863P - Safety and efficacy of four courses of pembrolizumab combined with carboplatin and albumin-binding paclitaxel versus two courses of neoadjuvant therapy in patients with resectable head and neck squamous cell carcinoma: An optimal efficacy study (prospective, two-arm, phase II)

Background

The effect of PD-1 inhibitors is delayed. In the study of neoadjuvant immunochemotherapy for head and neck squamous cell carcinoma (HNSCC), the topic of when to conduct surgical research has attracted the attention of many surgeons. This study aimed to define the number of courses of neoadjuvant immunochemotherapy.

Methods

This was a randomized, controlled, open label, phase II study. 192 pts were planned to enroll. Key inclusion criteria: cytological or histological diagnosis of surgically resectable HNSCC; Eligible pts were randomized 1:1 to A or B arm. A arm received 4 cycle of immunochemotherapy (Pembrolizumab+Carboplatin+albumin-bound paclitaxel), B arm received 2 cycle of immunochemotherapy. Then surgery and pathological remission evaluation were performed. The primary endpoint was pathologic complete response (pCR) rate. Secondary endpoints were Radiographic Response, Event-free survival (EFS), Operation delay rate,etc.

Results

28 patients were enrolled until April 30, 2024. They are radomized 1:1 to arm A and B. 22 patients finished the surgery. 68.2 % were men, mean age 53.04, the median follow-up time was 5.6 months. In arm A: of the 12 patients who underwent surgery, 0 % achieved a pCR in both lymph nodes and primary sites, ORR was 78.6%, the rate of adverse reactions above G3 was 28.57%. As to the rate of delayed surgery was 14.28%, and the rate of severe intraoperative complications (coagulation dysfunction, etc.) was 14.28%. In arm B: of the 12 patients who underwent surgery, 7.14 % achieved a pCR in both lymph nodes and primary sites. ORR was 92.85%. No adverse reactions above G3 bleeding occurred. No significant survival difference was observed.

Conclusions

In the neoadjuvant immunochemotherapy of HNSCC, 4 cycles of treatment have not shown good results and may cause more AEs. It is worth noting that there were 2 patients in Arm A who experienced PD due to delayed surgery for hypothyroidism. This study is ongoing. And we look forward to more clinical data to explore the appropriate treatment cycle of neoadjuvant immunochemotherapy.

Clinical trial identification

NCT05980702.

Editorial acknowledgement

Legal entity responsible for the study

Sun Yat-sen Momorial Hospital.

Funding

Guangdong Medical Association.

Disclosure

All authors have declared no conflicts of interest.