A phase 2 clinical trial found that adding the PD-1 inhibitor sintilimab to adjuvant capecitabine did not improve outcomes for patients with locoregionally advanced nasopharyngeal carcinoma who responded poorly to induction chemotherapy. The study enrolled 152 high-risk patients and randomly assigned them to receive either sintilimab plus capecitabine or capecitabine alone after chemoradiotherapy.
The trial failed to meet its primary endpoint, with 2-year progression-free survival rates of 88.2% in the combination group and 87.8% in the capecitabine-alone group. Researchers also observed no significant differences in overall survival, locoregional relapse-free survival, or distant metastasis-free survival. In patients whose tumors had low PD-L1 expression, a trend toward worse progression-free survival was seen in the sintilimab arm.
Safety profiles were generally consistent with known side effects. Severe neutropenia occurred more frequently with the combination therapy, while severe hand-foot syndrome was slightly more common with capecitabine alone. Immune-related adverse events, including hypothyroidism and myocarditis, were reported only among patients receiving sintilimab.