Ivacaftor

low (<0.05 µg/mL)

2.00e-03 g/L

Breast Feeding; Lactation; Milk, Human; Chloride Channel Agonists; Cystic Fibrosis Transmembrane Conductance Regulator Protein Modulator; CFTR Protein Modulator

FDA approved drugs -> Active ingredient

EMA approved medicines: Human medicine

FDA approved drugs -> Active ingredient

This chemical does not meet GHS hazard criteria for 50% (3 of 6) of reports.

Warning

H315 (33.3%): Causes skin irritation [Warning Skin corrosion/irritation]

P203, P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P318, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 6 reports by companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Ivacaftor

vLess-DILI-concern

3

Warnings & precautions

DOI:10.1016/j.drudis.2016.02.015

R07AX30

R - Respiratory system

QR - Respiratory system

The use of Ivacaftor has been shown to both improve CF symptoms and modulate underlying disease pathology. This is achieved by potentiating the channel opening probability (or gating) of CFTR protein in patients with impaired gating mechanisms. This is in contrast to [DB09280], another CF medication, that functions by preventing misfolding of the CFTR protein and thereby results in increased processing and trafficking of mature protein to the cell surface. Results from clinical trials indicated that treatment with ivacaftor results in improved lung function, reduced chance of experiencing a pulmonary exacerbation, reduced sweat chloride, increased weight gain, and improvements in CF symptoms and quality of life. When combined with tezacaftor, significant improvements in lung function have been observed in clinical studies. Ivacaftor was not found to increase the QTc interval in a clinically significant manner. Although ivacaftor given alone has not shown any significant improvements in patients with the delta-F508 mutation, it has shown significant improvements (>10% increase in FEV1 from baseline) in lung function for the following mutations: E56K, P67L, R74W, D110E, D110H, R117C, R117H, G178R, E193K, L206W, R347H, R352Q, A455E, S549N, S549R, G551D, G551S, D579G, S945L, S977F, F1052V, K1060T, A1067T, G1069R, R1070Q, R1070W, F1074L, D1152H, G1244E, S1251N, S1255P, D1270N, and G1349. This list was expanded by the FDA in May 2017 from 10 to 33 to accommodate more rare mutations. It is important to note that this drug may cause an increase in liver transaminases (ALT, AST). Ensure to assess liver transaminases before the initiation of treatment, every 3 months during the first year of administration, followed by every year thereafter.

A wide variety of CFTR mutations correlate to the Cystic Fibrosis phenotype and are associated with differing levels of disease severity. The most common mutation, affecting approximately 70% of patients with CF worldwide, is known as F508del-CFTR or delta-F508 (ΔF508), in which a deletion in the amino acid phenylalanine at position 508 results in impaired production of the CFTR protein, thereby causing a significant reduction in the amount of ion transporter present on cell membranes. Ivacaftor as monotherapy has failed to show a benefit for patients with delta-F508 mutations, most likely due to an insufficient amount of protein available at the cell membrane for interaction and potentiation by the drug. The next most common mutation, G551D, affecting 4-5% of CF patients worldwide is characterized as a missense mutation, whereby there is sufficient amount of protein at the cell surface, but opening and closing mechanisms of the channel are altered. Ivacaftor is indicated for the management of CF in patients with this second type of mutation, as it binds to and potentiates the channel opening ability of CFTR proteins on the cell membrane. Ivacaftor exerts its effect by acting as a potentiator of the CFTR protein, an ion channel involved in the transport of chloride and sodium ions across cell membranes of the lungs, pancreas, and other organs. Alterations in the CFTR gene result in altered production, misfolding, or function of the protein and consequently abnormal fluid and ion transport across cell membranes. Ivacaftor improves CF symptoms and underlying disease pathology by potentiating the channel open probability (or gating) of CFTR protein in patients with impaired CFTR gating mechanisms. The overall level of ivacaftor-mediated CFTR chloride transport is dependent on the amount of CFTR protein at the cell surface and how responsive a particular mutant CFTR protein is to ivacaftor potentiation.

Ivacaftor is extensively metabolized in humans. In vitro and clinical studies indicate that ivacaftor is primarily metabolized by CYP3A. From this metabolism, the major formed metabolites are M1 and M6. M1 is considered pharmacologically active even though it just presents approximately one-sixth the effect of the parent compound ivacaftor. On the other hand, M6 is not considered pharmacologically active as it represents less than one-fiftieth of the effect of the parent compound.

1Y740ILL1Z

IVACAFTOR

Established Pharmacologic Class [EPC] - Cystic Fibrosis Transmembrane Conductance Regulator Potentiator

Mechanisms of Action [MoA] - Chloride Channel Activation Potentiators

Mechanisms of Action [MoA] - Cytochrome P450 2C9 Inhibitors

Mechanisms of Action [MoA] - P-Glycoprotein Inhibitors

Ivacaftor is well absorbed in the gastrointestinal tract. Following administration of ivacaftor with fat-containing foods, peak plasma concentrations were reached at 4 hours (Tmax) with a maximum concentration (Cmax) of 768 ng/mL and AUC of 10600 ng * hr/mL. It is recommended that ivacaftor is taken with fat-containing foods as they increase absorption by approximately 2.5- to 4-fold.

After oral administration, ivacaftor is mainly eliminated in the feces after metabolic conversion and this elimination represents 87.8% of the dose. From the total eliminated dose, the metabolites M1 and M6 account for the majority of the eliminated dose, being 22% for M1 and 43% for M6. Ivacaftor shows negligible urinary excretion as the unchanged drug.

After oral administration of 150 mg every 12 hours for 7 days to healthy volunteers in a fed state, the mean (±SD) for apparent volume of distribution was 353 (122) L.

The CL/F (SD) for the 150 mg dose was 17.3 (8.4) L/hr in healthy subjects.