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Palbociclib

Pronunciation: pall-bow-see-clib
Generic name: palbociclib
Brand name: Ibrance
Dosage form: oral tablet, oral capsule
Drug class: CDK 4/6 inhibitors

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 7, 2024.

What is palbociclib?

Palbociclib (brand name Ibrance) may be used to treat adults with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer that has spread to other parts of the body (metastatic) in combination with an aromatase inhibitor as the first hormonal based therapy, or fulvestrant in those with breast cancer progression following hormonal therapy.

Palbociclib's mechanism of action involves blocking proteins involved in cell division called cyclin-dependent kinases (CDK), specifically CDK 4 and 6. By blocking these proteins, palbociclib prevents cancer cells from dividing and multiplying uncontrollably. HR+ breast cancer cells rely heavily on CDK 4/6 for growth. Palbociclib is not chemotherapy it is a targeted treatment (see: Is Ibrance a form of chemo? for more information).

Palbociclib gained FDA approval on February 3, 2015, under the brand Ibrance. An Ibrance generic is available (see generic Ibrance availability).

Palbociclib uses

Palbociclib is used to treat adult patients with HR-positive, HER2-negative advanced or metastatic breast cancer. It should always be used in combination with another medicine either:

Palbociclib side effects

The most common side effects of palbociclib are:

These palbociclib side effects are the most common that occur when used with either letrozole or fulvestrant.

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.

Serious side effects and warnings

Palbociclib may cause the following serious side effects.

Low white blood cell counts (neutropenia). 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 with palbociclib, your healthcare provider may stop your treatment, decrease your dose, or 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:

Your healthcare provider may interrupt or stop treatment with palbociclib completely if your symptoms are severe.

It is not known if palbociclib is safe and effective in children.

Tell your healthcare provider if you have any side effect that bothers you or does not go away. These are not all of the possible side effects of palbociclib. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Before taking

Before taking palbociclib, tell your healthcare provider about all of your medical conditions, including if you:

Pregnancy

Palbociclib can harm your unborn baby. Females who can become pregnant should use effective birth control during treatment and for at least 3 weeks after the last dose of palbociclib. Your healthcare provider may ask you to take a pregnancy test before you start treatment with palbociclib.

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 palbociclib. 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.

Breastfeeding

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.

How should I take palbociclib?

Take palbociclib exactly as your healthcare provider tells you.

Avoid grapefruit and grapefruit products during treatment with palbociclib. Grapefruit may increase the amount of palbociclib in your blood.

Do not change your dose or stop taking palbociclib unless your healthcare provider tells you.

Palbociclib dosing

The recommended palbociclib starting dose for breast cancer is palbociclib 125 mg 1 time daily with or without food for 21 days followed by 7 days without treatment.

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What happens if I miss a dose?

If you miss a dose of palbociclib or vomit after taking a dose of palbociclib, do not take another dose on that day. Take your next dose at your regular time.

What happens if I take too much palbociclib?

If you take too much palbociclib, call your healthcare provider right away or go to the nearest hospital emergency room.

What other drugs will affect palbociclib?

Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Palbociclib and other medicines may affect each other causing side effects. Especially tell your healthcare provider if you take:

Avoid grapefruit and grapefruit products.

Know the medicines you take. Keep a list of them to show your healthcare provider or pharmacist when you get a new medicine. This is not a full list of interactions with palbociclib. See the palbociclib prescribing information for a complete list.

Does palbociclib interact with my other drugs?

Enter medications to view a detailed interaction report using our Drug Interaction Checker.

How should I store palbociclib?

Store palbociclib at 68 °F to 77 °F (20 °C to 25 °C) in the original blister pack.

Keep out of the reach of children.

Palbociclib ingredients

Palbociclib is available as a generic and under the brand name Ibrance.

Active ingredient: palbociclib

Ibrance inactive ingredients: 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.

Who makes palbociclib?

Pfizer Labs makes palbociclib under the brand name Ibrance.

Synthon Pharms Inc. makes a generic palbociclib tablet but a generic palbociclib capsule is not available yet.

Popular FAQ

Will insurance pay for the cost of Ibrance?

Ibrance (palbociclib) is an expensive medicine used to treat breast cancer, but most people do not pay the full price for this drug. Your insurance, the manufacturer of Ibrance, or patient assistance programs may be available to help you pay for this medication. Continue reading

Is Verzenio better than Ibrance?

Verzenio appears just as effective as Ibrance in HR-positive, HER2-negative breast cancer but it does not seem to be as well tolerated, with more people stopping treatment with Verzenio due to gastrointestinal side effects, such as diarrhea, when compared with Ibrance. Ibrance appears more likely than Verzenio to cause Grade 3 to 4 neutropenia. Continue reading

Can you take Verzenio after Ibrance fails?

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, it is unknown if there is an 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 2023. Continue reading

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Further information

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