Brain radiotherapy combined with camrelizumab and platinum-doublet chemotherapy for previously untreated advanced non-small-cell lung cancer with brain metastases (C-Brain): a multicentre, single-arm, phase 2 trial

Background Brain metastases are a common complication in patients with non-small-cell lung cancer (NSCLC) lacking actionable driver mutations, with limited treatment options and poor prognosis. We aimed to investigate the efficacy and safety of brain radiotherapy combined with camrelizumab and platinum-doublet chemotherapy in patients with newly diagnosed advanced NSCLC and brain metastases. Methods This multicentre, single-arm, phase 2 trial was done across nine tertiary hospitals in China. Eligible patients were aged 18 years or older, had newly diagnosed brain metastases from NSCLC with no actionable driver mutations (EGFR, ALK, or ROS1), and had an Eastern Cooperative Oncology Group performance status of 0 or 1. Eligible patients were treated with stereotactic radiosurgery or whole-brain radiotherapy combined with camrelizumab (200 mg intravenously once every 3 weeks) and investigator-selected platinum-doublet chemotherapy (pemetrexed 500 mg/m(2) plus platinum [carboplatin, area under curve (AUC) of 5, or cis-platinum 75 mg/m(2)] for non-squamous NSCLC, and nab-paclitaxel 260 mg/m(2) plus platinum [carboplatin AUC 5, or cis-platinum 75 mg/m(2)] for squamous NSCLC) for four to six cycles. Patients with controlled disease then received maintenance treatment with camrelizumab alone (200 mg intravenously once every 3 weeks; for squamous NSCLC) or camrelizumab plus pemetrexed (500 mg/m(2) every 3 weeks; for non-squamous NSCLC). The primary endpoint was 6-month progression-free survival rate in the full analysis set, which included all patients who received at least one dose of study treatment regardless of whether they had measurable brain lesions per RECIST 1.1. The trial was registered with ClinicalTrials.gov, NCT04291092, and is ongoing. Findings Between May 6, 2020, and Jan 30, 2023, 67 patients were assessed for eligibility. Two patients were excluded (brain lesions less than 5 mm) and 65 patients were enrolled and treated. Median age was 66 years (IQR 62-70). 60 (92%) of 65 patients were male and five (8%) were female. All 65 patients were Han Chinese. 50 (77%) of 65 patients had non-squamous NSCLC and 46 (71%) were symptomatic. The 6-month progression-free survival rate was 71<middle dot>7% (95% CI 58<middle dot>9-81<middle dot>1) during the median follow-up of 14<middle dot>1 months (IQR 9<middle dot>0-20<middle dot>3; data cutoff Dec 13, 2023). The most common grade 3-4 treatment-related adverse events were decreased neutrophil count (14 [22%] of 65 patients), decreased white blood cell count (ten [15%]), decreased platelet count (ten [15%]), and decreased lymphocyte count (nine [14%]). Neurological toxic effects of grade 3 occurred in three (5%) of 65 patients. Radiation necrosis occurred in three (5%) of 65 patients; all were grade 1 or 2. There were no treatment-related deaths. Interpretation Brain radiotherapy combined with camrelizumab and platinum-doublet chemotherapy shows promising efficacy and manageable toxicity and could be a potential treatment option for patients with brain metastases from NSCLC. Randomised controlled trials will be required to confirm these findings.