Neoadjuvant pembrolizumab/nab-paclitaxel/cisplatin in patients with locally advanced head and neck squamous cell carcinoma: A single-arm phase II study.

e18043 Background: Despite multimodality standard therapy, patients with locally advanced head and neck squamous cell carcinoma are at high risk of recurrence and distant metastasis. The safety and efficacy of immunotherapy (pembrolizumab) has been reported in patients with recurrent/metastatic HNSCC. We hypothesized that neoadjuvant chemo-immunotherapy has a positive effect on decreasing distant metastasis, preserving organ function and extending survival time. Methods: In this prospective, non-randomized, single-arm phase II clinical trial, patients meeting the inclusion criteria were treated neoadjuvant therapy with 200 mg pembrolizumab combined with 75 mg/m 2 cisplatin and 260 mg/m 2 Nab-paclitaxel per 3 weeks for 2 cycles.Patients will undergo the first radiologic imaging assessment after neoadjuvant therapy. After multi-disciplinary team discussion, patients with Partial Response (PR) but the maximum diameter of tumor > 3cm or stable disease (SD) or progressive disease (PD) receive surgery and standard adjuvant therapy. On the other hand, patients with PR and maximum tumor diameter ≤ 3cm or Complete Response (CR) receive definitive CRT. Evaluation was performed 3 months after definitive CRT and patients with high-risk factors need maintenance treatment. Primary outcomes are objective response rate (ORR), safety, rate of organ preservation. Results: A total of 31 patients were enrolled with a median follow-up of 6.6 months (1.4-20.2m). The baseline characteristics were shown in the table. Among 31 LA HNSCC patients with 2 cycles of neoadjuvant therapy, ORR was 64.52% (20/31) and DCR was 100%. 10patients underwent surgery with R0 resection, and 17 patients received definitive CRT,4 patients refuse surgery or CRT and out of trial. There was 20/31 (64.5%) organ function preservation. Among those with definitive CRT, no recurrence or distant metastasis occurred. In this trial, there's no Grade≥3 treatment-related adverse events. One patient died due to cardiacarrest and the correlation with study cannot be evaluated. Conclusions: Neoadjuvant chemo-immunotherapy contributed to good ORR and organ function preservation, and generally tolerated in LA HNSCC. This study is ongoing. And we look forward to demonstrating that neoadjuvant immunochemotherapy is expected to improve long-term survival of LA-HNSCC. Clinical trial information: NCT05272696 . Table: see text