Ibrance (palbociclib) is a medicine that is used for certain types of breast cancer. Ibrance is used to treat breast cancer that is hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative and is advanced or has spread to other parts of the body (metastatic). It’s usually used along with another medicine.
How Does Ibrance Work for Breast Cancer?
Ibrance is a type of medicine called a kinase inhibitor. Kinases are enzymes in the body that can send and receive signals to help your cells do important functions. Ibrance blocks the action of cyclin-dependent kinases 4 and 6 (CDK4 and CDK6). Kinases CDK4 and CDK6 send signals to help cancer cells to grow and multiply. Ibrance blocks the activity of CDK4 and CDK6 to help stop cancer cells from growing and multiplying and to make tumors shrink in size.
What Kinds of Breast Cancer Does Ibrance Treat?
Breast cancer that is hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative and is advanced or has spread to other parts of the body (metastatic) may be treated by Ibrance. It is usually given with another medicine. The medicine that is used depends on whether your breast cancer has been treated with a medicine that is a hormone therapy.
How Do I Take Ibrance for Breast Cancer?
Ibrance is taken as a tablet or capsule that you swallow. If you are taking Ibrance capsules, you will take your dose with food. If you are taking Ibrance tablets, you can take it with or without food. You should try to take your Ibrance dose around the same time every day. Both Ibrance tablets and capsules should be taken whole, and you should not crush or chew them. Any tablets or capsules that are broken, cracked, or damaged should not be taken. You can contact your pharmacy about getting them replaced. If you vomit after taking a dose of Ibrance, skip the dose and do not take an extra dose. Take your next Ibrance dose as scheduled the next day.
You will continue taking Ibrance for as long as possible. This means you will take it until your cancer progresses or you have side effects that make it not safe for you to take. If you have certain side effects, your health care provider may change your dose of Ibrance.
If you are taking certain medications, your dose of Ibrance may need to be lowered. Tell your health care provider about all medications and supplements you are taking or plan to take while taking Ibrance. They will help to tell you how to take Ibrance so it can be safe and effective for treating your cancer.
How Well Does Ibrance Work for Breast Cancer?
The FDA approved Ibrance for HR-positive HER2-negative breast cancer that has spread to other parts of the body based on clinical trials that looked at how effective Ibrance was when combined with another medicine for certain people.
In the PALOMA-2 clinical trial, Ibrance was combined with letrozole, which is a type of medicine called an aromatase inhibitor and works to reduce the amount of estrogen in the body. People who were postmenopausal and had HR-positive HER2-negative breast cancer that had spread in the body and had not previously received a whole-body treatment such as chemotherapy since the cancer had spread in their body took either Ibrance with letrozole or a placebo with letrozole. A placebo is used in clinical trials as a control so that the potential benefit of a medicine in a group of people can be compared in a similar group of people who did not receive a medicine.
The clinical trial included 666 people, with 444 people taking Ibrance. About 78% of the people in this trial were White, about 14% were Asian, 1.7% Black, and 6.6% were classified as other. They were followed to see how long it took for their breast cancer to progress, meaning that the cancer grew or spread. This measurement is called progression-free survival. The median progression-free survival was 24.8 months for Ibrance plus letrozole, compared to 14.5 months for the placebo plus letrozole. This means that half of the people who took Ibrance did not have their cancer progress for at least 24.8 months, compared to 14.5 months for people who took the placebo.
This study also looked at median overall survival, which measured how long half of the people in the study who received a certain medicine survived after starting to use the medicine. People who took Ibrance plus letrozole in the study had a median overall survival of 53.8 months, while people who took a placebo plus letrozole had a median overall survival of 49.8 months. This means that half of the people who took Ibrance survived for at least 53.8 months, compared to 49.8 months for the people who took the placebo.
In the PALOMA-3 clinical trial, Ibrance was combined with fulvestrant, which is a hormone therapy that works to reduce the amount of estrogen in the body. People who had HR-positive HER2-negative breast cancer that had spread in the body after or while receiving hormone therapy took either Ibrance with fulvestrant or a placebo with fulvestrant.
The clinical trial included 521 people, with 347 people taking Ibrance. About 74% of the people in this trial were White, 20% were Asian, and 6% were classified as Black or other. The median progression-free survival was 9.5 months for Ibrance plus fulvestrant, compared to 4.6 months for the placebo plus fulvestrant. This means that half of the people who took Ibrance did not have their cancer progress for at least 9.5 months, compared to 4.6 months in people who took the placebo.
This study also looked at median overall survival. People who took Ibrance plus fulvestrant in the study had a median overall survival of 34.9 months, while people who took a placebo plus fulvestrant had a median overall survival of 28 months. This means that half of the people who took Ibrance survived for at least 34.9 months, compared to 28 months for the people who took the placebo.
How Will My Progress Be Monitored?
Ibrance will start working as soon as you start taking the medicine. Your health care provider will usually do a scan to see how your cancer is responding to the treatment 6 weeks after you start your medicine. They may choose to do the scan earlier or later than 6 weeks.
Your health care provider will also do regular bloodwork to monitor how Ibrance is working in your body. These tests will monitor your blood counts such as white blood cells, neutrophils, and platelets, so that your health care provider knows that you can continue to use Ibrance safely. If you have certain side effects, such as a coughing, your health care provider may do more tests to make sure it is safe for you to continue to use Ibrance.
How Can I Prevent and Manage Side Effects?
Side effects are common with medicines that treat cancer, including Ibrance. It is important to tell your health care provider about any side effects you have while you’re taking Ibrance and after. They can help to find out if your side effects are serious or provide more information to help you manage the side effects.
Your health care provider will have you do bloodwork regularly while taking Ibrance. It’s important to attend all of your appointments for bloodwork so that your health care provider can make sure Ibrance is safe for you. These tests will make sure you do not have any problems with your blood cell counts that make it unsafe for you to take Ibrance. This is because Ibrance can cause low white blood cell counts, also called neutropenia. If not treated, neutropenia can cause serious infections that can be dangerous and even life-threatening.
You can ask your health care provider what else you can do to prevent or treat common side effects. For example, you can help to prevent and treat nausea, vomiting, and diarrhea by eating bland foods and having multiple small meals throughout the day instead of three large meals.
If you have certain side effects while you take Ibrance, your health care provider may need to change your dose of medicine, pause your doses, or even stop your medicine altogether. This will depend on the side effects you have, how severe they are, and what treatment they need. If your Ibrance dose needs to be lowered, the medicine will continue to work in your body. If your medicine is paused, it is possible that your health care provider will restart the medication at the same dose or at a lower dose once your side effect is treated and gets better.
What Are Other Unique Considerations to Be Aware Of?
While taking Ibrance, you will need to avoid grapefruit. This includes not eating grapefruit or drinking any juice that has grapefruit. This is because grapefruit can block your body’s ability to break down (metabolize) Ibrance and cause too much of the medicine to stay in your body and increase your risk of side effects.
Is There Any Cost Assistance Available?
The maker of Ibrance has a program to help support financial assistance and may be able to offer coupons or savings for Ibrance.
