Among HER2-positive patients, DLTs occurred in all 3 patients enrolled in the first cohort at D 65 mg/m2, represented by G3 asthenia in the first 2 patients, occurred at the second and fourth cycle, respectively, and G2 asthenia lasting more than 2 weeks in the third patient, occurred at the first cycle. Here, ERBB2 is linked to asthenia.