The combination of rHuPH20 (2000 U/mL) and trastuzumab (600 mg/5 mL) is approved for SC administration for the treatment of HER2-positive early breast cancer, metastatic breast cancer, and metastatic gastric cancer in the EU (European Medicines Agency, 2018b), for the treatment of HER2-positive early and metastatic breast cancer in Canada (Roche Canada, 2018a), and is under review by the FDA for use in the US (Biologics License Application accepted in July 2018 for Herceptin SC; (Halozyme Therapeutics Inc., 2018). The gene discussed is ERBB2; the disease is breast carcinoma.