901P - A phase II trial of neoadjuvant nivolumab, docetaxel, and cisplatin therapy followed by surgery and radiation therapy for resectable high-grade salivary gland carcinoma

Background

Resectable salivary gland carcinoma (SGCs) conventionally undergoes surgical resection followed by adjuvant radio- or chemotherapy. Despite this approach, high-grade histologies frequently result in recurrence and distant metastasis. This study examines the efficacy of an immune checkpoint inhibitor combined with chemotherapy in high-risk, potentially resectable SGCs.

Methods

This phase II, open-label, single-center trial enrolled high-grade SGC patients with clinically positive lymph nodes. Participants received three cycles of nivolumab in conjunction with docetaxel and cisplatin every three weeks. The primary response was assessed three weeks post-treatment, and surgery followed at seven weeks in cases deemed operable. The pathologic outcomes determined the need for adjuvant radiotherapy, administered at 59.4Gy (R0) or 66.0Gy (R1 or R2). The study's primary endpoint was the major pathologic response rate (MPR). We aimed to recruit 50 patients.

Results

Since November 2022, 19 patients have enrolled; predominantly male (89.5%) with a median age of 62 (range 42-75). Histologic analysis identified various subtypes, primarily salivary duct carcinoma (68.4%). At the time point of analysis, surgery was performed on 16 patients, and 3 patients are still under neoadjuvant therapy. R0 was achieved in 87.5% (n=14) of the cases, with one patient having R1 and another R2 resection. Pathologic analysis showed 12.5% (n=2) achieving pathological complete response and 18.8% (n=3) achieving MPR. Tumor viability varied, with 37.5% (n=6) presenting with 10% to 50% viability and 31.3% (n=5) presenting with 50% or higher viability. Notably, throughout the neoadjuvant treatment phase, no patients discontinued due to toxicity or intolerance.

Conclusions

The preliminary findings of this study demonstrate that the neoadjuvant combination of immune checkpoint inhibitor with chemotherapy significantly reduces tumor burden in SGCs, as evidenced by the high rate of R0 and favorable pathologic responses. This treatment strategy not only facilitates surgical outcomes but also exhibits an acceptable safety profile.

Clinical trial identification

NCT05727410.

Editorial acknowledgement

Funding

Ono.

Disclosure

All authors have declared no conflicts of interest.