3474 - Stereotactic Body Radiotherapy Combined with PD-1 Inhibitor in Patients with Advanced Non-Small Cell Lung Cancer: A Phase II Single-Arm Trial

Purpose/Objective(s):

To evaluate the efficacy and safety of PD-1 inhibitor (camrelizumab) combined with stereotactic body radiation therapy (SBRT) in patients with stage IV non–small cell lung cancer (NSCLC) presenting with oligometastatic disease.

Materials/Methods:

This was a prospective, single-arm, phase II clinical trial conducted at one institution in Zhengzhou, China. Eligible patients were histologically confirmed stage IV NSCLC with oligometastatic disease (=5 lesions) and no actionable oncogenic driver alterations. Patients meeting the eligibility criteria received SBRT to the primary tumor and/or metastatic sites. Different tumor sites were irradiated at doses ranging from30-70Gy/3-10F. Camrelizumab (200 mg) was administered intravenously within 1 week after completion of SBRT and continued for up to 1 year, or until disease progression, unacceptable toxicity, or withdrawal for other reasons. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and objective response rate (ORR). The trial was registered at the Chinese Clinical Trial Registry with the registration number of ChiCTR2100050165.

Results: Between August 30, 2021, and October 14, 2024 , 46 eligible patients were enrolled. 42 (34 men and 8 women) received SBRT combined with camrelizumab and were included in the analyses. A total of 45 lesions were treated with SBRT, including 22 primary tumors and 23 metastatic lesions. The median age was 63.5 years (interquartile range [IQR], 36–74). At the data cutoff on October 1, 2025, the median follow-up duration was 26.5 months (IQR, 3.1–48.2). The median progression-free survival (mPFS) was 21.0 months, and the median overall survival (mOS) was 44.2 months. The 1- and 2-year PFS rates were 73.3% and 45.0%, respectively. The 1- and 2-year OS rates were 95.2% and 80.2%.The objective response rate (ORR) was 52.3%. Treatment-related grade =3 adverse events occurred in 6 patients. The most common treatment-related adverse event was neutropenia (12 patients [28.5%]), which was also the most frequent grade =3 toxicity (4 patients [9.5%]). No grade 4 or higher treatment-related adverse events were observed. In subgroup analyses, patients who received SBRT to the primary lesion demonstrated numerically higher 2-y PFS and OS rates compared with those who received SBRT to metastatic lesions, although the differences did not reach statistical significance (2-y PFS rate: 55.1% vs 39.0%; hazard ratio [HR], 1.80; 95% confidence interval [CI], 0.70–4.63; P =0.22; 2-y OS rate: 84.6% vs 76.6%; HR, 1.99; 95% CI, 0.54–7.43; P =0.30).

Conclusion:

SBRT combined with camrelizumab demonstrated favorable disease control in patients with advanced oligometastatic NSCLC, suggesting a potential clinical benefit of integrating local ablative radiotherapy with immunotherapy in this population. Treatment-related adverse events were predominantly mild to moderate and manageable, indicating an acceptable safety profile.