Trastuzumab Plus Chemotherapy vs Chemotherapy Alone in First-line HER2 Positive Advanced Biliary Tract Cancer Patients - a Randomized Non-blinded Two-arm Phase III Prospective Clinical Trial (TAB-2 Study).
This is a randomized, open-label, two-arm, Phase III clinical trial evaluating the efficacy and safety of trastuzumab plus chemotherapy versus chemotherapy alone as first-line treatment in patients with HER2-positive advanced or metastatic biliary tract cancers (BTC). HER2-positive BTCs represent a molecular subset of these rare cancers, associated with poor prognosis and limited treatment options. Eligible patients with histologically confirmed HER2-positive (IHC 3+ or IHC 2+ with FISH amplification) unresectable or metastatic biliary tract adenocarcinoma-including gallbladder cancer, intrahepatic, and perihilar cholangiocarcinoma-will be randomized in a 1:1 ratio. Participants in the intervention arm (Arm A) will receive either gemcitabine and cisplatin with or without nab-paclitaxel plus trastuzumab, while those in the control arm (Arm B) will receive chemotherapy alone (gemcitabine + cisplatin with or without nab-paclitaxel). Treatment will continue until disease progression, unacceptable toxicity, withdrawal of consent, or death. The primary endpoint is 6-month progression-free survival (PFS). Secondary endpoints include overall survival (OS), response rate (RR), quality of life (QOL), and adverse event (AE) profiles. The study aims to enroll 196 patients across a single center in India over a period of 5 years, with an additional 6-month follow-up. This trial builds on earlier Phase II findings suggesting improved outcomes with trastuzumab in HER2-positive BTC and aims to provide the first randomized evidence for the benefit of HER2-targeted therapy in this setting.
‣ Histologically confirmed adenocarcinoma of the biliary tract, with the following specifications -
• Biliary tract cancers include gallbladder cancer, intrahepatic cholangiocarcinoma, and perihilar cholangiocarcinoma.
• HER2-positive by IHC or FISH
• Age \>=18 years.
• ECOG performance status 0 - 2.
• Unresectable or metastatic cancer.
• Patient does not have any contraindications to receive chemotherapy or trastuzumab.
• Adequate hematological, hepatic, and renal function parameters- Hematological- Hb\> 80 g/L, ANC ≥ 1.5 x 109/L, platelets ≥ 100 x 109/L. Liver functions- bilirubin ≤ 2 x upper limit normal (ULN), AST/ALT ≤ 5 x ULN, alkaline phosphatase ≤ 6 x upper limit normal (ULN) S. albumin ≥ 30 g/L.
• Renal function- Creatinine ≤ 1.5 ULN, Creatinine clearance \>= 30 mL/min.
• Normal cardiac ejection fraction and cardiac function, as assessed by echocardiography, ejection fraction (EF) \>=50% or above the lower limit of normal. ECG with no clinically relevant abnormalities.
• Women of childbearing age should have a negative pregnancy test at the time of randomization and should be willing to use adequate contraception during the treatment phase of the trial.
⁃ Subjects must provide written informed consent prior to the performance of study-specific procedures or assessments, and must be willing to comply with treatment and follow-up assessments and procedures.
⁃ Subjects who have received adjuvant chemotherapy will be considered eligible provided that therapy is completed more than 12 months before study enrollment. Patients who have received radiation therapy and surgery will also be eligible provided the interventions have been completed 3 and 2 weeks, respectively, before enrolment in the study.
⁃ Negative serum pregnancy test (if applicable) and willing for adequate contraception.
⁃ At least one measurable disease according to RECIST criteria.
⁃ Life expectancy of at least 12 weeks.