Key points
- Trastuzumab (Herzuma) is the mainstay of treatment for HER2+ early breast cancer. For stage 2 and 3 breast cancers it is often given as neoadjuvant treatment. Most HER2+ patients will have 12 months adjuvant treatment following chemotherapy.
- Patients who do not achieve pathological complete response to neoadjuvant therapy will be offered 12 months adjuvant T-DM1 (Kadcyla)
- Additional unfunded anti-HER2 medicines have been shown to reduce recurrence in high-risk patients.
Content:
Around 20% of breast cancers are HER2+, where the Human Epidermal Growth Factor Receptor 2 gene is over-expressed.
Trastuzumab (Herzuma) is a monoclonal antibody that recognises and binds to the HER2 proteins on the surface of cancer cells. It slows or stops the growth of HER2+ breast cancer by attaching itself to the receptors and blocking growth signals. It also stimulates the body’s immune system to destroy the cancer cells.
Herzuma is the most widely used biological treatment for breast cancer and is used to treat both early and advanced HER2+ breast cancer. In early breast cancer, it is given in conjuction with a chemotherapy regime, and then continued every three weeks to complete 12 months. Herzuma is delivered via IV infusion (the subcutaneous version is not funded in New Zealand). Herceptin is generally well-tolerated; however it increases patient risk of developing congestive heart failure. Regular cardiac monitoring is therefore required before starting and during treatment. A shorter course may be recommended for patients with cardiovascular issues.
For more information about Herzuma and possible side effects see the Medsafe consumer information booklet.
T-DM1 (Kadcyla)
Trastuzumab-emtansine/T-DM1 (Kadcyla) is an adjuvant treatment prescribed to patients with incomplete response to neoadjuvant therapy.
There are also two biological medicines which are Medsafe-approved (but not publicly funded) for HER2+ early breast cancer:
- neratinib (Nerlynx) is an extended adjuvant treatment, used after Herzuma for patients at high-risk of recurrence.
- pertuzumab (Perjeta) is used as a neoadjuvant or adjuvant treatment in combination with Herzuma and chemotherapy for high-risk patients.
These new medicines are also used in advanced breast cancer (Perjeta and Kadcyla are publicly funded in the metastatic context), as is Herzuma.
