CFTR Gene Mutation

ARCT-032-02 is a Phase 2, open-label, multicenter, multiple-ascending dose study of ARCT-032 in adults with CF who are not eligible for CFTR modulator therapy or are not taking CFTR modulators due to drug intolerance, poor response, or lack of access to modulators.

In cystic fibrosis (CF) renal base excretion is impaired, due to mutations in the Cystic Fibrosis Transmembrane Regulator (CFTR) gene, since CFTR function is crucial in regulation of the kidney's HCO3- excretion. The investigators suggest that challenged urine HCO3- excretion is a biomarker of CFTR function, which can be used to evaluate the extent of CFTR dysfunction and the possible correcting effects of CFTR modulating therapy. This study aims to evaluate changes in challenged urine HCO3- excretion in CF patients, who are currently in treatment with the triple CFTR modulator combination therapy, Elexacaftor/tezacaftor/ivacaftor (ETI), before, during, and after a short treatment pause.