Ibrance Drug Information

• 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 ) 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 (125 mg/day) plus letrozole (2.5 mg/day) versus placebo plus letrozole was evaluated in PALOMA-2. The data described below reflect exposure to IBRANCE in 444 out of 666 patients with ER-positive, HER2-negative advanced breast cancer who received at least 1 dose of IBRANCE plus letrozole in PALOMA-2. 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 Grades % Grade 3 % Grade 4 % All Grades % Grade 3 % Grade 4 % Grading according to CTCAE 4.0. CTCAE=Common Terminology Criteria for Adverse Events; N=number of patients; N/A=not applicable; Infections and infestations Infections Infections includes all reported preferred terms (PTs) that are part of the System Organ Class Infections and infestations. 60 Most common infections (≥1%) include: nasopharyngitis, upper respiratory tract infection, urinary tract infection, oral herpes, sinusitis, rhinitis, bronchitis, influenza, pneumonia, gastroenteritis, conjunctivitis, herpes zoster, pharyngitis, cellulitis, cystitis, lower respiratory tract infection, tooth infection, gingivitis, skin infection, gastroenteritis viral, respiratory tract infection, respiratory tract infection viral, and folliculitis. 6 1 42 3 0 Blood and lymphatic system disorders Neutropenia 80 56 10 6 1 1 Leukopenia 39 24 1 2 0 0 Anemia 24 5 <1 9 2 0 Thrombocytopenia 16 1 <1 1 0 0 Metabolism and nutrition disorders Decreased appetite 15 1 0 9 0 0 Nervous system disorders Dysgeusia 10 0 0 5 0 0 Gastrointestinal disorders Stomatitis Stomatitis includes: aphthous stomatitis, cheilitis, glossitis, glossodynia, mouth ulceration, mucosal inflammation, oral pain, oral discomfort, oropharyngeal pain, and stomatitis. 30 1 0 14 0 0 Nausea 35 <1 0 26 2 0 Diarrhea 26 1 0 19 1 0 Vomiting 16 1 0 17 1 0 Skin and subcutaneous tissue disorders Alopecia 33 Grade 1 events – 30%; Grade 2 events – 3%. N/A N/A 16 Grade 1 events – 15%; Grade 2 events – 1%. N/A N/A Rash Rash includes the following PTs: rash, rash maculo-papular, rash pruritic, rash erythematous, rash papular, dermatitis, dermatitis acneiform, and toxic skin eruption. 18 1 0 12 1 0 Dry skin 12 0 0 6 0 0 General disorders and administration site conditions Fatigue 37 2 0 28 1 0 Asthenia 17 2 0 12 0 0 Pyrexia 12 0 0 9 0 0 Clinically relevant adverse reactions in <10% of patients who received IBRANCE plus letrozole in PALOMA-2 included epistaxis (9%), lacrimation increased (6%), dry eye (4.1%), vision blurred (3.6%), and febrile neutropenia (2.5%). Table 5. Laboratory Abnormalities in PALOMA-2 IBRANCE plus Letrozole (N=444) Placebo plus Letrozole (N=222) Laboratory Abnormality All Grades % Grade 3 % Grade 4 % All Grades % Grade 3 % Grade 4 % N=number of patients; WBC=white blood cells. WBC decreased 97 35 1 25 1 0 Blood creatinine increased 96 2 <1 91 0 0 Neutrophils decreased 95 56 12 20 1 1 Hemoglobin decreased 78 6 0 42 2 0 Platelets decreased 63 1 1 14 0 0 Aspartate aminotransferase increased 52 3 0 34 1 0 Alanine aminotransferase increased 43 2 <1 30 0 0 PALOMA-3: IBRANCE plus Fulvestrant Patients with HR-positive, HER2-negative advanced or metastatic breast cancer who have had disease progression on or after prior adjuvant or metastatic endocrine therapy The safety of IBRANCE (125 mg/day) plus fulvestrant (500 mg) versus placebo plus fulvestrant was evaluated in PALOMA-3. The data described below reflect exposure to IBRANCE in 345 out of 517 patients with HR-positive, HER2-negative advanced or metastatic breast cancer who received at least 1 dose of IBRANCE plus fulvestrant in PALOMA-3. The median duration of treatment for IBRANCE plus fulvestrant was 