Adding Nivolumab to Stereotactic Ablative Radiotherapy Might Extend Survival for Patients with Early-Stage NSCLC

For patients with inoperable stage I or II node-negative non–small-cell lung cancer (NSCLC), the standard therapy is stereotactic ablative radiotherapy (SABR). Despite local control, regional and systemic recurrences are unfortunately common. Because immunotherapy after chemoradiation for stage III, locally advanced NSCLC improves progression-free and overall survival, investigators wanted to understand its utility in earlier-stage NSCLC.

In this industry-supported, phase 2, open-label trial, 156 people with stage I or II NSCLC or with isolated parenchymal (<7 cm) node-negative NSCLC were randomized to either SABR alone or SABR plus nivolumab (I-SABR). SABR was given at 50 Gy in 4 once-daily fractions or 70 Gy in 10 once-daily fractions. Nivolumab was given intravenously (480 mg) every 4 weeks (beginning on the same day as the first SABR or within 36 hours afterwards) for four cycles.

In a median follow-up of 33 months, 4-year event-free survival (the study's primary endpoint) among the 141 participants receiving the assigned therapy was 77% in the I-SABR group versus 53% in the SABR-only group (hazard ratio, 0.38). Neither grade 3 pneumonitis nor treatment-related grade 4 or 5 adverse events were observed. In the I-SABR group, 10 patients (15%) had treatment-related grade 3 adverse events, and 5 patients (8%) discontinued nivolumab.