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.
How trastuzumab works
It 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.
How is trastuzumab given?
It’s usually used in combination with chemotherapy drugs for early breast cancer and it can increase the effect of the chemotherapy.
The drug 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 not common, but can include headache, fever and diarrhoea. In some cases, the drug can affect how the heart works, so you will have tests to check your heart function before and during treatment.
CDK inhibitors
These are a group of medicines that block cyclin-dependent kinases (CDKs), a group of proteins that help with regulating the cell cycle. They are used with hormone therapy to treat larger, high-risk ER+, HER2–breast cancers, for cancers involving several lymph nodes, or cancers at high risk of returning. They are used after surgery and chemotherapy.
Side effects – You may get nausea or diarrhoea, but this can be managed. Your blood count may be affected, so you will need regular blood tests.
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. Ask your doctor if they may be suitable for you.
Learn more about Targeted Therapy.
Due to ongoing research, there are many new targeted therapy drugs for breast cancer. Your doctor will be able to tell you which ones 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 (Open Settings 
to turn on auto-generated subtitles in your language).
Podcast: Immunotherapy & Targeted Therapy
More resources
A/Prof Cindy Mak, Breast Surgeon and Director of Breast Services, Chris O’Brien Lifehouse, Royal Prince Alfred Hospital, NSW; A/Prof Nick Murray, Consultant Medical Oncologist, Royal Adelaide Hospital and GenesisCare Adelaide, SA; Caroline Bennett, Consumer; Tamara Casey, Clinical Nurse Consultant, Breast Assessment Unit, Fiona Stanley Hospital, WA; A/Prof Joe Dusseldorp, Reconstructive Plastic Surgeon, Chris O’Brien Lifehouse, NSW; Lauren Lores, Consumer; Dr Linda Madigan, Breast Physician, Royal Adelaide Hospital, SA; Catherine Meredith, Consumer; Ash Mondolo, Breast Cancer Clinical Nurse Consultant, Mater Private Hospital, QLD; Chris Rivett, 13 11 20 Consultant, Cancer Council SA; Catrina Ross, McGrath Breast Care Nurse, Northern Sydney Local Health District, NSW; Prof Christobel Saunders AO, James Stewart Chair of Surgery and Director of Research, Melbourne Medical School, The University of Melbourne, VIC; Dr Janice Yeh, Radiation Oncologist, Peter MacCallum Cancer Centre, VIC; A/Prof Yvonne Zissiadis, Radiation Oncologist, Medical Director, GenesisCare WA and Adjunct A/Prof, Curtin University, WA.
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