An Open-label Study Using ASP-1929 Photoimmunotherapy in Combination With Anti-PD1 Therapy in EGFR Expressing Advanced Solid Tumors

This basket trial study has 3 sub-studies: Sub-study 1 (181 HNSCC) will enroll patients with recurrent or metastatic (R/M) squamous cell cancer of the head and neck (HNSCC). HNSCC patients are required to have positive expression of programmed cell death ligand 1 (PD-L1) defined by Combined Positive Score (CPS) ≥1. Sub-study 2 (181 cuSCC) will enroll patients with locally advanced or metastatic cutaneous squamous cell carcinoma (cuSCC). Sub-study 3 (181 2LcuSCC) will enroll patients with locally advanced or metastatic cutaneous squamous cell carcinoma who have progressed on anti-PD-1 therapy. Eligible patients will enroll in the applicable sub-study and receive ASP-1929 photoimmunotherapy (PIT) treatment in combination with an anti-PD-1 therapy for up to 24 months. During the treatment period, patients will undergo clinical assessments and be monitored for safety and tolerability and disease progression by modified RECIST 1.1 for overall response rate (ORR), progression-free survival (PFS), and duration of response (DOR). Each sub-study is an open-label, single-arm study. For each sub-study, the primary objectives are to characterize the safety and tolerability of ASP-1929 PIT treatment in combination with anti-PD-1 treatment and to assess the effect of ASP-1929 PIT treatment with anti-PD1 therapy on tumor response.