Table 1.

Summary of clinical studies evaluating tucatinib or its combination with other agents in HER2+ metastatic breast cancer patients

Treatment(s)	Other factor(s)	Study design and finding(s)
Tucatinib [65]	–	To determine the MTD, antitumor activity, and pharmacokinetic properties of tucatinib The tucatinib MTD was determined to be 600 mg twice daily; 22% of patients treated at the MTD had a partial response + SD
Tucatinib + trastuzumab + capecitabine [33]	ALT/AST	To evaluate the therapeutic responses of tucatinib vs. placebo combination with trastuzumab and capecitabine Tucatinib-combination resulted in improved PFS and increased OS with common adverse events compared to the placebo-combination group

HER2+ HER2-positive, MTD maximum tolerable dose, SD stable disease, ALT alanine aminotransferase, AST aspartate aminotransferase, PFS progression-free survival, OS overall survival