Tislelizumab Plus GX Versus Tislelizumab Plus GP in the Treatment of R/M NPC

This trial is comparing two immunotherapy-plus-chemotherapy combinations for people with recurrent or metastatic nasopharyngeal carcinoma (a type of head and neck cancer): tislelizumab plus gemcitabine/capecitabine (GX regimen) versus tislelizumab plus gemcitabine/cisplatin (GP regimen), to see which works better. **You may be eligible if...** - You are between 18 and 75 years old - You have confirmed recurrent or metastatic nasopharyngeal carcinoma - You have not had prior systemic treatment for your recurrent or metastatic disease (prior adjuvant or concurrent chemoradiotherapy is allowed if relapse occurred at least 6 months after finishing chemotherapy) - You have good performance status (ECOG 0-1) and at least one measurable lesion on imaging - Your blood counts and organ function meet the required levels **You may NOT be eligible if...** - You have already received systemic chemotherapy for metastatic/recurrent NPC - You have serious autoimmune disease or are on immune-suppressing drugs - You have uncontrolled infections or significant other medical conditions Talk to your doctor to see if this trial is right for you.