Pertuzumab

Pertuzumab (Perjeta) is a targeted therapy used to treat early-stage and metastatic HER2-positive breast cancer. Pertuzumab is a monoclonal antibody, a type of medicine made in a lab that targets a specific protein, HER2, produced on the outside of a cell. It falls in a class of medicines called targeted therapies.

In 2013, the FDA approved pertuzumab for use in early-stage disease when given at the same time as the targeted therapy trastuzumab (Herceptin and biosimilars) and the chemotherapy medicine docetaxel (Taxotere). It was the first breast cancer medicine to be approved by the FDA specifically as neoadjuvant therapy. It was approved in 2017 to be given with trastuzumab for adjuvant treatment as well and for people who have a high risk of recurrence.

How pertuzumab works

Pertuzumab works by blocking signals that tell breast cancer cells to multiply. After attaching to cancer cells, it can also alert the immune system to kill them.

Who gets pertuzumab

Pertuzumab may be given with trastuzumab after surgery to people with early-stage, HER2-positive breast cancer that is at high risk of returning or spreading away from the breast.

You may be able to take pertuzumab as neoadjuvant treatment, treatment given before breast surgery, for early-stage HER2-positive breast cancer if the cancer is:

• larger than 2 centimeters across, or
• locally advanced, meaning it has traveled to nearby tissue or lymph nodes, or
• inflammatory, a type of breast cancer in the skin of the breast that causes the breast to look red and swollen and feel warm to the touch

After getting neoadjuvant treatment and surgery, you may continue taking pertuzumab and trastuzumab to complete up to 1 year of treatment.

In metastatic breast cancer, pertuzumab is used for HER2-positive breast cancer that has not yet been treated with trastuzumab or with chemotherapy after a stage IV diagnosis. A 2014 ASCO guideline recommends the combination of trastuzumab and pertuzumab, two medicines that attack HER2 proteins, along with taxane-based chemotherapy, as a first treatment for metastatic breast cancer.

You and your doctor will discuss the best treatment plan for your situation.

How pertuzumab is given

Pertuzumab given by vein uses a needle or a port to drip medicine directly into a vein in a process called an infusion. The dose is based on how much you weigh. Infusions last between 30 minutes and an hour, after a first infusion that lasts an hour or longer. Infusions are given once every 3 weeks.

The treatment can also be given as pertuzumab, trastuzumab, and hyaluronidase-zzxf (Phesgo), a combination of trastuzumab and pertuzumab delivered together by inserting a needle under the skin, usually in the thigh, once every 3 weeks. The injection takes about 5 minutes and the dose is fixed, meaning it doesn’t change based on your weight.

In early-stage disease, you may receive pertuzumab for up to 18 weeks before surgery and continue to take it alongside trastuzumab or in pertuzumab, trastuzumab, and hyaluronidase-zzxf to complete a year of treatment. If recommended only after surgery, pertuzumab and trastuzumab or pertuzumab, trastuzumab, and hyaluronidase-zzxf may be taken for up to a year.

Side effects and things to remember

When pertuzumab is given with trastuzumab and chemotherapy, the side effects people experience most often are:

• diarrhea
• fatigue
• hair loss
• low white blood cell count, which can lead to infections
• nausea
• neuropathy
• rash

If you are getting chemotherapy and trastuzumab along with pertuzumab, you also may have side effects of trastuzumab and chemotherapy.

Trastuzumab is known to cause heart problems, but studies show that adding pertuzumab to trastuzumab doesn’t raise the risk. It’s unlikely you’ll have serious heart problems while taking these medicines, but it’s important your doctor monitor your heart health during treatment.

Before starting pertuzumab tell your doctor about any medicines you are taking, including vitamins, herbal supplements and over-the-counter medicines. Pertuzumab may be dangerous to a fetus if taken while pregnant. You should not take it if you are pregnant or breastfeeding, and you should take steps to avoid getting pregnant while on pertuzumab.

Your doctor, pharmacist or nurse can help you manage your side effects. You can also go to our section on side effects for more information.