Anti-PD-1 antibody penpulimab plus chemotherapy for recurrent or metastatic nasopharyngeal carcinoma: a randomized, double-blind phase 3 study

In this phase 3 trial, penpulimab combined with chemotherapy was assessed against a regimen of placebo plus chemotherapy for the first-line treatment of recurrent or metastatic nasopharyngeal carcinoma (R/M NPC). 291 patients were randomised and allocated in a 1:1 ratio in order to receive penpulimab (n = 144; 200 mg) or placebo (n = 147; 200 mg), plus chemotherapy (cisplatin/carboplatin and gemcitabine) every 3 weeks. Patients followed by maintenance therapy with penpulimab or placebo after 6 cycles. The primary endpoint of this study was progression-free survival (PFS) according to RECIST v1.1, and a significantly longer median PFS in the penpulimab arm versus the placebo arm (9.63 versus 7.00 months; hazard ratio 0.45, 95% CI: 0.33-0.62, P < 0.0001) was demonstrated in this prespecified interim analysis. The key secondary endpoint was the overall survival (OS). However, the OS data were still immature, and the median OS was not achieved (hazard ratio, 0.94; 95% CI: 0.63-1.40). The occurrence of treatment-related adverse events (grade ≥ 3) was 89.0% and 85.9% in two arms, with the most common being reduced the quantity of neutrophil (56.2% vs. 62.0%), reduced the quantity of white blood cell (54.1% vs. 54.9%), and anemia (45.2% vs. 38.7%). In the penpulimab arm, 6 patients (4.1%) experienced immune-related adverse events (grade ≥ 3). Adding penpulimab to chemotherapy led to a notable enhancement in PFS for the first-line R/M NPC treatment, alongside a safety profile that was both manageable and tolerable. ClinicalTrials.gov identifier NCT04974398.