The safety and effectiveness of TRIKAFTA for the treatment of CF have been established in pediatric patients aged 2 to less than 18 years who have at least one F508del mutation in the CFTR gene or a mutation in the CFTR gene that is responsive based on in vitro data. Use of TRIKAFTA for this indication for pediatric patients 12 years of age and older was supported by evidence from two adequate and well-controlled studies (Trials 1 and 2) in CF patients aged 12 years and older [see Adverse Reactions (6.1) and Clinical Studies (14)].

Use of TRIFAFTA for this indication in pediatric patients 2 to less than 12 years of age is based on the following:

  * Trial 1, 56 pediatric patients aged 12 to less than 18 years who had an F508del mutation on one allele and a mutation on the second allele that results in either no CFTR protein or a CFTR protein that is not responsive to ivacaftor and tezacaftor/ivacaftor [see Adverse Reactions (6) and Clinical Studies (14)].
  * Trial 2, 16 pediatric patients aged 12 to less than 18 years who were homozygous for the F508del mutation [see Adverse Reactions (6) and Clinical Studies (14)].
  * Trial 3, 66 pediatric patients aged 6 to less than 12 years who were homozygous for the F508del mutation or heterozygous for the F508del mutation with a mutation on the second allele that results in either no CFTR protein or a CFTR protein that is not responsive to ivacaftor and tezacaftor/ivacaftor [see Adverse Reactions (6) and Clinical Pharmacology (12.3)].
  * Trial 4, 75 pediatric patients aged 2 to less than 6 years who had at least one F508del mutation or a mutation known to be responsive to TRIKAFTA [see Adverse Reactions (6) and Clinical Pharmacology (12.3)].



The effectiveness of TRIKAFTA in patients aged 2 to less than 12 years was extrapolated from patients aged 12 years and older with support from population pharmacokinetic analyses showing elexacaftor, tezacaftor, and ivacaftor exposure levels in patients aged 2 to less than 12 years within the range of exposures observed in patients aged 12 years and older [see Clinical Pharmacology (12.3)]. Safety of TRIKAFTA in patients aged 6 to less than 12 years was derived from a 24-week, open-label, clinical trial in 66 patients aged 6 to less than 12 years (mean age at baseline 9.3 years) administered either a total dose of elexacaftor 100 mg/tezacaftor 50 mg/ivacaftor 75 mg in the morning and ivacaftor 75 mg in the evening (for patients weighing less than 30 kg) or a total dose of elexacaftor 200 mg/tezacaftor 100 mg/ivacaftor 150 mg in the morning and ivacaftor 150 mg in the evening (for patients weighing 30 kg or more) (Trial 3). Safety of TRIKAFTA in patients aged 2 to less than 6 years was derived from a 24-week, open-label, clinical trial in 75 patients aged 2 to less than 6 years (mean age at baseline 4.1 years) administered either a total dose of elexacaftor 80 mg/tezacaftor 40 mg/ivacaftor 60 mg in the morning and ivacaftor 59.5 mg in the evening (for patients weighing 10 kg to less than 14 kg) or a total dose of elexacaftor 100 mg/tezacaftor 50 mg/ivacaftor 75 mg in the morning and ivacaftor 75 mg in the evening (for patients weighing 14 kg or more) (Trial 4). The safety profile of patients in these trials was similar to that observed in Trial 1 [see Adverse Reactions (6)].

The safety and effectiveness of TRIKAFTA in patients with CF younger than 2 years of age have not been established. 

Juvenile Animal Toxicity Data

Findings of cataracts were observed in juvenile rats dosed from postnatal Day 7 through 35 with ivacaftor dose levels of 10 mg/kg/day and higher (0.21 times the MRHD based on systemic exposure of ivacaftor and its metabolites). This finding has not been observed in older animals [see Warnings and Precautions (5.5)]. 

Studies were conducted with tezacaftor in juvenile rats starting at postnatal day (PND) 21 and ranging up to PNDs 35 to 49. Findings of convulsions and death were observed in juvenile rats that received a tezacaftor dose level of 100 mg/kg/day (approximately equivalent to 1.9 times the MRHD based on summed AUCs of tezacaftor and its metabolite, M1-TEZ). A no effect dose level was identified at 30 mg/kg/day (approximately equivalent to 0.8 times the MRHD based on summed AUCs of tezacaftor and its metabolite, M1-TEZ). Findings were dose related and generally more severe when dosing with tezacaftor was initiated earlier in the postnatal period (PND 7, which would be approximately equivalent to a human neonate). Tezacaftor and its metabolite, M1-TEZ, are substrates for P-glycoprotein. Lower brain levels of P-glycoprotein activity in younger rats resulted in higher brain levels of tezacaftor and M1-TEZ. These findings are not relevant for the indicated pediatric population, 2 years of age and older, for whom levels of P-glycoprotein activity are equivalent to levels observed in adults.