Based on the results of a phase I trial, in which SYD985 showed significant clinical activity in heavily pretreated patients with HER2-positive and HER2-low breast cancer, the phase III TULIP trial evaluated SYD985 versus the physician’s choice of chemotherapy in 431 HER2-positive breast cancer patients who progressed after two or more HER2-targeted therapies [169]. This evidence concerns the gene ERBB2 and breast carcinoma.