The present study is based in large part on observations made during an exploratory Phase 1-2 study of the safety and efficacy of the IRX-2 regimen performed at the Instituto Nacional de Cancerologia (INCAN), Mexico's National Cancer Institute. Patients with head and neck (HN) squamous cell carcinoma (SCC) were treated with the IRX-2 regimen, some as neoadjuvant therapy prior to surgery and some for advanced disease. Three different doses and dose schedules were studied. Evaluation of clinical safety included regular clinical and laboratory evaluations. In the patients treated before surgery, evaluation of tumor response was undertaken by comparison of tumor size before and after the IRX-2 regimen. This study provided preliminary evidence of the safety and possible efficacy of IRX-2 in the pre-surgical, neoadjuvant treatment of HN SCC. The regimen was well tolerated in most patients, and histological and clinical tumor responses were observed.