10.8 months while the median duration of treatment for placebo plus fulvestrant arm was 4.8 months. Dose reductions due to an adverse reaction of any grade occurred in 36% of patients receiving IBRANCE plus fulvestrant. No dose reduction was allowed for fulvestrant in PALOMA-3. Permanent discontinuation associated with an adverse reaction occurred in 19 of 345 (6%) patients receiving IBRANCE plus fulvestrant, and in 6 of 172 (3%) patients receiving placebo plus fulvestrant. Adverse reactions leading to discontinuation for those patients receiving IBRANCE plus fulvestrant included fatigue (0.6%), infections (0.6%), and thrombocytopenia (0.6%). The most common adverse reactions (≥10%) of any grade reported in patients in the IBRANCE plus fulvestrant arm by descending frequency were neutropenia, leukopenia, infections, fatigue, nausea, anemia, stomatitis, diarrhea, thrombocytopenia, vomiting, alopecia, rash, decreased appetite, and pyrexia. The most frequently reported Grade ≥3 adverse reactions (≥5%) in patients receiving IBRANCE plus fulvestrant in descending frequency were neutropenia and leukopenia. Adverse reactions (≥10%) reported in patients who received IBRANCE plus fulvestrant or placebo plus fulvestrant in PALOMA-3 are listed in Table 6. Table 6. Adverse Reactions (≥10%) in PALOMA-3 Adverse Reaction IBRANCE plus Fulvestrant (N=345) Placebo plus Fulvestrant (N=172) All Grades Grade 3 Grade 4 All Grades Grade 3 Grade 4 % % % % % % Grading according to CTCAE 4.0. CTCAE=Common Terminology Criteria for Adverse Events; N=number of patients; N/A=not applicable. Infections and infestations Infections Infections includes all reported preferred terms (PTs) that are part of the System Organ Class Infections and infestations. 47 Most common infections (≥1%) include: nasopharyngitis, upper respiratory infection, urinary tract infection, bronchitis, rhinitis, influenza, conjunctivitis, sinusitis, pneumonia, cystitis, oral herpes, respiratory tract infection, gastroenteritis, tooth infection, pharyngitis, eye infection, herpes simplex, and paronychia. 3 1 31 3 0 Blood and lymphatic system disorders Neutropenia 83 55 11 4 1 0 Leukopenia 53 30 1 5 1 1 Anemia 30 4 0 13 2 0 Thrombocytopenia 23 2 1 0 0 0 Metabolism and nutrition disorders Decreased appetite 16 1 0 8 1 0 Gastrointestinal disorders Nausea 34 0 0 28 1 0 Stomatitis Stomatitis includes: aphthous stomatitis, cheilitis, glossitis, glossodynia, mouth ulceration, mucosal inflammation, oral pain, oropharyngeal discomfort, oropharyngeal pain, stomatitis. 28 1 0 13 0 0 Diarrhea 24 0 0 19 1 0 Vomiting 19 1 0 15 1 0 Skin and subcutaneous tissue disorders Alopecia 18 Grade 1 events – 17%; Grade 2 events – 1%. N/A N/A 6 Grade 1 events – 6%. N/A N/A Rash Rash includes: rash, rash maculo-papular, rash pruritic, rash erythematous, rash papular, dermatitis, dermatitis acneiform, toxic skin eruption. 17 1 0 6 0 0 General disorders and administration site conditions Fatigue 41 2 0 29 1 0 Pyrexia 13 <1 0 5 0 0 Clinically relevant adverse reactions in <10% of patients who received IBRANCE plus fulvestrant in PALOMA-3 included asthenia (8%), dysgeusia (7%), epistaxis (7%), lacrimation increased (6%), dry skin (6%), vision blurred (6%), dry eye (3.8%), and febrile neutropenia (0.9%). Table 7. Laboratory Abnormalities in PALOMA-3 Laboratory Abnormality IBRANCE plus Fulvestrant (N=345) Placebo plus Fulvestrant (N=172) All Grades % Grade 3 % Grade 4 % All Grades % Grade 3 % Grade 4 % N=number of patients; WBC=white blood cells. WBC decreased 99 45 1 26 0 1 Neutrophils decreased 96 56 11 14 0 1 Blood creatinine increased 95 1 0 82 0 0 Hemoglobin decreased 78 3 0 40 2 0 Platelets decreased 62 2 1 10 0 0 Aspartate aminotransferase