IBRANCE- palbociclib_capsule
Function and Efficacy
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. Cardiac Electrophysiology The effect of palbociclib on the QT interval corrected for heart rate (QTc) was evaluated using time-matched electrocardiograms (ECGs) evaluating the change from baseline and corresponding pharmacokinetic data in 77 patients with breast cancer. Palbociclib had no large effect on QTc (i. , >20 ms) at 125 mg once daily for 21 consecutive days followed by 7 days off treatment to comprise a complete cycle of 28 days. The pharmacokinetics (PK) of palbociclib were characterized in patients with solid tumors including advanced breast cancer and in healthy subjects. Absorption The mean maximum observed concentration (C max max max Food effect INF max Distribution Binding of palbociclib to human plasma proteins in vitro was approximately 85%, with no concentration dependence over the concentration range of 500 ng/mL to 5000 ng/mL. The mean fraction unbound (f u u z Metabolism In vitro and in vivo studies indicated that palbociclib undergoes hepatic metabolism in humans. Following oral administration of a single 125 mg dose of [ 14 Elimination The geometric mean apparent oral clearance (CL/F) of palbociclib was 63. 1 L/hr (29% CV), and the mean (+/- standard deviation) plasma elimination half-life was 29 (+/-5) hours in patients with advanced breast cancer. In 6 healthy male subjects given a single oral dose of [ 14 Age, Gender, and Body Weight Based on a population pharmacokinetic analysis in 183 patients with cancer (50 male and 133 female patients, age range from 22 to 89 years, and body weight range from 37. 9 to 123 kg), gender had no effect on the exposure of palbociclib, and age and body weight had no clinically important effect on the exposure of palbociclib. Pediatric Population Pharmacokinetics of IBRANCE have not been evaluated in patients <18 years of age. Hepatic Impairment Data from a pharmacokinetic trial in subjects with varying degrees of hepatic impairment indicate that palbociclib unbound AUC INF max Renal Impairment Data from a pharmacokinetic trial in subjects with varying degrees of renal impairment indicate that palbociclib AUC INF max Drug Interactions In vitro data indicate that CYP3A and SULT enzyme SULT2A1 are mainly involved in the metabolism of palbociclib. Palbociclib is a weak time-dependent inhibitor of CYP3A following daily 125 mg dosing to steady state in humans. In vitro, palbociclib is not an inhibitor of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, and 2D6, and is not an inducer of CYP1A2, 2B6, 2C8, and 3A4 at clinically relevant concentrations. CYP3A Inhibitors: INF max [see Drug Interactions (7. 1 CYP3A Inducers: INF max INF max [see Drug Interactions (7. 2) CYP3A Substrates: INF max [see Drug Interactions (7. 3) Gastric pH Elevating Medications: max INF INF max Letrozole: Fulvestrant: Goserelin: Anastrozole or Exemestane: Effect of Palbociclib on Transporters: Effect of Transporters on Palbociclib:.
Indication
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: 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: 1 1.
Usage and Dosage
IBRANCE capsules are taken orally with food in combination with an aromatase inhibitor or fulvestrant. ( 2 2. 2 The recommended dose 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 should be taken with food [see Clinical Pharmacology (12. 3) Administer the recommended dose of an aromatase inhibitor when given with IBRANCE. Please refer to the Full Prescribing Information for the aromatase inhibitor being used. When given with IBRANCE, the recommended dose of fulvestrant is 500 mg administered on Days 1, 15, 29, and once monthly thereafter. Please refer to the Full Prescribing Information of fulvestrant. Patients should be encouraged 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 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 therapy, consider treatment with an LHRH agonist according to current clinical practice standards. The recommended dose modifications for adverse reactions are listed in Tables 1, 2, and 3. 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. Dose Modification and Management en dash Hematologic Toxicities Table applies to all hematologic adverse reactions except lymphopenia (unless associated with clinical events, e. , opportunistic infections). Grading according to CTCAE 4. 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. CTCAE Grade Dose Modifications Grade 1 or 2 No dose adjustment is required. Grade 3 Day 1 of cycle same dose Day 15 of first 2 cycles Grade 4 Grade 3 neutropenia Absolute neutrophil count (ANC): Grade 1: ANC < LLN - 1500/mm 3 3 3 3 At any time next lower dose Grade 4 At any time next lower dose Table 3. Dose Modification and Management en dash Non-Hematologic Toxicities CTCAE Grade Dose Modifications Grading according to CTCAE 4. Grade 1 or 2 No dose adjustment is required. Grade >=3 non-hematologic toxicity (if persisting despite optimal medical treatment) Withhold until symptoms resolve to: Resume at the next lower dose Permanently discontinue IBRANCE in patients with severe interstitial lung disease (ILD)/pneumonitis. Refer to the Full Prescribing Information for coadministered endocrine therapy dose adjustment guidelines in the event of toxicity and other relevant safety information or contraindications. Dose Modifications for Use With Strong CYP3A Inhibitors Avoid concomitant use of strong CYP3A inhibitors and consider an alternative concomitant medication with no or minimal CYP3A inhibition. If patients must be coadministered a strong CYP3A inhibitor, reduce the IBRANCE dose to 75 mg once daily. If the strong inhibitor is discontinued, increase the IBRANCE dose (after 3 to 5 half-lives of the inhibitor) to the dose used prior to the initiation of the strong CYP3A inhibitor [see Drug Interactions (7. 1) Clinical Pharmacology (12. 3) Dose Modifications for Hepatic Impairment No dose adjustment is required for 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 Use in Specific Populations (8. 6) Clinical Pharmacology (12.
