The safety and efficacy of this agent(s), or use in this setting, has not been established or is subject to confirmation. For an agent(s) whose safety and efficacy has not been established or confirmed, future regulatory approval or commercial availability is not guaranteed.


Geo Regions


HER2 Tyrosine Kinase inhibitor

Overview + Rationale

  • Tucatinib is an orally bioavailable, reversible, highly selective small molecule tyrosine kinase inhibitor being investigated in multiple human epidermal growth factor receptor 2 (HER2) overexpressed/amplified and HER2 mutated cancers.1,2 
    • In cell signaling assays, tucatinib exhibits thousandfold greater selectivity for the HER2 receptor relative to epidermal growth factor receptor (EGFR).1 
    • HER2 selectivity may decrease the potential for EGFR-related toxicities (eg, diarrhea, skin rash).1 
    • Preclinical data suggest that tucatinib increases surface HER2 expression.2 
  • HER2 is overexpressed in multiple cancers, including breast, colorectal, ovarian, lung, gastroesophageal, and bladder.

Mechanism of Action

Stage of Development

Tucatinib is being investigated in the tumor types shown below. Safety and efficacy for the uses listed below have not been established.

Small icon representing Breast Cancer in pink
HER2+ Breast Cancer
Phase 2 Combination*

Phase 3 Combination
Small icon representing GI Cancer in light blue
HER2+ Colorectal Cancer
Phase 3 Combination
Small icon representing GI Cancer in light blue
HER2+ Gastrointestinal Cancers
Phase 1b/2 Combination
Small icon representing Early Solid Tumors in green
Solid Tumors with HER2 alterations
Phase 2 Combination*
Small icon representing GU cancer in yellow in green
Metastatic UC with HER2 Alterations
Phase 2 combination