What is it and how is it used?
Herceptin contains the active substance trastuzumab, which is a monoclonal antibody. Monoclonal antibodies attach to specific proteins or antigens. Trastuzumab is designed to bind selectively to an antigen called human epidermal growth factor 2 (HER2). HER2 is found in large amounts on the surface of some cancer cells where it stimulates their growth. When Herceptin binds to HER2 it stops the growth of such cells and causes them to die.
Your doctor may prescribe Herceptin for the treatment of breast and gastric cancer when:
- You have early breast cancer, with high levels of a protein called HER2..
- You have metastatic breast cancer (i.e. breast cancer that has spread beyond the original tumour) with high levels of HER2. Herceptin may be prescribed in combination with the chemotherapy agents paclitaxel or docetaxel as first treatment for metastatic breast cancer or it may be prescribed alone if other treatments have proved unsuccessful. It is also used in combination with medicines called aromatase inhibitors with patients with high levels of HER2 and hormone receptor-positive metastatic breast cancer (i.e. cancer that is sensitive to the presence of female sex hormones)
- You have metastatic gastric cancer with high levels of HER2, when it is in combination with the other cancer medicines capecitabine or 5-flououracil and cisplatin.
What do you have to consider before using it?
Do not use Herceptin
- If you are allergic to trastuzumab, to murine (mouse) proteins, or to any of the other ingredients.
- If you have severe breathing problems at rest due to your cancer or if you need oxygen treatment.
Tell your doctor before you use Herceptin
Your doctor will closely supervise your therapy. You should tell your doctor before you use Herceptin:
- If you have had heart failure, coronary artery disease, heart valve disease (heart murmers) or high blood pressure. Talk to your doctor about this because Herceptin can cause heart failure.
- If you suffer from breathlessness. Herceptin can cause breathing difficulties, especially when it is first given. This could be more serious if you are already breathless. Very rarely, patients with severe breathing difficulties before treatment have died when they were given Herceptin.
- If you have ever had chemotherapy with a medicine called doxorubicin or a medicine related to doxorubicin (your doctor can advise you here). These medicinal products can damage heart muscle and increase the risk of heart problems with Herceptin.
If you receive Herceptin with paclitaxel, docetaxel, an aromatase inhibitor, capecitabine, 5-fluorouracil, or cisplatin you should also read the patient informationackage leaflets for these products
Treatment with Herceptin may affect the heart. Therefore, your heart function will be checked before and during the treatment with Herceptin. If you develop any signs of heart failure (i.e., inadequate pumping of blood by the heart), you may have to stop Herceptin.
Taking other medicines:
Please inform your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.
It may take up to 6 months for Herceptin to be removed from the body. Therefore you should tell your doctor or pharmacist that you have had Herceptin if you start any new medication in the 6 months after stopping treatment
Use in children and adolescents
At present, Herceptin is not recommended for anyone under the age of 18 years because there is not enough information in this age group.
Pregnancy and breast-feeding
Before starting treatment, you must tell your doctor if you are pregnant, if you think you are pregnant or if you intend to become pregnant. You should use effective contraception during treatment with Herceptin and for at least 6 months after treatment has concluded. In rare cases, a reduction in the amount of (amniotic) fluid that surrounds the developing baby within the womb has been observed in pregnant women receiving Herceptin. Your doctor will advise you of the risks and benefits of taking Herceptin during pregnancy.
Do not breast-feed your baby during Herceptin therapy and for 6 months after the last dose of Herceptin.
Ask your doctor or pharmacist for advice before taking any medicine
Driving and using machines
We do not know whether Herceptin could affect your ability to drive a car or operate machines. However, if you experience symptoms, such as chills or fever, during an infusion of Herceptin (see section 4), you should not drive or use machines until these symptoms disappear.
How is it used?
Herceptin is given as an intravenous infusion (?drip?) directly into your veins. The first dose of your treatment is given over 90 minutes and you will be observed by a health professional while it is being given in case you have any side effects. If the first dose is well tolerated the next doses may be given over 30 minutes (see section 2 under ?Tell your doctor before you use Herceptin?).
Before starting the treatment your doctor will determine the amount of HER2 in your tumour. Only patients with a large amount of HER2 will be treated with Herceptin. Your doctor will prescribe a dose and treatment regimen that is right for you . The dose of Herceptin depends on your body weight. The number of infusions you receive will depend on how you respond to the treatment. Your doctor will discuss this with you.
For early breast cancer, metastatic breast cancer and metastatic gastric cancer, Herceptin is given every 3 weeks. Herceptin may also be given once a week for metastatic breast cancer