Ibrance

Indications and Usage ( 1.1 , 1.2 ) 6/2026 Dosage and Administration ( 2.1 , 2.2 ) 6/2026

1 INDICATIONS AND USAGE IBRANCE is a kinase inhibitor indicated: • for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer in combination with: o an aromatase inhibitor as initial endocrine-based therapy ( 1.1 ); or o fulvestrant in patients with disease progression following endocrine therapy. ( 1.1 ) • in combination with inavolisib and fulvestrant for the treatment of adult patients with endocrine-resistant, PIK3CA -mutated, HR-positive, HER2-negative, locally advanced or metastatic breast cancer, as detected by an FDA-authorized test, following recurrence on or after completing adjuvant endocrine therapy. ( 1.1 ) • in combination with trastuzumab, with or without pertuzumab, and endocrine therapy for the maintenance treatment of adult patients with HR-positive, HER2 positive locally advanced or metastatic breast cancer following induction treatment. ( 1.2 ) 1.1 HER2-Negative Metastatic Breast Cancer IBRANCE is indicated for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer in combination with: • an aromatase inhibitor as initial endocrine-based therapy; or • fulvestrant in patients with disease progression following endocrine therapy. IBRANCE is indicated in combination with inavolisib and fulvestrant for the treatment of adult patients with endocrine-resistant, PIK3CA -mutated, HR-positive, HER2-negative, locally advanced or metastatic breast cancer, as detected by an FDA- authorized test, following recurrence on or after completing adjuvant endocrine therapy. 1.2 HER2-Positive Metastatic Breast Cancer IBRANCE is indicated in combination with trastuzumab, with or without pertuzumab, and endocrine therapy for the maintenance treatment of adult patients with HR-positive, HER2-positive locally advanced or metastatic breast cancer following induction treatment.

2 DOSAGE AND ADMINISTRATION • Recommended starting dose: 125 mg once daily taken with food for 21 days followed by 7 days off treatment. ( 2.1 ) • Dosing interruption and/or dose reductions are recommended based on individual safety and tolerability. ( 2.2 ) 2.1 Recommended Dosage The recommended dosage of IBRANCE is a 125 mg capsule taken orally once daily for 21 consecutive days followed by 7 days off treatment to comprise a complete cycle of 28 days. IBRANCE capsule should be taken with food [see Clinical Pharmacology (12.3) ] . Advise patients to take their dose of IBRANCE at approximately the same time each day. If the patient vomits or misses a dose, an additional dose should not be taken. The next prescribed dose should be taken at the usual time. IBRANCE capsules should be swallowed whole (do not chew, crush, or open them prior to swallowing). Capsules should not be ingested if they are broken, cracked, or otherwise not intact. Pre/perimenopausal women treated with the combination IBRANCE plus an aromatase inhibitor or fulvestrant, IBRANCE plus inavolisib and fulvestrant therapy , or IBRANCE plus trastuzumab, with or without pertuzumab, plus endocrine therapy should also be treated with luteinizing hormone-releasing hormone (LHRH) agonists according to current clinical practice standards. For men treated with combination IBRANCE plus aromatase inhibitor, IBRANCE plus inavolisib and fulvestrant therapy, or IBRANCE plus trastuzumab, with or without pertuzumab, plus endocrine therapy, consider treatment with an LHRH agonist according to current clinical practice standards. Refer to the Prescribing Information for recommended dosage for endocrine therapy, inavolisib, trastuzumab and pertuzumab administered in combination with IBRANCE. 2.2 Dose Modification The recommended dose modifications for adverse reactions are listed in Tables 1, 2, and 3. Table 1. Recommended Dose Modification for Adverse Reactions Dose Level Dose Recommended starting dose 125 mg/day First dose reduction 100 mg/day Second dose reduction 75 mg/day If further dose reduction below 75 mg/day is required, discontinue. Table 2. Dose Modification and Management – Hematologic Toxicities Table applies to all hematologic adverse reactions except lymphopenia (unless associated with clinical events, e.g., opportunistic infections). Grading according to CTCAE 4.0. CTCAE=Common Terminology Criteria for Adverse Events; LLN=lower limit of normal. Monitor complete blood counts prior to the start of IBRANCE therapy and at the beginning of each cycle, as well as on Day 15 of the first 2 cycles, and as clinically indicated. For patients who experience a maximum of Grade 1 or 2 neutropenia in the first 6 cycles, monitor complete blood counts for subsequent cycles every 3 months, prior to the beginning of a cycle and as clinically indicated. CTCAE Grade Dose Modifications Grade 1 or 2 No dose adjustment is required. Grade 3 Day 1 of cycle : Withhold IBRANCE, repeat complete blood count monitoring within 1 week. When recovered to Grade ≤2, start the next cycle at the same dose . Day 15 of first 2 cycles : If Grade 3 on Day 15, continue IBRANCE at current dose to complete cycle and repeat complete blood count on Day 22. If Grade 4 on Day 22, see Grade 4 dose modification guidelines below. Consider dose reduction in cases of prolonged (>1 week) recovery from Grade 3 neutropenia or recurrent Grade 3 neutropenia on Day 1 of subsequent cycles. Grade 3 neutropenia Absolute neutrophil count (ANC): Grade 1: ANC < LLN - 1500/mm 3 ; Grade 2: ANC 1000 - <1500/mm 3 ; Grade 3: ANC 500 - <1000/mm 3 ; Grade 4: ANC <500/mm 3 . with fever ≥38.5 oC and/or infection At any time : Withhold IBRANCE until recovery to Grade ≤2. Resume at the next lower dose . Grade 4 At any time : Withhold IBRANCE until recovery to Grade ≤2. Resume at the next lower dose . Table 3. Dose Modification and Management – Non-Hematologic Toxicities CTCAE Grade Dose Modifications Grading according to CTCAE 4.0. CTCAE= …

