Ivacaftor-elexacaftor-tezacaftor and tacrolimus combination in cystic fibrosis.

The CFTR modulator combination elexacaftor/tezacaftor/ivacaftor (ETI) is a genetic mutation-targeted treatment in cystic fibrosis that results in profound improvements in clinical outcomes. Each of the compounds are substrates of CYP3A4/5, the cytochrome P450 enzyme family for which tacrolimus is also a substrate. The use of these compounds in an individual with a solid organ transplant has not been previously studied and there is potential for a drug interaction. In this report, we describe a pediatric liver transplant recipient with clinical decline related to cystic fibrosis who improved substantially with ETI, without significant impact on the systemic exposure of either ETI or tacrolimus.

Cholbam® and Zellweger spectrum disorders: treatment implementation and management.

BACKGROUND: Zellweger spectrum disorders (ZSDs) are a rare, heterogenous group of autosomal recessively inherited disorders characterized by reduced peroxisomes numbers, impaired peroxisomal formation, and/or defective peroxisomal functioning. In the absence of functional peroxisomes, bile acid synthesis is disrupted, and multisystem disease ensues with abnormalities in the brain, liver, kidneys, muscle, eyes, ears, and nervous system. MAIN BODY: Liver disease may play an important role in morbidity and mortality, with hepatic fibrosis that can develop as early as the postnatal period and often progressing to cirrhosis within the first year of life. Because hepatic dysfunction can have numerous secondary effects on other organ systems, thereby impacting the overall disease severity, the treatment of liver disease in patients with ZSD is an important focus of disease management. Cholbam® (cholic acid), approved by the U.S. Food and Drug Administration in March 2015, is currently the only therapy approved as adjunctive treatment for patients with ZSDs and single enzyme bile acid synthesis disorders. This review will focus on the use of CA therapy in the treatment of liver disease associated with ZSDs, including recommendations for initiating and maintaining CA therapy and the limitations of available clinical data supporting its use in this patient population. CONCLUSIONS: Cholbam is a safe and well-tolerated treatment for patients with ZSDs that has been shown to improve liver chemistries and reduce toxic bile acid intermediates in the majority of patients with ZSD. Due to the systemic impacts of hepatic damage, Cholbam should be initiated in patients without signs of advanced liver disease.