Pertuzumab (Perjeta) for breast cancer: the complete patient guide

Pertuzumab, sold under the brand name Perjeta, is a targeted antibody medicine for HER2-positive breast cancer. HER2 is a protein that, when present in large amounts on cancer cells, drives them to grow quickly. Pertuzumab is always given together with trastuzumab, another HER2-targeted antibody, and the two attach to different parts of the HER2 protein, blocking its growth signals more fully than trastuzumab alone. This is often called dual HER2 blockade. In early breast cancer, pertuzumab is commonly given with trastuzumab and chemotherapy before surgery for larger cancers or cancers that have reached the lymph nodes, and it may be continued after surgery for higher-risk cancers, usually to complete about a year of HER2-targeted treatment. In advanced, or metastatic, HER2-positive breast cancer, it is given with trastuzumab and chemotherapy as a first treatment, and the two antibodies usually continue after chemotherapy stops for as long as they keep the cancer under control. Pertuzumab is given every three weeks, either as a drip into a vein or, in a combined form with trastuzumab, as an injection under the skin of the thigh. The most common side effects it adds are loose motions and skin rash, and like trastuzumab it can sometimes weaken the heart's pumping, so heart scans are done regularly. It must not be used in pregnancy, and effective contraception is needed during treatment and for several months afterwards.

Always given with trastuzumab

Pertuzumab is not used on its own. Its value comes from working alongside trastuzumab, usually with chemotherapy at the start.

Every three weeks

Treatment follows a three-weekly cycle, as a drip or as a combined injection under the skin.

Heart checks are part of treatment

A heart scan before starting and at regular intervals helps your team spot any change early, when it usually recovers.

Pertuzumab is an important medicine, but its value varies a great deal from one situation to another.

The added benefit is smaller in lower-risk cancer

After surgery, most of the extra benefit has been seen in cancers that had spread to lymph nodes. For small, node-negative cancers, the gain is small.

Cost is a real consideration

It adds substantially to the cost of HER2 treatment, and it is fair to discuss whether the likely benefit justifies it for you.

Side effects are usually manageable, but real

Loose motions in particular can be troublesome during chemotherapy.

What this page cannot tell you

It cannot tell you whether pertuzumab is right for you. Your oncologist weighs your cancer, heart health and priorities.

Once chemotherapy finishes, many people find the three-weekly antibody visits fit reasonably well into normal life.

Work and routine

Many people continue working, especially after chemotherapy, arranging leave for treatment days and scans.

Managing loose motions and skin

Have anti-diarrhoea medicine at home, drink plenty, and use gentle, fragrance-free moisturisers for dry or itchy skin.

Staying active

Regular walking and light exercise help energy levels and heart health during a long course of treatment.

Keeping appointments

Heart scans and blood tests are timed around treatment. Missing them can delay your next dose.