Background: Photoimmunotherapy (PIT) is a new cancer-targeted therapy. PIT is a combination drug and device anti-cancer treatment that utilizes monoclonal antibodies conjugated to a dye, that can be activated upon nonthermal 690 nm red light illumination to induce rapid cell death only at cells expressing the antigen and only after antibody binding to the cellular antigen. The requirement of light-induced activation and antigen-antibody binding to induce cell death enables the selective and specific destruction of tumor cells with minimum damage to healthy tissue surrounding the tumor cells.

PIT requires two treatment steps in sequence: (i) the administration of the experimental drug by infusion and (ii) the illumination of the tumor with 690 nm nonthermal red light using sufficient energy to induce cell death. Light illumination is administered 24 ± 4 hours post-ASP-1929 infusion. The lag is intended to enable drug distribution within the tumor prior to drug activation by the application of light.

The experimental drug therapy targets epidermal growth factor receptor (EGFR) antigens. EGFR is highly expressed in squamous cell carcinomas of the head and neck.

Objectives: This global, multi-centered trial evaluates the efficacy and safety of PIT as monotherapy for the treatment of locoregional, recurrent HNSCC in patients who have failed or progressed on or after 2 lines of therapy.