, non–small cell lung cancer in addition to pembrolizumab,” said Julie Renee Brahmer, MD, of Johns Hopkins Medicine in Baltimore, who was the invited discussant for the trial.
Dr. Brahmer noted that the PFS hazard ratio in this trial – 0.37 – was “impressive.”
Patients and treatment
CAMEL-sq is a phase 3, double-blind, multicenter trial. The 390 patients enrolled had pathologically-confirmed stage IIIB or IV squamous NSCLC, and they had not received any prior treatment.
Patients received four to six cycles of chemotherapy, consisting of carboplatin and paclitaxel given every 3 weeks. Camrelizumab was added to one arm at a dose of 200 mg, and placebo was added to the other.
This was followed by a maintenance phase in which patients remained on active treatment with camrelizumab or placebo for up to 2 years. Patients in the placebo arm could cross over to camrelizumab at progression.
The median age of patients was similar in the camrelizumab and placebo arms (64 years and 62 years, respectively). The majority of study subjects in both arms were men (more than 90%), had a history of smoking (more than 80%), and had stage IV disease (more than 70%).
Efficacy and safety
The median PFS was 8.5 months in the camrelizumab arm and 4.9 months in the placebo arm (HR, 0.37; P < .0001). The median OS was not reached in the camrelizumab arm and was 14.5 months in the placebo arm (HR, 0.55, P < .0001).
The survival benefits were observed in spite of a crossover rate of 46.9%, Dr. Zhou noted.
Furthermore, survival benefits were consistent across all the subgroups tested. Regardless of age, sex, performance status, smoking history, disease stage, presence of liver or brain metastases, or PD-L1 expression, there was an apparent advantage of camrelizumab over placebo.
The objective response rate was higher in the camrelizumab arm than in the placebo arm, at 64.8% and 36.7%, respectively (P < .0001).
The clinical response seen with camrelizumab was “robust and durable,” Dr. Zhou said. Indeed, the duration of response was 13.1 months in the camrelizumab arm and 4.4 months in the placebo arm.
Grade 3/4 treatment-related adverse events (AEs) were reported in a similar percentage of camrelizumab- or placebo-treated patients (73.6% and 71.4%, respectively). However, “the majority of treatment-related adverse effects were chemotherapy related,” Dr. Zhou pointed out. This included decreased total white blood cell, neutrophil, red blood cell, and platelet counts as well as alopecia and increased liver enzymes.
Immune-related AEs occurred in 76.7% of patients in the camrelizumab arm and 20.4% of those in the placebo arm.
“The majority of immune-related adverse events were grade 1 or grade 2; easily manageable in our daily practice,” Dr. Zhou noted.