Table 4.

This table summarizes the trials investigating the use of cyclin-dependent kinase inhibitors in ER+/HER2+ breast cancer.

Trial	Phase	Setting	Arms	Primary Outcomes
PATINA Clinical study of the targeted therapy, palbociclib, to treat metastatic breast cancer (NCT02947685)	Phase III n = 496 International centers	Metastatic HR+/HER2+ breast cancer	Palbociclib + anti-HER2 therapy (trastuzumab/pertuzumab) + endocrine therapy (letrozole, anastrozole, exemestane, or fulvestrant) Control arm: anti-HER2 therapy (trastuzumab/pertuzumab) + endocrine therapy (letrozole, anastrozole, exemstane, or fulvestrant)	Progression-free survival (PFS)
PATRICIA II Palbociclib and trastuzumab with endocrine therapy in HER2-positive metastatic breast cancer (NCT02448420)	Phase II n = 102 Spain	Metastatic HR+/HER2+ breast cancer	Palbociclib + trastuzumab (HR-/HER2+) Palbociclib + trastuzumab (HR+/HER2+) Trastuzumab + palbociclib + letrozole (HR+/HER2+) Palbociclib, trastuzumab, and endocrine therapy (aromatase inhibitor, fulvestrant, or tamoxifen) for HR+/HER2+, luminal intrinsic subtype (PAM50) Control arm: physician’s choice (T-DM1 or chemotherapy (gemcitabine, vinorelbine, capecitabine, eribulin, or taxane) + trastuzumab or endocrine therapy + trastuzumab) for HR+/HER2+, luminal intrinsic subtype (PAM50)	Progression-free survival (PFS)