A Clinical Review of Subcutaneous Trastuzumab and the Fixed-Dose Combination of Pertuzumab and Trastuzumab for Subcutaneous Injection in the Treatment of HER2-Positive Breast Cancer

Therapy directed against human epidermal growth factor receptor type 2 (HER2) is the standard of care for patients with early-stage and metastatic HER2-positive breast cancer. Treating patients with HER2-positive breast cancer with anti-HER2-monoclonal antibodies, specifically trastuzumab and pertuzumab, is considered standard of care in the neoadjuvant and adjuvant settings and in the first-line setting for metastatic HER2-positive breast cancer. Pertuzumab and trastuzumab are commonly administered intravenously. Subcutaneous (SC) formulations of trastuzumab alone and as a combined product of pertuzumab and trastuzumab are now available for clinical use. Phase III trial results demonstrate that the efficacy and safety of SC trastuzumab and fixed-dose combination of pertuzumab, trastuzumab, and hyaluronidase-zzxf for subcutaneous (PH FDC SC) injection and the intravenous (IV) formulation counterparts are comparable. SC formulations of anti-HER2 monoclonal antibodies offer several advantages over IV counterparts, including shorter administration time, less need for IV access, and better resource utilization for treatment facilities. This review summarizes the clinical data supporting the use of SC trastuzumab and PH FDC SC injection in treating early-stage and metastatic HER2-positive breast cancer and highlights the benefits of SC injection compared to the IV formulations.