ESMO Congress 2024 | OncologyPRO

Abstract 890P

Background

There is an unmet need for more effective treatments in metastatic nasopharyngeal carcinoma (NPC) after chemo- and immune-therapy. The study aims to evaluate the outcomes of stereotactic body radiation therapy (SBRT) combined with chemotherapy and tislelizumab in treatment of metastatic NPC.

Methods

This is a single-centre, open-label, single-arm, phase II trial (NCT05652192). Patients(pts) should have at least one lesion eligible for SBRT (GTV 50Gy/5f). Then they received gemcitabine (1000 mg/m², d1/8) or nab-paclitaxel (240 mg/m², d1), cisplatin (80 mg/m², d1), tislelizumab (200 mg, d1) every 3 weeks for four to six cycles. Tislelizumab was administrated on Day1 every 3 weeks until disease progression (PD), intolerable toxicity, up to 35 cycles (two years), death, or withdrawal of consent. The primary endpoint was progression-free survival (PFS). The secondary endpoint is objective response rate (ORR) per RECIST 1.1 and safety/tolerability per CTCAE v5.0 criteria.

Results

Between Oct 2022 and Jan 2024, 36 pts were enrolled (median age: 52 years old, range:29-72; male: 80.6%). At the data cutoff date on January 31, 2024, 47 metastatic leisions of 28 patients were eligible for the evaluation of tumor response. 97.9% of the lesions (46 of 47) had a response with complete response 91.5%(n=43) and partial response 6.4% (n=3). one patient was evaluated as stable disease. Grade 3-4 adverse reactions occurred in 11.1% patients (4 of 36 patients) and no fatal adverse events occurred.

Conclusions

This preliminary analysis indicated that metastatic NPC patients could get high response from metastases-directed SBRT in combination with tislelizumab. Ongoing analysis of predictive biomarker on efficacy and safety will be available in the future meeting.