Label
Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling: [see Warnings and Precautions (5. 1) [see Warnings and Precautions (5. 2) Most common adverse reactions (incidence >=10%) were neutropenia, infections, leukopenia, fatigue, nausea, stomatitis, anemia, alopecia, diarrhea, thrombocytopenia, rash, vomiting, decreased appetite, asthenia, and pyrexia. ( 6 To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www. gov/medwatch Because clinical trials are conducted under varying conditions, the adverse reaction rates observed cannot be directly compared to rates in other trials and may not reflect the rates observed in clinical 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. 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 (9. 7%) patients receiving IBRANCE plus letrozole and in 13 of 222 (5. 9%) 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. 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. 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. 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 en dash 30%; Grade 2 events en dash 3%. N/A N/A 16 Grade 1 events en dash 15%; Grade 2 events en dash 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 Additional adverse reactions occurring at an overall incidence of <10. 0% of patients receiving IBRANCE plus letrozole in PALOMA-2 included alanine aminotransferase increased (9. 9%), aspartate aminotransferase increased (9. 7%), epistaxis (9. 2%), lacrimation increased (5. 6%), dry eye (4. 1%), vision blurred (3. 6%), and febrile neutropenia (2. 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 Neutrophils decreased 95 56 12 20 1 1 Anemia 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. 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. 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. 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. 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 en dash 17%; Grade 2 events en dash 1%. N/A N/A 6 Grade 1 events en dash 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 Additional adverse reactions occurring at an overall incidence of <10. 0% of patients receiving IBRANCE plus fulvestrant in PALOMA-3 included asthenia (7. 5%), aspartate aminotransferase increased (7. 5%), dysgeusia (6. 7%), epistaxis (6. 7%), lacrimation increased (6. 4%), dry skin (6. 1%), alanine aminotransferase increased (5. 8%), vision blurred (5. 8%), dry eye (3. 8%), and febrile neutropenia (0. 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 Anemia 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 Other Clinical Trials Experience The following adverse reaction has been reported following administration of IBRANCE: venous thromboembolism. 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 Skin and Subcutaneous Tissue Disorders: 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.
Special Population Medication
2 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) [see Data The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%en dash4% and 15%en dash20%, 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)] Contraception Females IBRANCE can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8. 1) 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 efficacy of IBRANCE in pediatric patients have not been studied. 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) INF max [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 (AUC INF max [see Clinical Pharmacology (12.
Drug Interactions
Palbociclib is primarily metabolized by CYP3A and sulfotransferase (SULT) enzyme SULT2A1. In vivo, palbociclib is a time-dependent inhibitor of CYP3A. 3 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. , 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) Clinical Pharmacology (12. 3) 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. , phenytoin, rifampin, carbamazepine, enzalutamide, and St John's Wort) [see Clinical Pharmacology (12. 3) 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. , 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.
Other Information
OVERDOSAGE
There is no known antidote for IBRANCE. The treatment of overdose of IBRANCE should consist of general supportive measures.
