ATS 2017. A4729 – Ivacaftor/Lumacaftor Improves Six Minute Walk Test Distance and Improves Lung Clearance Index and Functional Residual Capacity in Cystic Fibrosis Patients Homozygous for DF508 with Very Severe Lung Disease

P. A. Wark, MD, PhD (New Lambton, NSW, Australia), K. Cookson, B Nur (New Lambton, NSW, Australia), T. Thiruchelvenem, B Pharm (New Lambton, NSW, Australia), D. Dorahy, PhD (New Lambton, NSW, Australia), J. Brannan, PhD (New Lambton, NSW, Australia)

Conclusion: In subjects with severe lung disease treatment with Lumacaftor/Ivacaftor led to a significant improvement in 6MWT evident by 4 weeks, that continued to improve at 12 weeks. There was no improvement seen in FEV1, though the MBW demonstrates a change in LCI and a significant decline in FRC after 12 weeks of treatment.

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CARE™ FACULTY PERSPECTIVE

Study by Wark et al indicates that combination Ivacaftor/Lumacaftor therapy improves functional residual capacity and six-minute walk test distance in patients homozygous for DF508 with severe lung disease (FEV1>40% predicted). Ivacaftor/Lumacaftor (Orkambi™) therapy may lead to functional improvement by reducing airway mucus plugging and air trapping.  

Treatment paradigms for patients with CF have shifted with CFTR targeting therapies.  Some CFTR targeting therapies are already approved for clinical use (such as Orkambi™) and others are in clinical or pre-clinical testing.  Unresolved issues for the treating physician include which criteria to use to select patients for these treatments and how to assess treatment success.  This will lead to more options and sequencing considerations.  However, fundamental/unresolved issues require attention from treating physicians, so that they may can have clarity when treating CF patients.  In order to frame this practically, a case follows.      

Provided by Dr. Hartmutt Grasemann
CARE™ Respirology Faculty
The Hospital for Sick Children
Professor, University of Toronto