The Dosing Regimen of Pyrotinib in HER2-positive Advanced First-line Breast Cancer: a Phase I Clinical Study

Required: HER2 (ERBB2) overexpression (IHC 3+ (>10% of immunoreactive cells))

HER2-positive was defined as >10% of immunoreactive cells with an immunohistochemical (IHC) score of 3+

Required: HER2 (ERBB2) amplification

HER2 gene amplification as a result of in situ hybridization (ISH)

Cannot have received: systemic antitumor therapy

Exception: no prior systemic therapy at the stage of recurrence/metastasis; adjuvant/neoadjuvant therapy allowed if completed ≥12 months before recurrence/metastasis

The patient has received any systemic antitumor therapy at the stage of recurrence/metastasis, including any agents targeting EGFR or HER2, systemic chemotherapy, immunotherapy, and more than first-line endocrine therapy, as well as other antitumor therapies deemed by the investigators to be excluded

Cannot have received: tyrosine kinase inhibitor (TKI) or macromolecular antibody against HER

Exception: except for trastuzumab in the (new) adjuvant stage

Tyrosine kinase inhibitor (TKI) preparations or macromolecular antibodies against HER have been used at any stage of breast cancer, except for trastuzumab in the (new) adjuvant stage

Cannot have received: systemic therapy (except endocrine therapy)

Exception: adjuvant therapy completed ≥12 months before recurrence/metastasis

In the stage of breast cancer (new) adjuvant therapy, the time interval from the end of systemic therapy (except endocrine therapy) to the discovery of recurrence/metastasis is <12 months

Cannot have received: endocrine therapy

Exception: no use within 7 days prior to randomization; more than first-line endocrine therapy at recurrence/metastasis excluded

Use of endocrine therapy drugs within 7 days prior to randomization; more than first-line endocrine therapy