Key Points

• Ibrance (generic name: palbociclib) is not a traditional form of chemotherapy (chemo). Ibrance is a "targeted drug therapy" known as a CDK 4/6 inhibitor. Targeted therapies work only on certain cancers with specific genetic traits. For example, some cancer cells have proteins, like CDK, HER2 or mTOR, that promote rapid or unusual growth.
• Your doctor can test you to see if you have the kind of cancer that would respond to targeted drug therapy.
• Because these drugs target specific areas, they may be linked with fewer, less severe or different side effects compared to traditional chemotherapy. However, serious risks are still present, so be sure to discuss your options for cancer treatment with your physician.

What is chemo?

Chemotherapy ("chemo") is when oral or injectable medicines are used to kill cancer cells. Chemotherapy can also affect healthy cells, but the body can often repair the damage done to the healthy cell once treatment stops.

Chemotherapy can help prevent a cancer from coming back, from spreading in the body (metastasizing), and can kill cancer cells that have already spread.

Chemotherapy is usually given in cycles, with rest periods, over several months. Treatment is individualized for each patient and depends on several factors, such as cancer stage at diagnosis, previous treatments and how well you have tolerated other treatments.

Common chemotherapy treatments used in breast cancer include:

• the anthracyclines, such as doxorubicin (Adriamycin)
• epirubicin (Ellence)
• taxanes such as paclitaxel (Taxol) and docetaxel (Taxotere).

These may be combined with fluorouracil (5-FU), cyclophosphamide, and carboplatin.

Chemotherapy, endocrine (hormone) therapy, and targeted therapy are known as "adjuvant" systemic therapies. Adjuvant therapy for breast cancer is given after primary treatment (such as surgery) to increase the chance of long-term survival and may also include radiation.

How does Ibrance work in breast cancer?

Targeted drugs like Ibrance can be used with certain hormone therapies to fight advanced hormone receptor-positive (HR+) breast cancer in patients who are also determined to be HER2-negative.

Ibrance blocks CDK4 and CDK6, which are special proteins in the cell. Blocking these proteins helps to slow down cell division that leads to new cancer cell growth.

How is Ibrance used to treat breast cancer?

Ibrance is used two ways:

• with the aromatase inhibitor Femara (letrozole) as initial endocrine-based therapy in postmenopausal women and men
• with the estrogen receptor antagonist Faslodex (fulvestrant) in those with disease progression following endocrine therapy. Women who have not reached menopause are treated with Ibrance plus fulvestrant therapy and a luteinizing hormone-releasing hormone (LHRH) agonist to suppress ovarian function, according to current clinical practice standards.

Ibrance comes as capsule or a tablet, although the capsule form is being phased out in 2020. Ibrance capsules must be taken with food, but the tablets can be taken with or without food.

• Ibrance is normally given for 21 days in a row along with other medications, such as an aromatase inhibitor or fulvestrant.
• This cycle is repeated every 28 days as long as you are having a positive response to the medicine and tolerate the side effects well.
• Side effects due to Ibrance may include increased infections, low red blood cell counts (anemia), tiredness, nausea, hair loss, diarrhea and mouth sores.
• Tablets and capsules are both available in a 125 mg, 100 mg, and 75 mg strength.

Bottom Line

• Ibrance is not a traditional form of chemotherapy. It is an oral medication known as a “targeted therapy” and is in the class of drugs known as CDK 4/6 inhibitors. It helps to slow cell growth in both cancer cells and healthy cells.
• Ibrance comes as a capsule or tablet, although the capsules are being phased out by the manufacturer in 2020. It is normally given for 21 days in a row along with other medications, such as an aromatase inhibitor or fulvestrant.
• This cycle is repeated every 28 days as long as you are responding to the medicine and you don’t have serious side effects.

This is not all the information you need to know about Ibrance (generic name: palbociclib) for safe and effective use. Review the full Ibrance product information here, and discuss this information with your doctor or other health care provider.