NONCLINICAL TOXICOLOGY
Palbociclib was assessed for carcinogenicity in a 6-month transgenic mouse study and in a 2-year rat study. Oral administration of palbociclib for 2 years resulted in an increased incidence of microglial cell tumors in the central nervous system of male rats at a dose of 30 mg/kg/day (approximately 8 times the human clinical exposure based on AUC). There were no neoplastic findings in female rats at doses up to 200 mg/kg/day (approximately 5 times the human clinical exposure based on AUC). Oral administration of palbociclib to male and female rasH2 transgenic mice for 6 months did not result in increased incidence of neoplasms at doses up to 60 mg/kg/day. Palbociclib was aneugenic in Chinese Hamster Ovary cells in vitro and in the bone marrow of male rats at doses >=100 mg/kg/day for 3 weeks. Palbociclib was not mutagenic in an in vitro bacterial reverse mutation (Ames) assay and was not clastogenic in the in vitro human lymphocyte chromosome aberration assay. In a fertility study in female rats, palbociclib did not affect mating or fertility at any dose up to 300 mg/kg/day (approximately 4 times human clinical exposure based on AUC) and no adverse effects were observed in the female reproductive tissues in repeat-dose toxicity studies up to 300 mg/kg/day in the rat and 3 mg/kg/day in the dog (approximately 6 times and similar to human exposure [AUC], at the recommended dose, respectively). The adverse effects of palbociclib on male reproductive function and fertility were observed in the repeat-dose toxicology studies in rats and dogs and a male fertility study in rats. In repeat-dose toxicology studies, palbociclib-related findings in the testis, epididymis, prostate, and seminal vesicle at >=30 mg/kg/day in rats and >=0.2 mg/kg/day in dogs included decreased organ weight, atrophy or degeneration, hypospermia, intratubular cellular debris, and decreased secretion. Partial reversibility of male reproductive organ effects was observed in the rat and dog following a 4- and 12-week non-dosing period, respectively. These doses in rats and dogs resulted in approximately >=10 and 0.1 times, respectively, the exposure [AUC] in humans at the recommended dose. In the fertility and early embryonic development study in male rats, palbociclib caused no effects on mating but resulted in a slight decrease in fertility in association with lower sperm motility and density at 100 mg/kg/day with projected exposure levels [AUC] of 20 times the exposure in humans at the recommended dose.
CLINICAL STUDIES
PALOMA-2: IBRANCE plus Letrozole Patients with ER-positive, HER2-negative advanced or metastatic breast cancer for initial endocrine based therapy PALOMA-2 was an international, randomized, double-blind, parallel-group, multicenter study of IBRANCE plus letrozole versus placebo plus letrozole conducted in postmenopausal women with ER-positive, HER2-negative advanced breast cancer who had not received previous systemic treatment for their advanced disease. A total of 666 patients were randomized 2:1 to IBRANCE plus letrozole or placebo plus letrozole. Randomization was stratified by disease site (visceral versus non-visceral), disease-free interval (de novo metastatic versus <=12 months from the end of adjuvant treatment to disease recurrence versus >12 months from the end of adjuvant treatment to disease recurrence), and nature of prior (neo)adjuvant anticancer therapies (prior hormonal therapies versus no prior hormonal therapy). IBRANCE was given orally at a dose of 125 mg daily for 21 consecutive days followed by 7 days off treatment. Patients received study treatment until objective disease progression, symptomatic deterioration, unacceptable toxicity, death, or withdrawal of consent, whichever occurred first. The major efficacy outcome of the study was investigator-assessed progression-free survival (PFS) evaluated according to Response Evaluation Criteria in Solid Tumors Version 1. Additional efficacy outcome measures were confirmed overall response rate (ORR) as assessed by the investigator according to RECIST Version 1. 