ERBB2 and aneurysmal bone cyst: In one of two parallel phase Ib trials of tucatinib combinations, 23 heavily pre-treated patients with HER2-positive ABC, including patients with brain metastases, were treated with tucatinib in combination with capecitabine and/or trastuzumab, with an encouraging ORR of 61% in the triplet combination arm and a median duration of response of 10 months (95%CI: 2.8–19.3) [59].