From Evidence to Practice: Integrating Toripalimab into Frontline Care for Recurrent Locally Advanced or Metastatic Nasopharyngeal Carcinoma - Episode 3
Panelists discuss the biological rationale and consistent clinical data supporting PD-1 checkpoint inhibitors—such as toripalimab, nivolumab, and pembrolizumab—as active and meaningful treatments in recurrent/metastatic nasopharyngeal carcinoma (R/M NPC), particularly given the Epstein-Barr virus (EBV)-driven, immune-infiltrated nature of the disease.
The rationale for introducing immunotherapy into the treatment landscape for recurrent or metastatic nasopharyngeal carcinoma R/M NPC stems from both biological characteristics and broader oncology trends. Nasopharyngeal carcinoma (NPC) NPC is biologically distinct from other head and neck cancers. It's often driven by Epstein-Barr virus (EBV), EBV and these tumors tend to be immune-infiltrated. This suggests that the immune system is already engaged to some degree, and that viral antigens may serve as targets for immune-based therapies. Given the durable responses seen with immunotherapy in many other cancers, there's strong motivation to explore similar strategies in NPC.
Beyond the theoretical rationale, there’s evidence that these tumors often exhibit features predictive of response to immunotherapy, such as high PD-L1 expression. Because NPC is a virally mediated cancer, the immune system may be particularly well-positioned to recognize and attack tumor cells once checkpoint blockade is introduced. In patients with these cancers, the immune response may initially be suppressed by the tumor environment, but checkpoint inhibitors can help reactivate immune surveillance. These biologic underpinnings provide a solid rationale for the use of PD-1 or PD-L1 inhibitors.
This has been supported by clinical data. Multiple phase 2 studies have examined PD-1 blockade in previously treated NPC. In one single-arm trial of toripalimab, the objective response rate was approximately 20.5%, with a median overall survival of around 17.4 months. A similar study using nivolumab reported the same response rate and a comparable survival outcome. Another randomized study compared pembrolizumab to chemotherapy, showing response rates just over 20% and a slight survival benefit in the immunotherapy arm. These studies—despite using different agents—have shown remarkably consistent results, reinforcing the conclusion that PD-1 inhibition is active and clinically meaningful in recurrent/metastatic R/M NPC.