TPExtreme randomized trial: TPEx versus Extreme regimen in 1st line recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

Abstract

6002 Background: After promising results from the GORTEC TPEx phase II trial, the role of taxane instead of 5FU in 1st-line R/M HNSCC chemotherapy (CT) remained to be confirmed by comparing TPEx to the reference EXTREME regimen. Methods: Randomized (1:1), open-label trial. Main inclusion criteria were R/M HNSCC not suitable for locoregional treatment, age 18-70 years, PS <2, creatinine clearance >60ml/min, prior cisplatin <300 mg/m². Reference EXTREME regimen (arm A: 6 cycles every 3 weeks (Q3W) of 5FU–cisplatin-cetuximab (cetux) followed by weekly cetux maintenance) was compared to TPEx regimen (arm B: 4 cycles Q3W of docetaxel 75mg/m²–cisplatin 75mg/m²- cetux 250mg/m² with mandatory G-CSF support followed by every 2W cetux 500mg/m² maintenance). The primary endpoint was Overall Survival (OS). To detect a hazard ratio (HR) of 0.72 (median OS increase from 10.1 to 14.0 months (mo) with 88% power, 2-sided significance level of 0.05, 374 deaths were required. 540 patients (pts) were planned to enroll. Results: 539 pts were enrolled in 37 mo. Median age was 60 years, 93% were smokers, 40% had oropharyngeal tumor (p16 or HPV DNA was done in 85%, positive in 28%). In arm A, 44% of pts received all CT cycles vs 72% in arm B. Delays in administration were more frequent in arm A (27% vs 10%). Cisplatin was more frequently switched to carboplatin in arm A (34% vs 9%). Toxicity was lower in arm B: 34% pts had grade ≥4 adverse events during CT in arm B vs 50% in arm A (p<0.001). Less pts in arm A started maintenance than in arm B (53% vs 73%). At time of analysis, the median follow-up duration was 30 mo and 406 pts had died. OS was not significantly different between arms: HR=0.87 (95%CI: 0.71-1.05), p=0.15. Median OS was 13.4 mo in arm A vs 14.5 in arm B. 2-year OS rate was 21.0% in arm A vs 28.6% in arm B. Conclusions: This large randomized trial confirmed the encouraging survival results of the TPEx regimen observed in the first phase II. OS in both arms was higher than observed in previous randomized CT or immunotherapy combination trials. Despite lack of significant OS increase, taxane based TPEx regimen appears to be a new option in 1st line R/M HNSCC, with a shorter time on CT and significantly lower toxicity than the EXTREME regimen. Clinical trial information: NCT02268695.