The FDA on January 18, 2019 granted approval to ONTRUZANT®, a Trastuzumab (HERCEPTIN®) biosimilar, for the treatment of patients with HER2-overexpressing Breast cancer or metastatic Gastric or GastroEsophageal Junction adenocarcinoma. The newly approved biosimilar will also eventually compete with 2 prior FDA approved biosimilars, OGIVRI® (Trastuzumab-dkst) and HERZUMA® (Trastuzumab-pkrb). ONTRUZANT® is a product of Samsung Bioepis and will be marketed by Merck&Co.