The Headline: Nivolumab added to ablative radiotherapy for early-stage NSCLC improves survival, at least in I-SABR.
The Study: The prospective I-SABR trial
randomized 141 patients receiving ablative radiotherapy for systemic-therapy naive non-small cell lung cancer (NSCLC) to +/- the addition of 4 cycles of nivolumab to start before or within 3 days of the first radiotherapy treatment. All tumors were <7 cm and node-negative. We will pause here to reflect on the fact there was no tumor size minimum. In fact, 88% (124/141) had T1 tumors (≤3 cm). Radiotherapy schemas had to deliver a BED > 100 Gy in 10 or less fractions—so picture your ablative treatment of choice for a primary cN0 lung tumor not receiving chemo. The results were stark: at 6 years, the primary endpoints of overall (70% versus 56%, HR 0.55) and event-free (53% versus 32%, HR 0.52) were significantly improved. This seems like a gamechanger, but it’s a single bright spot among several negative trials including the larger, phase 3 S1914 trial. What was different in I-SABR? A shorter nivolumab course compared with much longer courses in other trials, as well as sequencing nivo with and after SBRT rather than before or only after completion of SBRT.
TBL: Long term results from I-SABR show improved event free and overall survival when a short course of nivolumab is given along with SABR for early stage NSCLC. | Chang, ASTRO 2026
The Study: The prospective I-SABR trial
randomized 141 patients receiving ablative radiotherapy for systemic-therapy naive non-small cell lung cancer (NSCLC) to +/- the addition of 4 cycles of nivolumab to start before or within 3 days of the first radiotherapy treatment. All tumors were <7 cm and node-negative. We will pause here to reflect on the fact there was no tumor size minimum. In fact, 88% (124/141) had T1 tumors (≤3 cm). Radiotherapy schemas had to deliver a BED > 100 Gy in 10 or less fractions—so picture your ablative treatment of choice for a primary cN0 lung tumor not receiving chemo. The results were stark: at 6 years, the primary endpoints of overall (70% versus 56%, HR 0.55) and event-free (53% versus 32%, HR 0.52) were significantly improved. This seems like a gamechanger, but it’s a single bright spot among several negative trials including the larger, phase 3 S1914 trial. What was different in I-SABR? A shorter nivolumab course compared with much longer courses in other trials, as well as sequencing nivo with and after SBRT rather than before or only after completion of SBRT.
TBL: Long term results from I-SABR show improved event free and overall survival when a short course of nivolumab is given along with SABR for early stage NSCLC. | Chang, ASTRO 2026