Biomarkers of nivolumab benefit in resectable non-small cell lung cancer

Perioperative nivolumab significantly improved event-free survival (EFS) compared with placebo in patients with resectable non-small cell lung cancer (NSCLC) in the CheckMate 77T study (ClinicalTrials.gov NCT04025879 )¹. Here, after randomization, 98 out of 229 patients who received nivolumab and 92 out of 232 patients who received placebo had evaluable biomarkers (41% of randomized patients). Of the 98 patients receiving nivolumab, 83 (85%) had detectable circulating tumour DNA (ctDNA) before initiating neoadjuvant treatment and 90 (92%) at neoadjuvant treatment completion. Of the 92 placebo-treated patients, 75 (82%) had detectable ctDNA at the treatment start and 78 (85%) at completion. Among the 98 nivolumab-treated patients, 76 (78%) had detectable and evaluable ctDNA before and after neoadjuvant treatment, and 50 of them (66%) had pre-surgical ctDNA clearance, and 25 out of 50 (50%) had pathologic complete response (pCR). For the placebo-treated group, these values were 64 out 92 (70%) for detectable and evaluable ctDNA before and after neoadjuvant treatment, and 24 out of 64 (38%) had pre-surgical ctDNA clearance, and 3 out of 24 (12%) had pCR. Furthermore, 4 out of 48 (8%) patients in the nivolumab group and 9 out of 44 (20%) in the placebo group who were negative for molecular residual disease (MRD) after surgery and before adjuvant treatment initiation became positive during the adjuvant treatment period; all had disease recurrence. EFS seemed to be prolonged with nivolumab (n = 60) versus placebo (n = 45) in patients with single or co-alterations in any of the KEAP1, STK11, CDKN2A and/or SMARCA4 driver genes (hazard ratio, 0.48; 95% confidence interval, 0.28-0.83). In a machine-learning model trained using biomarker-evaluable patients, top predictors of prolonged EFS included pre-surgical ctDNA clearance, non-N2 NSCLC, pCR, squamous tumour histology and nivolumab treatment. These findings provide insights into predictive markers for outcomes with perioperative nivolumab in resectable NSCLC.