Herceptin has been around for a number of years but its use has been restricted to patients with advanced breast cancer. That all changed on 1st October 2006 when it was listed on the PBS and made available as adjuvant therapy to prevent the cancer returning.

Of course, there are a couple of strings attached. To be eligible to receive this drug:

• A special gene amplification process must return a positive HER2 status
• Patients must have no existing heart dysfunction, or vulnerability to heart damage

Herceptin®, as an adjuvant therapy will be used after surgery in combination with other chemotherapeutic regimes. It will be given for a maximum of 12 months.

Before the 1st October 2006, patients wishing to receive Herceptin® as adjuvant therapy had to pay approximately $5000 per month.

PBS Information

The cost of the 52 weeks of treatment is likely to be in the order of $50 000 per patient for eligible patients. The listing of Herceptin® will add approximately $470 million to PBS and Repatriation Pharmaceutical Benefits Scheme expenditure between 2006-07 and 2009-10.

Funding for Herceptin® in advanced breast cancer will remain as it is. Since 2001 the Australian Government has funded trastuzumab for the treatment of late stage breast cancer under a special Herceptin Program, which Medicare Australia administers independently of the PBS.

What is Herceptin®?

Herceptin® is not chemotherapy. It is a monoclonal antibody (sometimes called biologic therapy). • Antibodies are part of the body's normal defence against bacteria, viruses, and abnormal cells such as cancer cells. • Monoclonal antibodies are mass-produced in a laboratory. Their name comes from the fact that they are identical and produced from a single cell (clones). Therapy with monoclonal antibodies is generally a more targeted form of therapy than chemotherapy. Herceptin® has been shown to benefit women with HER2 positive breast cancer - around 20% of all breast cancer cases.

What is HER2?

HER2 stands for human epidermal growth factor receptor 2. HER2 is a gene that helps control how cells grow, divide and repair themselves. The HER2 gene directs the production of special proteins, called HER2 receptors.

Figure 1: HER2 recieves messages (growth factors) that tell cells to divide and grow.

Each healthy breast cell contains 2 copies of the HER2 gene, which helps normal cells grow (Figure 2). Sometimes a cell may have too many copies of the HER2 gene, which may lead to too much HER2 protein. Too much HER2 protein may play an important role in turning a normal cell into a cancer cell and in how aggressive the cancer may be (Figure 3).

Figure 2: Normal cells only have a small amount of HER2 on their surface. Women with breast cancer that has too much HER2 protein on the outside of the cell (HER2 protein overexpression) may be less likely to respond to certain treatments.

Figure 3: Some cancer cells have a malfunctioning gene that causes too much HER2 on their surface.

How does Herceptin® work?

Herceptin® works by interfering with one of the ways in which breast cancer cells divide and grow.

Some breast cancer cells are stimulated to multiply when a protein produced naturally in the body (human epidermal growth factor) attaches itself to a protein (HER2) on the surface of the breast cancer cells.

Herceptin® attaches itself to the HER2 protein, blocking the message to cancer cells to divide and grow. Herceptin® also stimulates the body's immune system to help destroy the cancer cells.

How is Herceptin® given?

Herceptin® is given through a drip into a vein. It can be given as an outpatient. The first dose is given slowly, over about an hour and a half. Subsequent doses usually take 30 minutes to give.

What are the side effects of Herceptin®?

Like all medicines, Herceptin® may cause side-effects. Side effects are usually mild. The commonest problem is temporary flu-like symptoms (fever and chills) shortly after the drug is given. Other side effects include nausea, vomiting, headache or dizziness, rask and cough. Less often Herceptin® can cause heart problems.

Where can i get more information?

Please speak to your oncologist.