Human papillomavirus (HPV)-associated oropharyngeal cancer has a better prognosis than other head and neck cancers. However, rates of recurrence and metastasis are similar and the prognosis of recurrent or metastatic HPV-associated oropharyngeal cancer is poor. Near-infrared photoimmunotherapy (NIR-PIT) is a treatment involving administration of a photosensitizer (IRDye^®700DX) conjugated to a monoclonal antibody followed by activation with near-infrared light illumination. It is a highly tumor-specific therapy with minimal toxicity in normal tissues. Moreover, NIR-PIT is expected to have not only direct effects on a treated lesion but also immune responses on untreated distant lesions. NIR-PIT with cetuximab-IR700 (AlluminoxTM) has been in routine clinical use since January 2021 for unresectable locally advanced or locally recurrent head and neck cancer in patients that have previously undergone radiotherapy in Japan. NIR-PIT for head and neck cancer (HN-PIT) is expected to provide a curative treatment option for the locoregional recurrent or metastatic disease after radiotherapy and surgery. This article reviews the mechanism underlying the effect of NIR-PIT and recent clinical trials of NIR-PIT for head and neck cancers, treatment-specific adverse events, combination treatment with immune checkpoint inhibitors, illumination approach and posttreatment quality of life, and provides a case of series of two patients who receive NIR-PIT for oropharyngeal cancer at our institution.

Although nivolumab, a programmed cell death 1 (PD‐1) inhibitor, is a standard therapy for platinum‐refractory recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), no definitive biomarkers have been reported thus far. This study aimed to select promising prognostic markers in nivolumab therapy and to create a novel prognostic scoring system. In this retrospective cohort study, we reviewed patients with R/M HNSCC who were treated with nivolumab from April 2017 to April 2019. We developed a prognostic score for immune checkpoint inhibitor (ICI) therapy that was weighed using hazard ratio–based scoring algorithms. Significant variables were selected from the multivariate Cox proportional hazard analyses on overall survival (OS). A total of 85 patients with HNSCC were analyzed in the present study. The relative eosinophil count (REC), the ratio of eosinophil increase (REI), and Eastern Cooperative Oncology Group Performance Status (ECOG PS) were selected as variables affecting the prognostic score. The patients were divided into four groups: very good (score = 0), good (score = 1), intermediate (score = 2), and poor (score = 3). The OS hazard ratios were 2.77, 10.18, and 33.21 for the good, intermediate, and poor risk groups compared with the very good risk group, respectively. The Eosinophil Prognostic Score is a novel prognostic score that is effective for predicting the prognosis of HNSCC patients treated with nivolumab. This score is more precise as it includes changes in biomarkers before and after the treatment.

To investigate whether peripheral blood biomarkers predict the outcome of anti-PD-1 antibody treatment for head and neck squamous cell carcinoma (HNSCC). Patients treated with nivolumab for platinum-refractory recurrent or metastatic HNSCC were retrospectively reviewed. Fifty-three patients treated between April 2017 and March 2018 were included in the study. The median progression-free survival (PFS) and overall survival (OS) were 2.5 and 8.7 months, respectively. In the univariate analysis, performance status (PS) ≥ 3, relative neutrophil count ≥ 0.65, relative lymphocyte count ≥ 0.17, and relative eosinophil count (REC) ≥ 0.015 were significantly associated with both PFS and OS. On multivariate analysis, PS ≥ 3 and REC ≥ 0.015 were significantly associated with PFS and OS. Low REC and poor PS were independent poor prognostic factors for both PFS and OS in patients with recurrent or metastatic HNSCC treated with nivolumab.