Real-World Effectiveness and Safety of Photoimmunotherapy for Head and Neck Cancer: A Multicenter Retrospective Study

Background/Objectives: Photoimmunotherapy for head and neck cancer (HN-PIT) is an emerging treatment for unresectable locally advanced or recurrent head and neck cancer. However, real-world data (RWD) are limited. This study examined the safety and effectiveness of HN-PIT. Methods: This multicenter, retrospective cohort study included 40 patients with unresectable locally advanced or recurrent head and neck cancers who underwent HN-PIT from January 2021 to August 2024. The primary endpoint was time to treatment failure (TTF). Secondary endpoints included the objective response rate (ORR), overall survival (OS), progression-free survival (PFS), and adverse events (AEs). Results: The median TTF and 1-year treatment failure rate were 6.0 months and 23.2%, respectively. Moreover, the ORR, disease control rate, median OS, and median PFS were 75.0% (95% confidence interval [CI]: 60.0–86.0%), 95.0% (95% CI: 83.5–99.0%), 26.9 months, and 6.2 months, respectively. The incidence of grade ≥3 AEs was 17.5% (95% CI: 7.1–29.1%). Pain was the most common AE, occurring in 37 patients (92.5%), with grade III pain reported in 5 (12.5%). Mucositis occurred in 32 patients (80.0%), with grade III mucositis reported in 3 (7.5%). Hemorrhages occurred in 31 patients (77.5%), with no grade ≥III hemorrhages reported. Two patients experienced sepsis (5.0%; grades IV and V). Seventeen patients (42.5%) had laryngeal edema, with grade IV edema reported in four (10.0%). Conclusions: Our RWD shows that HN-PIT is effective with an acceptable safety profile. TTF may serve as an endpoint reflecting this treatment’s characteristics. This study provides important basic data for the development of future treatment strategies.