Class: Biological Therapy

Generic Name: Palbociclib

Trade Name: Ibrance®

For which conditions is this drug approved? Ibrance is approved in combination with the medicine Femara® (letrozole) for the treatment of postmenopausal women with advanced breast cancer that is estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative for first therapy. It is also used in combination with Faslodex® (fulvestrant) in women with disease progression following hormonal therapy.

What is the mechanism of action? Ibrance is a kinase inhibitor. These drugs work by blocking the action of enzymes called kinases, which are involved in many cell functions, including cell signaling, growth, and division. These enzymes may be too active or found at high levels in some types of cancer cells, and blocking them may help keep cancer cells from growing. Specifically, Ibrance inhibits cyclin-dependent kinase (CDK) 4 and 6.

How is Ibrance typically given (administered)? Ibrance is given as a capsule. Take Ibrance with food and in combination with Femara.

How are patients typically monitored? Your doctor will perform regular blood test to check for neutropenia (low count of neutrophils, a type of white blood cell that helps fight off infections). Your doctor will also check you for signs of infection.

What are the common (occur in 30% or more of patients) side effects of treatment with Ibrance?

• Infections
• Neutropenia
• Leukopenia (decreased number of white blood cells)
• Anemia
• Fatigue

What are the less common (occur in 10% to 29% of patients) side effects of treatment with Ibrance?

• Thrombocytopenia (low platelet count)
• Decreased appetite
• Peripheral neuropathy (damage to peripheral nerves, which often causes weakness, numbness and pain, usually in hands and feet)
• Nosebleed
• Stomatitis (inflammation of the mouth and lips)
• Nausea
• Diarrhea
• Vomiting
• Hair loss
• Lack of energy and strength

This is not a complete list of side effects. Some patients may experience other side effects that are not listed here. Patients may wish to discuss with their physician the other less common side effects of this drug, some of which may be serious.

Some side effects may require medical attention. Other side effects do not require medical attention and may go away during treatment. Patients should check with their physician about any side effects that continue or are bothersome.

What can patients do to help alleviate or prevent discomfort and side effects?

• Do not miss any of your blood tests or other exams during treatment.
• Take Ibrance exactly as your healthcare provider tells you.
• Take Ibrance with food and swallow the capsules whole. Do not chew, crush or open Ibrance capsules.
• Do not take Ibrance capsules that are broken, cracked, or that look damaged.
• Avoid grapefruit and grapefruit products during treatment with Ibrance. Grapefruit may increase the amount of the medication in your blood.
• Do not change your dose or stop taking Ibrance unless your healthcare provider 
tells you.
• If you miss a dose of Ibrance or vomit after taking a dose, do not
take another dose that day. Take your next dose at your regular time.
• If you take too much Ibrance, call your healthcare provider right away or go to the nearest hospital emergency room.

Are there any special precautions patients should be aware of before starting treatment?

• Tell your doctor about all of your medical conditions.
• Tell your doctor if you have: fever, chills, or any other signs or symptoms of infection, or liver or kidney problems.
• Tell your doctor if you are pregnant or plan to become pregnant. Ibrance can harm your unborn baby, so you should not become pregnant during treatment with Ibrance. If you become pregnant during treatment or think you may be pregnant, tell your healthcare provider right away.
• Women who are able to become pregnant should use effective birth control during treatment with Ibrance and for one month after the last dose.
• Men who are sexually active should use a condom during treatment with Ibrance and for three months after the last dose.
• Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if Ibrance will pass into your breast milk. You and your healthcare provider should decide if you will take Ibrance or breastfeed—you should not do both.
• Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Keep a list of the medicines you take and show them to your healthcare providers and pharmacist when you get a new medicine.

When should patients notify their physician?

• Ibrance may cause serious or life-threatening blood clots in the arteries of your lungs. Tell your healthcare provider right away if you have any of the following signs and symptoms: shortness of breath; rapid heart rate sudden; sharp chest pain that may become worse with deep breathing; rapid breathing.
• Ibrance may cause low blood cell and platelet counts. Tell your healthcare provider right away if your experience any of the following symptoms of this condition: dizziness, shortness of breath, weakness, bleeding or bruising more easily.

What is a package insert? A package insert is required by the FDA and contains a summary of the essential scientific information needed for the safe and effective use of the drug for healthcare providers and consumers.  A package insert typically includes information regarding specific indications, administration schedules, dosing, side effects, contraindications, results from some clinical trials, chemical structure, pharmacokinetics and metabolism of the specific drug. By carefully reviewing the package insert, you will get the most complete and current information about how to safely use this drug. If you do not have the package insert for the drug you are using, your pharmacist or physician may be able to provide you with a copy.