Insmed has reported positive results from the Phase III ARISE study of ARIKAYCE for the treatment of nontuberculous mycobacterial (NTM) lung disease, caused by Mycobacterium avium complex (MAC).

The study enrolled a total of 99 patients who were divided into the ARIKAYCE arm and a comparator arm.

The ARIKAYCE arm received ARIKAYCE plus macrolide-based background regimen while the comparator arm was given a placebo plus macrolide-based background regimen for six months.

Both groups were followed for one month off treatment.

The trial met its primary objective of demonstrating that the Quality of Life – Bronchiectasis (QOL-B) respiratory domain works effectively as a patient-reported outcome (PRO) instrument in MAC lung disease patients.

Improvement in respiratory score was observed in 43.8% of patients within-subject score difference of 14.8, compared with 33.3% of patients in the comparator arm.

At month seven, the ARIKAYCE arm also showed statistically significantly higher culture conversion rates in comparison to the comparator arm.

Insmed chief medical officer Martina Flammer said: “We are thrilled that these results not only validate a PRO tool in NTM lung disease but also show that patients treated with an ARIKAYCE-based regimen felt better versus patients in the comparator arm, as measured by this instrument.

“Coupled with extraordinary culture conversion outcomes, these findings give us great confidence that our Phase III registrational trial, ENCORE, is well-positioned to achieve both statistically and clinically meaningful results, leading to a sizeable increase in the number of patients who could hope to benefit from ARIKAYCE.”

Based on the study results, Insmed plans to propose to the US Food and Drug Administration (FDA) that the QOL-B respiratory domain PRO be measured as the primary endpoint in its ENCORE study.

The company intends to enrol 250 patients for the ENCORE study by the end of this year and continue enrolment until 2024 to ensure a high degree of statistical powering.

Topline data from the ENCORE trial is anticipated in 2025.