Skip to main content

Palbociclib

Generic name: palbociclib
Brand name: Ibrance
Dosage form: tablet, capsule
Drug class: CDK 4/6 inhibitors

Medically reviewed by Melisa Puckey, BPharm. Last updated on Apr 19, 2022.

What is palbociclib?

Palbociclib is an oral medicine that is used to treat specific types of breast cancer in adults. Your doctor will prescribe it for you if it has a proven benefit for your type of cancer. 

It is used in combination with other cancer treatments, either aromatase inhibitor or fulvestrant, which one you use will depend on your clinical factors.  

It is a targeted therapy which blocks CDK4 and CDK6, which are enzymes in cells that are important for cell division. Blocking these proteins helps to slow down cells that are dividing, which slows down cancer growth.

What is palbociclib used for?

Palbociclib is used to treat adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer. It should always be used in combination with another medicine either:

  • an aromatase inhibitor as initial endocrine-based therapy in postmenopausal women or in men; or
  • fulvestrant in patients with disease progression following endocrine therapy.

Important information

Palbociclib may cause serious side effects, including:

Low white blood cell counts (neutropenia). This increases your risk of serious infections. Low white blood cell counts are very common when taking palbociclib and may cause serious infections that can lead to death. Your healthcare provider should check your white blood cell counts before and during treatment.

If you develop low white blood cell counts during treatment, your healthcare provider may stop your treatment, decrease your dose, or may tell you to wait to begin your treatment cycle. Tell your healthcare provider right away if you have signs and symptoms of low white blood cell counts or infections such as fever and chills.

Lung problems (pneumonitis). Palbociclib may cause severe or life-threatening inflammation of the lungs during treatment that can lead to death. Tell your healthcare provider right away if you have any new or worsening symptoms, including:

  • trouble breathing or shortness of breath
  • cough with or without mucus
  • chest pain

Other possible side effects are listed further down the page. 

What should I tell my doctor before taking palbociclib?

Before you take palbociclib, tell your healthcare provider if you:

  • have fever, chills, or any other signs or symptoms of infection.
  • have liver or kidney problems.
  • have any other medical conditions.
  • are pregnant, or plan to become pregnant. See below for more information on palbociclib and pregnancy, as it can harm your unborn baby.
  • are breastfeeding or plan to breastfeed. Do not breastfeed during treatment with palbociclib and for 3 weeks after the last dose.  See below for more information on palbociclib and breastfeeding.

How should I take palbociclib?

  • Take palbociclib tablets and capsules exactly as your healthcare provider tells you.
  • Try to take it at the same time each day.
  • You should take palbociclib capsules with food.
  • You can take palbociclib tablets with or without food
  • Swallow capsules and tablets whole. 
  • Palbociclib tablets should not be chewed, crushed, or split before swallowing. Palbociclib capsules should not be chewed, crushed. You should not open capsules before swallowing.
  • Do not take tablets or capsules if they are broken, cracked, or otherwise not whole.
  • You should not have grapefruit and grapefruit products during treatment with this medicine. Grapefruit can increase the amount of it in your blood.
  • You should not change your dose or stop taking this medicine unless your healthcare provider tells you.
  • If you miss a dose of palbociclib or vomit after taking a dose,  you should not take another dose on that day. Take your next dose at your regular time.
  • If you take too much of this medicine, call your healthcare provider right away or go to the nearest hospital emergency room.

Dosing information

The usual dose of palbociclib is a 125 mg tablet or capsule swallowed once a day for 21 days in a row. You then have 7 days in a row of not taking Palbociclib tablets or capsules. This makes up a complete cycle of 28 days.

  • Take the recommended dose of an aromatase inhibitor when given with Palbociclib. Please refer to the Full Prescribing Information for the aromatase inhibitor being used.
  • Take the recommended dose of fulvestrant on Days 1,15, 29, and once monthly  thereafter. Please refer to the Full Prescribing Information of fulvestrant.
  • If you are a pre/perimenopausal woman being treated with the combination palbociclib plus fulvestrant therapy you should also be treated with luteinizing hormone-releasing hormone (LHRH) agonists according to current clinical practice standards.
  • If you are a man being treated with combination palbociclib plus aromatase inhibitor therapy, consider treatment with an LHRH agonist according to current clinical practice standards. 

Your dosage may be changed by your health professional if you are having side effects, changes in your blood tests, liver problems or if you are taking certain medications that interact with palbociclib.

