ADDING nivolumab to postoperative chemoradiotherapy may reduce the likelihood of recurrence in patients with resected, high-risk head and neck squamous cell carcinoma (HNSCC), according to results from the Phase III NIVOPOSTOP trial presented at the 2025 ASCO Annual Meeting.
HNSCC is the sixth most common cancer globally, with most patients diagnosed at a locoregionally advanced stage. Standard treatment for patients at high risk of recurrence includes surgery followed by chemoradiotherapy. However, recurrence rates remain significant, with only about 50% to 55% of patients remaining disease-free at three years.
The NIVOPOSTOP study evaluated whether adding nivolumab, a PD-1 immune checkpoint inhibitor, to standard postoperative chemoradiotherapy could improve outcomes in this population. A total of 680 patients with surgically resected, locoregionally advanced HNSCC were enrolled, and 666 were included in the analysis. Participants were randomized into two groups following surgery: one received chemoradiotherapy alone, and the other received nivolumab plus chemoradiotherapy followed by maintenance nivolumab.
After a median follow-up of 30.3 months, 252 patients had experienced disease recurrence or death. The disease-free survival (DFS) rate at three years was 63.1% in the nivolumab group compared with 52.5% in the chemoradiotherapy-only group, representing a 24% improvement in DFS odds.
Grade 4 adverse events were more frequent among those who received nivolumab, reported in 13.1% of patients versus 5.6% in the control group. The most commonly observed severe adverse events were neutropenia and lymphocytopenia.
These results suggest a potential role for adjuvant immunotherapy in improving disease control in resected high-risk HNSCC. Additional analyses, including overall survival, are planned once mortality data mature, expected by 2026 or 2027.
The trial represents a notable attempt to improve a standard of care that has remained largely unchanged for over two decades.
Reference:
ASCO. Adding Nivolumab to Chemoradiotherapy After Surgery Can Decrease Chance of Recurrence in Patients With Head and Neck Cancer. 2025. Available at: https://www.asco.org/about-asco/press-center/news-releases/adding-nivolumab-chemoradiotherapy-after-surgery-can-decrease. Last accessed: 2 June 2025.
