A Prospective, Open-label, Multicenter Phase II Clinical Study of Rikang Trastuzumab in Combination With Adebrelimab and Lenvatinib for First-line Treatment of HER2-positive or Low-expressing Locally Advanced or Metastatic Biliary Tract Cancer
This phase II study evaluates the efficacy and safety of Trastuzumab Rezetecan in combination with Adebrelimab and Lenvatinib as first-line therapy for patients with locally advanced or metastatic HER2-positive or HER2-low biliary tract cancer. The primary objective is the objective response rate (ORR). Key secondary objectives include efficacy endpoints-progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and duration of response (DoR)-and safety assessments comprising adverse events (AEs), serious adverse events (SAEs), vital signs, and laboratory findings.
• The HER2-positive subjects voluntarily participated in the study and agreed to sign the written informed consent form, and they had good compliance.
• Age ≥ 18 years old, gender not limited;
• Locally advanced or metastatic cholangiocarcinoma, including cholangiocarcinoma (intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma) and gallbladder cancer, which has been confirmed by pathological histology or cytology;
• Not suitable for radical surgical resection or local treatment. Subjects who have not received any systemic anti-tumor therapy in the past; allowed to have received radical treatment previously (including surgical treatment and postoperative adjuvant chemotherapy and/or radiotherapy), and the interval from the last administration of radical treatment to disease recurrence is at least 6 months, and no systemic anti-tumor treatment was received during the recurrence or metastasis stage.
• HER2 positive (IHC 3+ or IHC 2+ and FISH detects HER2/CEP17 ≥ 2.0), HER2 low expression (IHC 2+/FISH- or IHC 1+);
• There is at least one measurable lesion that meets the requirements of RECIST v1.1.
• The ECOG score is between 0 and 1.
• Expected survival period ≥ 12 weeks;
• The organs and bone marrow have sufficient functions and meet the following requirements: (within 14 days before starting the treatment) 1) Blood routine examination: (within 14 days before the screening, no blood transfusion, no use of granulocyte colony-stimulating factor \[G-CSF\], no use of drugs to correct): A. Hemoglobin (Hb) ≥ 90 g/L; B. Neutrophil count (ANC) ≥ 1.5 × 109/L; C. Platelet count (PLT) ≥ 75 × 109/L; 2) Blood biochemical examination should meet the following standards (no albumin transfusion within 14 days before the screening): A. Serum total bilirubin \[BIL\] ≤ 2xULN (for Gibert syndrome patients, ≤ 3xULN); B. Alanine aminotransferase \[ALT\] and aspartate aminotransferase \[AST\] ≤ 3.0xULN; C. For patients with liver metastasis, ALT and AST should be ≤ 5xULN; Serum creatinine (Cr) ≤ 1.5xULN or endogenous creatinine clearance rate ≥ 50 ml/min (Cockcroft-Gault formula): Male: Cr clearance rate = ((140 - age) × weight) / (72 × blood Cr); Female: Cr clearance rate = ((140 - age) × weight) / (72 × blood Cr) × 0.85 (weight unit: kg; blood Cr unit: mg/mL)
⁃ For both male subjects with fertile partners and female subjects with fertile partners, they must take effective contraceptive measures from the moment they sign the informed consent form until 7 months after the last administration of the test drug. During the same period, male subjects must agree not to donate sperm, and female subjects must agree not to donate eggs. For female subjects with fertility, the serum HCG test must be negative within 7 days before the first administration of the drug, and they must be in the non-breastfeeding period.