Lumacaftor

Lumacaftor Uses, Dosage, Side Effects, Food Interaction and all others data.

Lumacaftor is a drug used in combination with Ivacaftor as the fixed dose combination product Orkambi for the management of Cystic Fibrosis (CF) in patients aged 6 years and older. Cystic Fibrosis is an autosomal recessive disorder caused by one of several different mutations in the gene for the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein, a transmembrane ion channel involved in the transport of chloride and sodium ions across cell membranes of the lungs, pancreas, and other organs. Mutations in the CFTR gene result in altered production, misfolding, or function of the CFTR protein and consequently abnormal fluid and ion transport across cell membranes. As a result, CF patients produce thick, sticky mucus that clogs the ducts of organs where it is produced making patients more susceptible to infections, lung damage, pancreatic insufficiency, and malnutrition. Lumacaftor improves CF symptoms and underlying disease pathology by aiding the conformational stability of F508del-mutated CFTR proteins, preventing misfolding and resulting in increased processing and trafficking of mature protein to the cell surface.

Results from clinical trials indicated that treatment with Orkambi (lumacaftor/ivacaftor) results in improved lung function, reduced chance of experiencing a pulmonary exacerbation, increased weight gain, and improvements in CF symptoms. This data has been heavily scrutinized, however, with clinical trials showing only modest improvements despite a hefty yearly cost of $259,000 for Orkambi. Improvements in lung function (ppFEV1) were found to be statistically significant, but minimal, with only a 2.6-3.0% change from baseline with more than 70% of patients failing to achieve an absolute improvement of at least 5%.

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. When used in combination with Ivacaftor as the fixed dose combination product Orkambi, lumacaftor is specific for the management of CF in patients with delta-F508 mutations as it acts as a protein-folding chaperone, aiding the conformational stability of the mutated CFTR protein. Consequently, lumacaftor increases successful production of CFTR ion channels and the total number of receptors available for use at the cell membrane for fluid and ion transport. 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. Treatment of patients with G551D and other rarer missense mutations is usually managed with Ivacaftor (Kalydeco), as it aids with altered gating mechanisms by potentiating channel opening probability of CFTR protein.

Lumacaftor
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Lumacaftor
Generic	Lumacaftor
Lumacaftor Other Names	Lumacaftor
Type
Formula	C₂₄H₁₈F₂N₂O₅
Weight	Average: 452.414 Monoisotopic: 452.118378014
Protein binding	Lumacaftor is extensively protein bound in the plasma (99%), and binds primarily to albumin.
Groups	Approved
Therapeutic Class
Manufacturer
Available Country
Last Updated:	September 19, 2023 at 7:00 am

Uses

Lumacaftor is a protein chaperone used in combination with ivacaftor for the treatment of cystic fibrosis in patients who are homozygous for the F508del mutation in the CFTR gene.

When given in combination with Ivacaftor as the fixed dose combination product Orkambi, lumacaftor is indicated for the treatment of cystic fibrosis (CF) in patients age 6 years and older who are homozygous for the F508del mutation in the CFTR gene.

Lumacaftor is also used to associated treatment for these conditions: Cystic Fibrosis (CF)

How Lumacaftor works

Lumacaftor improves CF symptoms and underlying disease pathology by aiding the conformational stability of F508del-mutated CFTR, resulting in increased processing and trafficking of mature protein to the cell surface. More specifically, lumacaftor acts as a protein-folding chaperone, preventing misfolding of CFTR ion channels and consequent destruction during processing in the endoplasmic reticulum.

Toxicity

The most common side effects (occuring in >5% of patients during clinical trials) associated with the use of Orkambi include dyspnea, nasopharyngitis, nausea, diarrhea, upper respiratory tract infection, fatigue, respiration abnormal, blood creatine phosphokinase increased, rash, flatulence, rhinorrhea, and influenza.

Food Interaction

No interactions found.

Volume of Distribution

Following oral administration of 200 mg of lumacaftor every 24 hours to cystic fibrosis patients in a fed state for 28 days, the mean (+/-SD) for apparent volumes of distribution was 86.0 (69.8) L.

Elimination Route

Following administration of Orkambi (lumacaftor/Ivacaftor) with fat containing foods, peak plasma concentrations were reached at 4 hours (Tmax). It's recommended that Orkambi should be taken with fat-containing foods as they increase absorption of lumacaftor by approximately 2-fold, and[DB08820 by 3-fold.