(palbociclib)
Risk Summary
Based on findings from animal studies and its mechanism of action, IBRANCE can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1)]. There are no available data in pregnant women to inform the drug-associated risk. In animal reproduction studies, administration of palbociclib to pregnant rats and rabbits during organogenesis resulted in embryo-fetal toxicity at maternal exposures that were ≥4 times the human clinical exposure based on AUC (see Data). Advise pregnant women of the potential risk to a fetus.
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%–4% and 15%–20%, respectively.
Data
Animal Data
In a fertility and early embryonic development study in female rats, palbociclib was administered orally for 15 days before mating through to Day 7 of pregnancy, which did not cause embryo toxicity at doses up to 300 mg/kg/day with maternal systemic exposures approximately 4 times the human exposure (AUC) at the recommended dose.
In embryo-fetal development studies in rats and rabbits, pregnant animals received oral doses of palbociclib up to 300 mg/kg/day and 20 mg/kg/day, respectively, during the period of organogenesis. The maternally toxic dose of 300 mg/kg/day was fetotoxic in rats, resulting in reduced fetal body weights. At doses ≥100 mg/kg/day in rats, there was an increased incidence of a skeletal variation (increased incidence of a rib present at the seventh cervical vertebra). At the maternally toxic dose of 20 mg/kg/day in rabbits, there was an increased incidence of skeletal variations, including small phalanges in the forelimb. At 300 mg/kg/day in rats and 20 mg/kg/day in rabbits, the maternal systemic exposures were approximately 4 and 9 times the human exposure (AUC) at the recommended dose, respectively.
CDK4/6 double knockout mice have been reported to die in late stages of fetal development (gestation Day 14.5 until birth) due to severe anemia. However, knockout mouse data may not be predictive of effects in humans due to differences in degree of target inhibition.
Risk Summary
There is no information regarding the presence of palbociclib in human milk, its effects on milk production, or the breastfed infant. Because of the potential for serious adverse reactions in breastfed infants from IBRANCE, advise a lactating woman not to breastfeed during treatment with IBRANCE and for 3 weeks after the last dose.
Pregnancy Testing
Based on animal studies, IBRANCE can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)]. Females of reproductive potential should have a pregnancy test prior to starting treatment with IBRANCE.
Contraception
Females
IBRANCE can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)]. Advise females of reproductive potential to use effective contraception during treatment with IBRANCE and for at least 3 weeks after the last dose.
Males
Because of the potential for genotoxicity, advise male patients with female partners of reproductive potential to use effective contraception during treatment with IBRANCE and for 3 months after the last dose [see Nonclinical Toxicology (13.1)].
Infertility
Males
Based on animal studies, IBRANCE may impair fertility in males of reproductive potential [see Nonclinical Toxicology (13.1)].
The safety and effectiveness of IBRANCE in pediatric patients have not been established.
The safety and effectiveness of IBRANCE were assessed but not established in three trials: one open-label trial [A5481092, (NCT03709680)] that included 98 pediatric patients 2 to <17 years of age who received IBRANCE in combination with chemotherapy for recurrent or refractory solid tumors and two open-label trials that included 42 pediatric patients 4 to <17 years of age who received IBRANCE as a single agent for recurrent or refractory solid tumors [APEC1621I, (NCT03526250)] or primary central nervous system (CNS) tumors [PBTC-042, (NCT02255461)].
No new safety signals were observed in these trials. Palbociclib exposures in pediatric patients who received IBRANCE as a single agent or in combination were within range of those observed in adults given a similar dose based on body surface area.
Juvenile Animal Toxicity Data
Altered glucose metabolism (glycosuria, hyperglycemia, decreased insulin) associated with changes in the pancreas (islet cell vacuolation), eye (cataracts, lens degeneration), kidney (tubule vacuolation, chronic progressive nephropathy) and adipose tissue (atrophy) were identified in a 27 week repeat-dose toxicology study in rats that were immature at the beginning of the studies and were most prevalent in males at oral palbociclib doses ≥30 mg/kg/day (approximately 11 times the adult human exposure [AUC] at the recommended dose). Some of these findings (glycosuria/hyperglycemia, pancreatic islet cell vacuolation, and kidney tubule vacuolation) were present with lower incidence and severity in a 15 week repeat-dose toxicology study in immature rats. Altered glucose metabolism or associated changes in the pancreas, eye, kidney and adipose tissue were not identified in a 27-week repeat-dose toxicology study in rats that were mature at the beginning of the study and in dogs in repeat-dose toxicology studies up to 39 weeks duration.
Toxicities in teeth independent of altered glucose metabolism were observed in rats. Administration of 100 mg/kg palbociclib for 27 weeks (approximately 15 times the adult human exposure [AUC] at the recommended dose) resulted in abnormalities in growing incisor teeth (discolored, ameloblast degeneration/necrosis, mononuclear cell infiltrate). Other toxicities of potential concern to pediatric patients have not been evaluated in juvenile animals.
