Plenary: The NIVOPOSTOP Trial

During the plenary session at ASCO 2025, Professor Jean Bourhis (CHUV, Bâtiment Hospitalier Lausanne) presented the results from the NIVOPOSTOP study. MediMix arranged an interview with him on this important study in the field of head and neck cancer.

This study focused on a specific subgroup of head and neck cancer patients who, despite undergoing surgery, are at high risk of relapse due to adverse pathological features. Historically, such patients have a relapse rate of 40–50%, representing a clear unmet clinical need. The trial employed a straightforward design, comparing the current standard of care—surgery followed by chemoradiotherapy—with the same regimen plus adjuvant nivolumab, an immune checkpoint inhibitor. The goal was to determine whether adding immunotherapy could improve outcomes by enhancing the immune system’s ability to control the disease post-surgery.

The primary endpoint was DFS. The study included 680 patients and observed 252 DFS events, the pre-specified number required for analysis. Results showed an increase in three-year DFS from 52% in the control group to 63% in the nivolumab group. This improvement is considered clinically meaningful, especially given the lack of advances in this setting over the past three decades. The benefit of nivolumab appeared primarily in improving local tumour control rather than reducing distant metastasis. While there was a trend toward improved OS with nivolumab, these data are not yet mature, as the necessary number of deaths for final analysis has not been reached.

In terms of safety and tolerability, the addition of nivolumab did not interfere with patients’ ability to complete chemoradiotherapy. Although there was a slight increase in expected immune-related adverse events such as thyroid dysfunction, the overall safety profile was acceptable. No significant differences in compliance or major toxicities were observed between the treatment arms.

In summary, this study demonstrates that adding nivolumab to standard postoperative treatment improves disease-free survival in high-risk head and neck cancer patients without compromising safety or treatment adherence.