MECHANISM OF ACTION
- Elexacaftor and tezacaftor work to improve cellular processing and trafficking, allowing for more CFTR proteins to come to the cell surface
- Ivacaftor potentiates the channel open probability (or gating) of the CFTR protein at the cell surface
- The combined effect of elexacaftor, tezacaftor, and ivacaftor is increased quantity and function of CFTR at the cell surface, resulting in increased CFTR activity
TRIKAFTA is approved for patients with CF aged 2 years and older 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
CF, cystic fibrosis; CFTR, cystic fibrosis transmembrane conductance regulator.
Important Safety Information
Warnings and Precautions
Elevated Transaminases and Hepatic Injury
- Liver failure leading to transplantation has been reported in a patient with cirrhosis and portal hypertension while receiving TRIKAFTA. Avoid use of TRIKAFTA in patients with pre-existing advanced liver disease (e.g., as evidenced by cirrhosis, portal hypertension, ascites, hepatic encephalopathy) unless the benefits are expected to outweigh the risks. If used in these patients, they should be closely monitored after the initiation of treatment
- Isolated elevations of transaminases or bilirubin have been observed in patients with CF treated with TRIKAFTA. In some instances, transaminase elevations have been associated with concomitant elevations in total bilirubin and/or international normalized ratio (INR) and have resulted in patients being hospitalized for intervention, including in patients without a history of pre-existing liver disease
Indications and Usage
TRIKAFTA is indicated for the treatment of cystic fibrosis (CF) in patients aged 2 years and older who have at least one F508del mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene or a mutation in the CFTR gene that is responsive based on in vitro data.
If the patient’s genotype is unknown, an FDA-cleared CF mutation test should be used to confirm the presence of at least one F508del mutation or a mutation that is responsive based on in vitro data.
- Assessments of liver function tests (ALT, AST, and bilirubin) are recommended prior to initiating TRIKAFTA, every 3 months during the first year of treatment, and annually thereafter
- In the event of significant elevations in liver function tests, e.g. ALT or AST >5x the upper limit of normal (ULN) or ALT or AST >3x ULN with bilirubin >2x ULN, dosing should be interrupted and laboratory tests closely followed until the abnormalities resolve. Following the resolution of liver function test elevations, consider the benefits and risks of resuming treatment
- For patients with a history of hepatobiliary disease or liver function test elevations, more frequent monitoring should be considered
Concomitant Use With CYP3A Inducers
- Exposure to ivacaftor is significantly decreased and exposure to elexacaftor and tezacaftor are expected to decrease by the concomitant use of strong CYP3A inducers, which may reduce the therapeutic effectiveness of TRIKAFTA. Co‑administration with strong CYP3A inducers is not recommended
Concomitant Use With CYP3A Inhibitors
- Exposure to elexacaftor, tezacaftor, and ivacaftor are increased when co-administered with strong or moderate CYP3A inhibitors. The dose of TRIKAFTA should be reduced when used concomitantly with moderate or strong CYP3A inhibitors
- Cases of non-congenital lens opacities have been reported in pediatric patients treated with ivacaftor-containing regimens. Baseline and follow up ophthalmological examinations are recommended in pediatric patients initiating treatment with TRIKAFTA
Serious Adverse Reactions
- Serious adverse reactions that occurred more frequently in patients treated with TRIKAFTA compared to placebo were rash (1% vs <1%) and influenza (1% vs 0)
Most Common Adverse Reactions
- The most common adverse reactions occurring in ≥5% of patients treated with TRIKAFTA (N=202) and higher than placebo (N=201) by ≥1% in the 24-week placebo-controlled, parallel-group Phase 3 trial (Trial 1) were headache, upper respiratory tract infection, abdominal pain, diarrhea, rash, alanine aminotransferase increased, nasal congestion, blood creatine phosphokinase increased, aspartate aminotransferase increased, rhinorrhea, rhinitis, influenza, sinusitis, and blood bilirubin increased
- The safety profile for the patients with CF receiving TRIKAFTA (N=55) enrolled in the 4-week, randomized, double-blind, active-controlled Phase 3 trial (Trial 2) was similar to that observed in Trial 1
- The safety profile in patients age 6 through 11 years from an open-label trial (Trial 3; N=66) was similar to that observed in Trial 1. The safety profile in patients age 2 through 5 years from an open-label trial (Trial 4; N=75) was similar to that observed in Trial 1
Use in Specific Populations
- The safety and effectiveness of TRIKAFTA in patients with CF younger than 2 years of age have not been established
Click here to access full Prescribing Information for TRIKAFTA.
1. Middleton PG, Mall MA, Drevinek P, et al. Elexacaftor–tezacaftor–ivacaftor for cystic fibrosis with a single Phe508del allele. N Engl J Med. 2019;381(19):1809-1819. 2. TRIKAFTA [prescribing information]. Boston, MA: Vertex Pharmaceuticals Incorporated; April 2023.