Enrollment consists of six cohorts of patients with locally advanced cuSCC or HNSCC that has recurred or progressed on or after at least one prior line of therapy, which must include prior platinum-based chemotherapy and is not eligible for further locoregional therapy, or with metastatic disease that has recurred or progressed after all available standard therapies. Patients will receive anti-CD25 antibody, conjugated to the light-activatable dye, IRDye® 700DX, followed by illumination with non-thermal red light (RM-1995 photoimmunotherapy)) as monotherapy (phase 1a), or in combination with pembrolizumab (phase 1b).~Patients are required to have measurable disease by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1,Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2, and a superficial lesion accessible to photoimmunotherapy at the time of screening.~Phase 1a primary objectives are to evaluate the safety and tolerability of RM-1995 photoimmunotherapy treatment as monotherapy and determine the maximum tolerated dose (MTD) or maximum administered dose (MAD).~Phase 1b primary objectives are to evaluate the safety and tolerability of RM-1995 photoimmunotherapy treatment in combination with pembrolizumab and determine the MTD or MAD.
A phase 1a/1b, open-label, RM-1995 drug-dose escalation study designed to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of RM-1995 photoimmunotherapy treatment as monotherapy (phase 1a) or combined with pembrolizumab (phase 1b) in patients with cutaneous squamous cell carcinoma (cuSCC) or head and neck squamous cell carcinoma (HNSCC) that has progressed despite all available standard therapies.