Dynamic Plasma EBV DNA-Guided Risk-Adapted Treatment With Becotatug Vedotin (MRG003) Plus PD-1 Blockade in Locoregionally Advanced Nasopharyngeal Carcinoma

The purpose of this study is to evaluate the efficacy and safety of a risk-adapted treatment strategy incorporating induction therapy with becotatug vedotin (MRG003) plus pucotenlimab, followed by treatment allocation based on post-induction plasma cell-free Epstein-Barr virus DNA (cfEBV DNA) status and radiographic response in patients with locoregionally advanced nasopharyngeal carcinoma. All participants will receive three cycles of induction therapy with becotatug vedotin (MRG003) plus the PD-1 inhibitor pucotenlimab. After induction therapy, participants with cfEBV DNA clearance and a complete or partial response will be classified as low risk and receive intensity-modulated radiotherapy alone, followed by adjuvant pucotenlimab. Participants without cfEBV DNA clearance or with stable or progressive disease will be classified as high risk and receive intensity-modulated radiotherapy with concurrent cisplatin, followed by adjuvant pucotenlimab and capecitabine. The primary objectives are to evaluate the post-induction therapy complete response rate in the overall study population and event-free survival in the high-risk group.