increased 43 4 0 48 4 0 Alanine aminotransferase increased 36 2 0 34 0 0 INAVO120: IBRANCE plus Inavolisib and Fulvestrant Adults with PIK3CA-mutated, HR-positive, HER2-negative, locally advanced or metastatic breast cancer whose disease progressed during or within 12 months of completing adjuvant endocrine therapy and who have not received prior systemic therapy for locally advanced or metastatic disease The safety of the combination of IBRANCE plus inavolisib and fulvestrant was evaluated in a randomized, double-blind, placebo-controlled study (INAVO120) in 324 patients with PIK3CA -mutated, HR-positive, HER2-negative, locally advanced or metastatic breast cancer [see Clinical Studies (14) ] . Patients received either IBRANCE 125 mg orally once daily for 21 consecutive days followed by 7 days off treatment to comprise a cycle of 28 days plus fulvestrant in combination with inavolisib (n=162) or placebo (n=162). The median duration of treatment for IBRANCE plus inavolisib and fulvestrant was 9 months (range: 0 to 39 months). Serious adverse reactions occurred in 24% of patients who received IBRANCE plus inavolisib and fulvestrant. Serious adverse reactions occurring in ≥1% of patients receiving IBRANCE plus inavolisib and fulvestrant included anemia (1.9%), diarrhea (1.2%), and urinary tract infection (1.2%). Fatal adverse reactions occurred in 3.7% of patients who received IBRANCE plus inavolisib and fulvestrant, including (0.6% each) acute coronary syndrome, cerebral hemorrhage, cerebrovascular accident, COVID-19 infection, and gastrointestinal hemorrhage. Permanent discontinuation of IBRANCE associated with an adverse reaction occurred in 8 of 162 (4.9%) patients receiving IBRANCE plus inavolisib and fulvestrant and in 0 of 162 patients receiving IBRANCE plus placebo and fulvestrant. Adverse reactions leading to discontinuation of IBRANCE in patients receiving IBRANCE plus inavolisib and fulvestrant were neutropenia, infections, alanine aminotransferase increased, gastric ulcer, intestinal perforation, hyperglycemia, type 2 diabetes mellitus, bone pain, musculoskeletal pain, transitional cell carcinoma, and acute kidney injury (0.6% each). Dose reduction of IBRANCE due to an adverse reaction occurred in 38% of patients receiving IBRANCE plus inavolisib and fulvestrant and in 30% of patients receiving IBRANCE plus placebo and fulvestrant. Adverse reactions leading to dose reductions of IBRANCE in ≥2% patients receiving IBRANCE plus inavolisib and fulvestrant were neutropenia (30%), leukopenia (6%), and thrombocytopenia (3.7%). Dose interruption of IBRANCE due to an adverse reaction occurred in 71% of patients receiving IBRANCE plus inavolisib and fulvestrant and in 61% of patients receiving IBRANCE plus placebo and fulvestrant. Adverse reactions leading to dose interruption of IBRANCE in ≥2% patients receiving IBRANCE plus inavolisib and fulvestrant were neutropenia (56%), infections (29%), leukopenia (12%), stomatitis (4.9%), anemia (6%), thrombocytopenia (4.3%), diarrhea (3.7%), pyrexia (3.1%), alanine aminotransferase increased (2.5%), hyperglycemia (2.5%), and nausea (2.5%). The most common (≥20%) adverse reactions, including laboratory abnormalities, were decreased neutrophils, decreased hemoglobin, increased fasting glucose, decreased platelets, decreased lymphocytes, stomatitis, diarrhea, decreased calcium, fatigue, decreased potassium, increased creatinine, increased alanine aminotransferase (ALT), nausea, decreased sodium, decreased magnesium, rash, decreased appetite, COVID-19 infection, and headache. Adverse reactions and laboratory abnormalities in INAVO120 are summarized in Table 8 and Table 9, respectively. Table 8. Adverse Reactions (≥10% with ≥5% [All Grades] or ≥2% [Grade 3-4] Higher Incidence in the IBRANCE plus inavolisib and fulvestrant Arm) in INAVO120 Adverse Reaction IBRANCE plus Inavolisib and Fulvestrant (N=162) IBRANCE plus Placebo and Fulvestrant (N=162) All Grades (%) Grade 3-4 (%) All Grades (%) Grade 3-4 (%) Gastrointestinal Disorders Stomatitis Includes aphthous ulcer, glossitis, glossodynia, lip ulceration, mouth ulceration, mucosal inflammation, and stomatitis. 