Combo therapy of elexacaftor, tezacaftor, and ivacaftor improves sinonasal outcomes in cystic fibrosis: Study

Many cystic fibrosis patients have chronic rhinosinusitis leading to sinus infections, nasal obstruction, and repeated surgeries. Elexacaftor-tezacaftor-ivacaftor is a highly effective modulator treatment approved for CF patients aged six years or older having at least one F508del allele or other responsive mutation.

Against the above background, Amanda L. Stapleton, University of Pittsburgh, United States, and colleagues performed a prospective, observational study on the effects of ELX/TEZ/IVA on the sinonasal tract of ≥12 years old patients with cystic fibrosis. The latter were homozygous or heterozygous for F508del mutations.

The cohort is unique in including patients as young as 12 and consists of an endoscopic assessment of sinonasal disease. The researcher hypothesized that ELX/TEZ/IVA would improve overall sinonasal outcomes, with sinonasal quality of life being the primary endpoint.

For this purpose, the researchers underwent a study visit before ELX/TEZ/IVA initiation and a second visit at nine months of treatment. Each visit included rigid nasal endoscopy, sinus CT scan, and sweat chloride measurement. Measurement of symptoms was done with the 22-item Sinonasal Outcome Test at scheduled intervals during the study. To test for improvement in symptoms, endoscopy, CT scales, regression models were used.

The study led to the following findings:

· The study enrolled 34 patients (median age 27 years).

· Symptoms improved within seven days of therapy and plateaued by day 28.

· Endoscopic crusting resolved, and nasal polyposis improved, with a decrease in the size or resolution of polyps.

· Sinus opacification and mucosal thickening improved on CT radiographs with treatment.

"Cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy has been a transformative treatment for many CF patients. ELX/TEZ/IVA was approved as a highly effective modulator CFTR therapy in late 2019, dramatically improving the rate of CF pulmonary exacerbations and lung function," the researchers wrote in their study. "Due to the abundance of expression of CFTR in the sinuses, the effects of improved chloride channel function are predicted to extend the sinuses."

The new study showed improvements in nasal polyp burden, sinonasal quality of life, and radiographic disease severity.

"ELX/TEZ/IVA results in improved nasal endoscopy scores, regression of nasal polyps, improved sinonasal CT scans, and improved sinonasal quality of life scores in individuals 12 years old and older newly started on treatment," the researchers wrote in their conclusion.

Reference:

The study, "Elexacaftor-Tezacaftor- Ivacaftor improves sinonasal outcomes in cystic fibrosis," was published in the Journal of Cystic Fibrosis. DOI: https://doi.org/10.1016/j.jcf.2022.03.002