Of 444 patients who received IBRANCE in PALOMA-2, 181 patients (41%) were ≥65 years of age and 48 patients (11%) were ≥75 years of age. Of 347 patients who received IBRANCE in PALOMA-3, 86 patients (25%) were ≥65 years of age and 27 patients (8%) were ≥75 years of age. No overall differences in safety or effectiveness of IBRANCE were observed between these patients and younger patients.
No dose adjustment is required in patients with mild or moderate hepatic impairment (Child-Pugh classes A and B). For patients with severe hepatic impairment (Child-Pugh class C), the recommended dose of IBRANCE is 75 mg once daily for 21 consecutive days followed by 7 days off treatment to comprise a complete cycle of 28 days [see Dosage and Administration (2.2)]. Based on a pharmacokinetic trial in subjects with varying degrees of hepatic function, the palbociclib unbound exposure (unbound AUCINF) decreased by 17% in subjects with mild hepatic impairment (Child-Pugh class A), and increased by 34% and 77% in subjects with moderate (Child-Pugh class B) and severe (Child-Pugh class C) hepatic impairment, respectively, relative to subjects with normal hepatic function. Peak palbociclib unbound exposure (unbound Cmax) increased by 7%, 38% and 72% for mild, moderate and severe hepatic impairment, respectively, relative to subjects with normal hepatic function [see Clinical Pharmacology (12.3)].
Review the Full Prescribing Information for the aromatase inhibitor or fulvestrant for dose modifications related to hepatic impairment.
No dose adjustment is required in patients with mild, moderate, or severe renal impairment (CrCl >15 mL/min). Based on a pharmacokinetic trial in subjects with varying degrees of renal function, the total palbociclib exposure (AUCINF) increased by 39%, 42%, and 31% with mild (60 mL/min ≤ CrCl <90 mL/min), moderate (30 mL/min ≤ CrCl <60 mL/min), and severe (CrCl <30 mL/min) renal impairment, respectively, relative to subjects with normal renal function. Peak palbociclib exposure (Cmax) increased by 17%, 12%, and 15% for mild, moderate, and severe renal impairment, respectively, relative to subjects with normal renal function. The pharmacokinetics of palbociclib have not been studied in patients requiring hemodialysis [see Clinical Pharmacology (12.3)].
| This Patient Information has been approved by the U.S. Food and Drug Administration. Revised September 2025 | ||
PATIENT INFORMATION | ||
What is the most important information I should know about IBRANCE? IBRANCE may cause serious side effects, including: Low white blood cell counts (neutropenia). Low white blood cell counts are very common when taking IBRANCE 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 IBRANCE, 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). IBRANCE 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 IBRANCE completely if your symptoms are severe. See "What are the possible side effects of IBRANCE?" for more information about side effects. | ||
What is IBRANCE? IBRANCE is a prescription medicine used: In adults to treat 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:
In adults with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative and with an abnormal phosphatidylinositol-3-kinase catalytic subunit alpha (PIK3CA) gene breast cancer that has spread to nearby tissue or lymph nodes (locally advanced), or to other parts of the body (metastatic) in combination with:
It is not known if IBRANCE is safe and effective in children. | ||
What should I tell my healthcare provider before taking IBRANCE? Before taking IBRANCE, tell your healthcare provider about all of your medical conditions, including if you:
Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. IBRANCE and other medicines may affect each other causing side effects. Know the medicines you take. Keep a list of them to show your healthcare provider or pharmacist when you get a new medicine. | ||
How should I take IBRANCE?
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What are the possible side effects of IBRANCE? IBRANCE may cause serious side effects. See "What is the most important information I should know about IBRANCE?" The most common side effects of IBRANCE when used with either letrozole or fulvestrant include:
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The most common side effects of IBRANCE when used in combination with inavolisib plus fulvestrant include:
IBRANCE 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 IBRANCE 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 IBRANCE. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. | ||
How should I store IBRANCE?
Keep IBRANCE and all medicines out of the reach of children. | ||
General information about the safe and effective use of IBRANCE Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use IBRANCE for a condition for which it was not prescribed. Do not give IBRANCE to other people, even if they have the same symptoms you have. It may harm them. You can ask your pharmacist or healthcare provider for more information about IBRANCE that is written for health professionals. | ||
What are the ingredients in IBRANCE? Active ingredient: palbociclib Inactive ingredients: 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. The printing ink contains: shellac, titanium dioxide, ammonium hydroxide, propylene glycol, and simethicone. ![]()
For more information, go to www.pfizer.com or call 1-800-438-1985. | ||
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