Neoadjuvant tislelizumab plus pazopanib in renal cell carcinoma with venous tumour thrombus: A retrospective study.

Objectives: Neoadjuvant therapy with immune checkpoint inhibitors and tyrosine kinase inhibitors has been shown to reduce the tumour size and thrombus length in patients with renal cell carcinoma with venous tumour thrombus (RCC-VTT). This study aimed to evaluate the effectiveness and safety of neoadjuvant tislelizumab plus pazopanib in patients with RCC-VTT. Patients and Methods: From November 2021 to January 2024, nine patients with RCC-VTT were included in this retrospective study. All patients received neoadjuvant tislelizumab (200 mg intravenously every 3 weeks) and pazopanib (800 mg orally once daily), followed by surgery. Key effectiveness outcomes included the objective response rate (ORR) of the primary tumour, the percentage change in VTT length and safety. Results: Among the nine patients with RCC-VTT, the median age was 58 years (range, 39-78). Following neoadjuvant tislelizumab plus pazopanib, six patients achieved partial response in the primary tumour and three had stable disease, yielding an ORR of 66.7%. The VTT length decreased from 4.9 cm (range, 1.1-9.3 cm) to 3.8 cm (range, 0-8.1 cm), with a median reduction of 29.2% (range, -153.1% to 100.0%). Treatment-related adverse events (TRAEs) of any grade and grade 3 were reported in 88.9% and 55.6% of patients, respectively. The common TRAEs of any grade were vomiting (77.8%), fatigue (33.3%), pruritus (33.3%), weight loss (33.3%), poor appetite (33.3%), pruritus (33.3%) and hepatic impairment (33.3%). No grade 4-5 TRAEs or deaths were observed. Conclusion: The neoadjuvant combination of tislelizumab and pazopanib effectively reduced tumour size and thrombus length, narrowing the surgical scope and potentially leading to better postoperative outcomes.