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Last Updated: 11/16/23

Information below provided by the Pharmaceutical Company.

Trastuzumab and hyaluronidase-oysk (HERCEPTIN HYLECTA)

Agent Description

HERCEPTIN HYLECTA is a combination of trastuzumab, a HER2/neu receptor antagonist, and hyaluronidase, an endoglycosidase, indicated as adjuvant treatment of HER2-overexpressing breast cancer.

Mechanism of Action

Trastuzumab is a recombinant humanized immunoglobulin (Ig) G1κ monoclonal antibody, which targets the human epidermal growth factor receptor 2(HER2, also known as c-erbB-2), a transmembrane glycoprotein with intrinsic tyrosine kinase activity. Trastuzumab binds to distinct HER2 epitopes without competing and has complementary mechanisms for disrupting HER2 signaling. This results in augmented anti-proliferative activity in vitro and in vivo when trastuzumab is administered.


Fully human immunoglobulin monoclonal antibody produced in Chinese hamster ovary cells.

Molecular Targets

Human epidermal growth factor receptor 2 (HER2, also known as c-erbB-2)


The product for SC delivery of trastuzumab has been developed for the treatment of HER2-positive breast cancer. It is expected that SC administration will result in a less invasive and faster administration of trastuzumab, while maintaining similar efficacy and safety to the Herceptin® IV formulation.

Package insert:

Studies of Interest

In general, study proposals listed below will NOT be supported:

  • Combinations with ado-trastuzumab emtansine
  • Combinations with bevacizumab
  • Combinations with biosimilar Trastuzumab
  • Novel combinations in the absence of Phase I data

Information collaborator would like included in investigator proposals

Sponsor-investigator must indicate appropriate facilities/personnel, experience treating patients in desired research population and that they have an adequate sample size they can enroll into study, and a proven track record for conducting and publishing research. Formulary LOI proposal needs to describe if they have ongoing studies at their institution that would compete with the research population of interest during the expected patient accrual window.