Tyverb is a medicine that contains the active substance lapatinib. It is available as yellow, oval tablets (250 mg).
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Tyverb is used to treat patients with breast cancer that has been shown to be ?expressing? large amounts of HER2. This means that the cancer produces a specific protein called HER2 (also known as ErbB2) in large quantities on the surface of the tumour cells. Tyverb is used in the following ways:
in combination with capecitabine another anticancer medicine when the cancer is advanced or metastatic and is getting worse following previous treatment including an anthracycline and a taxane other types of anticancer medicine, and following treatment of the patients metastatic disease with trastuzumab another anticancer medicine. Advanced means that the cancer has started to spread and metastatic means that the cancer has already spread to other parts of the body
in combination with an aromatase inhibitor another type of anticancer medicine in women who have been through the menopause, when the cancer is metastatic and responds to hormones. This combination is used in women who do not currently need to receive standard chemotherapy to treat their cancer.
The medicine can only be obtained with a prescription.
Tyverb should only be started by a doctor who has experience in giving anticancer medicines.
The recommended dose of Tyverb is five tablets a day when it is used with capecitabine, and six tablets a day when taken with an aromatase inhibitor. All of the tablets must be taken together at the same time every day, at least one hour before or one hour after food. Each patient should take the medicine at the same time each day with respect to food, such as always before or always after a meal. The doctor may decide to interrupt or stop treatment in patients experiencing certain side effects, especially those affecting the heart, lungs or liver. If patients start to take Tyverb again, they may need to use a lower dose. Patients who stop taking Tyverb after developing severe liver problems should not start to take the medicine again.
The active substance in Tyverb, lapatinib, belongs to a group of medicines called protein kinase inhibitors. These compounds work by blocking enzymes known as protein kinases, which can be found in some receptors on the surface of cancer cells including HER2. HER2 is a receptor for epidermal growth factor and is involved in stimulating the cells to divide uncontrollably. By blocking these receptors, Tyverb helps to control cell division. About a quarter of breast cancers express HER2.
Tyverb was studied in two main studies involving women with breast cancer.
The first study involved 408 women with advanced or metastatic disease that was expressing large quantities of HER2 who had already been treated with anthracyclines, taxanes and trastuzumab but whose disease had got worse or come back. The study compared Tyverb in combination with capecitabine, with capecitabine taken alone.
The second study involved 1,286 women who had been through the menopause with metastatic breast cancer that was sensitive to hormones. 219 of the women had cancer that was expressing large quantities of HER2. The study compared Tyverb with placebo (a dummy treatment), both of which were taken together with letrozole (an aromatase inhibitor). The women had not received trastuzumab or an aromatase inhibitor before entering this study.
In both studies, the main measure of effectiveness was how long the patients lived without their disease getting worse, which was assessed in scans. The studies also looked at how long the patients survived.
Tyverb in combination with another anticancer medicine was more effective than the comparator treatment in both studies.
In the first study, the women taking Tyverb in combination with capecitabine lived for an average of 23.9 weeks without their disease getting worse, as assessed by their doctors, compared with 18.3 weeks in the women taking capecitabine alone. Women taking Tyverb with capecitabine survived for an average of 75.0 weeks, and those taking capecitabine alone survived for an average of 64.7 weeks.
In the second study, the women whose cancer was expressing large quantities of HER2 taking Tyverb in combination with letrozole survived for an average of 35.4 weeks without their disease getting worse. This compared with 13.0 weeks in those taking placebo in combination with letrozole.
The most common side effects with Tyverb (seen in more than 1 patient in 10) are loss of appetite, diarrhoea (which may lead to dehydration), nausea (feeling sick), vomiting, rash and fatigue (tiredness). For the full list of all side effects reported with Tyverb, see the Package Leaflet.
Tyverb should not be used in people who may be hypersensitive (allergic) to lapatinib or any of the other ingredients.
The CHMP decided that Tyverb?s benefits are greater than its risks and recommended that it be given marketing authorisation.
Tyverb has been given ?conditional approval?. This means that there is more evidence to come about the medicine, in particular its effects on the spread of breast cancer. Every year, the European Medicines Agency will review any new information that may have become available and this summary will be updated as necessary.