889P - Tislelizumab combined with induction chemotherapy and concurrent chemoradiotherapy for locoregionally advanced nasopharyngeal carcinoma: A prospective, single-arm, phase II trial

Background

The success of PD-1 blockade in not only recurrent/metastatic but also in locoregionally advanced nasopharyngeal carcinoma (LANPC) has been proven. However, PD-1 blockade with standard induction chemotherapy docetaxel /cisplatin/5-FU (TPF regimen) for LANPC has not been evaluated. This trial aimed to evaluate the efficacy and safety of tislelizumab combined with the induction TPF regimen and concurrent chemoradiotherapy (CCRT) in previously untreated LANPC.

Methods

Patients with nonkeratinizing LANPC (staged III-IVa, AJCC 8th, exclude T3N0), aged 18-70 were enrolled. Docetaxel (60 mg/m² D1), cisplatin (60 mg/m² D2), continuous 5-FU (400 mg/m² D2-6) and tislelizumab (200mg D1) were intravenous given every 3 weeks of 3 cycles. The patient received 2 cycles of cisplatin (80 mg/m², D1) and tislelizumab (200mg, D1) during radiotherapy. Tislelizumab (200mg, D1) as maintenance treatment was administrated 3 cycles every 3 weeks. The primary endpoint was complete response rate (CRR) after induction therapy, the secondary endpoints included progression-free survival, locoregional failure-free survival, distant metastasis-free survival, overall survival and toxicity.

Results

From June 2023 to February 2024, a total of 35 patients were enrolled at the People’s Hospital of Guangxi Zhuang Autonomous Region. One patient did not meet the inclusion criteria so failed to enroll. One patient discontinued treatment after cycle one because of treatment-related adverse events and economic condition. As of April 30th, 2024, 34 patients (median age 51y, 70.6% male) who completed induction therapy were evaluable for response. The median follow-up time was 5.0 months. The CRR and ORR were 23.5% (95%CI: 10.7%, 41.2%) and 94.1% (95%CI: 80.3%, 99.3%) respectively. No grade 3-4 immune-related adverse events were observed in evaluable patients. Compared to the standard TPF regimen, the combination with tislelizumab did not increase the incidence of hematological toxicity events.

Conclusions

Tislelizumab combined with TPF induction chemotherapy and CCRT is promising and safe in the treatment of LANPC. Long-term efficacy needs to be confirmed by further follow-up.

Clinical trial identification

ChiCTR2300072053.

Editorial acknowledgement

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.