3 DOSAGE FORMS AND STRENGTHS 125 mg capsules: opaque, hard gelatin capsules, size 0, with caramel cap and body, printed with white ink "Pfizer" on the cap, "PBC 125" on the body. 100 mg capsules: opaque, hard gelatin capsules, size 1, with caramel cap and light orange body, printed with white ink "Pfizer" on the cap, "PBC 100" on the body. 75 mg capsules: opaque, hard gelatin capsules, size 2, with light orange cap and body, printed with white ink "Pfizer" on the cap, "PBC 75" on the body. Capsules: 125 mg, 100 mg, and 75 mg. ( 3 )

4 CONTRAINDICATIONS None. None. ( 4 )

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: • Neutropenia [see Warnings and Precautions (5.1) ] • ILD/Pneumonitis [see Warnings and Precautions (5.2) ] Most common adverse reactions (incidence ≥20%) in combination with either letrozole or fulvestrant, including laboratory abnormalities, were white blood cell count decreased, neutrophils decreased, blood creatinine increased, hemoglobin decreased, platelets decreased, infections, aspartate aminotransferase increased, alanine aminotransferase increased, fatigue, nausea, stomatitis, diarrhea, and alopecia. ( 6.1 ) The most common adverse reactions (incidence ≥20%) in combination with inavolisib and fulvestrant, including laboratory abnormalities, were neutrophils decreased, hemoglobin decreased, fasting glucose increased, platelets decreased, lymphocytes decreased, stomatitis, diarrhea, calcium decreased, fatigue, potassium decreased, creatinine increased, alanine aminotransferase (ALT) increased, nausea, sodium decreased, magnesium decreased, rash, decreased appetite, COVID-19 infection, and headache. ( 6.1 ) The most common adverse reactions (incidence ≥20%) in combination with trastuzumab, with or without pertuzumab, and endocrine therapy, including laboratory abnormalities, were white blood cell decreased, neutrophil count decreased, creatinine increased, hemoglobin decreased, diarrhea, infections, platelet count decreased, stomatitis, aspartate aminotransferase increased, decreased calcium, alanine aminotransferase increased, decreased potassium, fatigue, alkaline phosphatase increased, nausea, asthenia, headache, rash, pruritus, and muscle spasms. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. PALOMA-2: IBRANCE plus Letrozole Patients with estrogen receptor (ER)-positive, HER2-negative advanced or metastatic breast cancer for initial endocrine-based therapy The safety of IBRANCE plus letrozole was evaluated in a randomized, double-blind trial (PALOMA-2) in 666 patients with ER-positive, HER2-negative advanced breast cancer [see Clinical Studies (14.1) ] . The median duration of treatment for IBRANCE plus letrozole was 19.8 months while the median duration of treatment for placebo plus letrozole arm was 13.8 months. Dose reductions due to an adverse reaction of any grade occurred in 36% of patients receiving IBRANCE plus letrozole. No dose reduction was allowed for letrozole in PALOMA-2. Permanent discontinuation associated with an adverse reaction occurred in 43 of 444 (10%) patients receiving IBRANCE plus letrozole and in 13 of 222 (6%) patients receiving placebo plus letrozole. Adverse reactions leading to permanent discontinuation for patients receiving IBRANCE plus letrozole included neutropenia (1.1%) and alanine aminotransferase increase (0.7%). The most common adverse reactions (≥10%) of any grade reported in patients in the IBRANCE plus letrozole arm by descending frequency were neutropenia, infections, leukopenia, fatigue, nausea, alopecia, stomatitis, diarrhea, anemia, rash, asthenia, thrombocytopenia, vomiting, decreased appetite, dry skin, pyrexia, and dysgeusia. The most frequently reported Grade ≥3 adverse reactions (≥5%) in patients receiving IBRANCE plus letrozole by descending frequency were neutropenia, leukopenia, infections, and anemia. Adverse reactions (≥10%) reported in patients who received IBRANCE plus letrozole or placebo plus letrozole in PALOMA-2 are listed in Table 4. Table 4. Adverse Reactions (≥10%) in PALOMA-2 IBRANCE plus Letrozole (N=444) Placebo plus Letrozole (N=222) Adverse Reaction All Gra …

7 DRUG INTERACTIONS Palbociclib is primarily metabolized by CYP3A and sulfotransferase (SULT) enzyme SULT2A1. In vivo, palbociclib is a time-dependent inhibitor of CYP3A. • CYP3A Inhibitors: Avoid concurrent use of IBRANCE with strong CYP3A inhibitors. If the strong inhibitor cannot be avoided, reduce the IBRANCE dose. ( 2.2 , 7.1 ) • CYP3A Inducers: Avoid concurrent use of IBRANCE with strong CYP3A inducers. ( 7.2 ) • CYP3A Substrates: The dose of sensitive CYP3A4 substrates with narrow therapeutic indices may need to be reduced when given concurrently with IBRANCE. ( 7.3 ) 7.1 Agents That May Increase Palbociclib Plasma Concentrations Effect of CYP3A Inhibitors Coadministration of a strong CYP3A inhibitor (itraconazole) increased the plasma exposure of palbociclib in healthy subjects by 87%. Avoid concomitant use of strong CYP3A inhibitors (e.g., clarithromycin, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, and voriconazole). Avoid grapefruit or grapefruit juice during IBRANCE treatment. If coadministration of IBRANCE with a strong CYP3A inhibitor cannot be avoided, reduce the dose of IBRANCE [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3) ] . 7.2 Agents That May Decrease Palbociclib Plasma Concentrations Effect of CYP3A Inducers Coadministration of a strong CYP3A inducer (rifampin) decreased the plasma exposure of palbociclib in healthy subjects by 85%. Avoid concomitant use of strong CYP3A inducers (e.g., phenytoin, rifampin, carbamazepine, enzalutamide, and St John's Wort) [see Clinical Pharmacology (12.3) ] . 7.3 Drugs That May Have Their Plasma Concentrations Altered by Palbociclib Coadministration of midazolam with multiple doses of IBRANCE increased the midazolam plasma exposure by 61%, in healthy subjects, compared to administration of midazolam alone. The dose of the sensitive CYP3A substrate with a narrow therapeutic index (e.g., alfentanil, cyclosporine, dihydroergotamine, ergotamine, everolimus, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus) may need to be reduced, as IBRANCE may increase its exposure [see Clinical Pharmacology (12.3) ] .

