864P - Clinical/biomarker data for neoadjuvant tislelizumab (TIS) plus chemotherapy (Chemo) in resectable locally advanced head and neck squamous cell carcinoma (LA-HNSCC): A single-arm, phase II trial

Background

This study aimed to assess the activity and safety of neoadjuvant TIS plus Chemo in patients(pts) with resectable LA-HNSCC.

Methods

In this single-arm, phase II trial (NCT06235918), pts with stage T3-4 or N2 resectable HNSCC received TIS combined with nab-paclitaxel and carboplatin for 2 cycles prior to surgery. The primary endpoint was pathological complete response (pCR) rate. Secondary endpoints included major pathologic response rate (MPR), objective response rate (ORR), 3-years disease-free survival rates, 3-years overall survival rates and safety. Exploratory predictive efficacy biomarkers include circulating tumor cells (CTCs) and T cell senescence.

Results

Between April 2023 and Apirl 2024, 28 pts were enrolled and administrated the neoadjuvant therapy, with an ORR of 77.3% (17/22). The baseline characteristics were shown in the table. After neoadjuvant treatment, 22 pts underwent surgery and 21(95.5%) pts achieved R0 resection. Among the 22 pts,10 (45.5%) pts achieved pCR. T cell senescence and CTCs concentration and dynamic changes at baseline and after neoadjuvant treatment were compared between pCR and non-pCR pts. CTCs level decreased in 66.7% (4/6) of pts in the pCR group, compared to 37.5% (3/8) of pts in the non-pCR group. T cell senescence level decreased in 66.7% (4/6) of pts in the pCR group, compared to 44.4% (4/9) of pts in the non-pCR group. No pts had grade 3 treatment-related adverse events (AEs) and no unexpected immune-related AEs were observed. Table: 864P

Conclusions

Neoadjuvant TIS and Chemo showed promising activity and manageable safety profile in pts with resectable LA HNSCC. T cell senescence and CTC might be potential predictors for the efficacy.

Clinical trial identification

NCT06235918.

Editorial acknowledgement

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.