SGNTUC-019

NCT03043313 📎

Regimen

Experimental
Tucatinib 300 mg PO BID + trastuzumab 8 mg/kg IV loading then 6 mg/kg IV q21d (HER2-targeted tyrosine kinase inhibitor + monoclonal antibody)
Control
single-arm / no comparator

Population

Previously treated (≥1 prior line) HER2-positive (IHC 3+ or IHC 2+/FISH+) advanced BTC; BTC cohort n=30. HER2-positive BTC includes GBC-enriched population; specific ICC/ECC/GBC split not reported. Median 1 prior line. SGNTUC-019 is a basket trial (HER2+ solid tumors) with the BTC cohort published separately (Nakamura Y, JCO 2023).

Key finding

Tucatinib (oral HER2-selective TKI) + trastuzumab demonstrated ORR of 46.7% in HER2+ BTC, numerically the highest single-arm ORR among HER2-directed doublets in BTC at time of publication. The combination leverages complementary mechanisms (kinase inhibition + antibody-dependent cellular cytotoxicity). The small cohort (n=30) limits precision of estimates. Tucatinib's CNS penetrance — established in breast cancer (HER2CLIMB) — has not been evaluated in BTC, though BTC brain metastases are rare.

Source: PMID 37751561

Timeline

    Guideline citations

    • NCCN BTC (p.35)