History of hypersensitivity to VX 445, VX 659, tezacaftor and/or ivacaftor

Any acute lower respiratory symptoms treated with oral, inhaled or IV antibiotics or systemic corticosteroids within the 2 weeks prior to Visit 1.

Major or traumatic surgery within 12 weeks prior to Visit 1.

Initiation of any new chronic therapy (e.g., ibuprofen, Pulmozyme®, hypertonic saline, azithromycin, TOBI®, Cayston®) within 4 weeks prior to Visit 1.

Use of an investigational agent within 28 days prior to Visit 1.

History of lung or liver transplantation or listing for organ transplantation.

Clinical Outcomes of Triple Combination Therapy in Severe Cystic Fibrosis Disease.

What this study is about