Nivolumab added to cisplatin and radiotherapy versus cisplatin and radiotherapy alone after surgery for people with squamous cell carcinoma of the head and neck at a high risk of relapse (GORTEC 2018-01 NIVOPOST-OP): a randomised, open-label, phase 3 trial

BACKGROUND: Postoperative cisplatin and radiotherapy is the standard of care for high-risk resected locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). The NIVOPOST-OP trial aimed to assess the efficacy and safety of programmed death 1 blockade by nivolumab added to cisplatin and radiotherapy in this setting. METHODS: This open-label, phase 3 trial evaluated adding nivolumab to cisplatin and radiotherapy after surgery for LA-SCCHN with high-risk pathological features. The main inclusion criteria were age 19-74 years, an Eastern Cooperative Oncology Group performance status 0-1, squamous cell carcinoma of the oral cavity, oropharynx, larynx, or hypopharynx resected with macroscopic complete resection, and at least one high-risk pathological feature: nodal extracapsular extension, microscopically positive margins, four or more cervical nodal involvements without extracapsular extension, and multiple perineural invasions. 680 participants recruited in 82 sites across six countries (France, Spain, Poland, Belgium, Greece, and Switzerland) were randomly assigned 1:1 to receive cisplatin and radiotherapy (66 Gy, cisplatin 100 mg/m FINDINGS: The 680 patients were recruited from Oct 15, 2018, to July 3, 2024. The analysis was based on 666 participants randomly assigned until the cutoff date (April 30, 2024), at which point the required number of events was reached (median follow-up 30·3 months). Disease-free survival was significantly improved with nivolumab, cisplatin, and radiotherapy versus cisplatin and radiotherapy alone, irrespective of programmed death ligand 1 expression (HR 0·76; 95% CI 0·60-0·98; stratified log-rank test p value=0·034). There was an increase in the rate of participants with treatment-related grade 4 adverse events with nivolumab, cisplatin, and radiotherapy compared with cisplatin and radiotherapy (30 [10%] of 312 vs 16 [5%] of 306). Treatment-related deaths occurred in two participants in each group. INTERPRETATION: Nivolumab added to cisplatin and radiotherapy in high-risk resected LA-SCCHN improves disease-free survival with moderate toxic effect increase, and can be proposed as a new standard treatment.