1 and overall survival (OS). Patients enrolled in this study had a median age of 62 years (range 28 to 89). The majority of patients were White (78%), and most patients had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1 (98%). Forty-eight percent of patients had received chemotherapy and 56% had received antihormonal therapy in the neoadjuvant or adjuvant setting prior to their diagnosis of advanced breast cancer. Thirty-seven percent of patients had no prior systemic therapy in the neoadjuvant or adjuvant setting. The majority of patients (97%) had metastatic disease. Twenty-three percent of patients had bone only disease, and 49% of patients had visceral disease. Major efficacy results from PALOMA-2 are summarized in Table 8 and Figure 1. Consistent results were observed across patient subgroups of disease-free interval (DFI), disease site, and prior therapy. The treatment effect of the combination on PFS was also supported by an independent review of radiographs. Based on the prespecified final OS analysis conducted after 435 events, OS was not statistically significant. Efficacy Results en dash PALOMA-2 IBRANCE plus Letrozole Placebo plus Letrozole CI=confidence interval; ITT=Intent-to-Treat; N=number of patients; NE=not estimable; OS=overall survival; PFS=progression-free survival. Progression-free survival for ITT (investigator assessment) N=444 N=222 Number of PFS events (%) 194 (43. 7) Median progression-free survival (months, 95% CI) 24. 1) Hazard ratio (95% CI) and p-value 0. 718) Cox proportional hazards model stratified by disease site (visceral vs. non-visceral) per randomization. Stratified log-rank test one-sided p-value. Objective Response for patients with measurable disease (investigator assessment) N=338 N=171 Objective response rate Response is based on confirmed responses. 2) Overall survival for ITT N=444 N=222 Number of OS events (%) 287 (64. 7) Median OS (months, 95% CI) 53. 4) Hazard ratio (95% CI) and p‑value 0. 124) Figure 1. Kaplan-Meier Plot of Progression-Free Survival en dash PALOMA-2 (Investigator Assessment, Intent-to-Treat Population) LET=letrozole; PAL=palbociclib; PBO=placebo. Figure 1 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 PALOMA-3 was an international, randomized, double-blind, parallel group, multicenter study of IBRANCE plus fulvestrant versus placebo plus fulvestrant conducted in women with HR-positive, HER2-negative advanced breast cancer, regardless of their menopausal status, whose disease progressed on or after prior endocrine therapy. A total of 521 pre/postmenopausal women were randomized 2:1 to IBRANCE plus fulvestrant or placebo plus fulvestrant and stratified by documented sensitivity to prior hormonal therapy, menopausal status at study entry (pre/peri versus postmenopausal), and presence of visceral metastases. Pre/perimenopausal women were enrolled in the study and received the LHRH agonist goserelin for at least 4 weeks prior to and for the duration of PALOMA-3. Patients continued to receive assigned treatment until objective disease progression, symptomatic deterioration, unacceptable toxicity, death, or withdrawal of consent, whichever occurred first. The major efficacy outcome of the study was investigator-assessed PFS evaluated according to RECIST 1. Patients enrolled in this study had a median age of 57 years (range 29 to 88). The majority of patients on study were White (74%), all patients had an ECOG PS of 0 or 1, and 80% were postmenopausal. All patients had received prior systemic therapy, and 75% of patients had received a previous chemotherapy regimen. Twenty-five percent of patients had received no prior therapy in the metastatic disease setting, 60% had visceral metastases, and 23% had bone only disease. The results from the investigator-assessed PFS and final OS from PALOMA-3 are summarized in Table 9. The relevant Kaplan-Meier plots are shown in Figures 2 and 3, respectively. Consistent PFS results were observed across patient subgroups of disease site, sensitivity to prior hormonal therapy, and menopausal status. After a median follow-up time of 45 months, the final OS results were not statistically significant. Efficacy Results en dash PALOMA-3 IBRANCE plus Fulvestrant Placebo plus Fulvestrant CI=confidence interval; ITT=Intent-to-Treat; N=number of patients; OS=overall survival; PFS=progression-free survival. Progression-free survival for ITT (investigator assessment) N=347 N=174 Number of PFS events (%) 145 (41. 5) Median PFS (months, 95% CI) 9. 6) Hazard ratio (95% CI) and p-value 0. 0001 Objective Response for patients with measurable disease (investigator assessment) N=267 N=138 Objective response rate Responses are based on confirmed responses. 3) Overall survival for ITT N=347 N=174 Number of OS events (%) 201 (57. 6) Median OS (months, 95% CI) 34. 0857 Not statistically significant at the pre-specified 2-sided alpha level of 0. 2-sided p-value from the log-rank test stratified by the presence of visceral metastases and sensitivity to prior endocrine therapy per randomization. Kaplan-Meier Plot of Progression-Free Survival en dash PALOMA-3 (Investigator Assessment, Intent-to-Treat Population) FUL=fulvestrant; PAL=palbociclib; PBO=placebo. Kaplan-Meier Plot of Overall Survival (Intent-to-Treat Population) en dash PALOMA-3 FUL=fulvestrant; PAL=palbociclib; PBO=placebo. Figure 2 Figure 3.