Radiation Therapy in Unresectable Gall Bladder Cancer

"Participants will receive one of the following Gemcitabine-based systemic therapy alone:~Gemcitabine 1000mg/m2 and Cisplatin 25 mg/m2, each administered on Days 1 and 8 every 3 weeks (q3w)~Duration: 3 months (in addition to 3 months previously received)"

"Participants will receive radiation therapy in addition to systemic therapy Hypofractionated external image guided radiation to a dose of 40-55Gy in 10 sessions (up to 60Gy in 15 sessions) over 2-3 weeks.~This is followed by systemic therapy as in the Systemic therapy alone arm."

"Gemcitabine 1000 mg/m2 and oxaliplatin 100 mg/m2 IV infusion on days 1 and 8 q2w.~Duration: 3 months"

"Durvalumab 1500 mg via intravenous (IV) infusion q4w, starting on Cycle 1 in combination with cisplatin 25 mg/m2 and gemcitabine 1000 mg/m2 each administered on Days 1 and 8, q3w.~Duration 3 months Durvalumab (12 months)"

Gemcitabine 800 mg/m2, cisplatin, 25 mg/m2, and nab-paclitaxel 100 mg/m2, on days 1 and 8, q3w Duration: 3 months