HPV 16-positive and/or HPV 18-positive Recurrent and/or For Patients With Metastatic Head and Neck Cancer to Evaluate GX-188E DNA Vaccination, GX-I7 and Nivolumab Combination Therapy

This study tests a combination of two treatments — a DNA vaccine (GX-188E) plus an immune-boosting injection (GX-I7) — together with the immunotherapy drug nivolumab for patients with advanced head and neck cancer caused by the HPV virus (specifically HPV-16 or HPV-18). The hope is that stimulating the immune system to recognize HPV can help shrink tumors. **You may be eligible if...** - You are 19 or older with confirmed HPV-16 or HPV-18 positive head and neck cancer that has returned or spread - Your cancer progressed during or after platinum-based chemotherapy - Your tumor shows a protein called PD-L1 at 1% or higher - You have had up to 2 prior lines of chemotherapy - Your overall health and organ function are adequate **You may NOT be eligible if...** - You have already received immunotherapy drugs (anti-PD-1/PD-L1 agents) - You have active autoimmune disease requiring treatment - You have active brain metastases or a history of organ transplant - You are pregnant or breastfeeding - You have active HIV or hepatitis B/C infection Talk to your doctor to see if this trial is right for you.