Risk Summary
Based on findings from animal studies, VYNDAQEL and VYNDAMAX may cause fetal harm when administered to a pregnant woman. However, limited available human data with VYNDAQEL use in pregnant women (at a dose of 20 mg per day) have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal reproductive studies, oral administration of tafamidis meglumine to pregnant rabbits during organogenesis resulted in adverse effects on development (embryofetal mortality, fetal body weight reduction and fetal malformation) at a dosage providing approximately 9 times the human exposure (AUC) at the maximum recommended human dose (MRHD) of VYNDAQEL (80 mg), and increased incidence of fetal skeletal variation at a dosage providing equivalent human exposure (AUC) at the MRHD. Postnatal mortality, growth retardation, and impaired learning and memory were observed in offspring of pregnant rats administered tafamidis meglumine during gestation and lactation at a dosage approximately 2 times the MRHD based on body surface area (mg/m2) (see Data). Advise pregnant women of the potential risk to a fetus. Report pregnancies to the Pfizer reporting line at 1-800-438-1985.
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defects, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Data
Animal Data
In pregnant rats, oral administration of tafamidis meglumine (0, 15, 30, and 45 mg/kg/day) throughout organogenesis resulted in decreased fetal body weights at ≥30 mg/kg/day (approximately 10 times the human exposure at the MRHD based on AUC). The no-observed-adverse-effect-level (NOAEL) for embryofetal development in rats was 15 mg/kg/day (approximately 7 times the human exposure at the MRHD based on AUC).
In pregnant rabbits, oral administration of tafamidis meglumine (0, 0.5, 2, and 8 mg/kg/day) throughout organogenesis resulted in increased embryofetal mortality, reduced fetal body weights, and an increased incidence of fetal malformations at 8 mg/kg/day (approximately 9 times the human exposure at the MRHD based on AUC), which was also maternally toxic. Increased incidences of fetal skeletal variations were observed at doses ≥0.5 mg/kg/day (approximately equivalent to the human exposure at the MRHD based on AUC).
In the pre- and postnatal study, pregnant rats received oral administration of tafamidis meglumine at doses of 0, 5, 15, or 30 mg/kg/day throughout pregnancy and lactation (Gestation Day 7 to Lactation Day 20). Decreased survival and body weights, delayed male sexual maturation and neurobehavioral effects (learning and memory impairment) were observed in the offspring of dams treated at 15 mg/kg/day (approximately 2 times the MRHD on a mg/m2 basis). The NOAEL for pre- and postnatal development in rats was 5 mg/kg/day (approximately equivalent to the MRHD on a mg/m2 basis).
Risk Summary
There are no available data on the presence of tafamidis in human milk, the effect on the breastfed infant, or the effect on milk production. Tafamidis is present in rat milk (see Data). When a drug is present in animal milk, it is likely the drug will be present in human milk. Based on findings from animal studies which suggest the potential for serious adverse reactions in the breastfed infant, advise patients that breastfeeding is not recommended during treatment with VYNDAQEL or VYNDAMAX.
Data
Pregnant and lactating female rats were administered repeated daily oral doses of tafamidis meglumine (15 mg/kg/day) followed by a single oral gavage dose of 14C-tafamidis meglumine on Lactation Day 4 or 12. Radioactivity was observed in milk by 1 hour post-dose and increased thereafter. The ratio of the highest radioactivity associated with 14C tafamidis meglumine in milk (8 hours post-dose) vs. plasma (1 hour post-dose) was approximately 1.6 on Day 12, indicating tafamidis meglumine is transferred to milk after oral administration.
Contraception
Females
Based on findings from animal studies, VYNDAQEL and VYNDAMAX may cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)]. Consider pregnancy planning and prevention for females of reproductive potential.
Cardiac Electrophysiology
At approximately 2.2 times the steady state peak plasma concentration (Cmax) at the recommended dose, tafamidis does not prolong the QTc interval to any clinically relevant extent.
Absorption
Median tafamidis peak concentrations occurred within 4 hours following dosing.
Effect of Food
No clinically significant differences in the pharmacokinetics of tafamidis were observed following administration of a high fat, high calorie meal.
Distribution
The apparent steady state volume of distribution of tafamidis is approximately 18.5 liters. Plasma protein binding of tafamidis is >99% in vitro. Tafamidis primarily binds to TTR.
Elimination
The mean half-life of tafamidis is approximately 49 hours. The apparent oral clearance of tafamidis is 0.263 L/hr. The degree of drug accumulation at steady state after repeated tafamidis daily dosing is approximately 2.5-fold greater than that observed after a single dose.
