Tislelizumab as adjuvant therapy following endoscopic surgery for resectable recurrent nasopharyngeal carcinoma: a randomized clinical trial.

Background: Endoscopic surgery has become the first-line treatment for surgically resectable recurrent nasopharyngeal carcinoma (rNPC), but it is associated with a high risk of postoperative tumor progression. Currently, there is a lack of effective and well-tolerated adjuvant treatment regimens. Thus, the primary objective was to investigate the efficacy and safety of tislelizumab as adjuvant therapy with endoscopic surgery for the treatment of patients with rNPC.

Methods: This was a single-center, open-label, randomized, controlled, phase 2 trial between November 23, 2021, and May 8, 2024. Eligible patients included those with complete tumor disappearance as indicated by postoperative imaging, histopathologically diagnosed with undifferentiated or differentiated non-keratinizing rNPC. Patients with rNPC were randomized to receive endoscopic surgery alone or adjuvant tislelizumab treatment 2-6 weeks after endoscopic surgery. Tislelizumab was administered as a 200 mg intravenous infusion every 3 weeks until disease progression, death, unacceptable toxicity, withdrawal of consent, investigator's decision, or 1 year. The primary endpoint was progression-free survival (PFS) at 1 year, and secondary endpoints included 1-year progression-free interval (PFI), 1-year overall survival (OS), and safety.

Results: The trial is ongoing. 42 patients were enrolled at a median follow-up of 18 months (IQR 10-27), the 1-year PFS was significantly higher in the tislelizumab group (94%, 95% CI: 83% to 100%) than in the endoscopic surgery alone group (57%, 95% CI: 38% to 85%). The 1-year PFI was also higher in the tislelizumab group (100%, 95% CI: 100% to 100%) than in the endoscopic surgery alone group (60%, 95% CI: 40% to 89%). No significant difference in the 1-year OS was observed at the data cut-off. Grade ≥3 immune-related adverse events (irAEs) occurred in 9% of tislelizumab recipients, and all of these events were elevated blood creatine phosphokinase levels. Additionally, the most common irAEs in this group were hypothyroidism, affecting 27%, and pruritus, observed in 9%.

Conclusions: Tislelizumab as adjuvant therapy significantly enhanced PFS and PFI, with a favorable safety profile. Longer follow-up is necessary to determine whether this regimen can be considered as the standard of care for patients with resectable rNPC following endoscopic surgery.

Trial registration number: NCT05092217.