Feasibility of Near-infrared Photoimmunotherapy Combined With Immune Checkpoint Inhibitor Therapy in Unresectable Head and Neck Cancer
Hitoshi Hirakawa, Taro Ikegami, Hidetoshi Kinjyo, YOSHIKAZU HAYASHI, Shinya Agena, TERUYUKI HIGA, Shunsuke Kondo, Masatomo Toyama, Hiroyuki Maeda, Mikio Suzuki
Abstract
BACKGROUND/AIM: Near-infrared photoimmunotherapy (NIR-PIT) is a recently developed cancer treatment modality that selectively kills cancer cells and may induce a therapeutic host immune response. The aim of this study was to determine the feasibility of combining NIR-PIT with immune checkpoint inhibitor (ICI) therapy for unresectable recurrent head and neck cancer. PATIENTS AND METHODS: Five patients underwent NIR-PIT at Ryukyu University Hospital between January 2022 and April 2024. These patients had unresectable recurrent head and neck squamous cell carcinoma. Among these five patients, four received a combination NIR-PIT and pembrolizumab administration. RESULTS: A total of seven lesions in the oropharynx and oral cavity were targeted. One patient was treated for three different target lesions. The best observed response (BOR) rate was 100%, with three complete responses and four partial responses. The most common treatment-related adverse event was Grade 1 or 2 local pain lasting one to two days postoperatively, which occurred in all patients. Grade 3 adverse events occurred in three cases (42.9%), including pneumonia, pharynx-cutaneous fistula, and trismus. Three patients received ICI therapy following NIR-PIT, achieving a 60% BOR rate. No immune-related adverse events were noted, and the aforementioned Grade 3 adverse events did not worsen during ICI therapy. At a median follow-up of 376 days (range=157-845 days), four target lesions showed no recurrence, while three had recurred. All five patients were alive, including three with no evidence of disease. CONCLUSION: The combination of NIR-PIT and ICI therapy for unresectable recurrent head and neck cancer was feasible.