Metabolism
The metabolism of tafamidis has not been fully characterized. However, glucuronidation has been observed.
Excretion
After a single oral dose of tafamidis meglumine 20 mg, approximately 59% of the dose was recovered in feces (mostly as the unchanged drug) and approximately 22% of the dose was recovered in urine (mostly as the glucuronide metabolite).
Specific Populations
No clinically significant differences in the pharmacokinetics of tafamidis were observed based on age, race/ethnicity (Caucasian and Japanese) or renal impairment.
Patients with Hepatic Impairment
Patients with moderate hepatic impairment (Child-Pugh Score of 7 to 9) had decreased systemic exposure (approximately 40%) and increased clearance (approximately 68%) of tafamidis compared to healthy subjects. As TTR levels are lower in subjects with moderate hepatic impairment than in healthy subjects, the exposure of tafamidis relative to the amount of TTR is sufficient to maintain stabilization of the TTR tetramer in these patients. No clinically significant differences in the pharmacokinetics of tafamidis were observed in patients with mild hepatic impairment (Child Pugh Score of 5 to 6) compared to healthy subjects. The effect of severe hepatic impairment on tafamidis is unknown.
Drug Interaction Studies
Clinical Studies
No clinically significant differences in the pharmacokinetics of midazolam (a CYP3A4 substrate) or on the formation of its active metabolite (1-hydroxymidazolam) were observed when a single 7.5-mg dose of midazolam was administered prior to and after a 14-day regimen of VYNDAQEL 20-mg once daily.
In Vitro Studies
Cytochrome P450 Enzymes: Tafamidis induces CYP2B6 and CYP3A4 and does not induce CYP1A2. Tafamidis does not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP3A4/5 or CYP2D6.
UDP glucuronosyltransferase (UGT): Tafamidis inhibits intestinal activities of UGT1A1 but neither induces nor inhibits other UDP glucuronosyltransferase (UGT) systemically.
Transporter Systems: Tafamidis inhibits breast cancer resistant protein (BCRP). In vitro studies and model predictions show that tafamidis has a low potential to inhibit organic anion transporters OAT1 and OAT3 at clinically relevant concentrations. Tafamidis did not show a potential to inhibit Multi-Drug Resistant Protein (MDR1) (also known as P-glycoprotein; P-gp), organic cation transporter OCT2, multidrug and toxin extrusion transporters MATE1 and MATE2K and, organic anion transporting polypeptide OATP1B1 and OATP1B3.
Carcinogenesis
There was no evidence of an increased incidence of neoplasia in the transgenic (Tg)-rasH2 mouse following repeated daily administration for 26 weeks at daily doses of 0, 10, 30 or 90 mg/kg. There was no evidence of increased incidence of neoplasia in a 2-year carcinogenicity study in rats at exposures up to 18 times the AUC at the MRHD.
Mutagenesis
There was no evidence of mutagenicity or clastogenicity in vitro, and an in vivo rat micronucleus study was negative.
Impairment of Fertility
There were no effects of tafamidis meglumine on fertility, reproductive performance, or mating behavior in the rat at any dose. Rats were dosed daily (0, 5, 15, and 30 mg/kg/day) prior to cohabitation (for at least 15 days for females and 28 days for males), throughout the cohabitation period to the day prior to termination of males and through to implantation of females (Gestation Day 7). No adverse effects were noted on male and female rats in toxicity, fertility, and mating behavior at any dose. The paternal and maternal no observed adverse effect level for reproductive toxicity of tafamidis meglumine is 30 mg/kg/day, approximately 4 times the MRHD on a mg/m2 basis.
Pregnancy
Report pregnancies to the Pfizer reporting line at 1-800-438-1985. Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females to inform their healthcare provider of a known or suspected pregnancy [see Use in Specific Populations (8.1)].
Lactation
Advise females not to breastfeed during treatment with VYNDAQEL or VYNDAMAX [see Use in Specific Populations (8.2)].
Transthyretin Amyloidosis Outcome Survey (THAOS)
Advise all patients prescribed VYNDAQEL or VYNDAMAX of the availability of the Transthyretin Amyloidosis Outcome Survey (THAOS) registry, that their participation is voluntary, and may involve long-term follow-up. THAOS is an international disease registry designed to assess disease progression, genotype/phenotype relationships, and the impact of interventions, including VYNDAQEL and VYNDAMAX on disease progression. For information regarding the registry, visit www.thaos.net.
This product's label may have been updated. For full prescribing information, please visit www.pfizer.com.
LAB-0497-1.0