Abstract GS6-04: Co-occurring gain-of-function mutations in HER2 and HER3 modulate HER2/HER3 activation, breast cancer progression, and HER2 inhibitor sensitivity

Activating mutations in HER2 (ERBB2) drive the growth of a subset of breast cancers. The HER2 tyrosine kinase inhibitor (TKI) neratinib has shown clinical activity against cancers harboring HER2 activating mutations. Co-occurring HER2 and HER3 (ERBB3) mutations have been reported to co-occur in patients with breast cancer, suggesting the possibility of cooperativity of both oncogenes. Interrogation of the Project GENIE database revealed that...