What are the side effects of palbociclib?

Palbociclib may cause serious side effects. Also see “Important information’ on this page.

Common side effects of palbociclib when used with either letrozole or fulvestrant include:

  • Low red blood cell counts and low platelet counts are common with this medicine. Call your healthcare provider right away if you develop any of these symptoms during treatment:
    • dizziness
    • bleeding or bruising more easily
    • shortness of breath
    • weakness
    • nosebleeds
  • infections (see ‘Important information’ above on this page)
  • tiredness
  • diarrhea
  • hair thinning or hair loss
  • vomiting
  • nausea
  • sore mouth
  • abnormalities in liver blood tests
  • rash
  • loss of appetite

Palbociclib may cause fertility problems in males. This may affect your ability to father a child. Talk to your healthcare provider about family planning options before starting palbociclib if this is a concern for you.

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all of the possible side effects of this medicine.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Interactions

Some medications interact with ipilimumab, so it is important to tell your doctor about any medicines that you are currently taking, or if you start or stop any medicine while you are having cancer treatment. Also tell your doctor about any over-the-counter medicines, vitamins, minerals or herbal products that you take.

To find out more about interactions with ipilimumab click the link below:

Pregnancy and breastfeeding

You should not take ipilimumab if you are pregnant or planning a pregnancy, as it can harm your unborn baby.

  • Females who are able to become pregnant should use effective birth control during treatment and for at least 3 weeks after the last dose ofpalbociclib.
  • Males with female partners who can become pregnant should use effective birth control during treatment with palbociclib for at least 3 months after the last dose of this medicine.
  • Talk to your healthcare provider about birth control methods that may be right for you during this time.
  • If you become pregnant or think you are pregnant, tell your healthcare provider right away.
  • Palbociclib may cause fertility problems in males. This may affect your ability to father a child. Talk to your healthcare provider about family planning options before starting palbociclib if this is a concern for you.

If you are breastfeeding or planning to breastfeed. It is not known if palbociclib passes into your breast milk. Do not breastfeed during treatment with palbociclib and for 3 weeks after the last dose.

Storage

  • Store palbociclib at 68 °F to 77 °F (20 °C to 25 °C).

Keep palbociclib and all medicines out of the reach of children.

What are the ingredients in palbociclib?

Active ingredient: palbociclib

Inactive ingredients:

Ibrance Capsule: microcrystalline cellulose, lactose monohydrate, sodium starch glycolate, colloidal silicon dioxide, magnesium stearate, and hard gelatin capsule shells.The light orange, light orange/caramel and caramel opaque capsule shells contain: gelatin, red iron oxide, yellow iron oxide, and titanium dioxide.

Ibrance tablet: microcrystalline cellulose, colloidal silicon dioxide, crospovidone, magnesium stearate, succinic acid, HPMC 2910/hypromellose, titanium dioxide, triacetin, and FD&C Blue #2/Indigo Carmine Aluminum Lake. In addition, the 75 mg and 125 mg tablets contain red iron oxide and the 100 mg tablets contain yellow iron oxide.

Popular FAQ

Head-to-head trials comparing Verzenio to Ibrance have not been conducted. However, one is currently underway with results expected in 2022. Verzenio is taken twice daily, every day. Ibrance is taken every day for 21 days followed by a 7-day break. Verzenio can be used as monotherapy or in combination with other treatments. Ibrance is always taken in combination with either an aromatase inhibitor or fulvestrant. Verzenio is more likely than Ibrance to cause severe diarrhea. Both Verzenio and Ibrance can be used as combination treatment to treat breast cancer in men. Verzenio is also approved to treat adults with early breast cancer at high risk of recurrence and a Ki 67 score of at least 20% (by FDA approved test) in combination with endocrine treatment (tamoxifen or an aromatase inhibitor). Continue reading

Both Verzenio and Ibrance belong to the same class of medicine, called CDK 4/6 inhibitors, therefore, because they are both in the same class of medicines, clinically, there seems no advantage in switching from one to another if one fails. However, research has shown breast cancer cells can acquire resistance to CDK 4/6 inhibitors by producing higher amounts of CDK6. Laboratory trials have shown that a “treatment holiday” of 28 days reversed this resistance, which implies that there may be some benefit of either stopping Ibrance temporarily or switching from Ibrance to Verzenio after a treatment break. Comparative trials comparing Verzenio to Ibrance are currently underway with results expected in 2022. Continue reading

More FAQ

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.