Compassionate Use of Lumacaftor/Ivacaftor in Cystic Fibrosis: Spanish Experience

Background: The most common cystic fibrosis (CF)-causing mutation is deltaF508 (F508del), which is present in 28% of CF Spanish patients. While the literature based on real-life studies on CF patients homozygous F508del treated with lumacaftor/ivacaftor is limited, it demonstrates the need for better strategies to prevent related adverse events (AEs) as well as the development of newer drugs.

Methods: We conducted a multicenter, retrospective, observational study to describe the effects of lumacaftor/ivacaftor treatment in real-life in Spain. 20 CF patients were included, all aged 6 and upwards and presented with ppFEV1<40%, chosen from CF units country-wide. For the purposes of the study, they were treated with lumacaftor/ivacaftor 200/125mg two tablets twice a day on a compassionate use programme throughout 2016. The primary endpoint was measured in all of the sample patients. Data were analysed from ppFEV1 at baseline and was measured every 6 months.

Results: The mean age was 26.65 (range of 10-45), while the mean ppFEV1 before the treatment was 32.4% and mean BMI was 19.9kg/m². We analysed the changes in ppFEV1 and BMI from baseline during the treatment with lumacaftor/ivacaftor, but no differences were found. However, a moderate association between days of intravenous antibiotic needed and the use of lumacaftor/ivacaftor (p=0.001) was established. Indeed, under the lumacaftor/ivacaftor, patients required 5.8 days of intravenous antibiotic treatment compared to 14.9 days prior to study. Also, severe pulmonary exacerbations requiring hospitalisation were statistically fewer under lumacaftor/ivacaftor treatment (p=0.003). Finally, 75% of the sample presented with AEs, which led 35% of the subjects to discontinue the treatment.

Conclusions: While treatment with lumacaftor/ivacaftor resulted in an improvement in the number of pulmonary severe exacerbations, no improvement in ppFEV1 or BMI was found.