Summary of Clinical Use

Trastuzumab is approved for use as adjuvant treatment of HER2 positive breast cancer, metastatic breast cancer and metastatic gastric cancer or gastroesophageal junction adenocarcinoma in patients who have not received prior treatment for metastatic disease. Herceptin Hylecta® is a combination of trastuzumab plus recombinant hyaluronidase PH20 (hyaluronidase-oysk) that was FDA approved in early 2019 for the treatment of certain patients with HER2-positive early breast cancer. The hyaluronidase component facilitates reletively quick, subcutaneous delivery of the trastuzumab mAb component, in comparison to earlier formulations that relied on much slower intravenous delivery.

Mechanism Of Action and Pharmacodynamic Effects

Trastuzumab binds to the cell surface HER2 epidermal growth factor receptor, whose upregulated expression promotes uncontrolled proliferation in many breast cancer cells [2]. It blocks the formation of the HER2 homodimers that are one of the functional signalling complexes that promote cancer cell proliferation. Trastuzumab blocks HER2 homodimer signalling and causes cell cycle arrest during the G1 phase, thereby inhibiting the replication of HER2 positive cancer cells.

External links

For extended ADME data see the following: Electronic Medicines Compendium (eMC) Drugs.com European Medicines Agency (EMA)