Tislelizumab plus neoadjuvant chemotherapy and concurrent chemoradiotherapy versus neoadjuvant chemotherapy and concurrent chemoradiotherapy in local advanced nasopharyngeal carcinoma.

6045 Background: Given the recent successes of immunotherapy in local advanced nasopharyngeal carcinoma (LA-NPC), maybe it is promising to achieve better response and improve the survival of LA-NPC if immunotherapy plus neoadjuvant and concurrent chemoradiotherapy (CCRT). Therefore, we retrospectively analysed the safety and efficacy of tislelizumab plus neoadjuvant chemotherapy and CCRT and neoadjuvant chemotherapy followed CCRT in the treatment of LA-NPC. Methods: A total of 90 patients with stage III-IVa NPC were enrolled between January 2020 and March 2021 at Affiliate Hospital of Guangdong Medical University. 43 patients were treated with tislelizumab plus TP (nab-paclitaxel 260mg/m 2 , cisplatin 80mg/m 2 , Q3W, 3 cycles) regimen followed tislelizumab plus CCRT as the combination therapy group (CG) and 47 patients were treated with TP regimen followed CCRT as the observation group (OG). Results: As of January 30th, 2024, the median follow-up time is 37.5 months. The median age was 42 years (range: 16–75 years). A total of 37 patients had stage III cancer and 53 had stage IVa , with 43 and 47 patients in OG and CG, respectively. The male–female ratio in the entire cohort was approximately 2.15:1. All reported parameters were balanced between the two groups with no statistical differences. The complete response rate (CRR) in CG after neoadjuvant therapy improved significantly (37.2% in CG vs 12.8% in OG). The ORR was 88.4% in CG and 70.2% in OG, respectively. The 3-year PFS was 93.75% in CG and 80% in OG. The incidence of acute treatment related adverse events in grades 3 or 4 was 70.2% and 65.6%, respectively. The most common grade 3-4 immune-related adverse events were hypothyroidism (7.0%) and hepatotoxicity (4.7%). No patients in CG had disease progression during treatment. Conclusions: Compared with regular treatment, tislelizumab plus neoadjuvant chemotherapy and concurrent chemoradiotherapy was feasible and well tolerated in LA-NPC patients. This trial is supportive of further prospective trials in LA-NPC.