Investigators identified HER2 amplification as a potential onco-driver and marker of de novo resistance to anti-EGFR therapy in mCRC patients for which other known genetic alterations conferring resistance to anti EGFR antibodies were excluded.
This study is an open-label Phase II, 2-sequential cohorts trial, assessing the response rate (ORR) of Pyrotinib (Cohort 1) or Trastuzumab combined Pyrotinib (Cohort 2), in metastatic colorectal patients harboring an amplified HER2 tumors .
HER2 positivity is centrally established by immunohistochemistry (IHC) and Silver In Situ Hybridization (SISH). To be HER2 eligible the original tumor, or the biopsied metastasis (whichever is last available), must be IHC 3+ or 2+ in more than 50% of cells, confirmed by SISH or FISH with a HER2:CEP17 ratio 2.0. For IHC a positive staining (3+) is defined as an intense membrane staining which can be circumferential, basolateral, or lateral of the tumor cells.
The study was a investigator-initiated multicenter clinical study to enroll 40 colorectal cancer patients with Her-2 Variation who were treated with either Pyrotinib alone or with Trastuzumab, 20 Patients in each group.The inclusion time was 1 year, and the follow-up time was 1 year. The Efficacy and Safety of Pyrotinib in Combination With or Without Trastuzumab in the treatment of Advanced Colorectal Cancer were evaluated with objective efficacy and safety as the main indicators.
