Study Analyzes Benefits of Ivacaftor Treatment for Cystic Fibrosis

Patients with cystic fibrosis (CF) who were treated with ivacaftor have demonstrated favorable results for clinically important outcomes, including a lower prevalence of CF-related complications and improved lung function, according to a new study.

The study, published in Thorax, assessed the clinical outcomes and disease progression in ivacaftor-treated patients using data from the US and United Kingdom (UK) CF registries. Ivacaftor was described as the first CF transmembrane conductance regulator (CFTR) modulator that demonstrated clinical benefits in patients with CF.

“Ivacaftor is intended for chronic, lifelong use. Therefore, understanding the long-term effects of therapy is important for patients, caregivers, healthcare providers, payers and regulators,” the authors said. “Furthermore, since the therapy addresses the underlying cause of CF, long-term data are complementary to data from the clinical development programs.”

The researchers collected data from the US CF Foundation Patient Registry (US CFFPR) and the UK CF Registry (UK CFR) to compare ivacaftor-treated and untreated matched comparator patients for risks of death, transplantation, hospitalization, pulmonary exacerbation, prevalence of CF-related complications, and microorganism and lung function changes.

A total of 1256 ivacaftor-treated patients and 6200 comparator patients from the US were included, while 411 ivacaftor-treated and 2069 comparator patients from the UK were included in the analysis. According to the safety evaluations, ivacaftor-treated US patients had significantly lower risks of death, transplantation, hospitalization, and pulmonary exacerbation relative to comparators. The results and trends were similar in the UK.

“We aimed to monitor patients treated with ivacaftor for any potential new safety concerns via evaluation of important clinical outcomes captured in the national CF registries in the [United States] and UK,” explained the authors. “The analyses also allowed to further assess if the effects of ivacaftor on long-term clinical outcomes, including mortality, are consistent with data supporting the disease modification potential for CFTR modulator therapy.”

Additionally, in both of the registries, ivacaftor-treated patients had a lower prevalence of CF-related complications and select microorganisms, and had more greatly improved lung function.

“Data from [2] large independent national CF patient registries evaluated in this study revealed consistently favorable findings with respect to clinically important outcomes among ivacaftor-treated patients, adding to the literature on the effects of ivacaftor therapy,” the study said.

The authors acknowledged the potential limitations of the analysis because of the observational research that lacks scheduled visits and standardized assessments, with no specific dates of therapy initiation. However, since the study represented such a large analysis, the results can be relevant to the broader CF population.

Reference

Bessonova L, Volkova N, Higgins M, et al. Data from the US and UK cystic fibrosis registries support disease modification by CFTR modulation with ivacaftor. [Published online May 10, 2018.] Thorax. doi:10.1136/thoraxjnl-2017-210394.