Brief Summary
The goal of this clinical trial is to test whether the combination of Envafolimab (an immunotherapy drug), chemotherapy (gemcitabine + cisplatin), and simvastatin can help treat advanced biliary tract cancer (BTC) that cannot be removed by surgery or has spread. The study will also evaluate the safety of this treatment combination.
Key Questions Does the combination treatment help shrink tumors or slow cancer growth better than standard options? What side effects do participants experience with this treatment?
What Will Participants Do? Receive Envafolimab (IV infusion) + gemcitabine/cisplatin (chemotherapy) + simvastatin (oral pill) every 3 weeks for up to 8 cycles (\~6 months).
After 8 cycles, continue with Envafolimab + simvastatin alone every 4 weeks until cancer worsens or side effects become too severe.
Undergo regular scans, blood tests, and clinic visits to monitor tumor response and safety.