Effect of Concurrent Chemoradiotherapy With Nedaplatin vs Cisplatin on the Long-term Outcomes of Survival and Toxic Effects Among Patients With Stage II to IVB Nasopharyngeal Carcinoma: A 5-Year Follow-up Secondary Analysis of a Randomized Clinical Trial.

Importance: Nedaplatin-based concurrent chemoradiotherapy (CCRT) regimen at 2 years was noninferior to cisplatin-based regimen in patients with locoregional, stage II to IVB nasopharyngeal carcinoma (NPC) and was associated with fewer late adverse events, but longer-term outcomes and toxicity are unclear. Objective: To evaluate the 5-year outcomes and late toxicity profile of nedaplatin-based CCRT in patients with locoregional, stage II to IVB NPC. Design, Settings, and Participants: This 5-year follow-up secondary analysis of an open-label, noninferiority, multicenter randomized clinical trial enrolled patients with nonkeratinizing stage II to IVB NPC between January 16, 2012, and July 16, 2014, with a median follow-up duration of 78 months (IQR, 3-99 months). Data analysis was conducted from November 10, 2020, to July 8, 2021. Interventions: Patients were randomly assigned (1:1) to receive nedaplatin (100 mg/m2)- or cisplatin (100 mg/m2)-based chemotherapy every 3 weeks for 3 cycles concurrently with intensity-modulated radiotherapy. Main Outcomes and Measures: The primary end point was progression-free survival (PFS). Secondary end points were overall survival, distant metastasis-free survival, and locoregional relapse-free survival. Results: A total of 402 eligible participants were enrolled (median [IQR] age, 45 [18-65] years; 302 [75.1%] male). Patients were randomly assigned to receive nedaplatin- or cisplatin-based CCRT (n = 201 for each): 196 patients (97.5%) started nedaplatin-based CCRT and 197 patients (98.0%) started cisplatin-based CCRT. Intention-to-treat analysis demonstrated a 5-year progression-free survival rate of 81.4% (95% CI, 75.9%-86.9%) for the cisplatin group and 79.8% (95% CI, 74.1%-85.5%) for nedaplatin group, with a difference of 1.6% (95% CI, -6.3% to 9.5%; P = .002 for noninferiority). No significant survival differences were observed between the cisplatin and nedaplatin groups for 5-year overall survival (89.4% vs 88.8%, P = .63), distant metastasis-free survival (85.9% vs 90.4%, P = .17), and locoregional relapse-free survival (92.6% vs 89.6%, P = .17) rates. The cisplatin group had a higher incidence of grade 3 and 4 auditory toxic effects than the nedaplatin group (35 [17.7%] vs 21 [10.5%], P = .04). Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, long-term analysis confirmed that nedaplatin-based CCRT could be regarded as an alternative doublet treatment strategy to cisplatin-based CCRT in stage II to IVB NPC. Trial Registration: ClinicalTrials.gov Identifier: NCT01540136.