Targeted therapy drugs attack specific features of cancer cells to stop the cancer growing and spreading. Different types of targeted therapy drugs are used for different types of breast cancer.
Learn more about:
- What drugs are available?
- How trastuzumab works
- How is trastuzumab given?
- Side effects of trastuzumab
- CDK inhibitors
- PARP inhibitors
- Video: What are immunotherapy and targeted therapy?
- Podcast: Immunotherapy and Targeted Therapy
What drugs are available?
For early or locally advanced HER2+ breast cancer, the most common targeted therapy drug used is trastuzumab. Your treatment team may refer to trastuzumab by a brand name (e.g. Herzuma, Kanjinti or Ogivri). It is also known as Herceptin, although this version is now rarely used in Australia.
How trastuzumab works
Trastuzumab works by attaching itself to HER2+ breast cancer cells, destroying the cells or reducing their ability to divide and grow. It also encourages the body’s own immune cells to help find and destroy cancer cells. Usually used in combination with chemotherapy drugs for early breast cancer, trastuzumab can increase the effect of the chemotherapy.
How is trastuzumab given?
Trastuzumab can be given through a drip into a vein (infusion) or as an injection under the skin. The first infusion takes about 90 minutes (called the loading dose). The following infusions each take 30–60 minutes.
You will usually have a dose every 3 weeks, for up to 12 months. The first 4–6 doses are given while you are having chemotherapy treatment.
Side effects of trastuzumab
Side effects are usually caused by the chemotherapy drugs, and often ease once chemotherapy finishes and you are having trastuzumab only. Side effects from trastuzumab are uncommon, but can include headache, fever and diarrhoea.
In some cases, trastuzumab can affect how the heart works, so you will have tests to check your heart function before and during treatment.
Several new drugs have been developed to treat HER2+ breast cancer with or after trastuzumab.
These include:
- pertuzumab, which is given before surgery (neoadjuvant)
- trastuzumab emtansine (T-DM1), which is given after surgery (adjuvant).
Your doctor will let you know if these drugs are appropriate for you.
CDK inhibitors
Abemaciclib is a type of cyclin-dependent kinase (CDK) inhibitor. It is used with hormone therapy. Abemaciclib may be used after surgery and chemotherapy for larger, high-risk ER+, HER2– breast cancers, for cancers involving several lymph nodes, or cancers at high risk of returning. Another drug (ribociclib) may soon become more widely available.
Side effects – Nausea or diarrhoea may occur, but this can be managed. Your blood count may be affected, so regular blood tests are needed.
PARP inhibitors
There are several new drugs for people who have inherited a BRCA mutation, or whose cancer has developed BRCA mutations. These are called poly (ADP-ribose) polymerase (PARP) inhibitors and include the drug olaparib. Ask your doctor if this may be suitable for you.
→ READ MORE: Immunotherapy for breast cancer
Video: What are immunotherapy and targeted therapy?
Watch this short video to learn more about targeted and immunotherapy
Podcast: Immunotherapy & Targeted Therapy
More resources
Dr Diana Adams, Medical Oncologist, Macarthur Cancer Therapy Centre, NSW; Prof Bruce Mann, Specialist Breast Surgeon and Director, Breast Cancer Services, The Royal Melbourne and The Royal Women’s Hospitals, VIC; Dr Shagun Aggarwal, Specialist Plastic and Reconstructive Surgeon, Prince of Wales, Sydney Children’s and Royal Hospital for Women, NSW; Andrea Concannon, consumer; Jenny Gilchrist, Nurse Practitioner Breast Oncology, Macquarie University Hospital, NSW; Monica Graham, 13 11 20 Consultant, Cancer Council WA; Natasha Keir, Nurse Practitioner Breast Oncology, GenesisCare, QLD; Dr Bronwyn Kennedy, Breast Physician, Chris O’Brien Lifehouse and Westmead Breast Cancer Institute, NSW; Lisa Montgomery, consumer; A/Prof Sanjay Warrier, Specialist Breast Surgeon, Chris O’Brien Lifehouse, NSW; Dr Janice Yeh, Radiation Oncologist, Peter MacCallum Cancer Centre, VIC.
View the Cancer Council NSW editorial policy.
