Radiofrequency ablation via catheter and transpapillary access in patients with cholangiocarcinoma (ACTICCA-2 trial) - a multicenter, randomized, controlled, open-label investigator-initiated trial.

Background: Despite the recent advances in cancer treatment, the therapeutic options for patients with biliary tract cancer are still very limited and the prognosis very poor. More than 50% of newly diagnosed patients with biliary tract cancer are not amenable to curative surgical treatment and thus treated with palliative systemic treatment. Malignant bile duct obstructions in patients with perihilar and/or ductal cholangiocarcinoma (CCA) represents one of the most important challenges in the management of these patients, owning to the risk represented by developing life-threatening cholangitis which, in turn, limits the use of systemic treatment. For this reason, endoscopic stenting and/or bile duct decompression is the mainstay of treatment of these patients. Data on efficacy and safety of adding radiofrequency ablation (RFA) to biliary stenting is not conclusive. The aim of this multicenter, randomized trial is to evaluate the effect of intraductal RFA prior to bile duct stenting in patients with unresectable perihilar or ductal CCA undergoing palliative systemic therapy.

Methods/design: ACTICCA-2 is a multicenter, randomized, controlled, open-label, investigator-initiated trial. 120 patients with perihilar or ductal CCA with indication for biliary stenting and systemic therapy will be randomized 1:1 to receive either RFA plus bile duct stenting (interventional arm) or bile duct stenting alone (control arm). Patients will be stratified by trial site and tumor location (perihilar vs. ductal). Both arms receive palliative systemic treatment according to the local standard of care determined by a multidisciplinary tumorboard. The primary endpoint is time to first biliary event, which is determined by an increase of bilirubin to > 5 mg/dl and/or the occurrence of cholangitis leading to premature stent replacement and/or disruption of chemotherapy. Secondary endpoints include overall survival, safety according to NCI CTCAE v5, quality of life assessed by questionnaires (EORTC QLQ-C30 and QLQ-BIL21), clinical event rate at 6 months after RFA and total days of over-night stays in hospital. Follow-up for the primary endpoint will be 6 months, while survival assessment will be continued until end of study (maximum follow-up 30 month). All patients who are randomized and who underwent endoscopic stenting will be used for the primary endpoint analysis which will be conducted using a cause-specific Cox proportional hazards model with a frailty for trial site and fixed effects for the treatment group, tumor location, and stent material.

Discussion: ACTICCA-2 is a multicenter, randomized, controlled trial to assess efficacy and safety of adding biliary RFA to bile duct stenting in patients with CCA receiving palliative systemic treatment.

Trial Registration: The study is registered with ClinicalTrials.gov (NCT06175845) and approved by the local ethics committee in Hamburg, Germany (2024-101232-BO-ff). This manuscript reflects protocol version 1 as of January 9th, 2024.