ERBB2 and neutropenia: When docetaxel at a dose of 75 mg/m2 was used, in either dual or single HER2 blockade groups, 45 to 57% of patients in the NeoSphere study and 32.7 to 38.1% of patients in the PEONY study suffered grade 3 or worse neutropenia, and 7 to 8% of patients in the NeoSphere study suffered febrile neutropenia.