Pilot Study Testing the Effect of Ivacaftor on Lung Function in Subjects With Cystic Fibrosis and Residual CFTR Function

CFTR Mutations associated with residual CFTR function or defective mRNA splicing include the
following:

R117H, E56K, P67L, D110E, D110H, R117C, R347H, R352Q, A455E, D579G, S945L, L206W, R1070W,
F1074L, D1152H, S1235R, D1270N, 2789+5G->A, 3849+10kbC->T, 3272-26A->G, 711+5G->A, 3120G->A,
1811+1.6kbA->G, 711+3A->G, 1898+3A->G, 1898+1G->A, 1717-1G->A, 1717-8G->A, 1342-2A->C,
405+3A->C, 1716G/A 1811+1G->C, 1898+5G->T, 3850-3T->G, IVS14b+5G->A, 1898+1G->T, 4005+2T->C,
621+3A->G, 621+1G->T

Inclusion Criteria:

- Male or female subjects with confirmed diagnosis of CF

- Clinical evidence of residual CFTR function based on any 1 of the following:
1)Clinically documented residual exocrine pancreatic function, 2)Sweat chloride value
≤80 mmol/L at screening, or 3) Age of diagnosis ≥12 years and at least 1 copy of a
CFTR mutation associated with residual CFTR function or defective mRNA splicing

- FEV1 ≥40%

- 12 years of age or older

- Willing to agree to meet the contraception requirements

- Able to swallow tablets

Exclusion Criteria:

- A copy of any of the following CFTR mutations: G551D, G178R, S549N, S549R, G551S,
G970R, G1244E, S1251N, S1255P, G1349D

- Unable to perform spirometry

- An acute upper or lower respiratory infection, pulmonary exacerbation, or changes in
therapy (including antibiotics) for pulmonary disease within 4 weeks before Day 1

- Ongoing participation in another therapeutic clinical study or prior participation in
an investigational drug study within the 30 days prior to screening