Herceptin is the current standard-of-care (SoC) therapy, and is used in every line of treatment, primarily as part of combination regimens. However, it has steadily lost market share following the introduction of trastuzumab biosimilars in 2019. 

Despite initially encountering reimbursement challenges, Perjeta + Herceptin has become the SoC for both neoadjuvant and adjuvant first-line treatment of HER2+ breast cancer, after demonstrating an overall survival benefit in the Phase II BERENICE study, and Phase III APHINITY and CLEOPATRA studies, respectively. Additionally, Roche has launched Phesgo, a subcutaneous fixed-dose formulation of the combination.