51 6 No Grade 4 adverse reactions were observed. 27 0 Diarrhea 48 3.7 16 0 Nausea 28 0.6 17 0 Vomiting 15 0.6 4.9 1.2 General Disorders and Administration Site Conditions Fatigue 38 1.9 25 1.2 Skin and Subcutaneous Tissue Disorders Rash Includes other related terms. 26 0 19 0 Alopecia 19 0 6 0 Dry skin Includes dry skin, skin fissures, xerosis, and xeroderma. 13 0 4.3 0 Metabolism and Nutrition Disorders Decreased appetite 24 0 9 0 Infections and Infestations COVID-19 infection 23 1.9 10 0.6 Urinary tract infection 15 1.2 9 0 Nervous System Disorders Headache 22 0 14 0 Investigations Decreased weight 17 3.7 0.6 0 Clinically relevant adverse reactions occurring in <10% of patients who received the triplet combination of IBRANCE plus inavolisib and fulvestrant included abdominal pain, dry eye, dysgeusia, and dyspepsia. Table 9. Select Laboratory Abnormalities (≥10% with a ≥2% [All Grades or Grade 3-4] Higher Incidence in the IBRANCE plus Inavolisib and Fulvestrant Arm) in INAVO120 ALT=alanine aminotransferase. Laboratory Abnormality IBRANCE plus Inavolisib and Fulvestrant The denominator used to calculate the rate varied from 122 to 160 based on the number of patients with a baseline value and at least one post-treatment value. IBRANCE plus Placebo and Fulvestrant The denominator used to calculate the rate varied from 131 to 161 based on the number of patients with a baseline value and at least one post-treatment value. All Grades (%) Grade 3-4 (%) All Grades (%) Grade 3-4 (%) Hematology Neutrophils (total, absolute) decreased 95 82 97 79 Hemoglobin decreased 88 8 No Grade 4 laboratory abnormalities were observed. 85 2.5 Platelets decreased 8 16 71 3.7 Lymphocytes (absolute) decreased 72 9 68 14 Chemistry Glucose (fasting) increased Grading according to CTCAE version 4.03. 85 12 43 0 Calcium decreased 42 3.1 32 3.7 Potassium decreased 38 6 21 0.6 Creatinine increased 38 1.9 30 1.2 ALT increased 34 3.1 29 1.2 Sodium decreased 28 2.5 19 2.5 Magnesium decreased 27 0.6 21 0 Lipase (fasting) increased 16 1.4 7 0 Other Clinical Trials Experience The following adverse reaction has been reported following administration of IBRANCE: venous thromboembolism. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of IBRANCE. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Respiratory Disorders : Interstitial lung disease (ILD)/non-infectious pneumonitis Skin and Subcutaneous Tissue Disorders: Palmar-plantar erythrodysesthesia syndrome (PPES) Male Patients with HR-Positive, HER2-Negative Advanced or Metastatic Breast Cancer Based on limited data from postmarketing reports and electronic health records, the safety profile for men treated with IBRANCE is consistent with the safety profile in women treated with IBRANCE.

• 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) ] .

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 . 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.

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 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 or primary central nervous system (CNS) tumors. 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 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 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.