Abstract 284P
Background
Immunotherapies have demonstrated limited response rates in biliary tract cancer (BTC). Radiotherapy, known for its "distant effect," enhances the immune response and synergizes with immunotherapy, emerging as a potent treatment approach in oncology. Surufatinib (a small-molecule inhibitor of VEGFR1-3, FGFR1 and CSF-1R) has showed encouraging efficacy and safety as a second-line BTC therapy. This study aims to enhance the immunotherapy response in BTC by combining it with stereotactic body radiation therapy (SBRT) and surufatinib.
Methods
This single-center, single-arm prospective study enrolled patients who initially underwent SBRT (25Gy/5F). One-week post-SBRT, patients received sintilimab (200 mg, intravenous infusion, day 1, q3w) and surufatinib (250mg, once daily, orally). The primary outcome was progression-free survival (PFS), while secondary endpoints encompassed disease control rate (DCR), objective response rate (ORR), overall survival (OS), and safety.
Results
Between November 2022 and March 2024, eight patients with BTC failed with standard therapy were enrolled and evaluated. Notably, 62.5% had prior anti-VEGF therapy, and 75.0% received immunotherapy. The study reported a DCR of 100% and an ORR of 33.3%. Median PFS and OS were not reached, but the PFS rate at 3 months was 100%, and the PFS rate at 6 months stood at 62.5%. The OS rate at 6 months was 87.5%. Remarkably, this novel treatment approach appeared to reverse drug resistance in BTC. 50% patients (2/4) surviving over 1 year after progressing in the study. The most common treatment-related adverse events were leukopenia (66.7%), neutropenia (50%), hyperbilirubinemia (33.3%), and hypertriglyceridemia (33.3%). No grade 3 or higher TEAEs were observed. This study is still recruiting.
Conclusions
The combination of SBRT and surufatinib demonstrated enhanced efficacy of PD1 inhibitors with tolerable safety in BTC. This innovative treatment modality offers a promising new avenue for patients with advanced BTC, potentially reversing drug resistance and extending survival.
Clinical trial identification
NCT05527821.
Legal entity responsible for the study
Hong Ma.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.