TOURMALINE: A phase 3b study of durvalumab with gemcitabine-based chemotherapy regimens in advanced biliary tract cancer.

TPS4188 Background: In the Phase 3 TOPAZ-1 study (NCT03875235), durvalumab plus gemcitabine + cisplatin (GC) significantly improved overall survival (OS) versus placebo + GC in participants with advanced biliary tract cancer (aBTC) with a manageable safety profile. To expand on TOPAZ-1, there is a need to further assess the safety and efficacy of durvalumab in combination with other gemcitabine (G)-based chemotherapy regimens used in aBTC, and in a more diverse population to reflect real-world clinical practice. Methods: TOURMALINE (NCT05771480) is a Phase 3b, single-arm, multicenter, international study. Approximately 140 adults with aBTC (intra- or extra-hepatic cholangiocarcinoma, gallbladder or ampulla of Vater carcinoma) will be enrolled. Key inclusion criteria include unresectable disease (advanced, metastatic), WHO/ECOG PS of 0–2, and no prior systemic therapy. Key exclusion criteria include any prior immune-mediated therapy and history of another primary malignancy. Participants will receive durvalumab 1500 mg IV plus an investigator-selected, G-based background chemotherapy; durvalumab will be administered Q3W when combined with a G-based chemotherapy Q3W (8 cycles of durvalumab) except for when combined with GC + S-1 Q2W, in which case durvalumab will be administered Q4W (4 cycles of durvalumab/8 cycles of chemotherapy). G-based chemotherapy will consist of G monotherapy, GC (for WHO/ECOG PS 2 participants only), G + oxaliplatin, G + carboplatin, GC + S-1, G + S-1, and GC + albumin-bound paclitaxel. Following the treatment period, durvalumab Q4W +/- chemotherapy (except for paclitaxel) may continue, at the investigator’s discretion, until discontinuation criteria are met. The primary endpoint is the incidence of Grade 3 or 4 adverse events, assessed by the investigator to be possibly related to any study treatment within 6 months after initiation of durvalumab. Secondary endpoints include OS, objective response rate, progression-free survival, and duration of response. Enrollment is ongoing and planned in France, Germany, United States, Spain, Italy, Japan, South Korea, and Singapore. Clinical trial information: NCT05771480 .