Ma BBY, et al. - Experts assessed the antitumor activity of nivolumab in nasopharyngeal carcinoma (NPC) in this multicenter study of the Mayo Clinic phase 2 consortium. They also investigated tumor and plasma-based biomarkers in an exploratory analysis. It was deduced that nivolumab exhibited promising activity in NPC. Furthermore, data displayed that the 1-year overall survival rate compared favorably with historic data in similar cohorts.

Methods

• Nivolumab treatment was given to patients with multiply pretreated recurrent or metastatic NPC until disease progression.
• Objective response rate (ORR) served as the primary end point and secondary end points included survival and toxicity.
• A correlation between the expression of programmed death-ligand 1 (PD-L1) and human leukocyte antigens A and B in archived tumors and plasma clearance of Epstein-Barr virus DNA with ORR and survival was seen.

Results

• Researchers evaluated a total of 44 patients and the overall ORR was 20.5% (complete response, n = 1; partial response, n = 8).
• Nivolumab was given to 9 patients for > 12 months (20%).
• Findings suggested the 1-year overall survival rate to be 59% (95% CI, 44.3% to 78.5%) and 1-year progression-free survival (PFS) rate to be 19.3% (95% CI, 10.1% to 37.2%).
• No statistical correlation between ORR and the biomarkers was seen, nonetheless, a descriptive analysis demonstrated that the proportion of patients who responded was higher among those with PD-L1 positive tumors (> 1% expression) vs those with PD-L1-negative tumors.
• Better PFS was seen to be associated with the loss of expression of one or both human leukocyte antigen class 1 proteins vs when both proteins were expressed (1-year PFS, 30.9% v 5.6%; log-rank P=.01).
• No link between survival and PD-L1 expression or plasma Epstein-Barr virus DNA clearance was noted.
• Results did not demonstrate any unexpected toxicity to nivolumab.