Anti-programmed death-1 inhibitors and nimotuzumab in combination with induction chemotherapy for locoregionally advanced nasopharyngeal carcinoma: A propensity score-matched analysis.

6060 Background: The poor prognosis of locoregionally advanced nasopharyngeal carcinoma (LANPC) due to the high incidence of metastasis necessitates effective treatment strategies. Synergistic effects have been observed when anti-programmed death-1 (anti-PD-1) inhibitors are combined with chemotherapy or targeted therapy. Methods: In total, 319 patients with LANPC were retrospectively enrolled between December 2017 and November 2022. The primary endpoint was progression-free survival. Propensity score matching was performed to adjust for potential confounders. Results: Overall, 150 patients were included after propensity score matching. The immunotherapy + nimotuzumab + chemotherapy (INC) group (n=50) had a higher 3-year progression-free survival rate (96.6% [95% confidence interval (CI): 93.2–100.0]) than the nimotuzumab + chemotherapy (NC) group (n=100) (79.8% [95% CI: 75.6–84.0]). The INC group had a hazard ratio of 0.16 (95% CI: 0.02–1.22; P=0.04). The objective response rates were 100% and 99% for the INC and NC groups, respectively. Grade ≥3 treatment-related adverse events were reported in eight (5.3%) patients, and hyponatremia (2.0%) was the most common. Grade ≥3 immune-related adverse events (rash and reactive capillary proliferation) were reported in two (4.0%) patients. Conclusions: Neoadjuvant therapy with anti-PD-1 inhibitors and nimotuzumab combined with chemotherapy demonstrates promising anti-tumor activity with acceptable safety for LANPC. More well-designed randomized trials with larger patient cohorts are needed to confirm long-term efficacy. Short-term efficacy of three months after the end of treatment. Response evaluation INC group [n = 50 (%)] NC group [n = 100 (%)] CR 38（76.0） 19（19.0） PR 12（24.0） 80（80.0） SD 0 1（1.0） PD 0 0 ORR (95% CI) 100% (92.9%, 100%) 99% (94.6%, 100%) DCR (95% CI) 100% (92.9%, 100%) 100% (96.4%, 100%) CI, confidence interval; CR, complete response; DCR, disease control rate; IC, induction chemotherapy; ORR, objective response rate; PD, progressive disease; PR, partial response; SD, stable disease.