8 USE IN SPECIFIC POPULATIONS • Lactation: Advise not to breastfeed. ( 8.2 ) 8.1 Pregnancy 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. 8.2 Lactation 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. 8.3 Females and Males of Reproductive Potential 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) ] . 8.4 Pediatric Use 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 15 m …

12.1 Mechanism of Action Palbociclib is an inhibitor of cyclin-dependent kinases (CDK) 4 and 6. Cyclin D1 and CDK4/6 are downstream of signaling pathways which lead to cellular proliferation. In vitro, palbociclib reduced cellular proliferation of estrogen receptor (ER)-positive breast cancer cell lines by blocking progression of the cell from G1 into S phase of the cell cycle. Treatment of breast cancer cell lines with the combination of palbociclib and antiestrogens leads to decreased retinoblastoma (Rb) protein phosphorylation resulting in reduced E2F expression and signaling, and increased growth arrest compared to treatment with each drug alone. In vitro treatment of ER-positive breast cancer cell lines with the combination of palbociclib and antiestrogens led to increased cell senescence compared to each drug alone, which was sustained for up to 6 days following palbociclib removal and was greater if antiestrogen treatment was continued. In vivo studies using a patient-derived ER-positive breast cancer xenograft model demonstrated that the combination of palbociclib and letrozole increased the inhibition of Rb phosphorylation, downstream signaling, and tumor growth compared to each drug alone. Human bone marrow mononuclear cells treated with palbociclib in the presence or absence of an anti-estrogen in vitro did not become senescent and resumed proliferation following palbociclib withdrawal.

11 DESCRIPTION IBRANCE capsules for oral administration contain 125 mg, 100 mg, or 75 mg of palbociclib, a kinase inhibitor. The molecular formula for palbociclib is C 24 H 29 N 7 O 2 . The molecular weight is 447.54 daltons. The chemical name is 6-acetyl-8-cyclopentyl-5-methyl-2-{[5-(piperazin-1-yl)pyridin-2-yl]amino}pyrido[2,3- d ]pyrimidin-7(8 H )-one, and its structural formula is: Palbociclib is a yellow to orange powder with pKa of 7.4 (the secondary piperazine nitrogen) and 3.9 (the pyridine nitrogen). At or below pH 4, palbociclib behaves as a high-solubility compound. Above pH 4, the solubility of the drug substance reduces significantly. 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. Chemical Structure

16 HOW SUPPLIED/STORAGE AND HANDLING IBRANCE is supplied in the following strengths and package configurations: IBRANCE Capsules Package Configuration Capsule Strength (mg) NDC Capsule Description Bottles of 21 capsules 125 NDC 0069-0189-21 opaque, hard gelatin capsules, size 0, with caramel cap and body, printed with white ink "Pfizer" on the cap, "PBC 125" on the body Bottles of 21 capsules 100 NDC 0069-0188-21 opaque, hard gelatin capsules, size 1, with caramel cap and light orange body, printed with white ink "Pfizer" on the cap, "PBC 100" on the body Bottles of 21 capsules 75 NDC 0069-0187-21 opaque, hard gelatin capsules, size 2, with light orange cap and body, printed with white ink "Pfizer" on the cap, "PBC 75" on the body Store at 20 °C to 25 °C (68 °F to 77 °F); excursions permitted between 15 °C to 30 °C (59 °F to 86 °F) [see USP Controlled Room Temperature] .