This study will evaluate the long-term safety, efficacy and pharmacodynamics of ELX/TEZ/IVA in participants with cystic fibrosis (CF) with at least 1 non-F508del ELX/TEZ/IVA-responsive CF transmembrane conductance regulator (CFTR) gene mutation.

Key Inclusion Criteria:

Part A: Completed study drug treatment in parent study or had study drug interruption(s) in parent study but completed study visits up to the last scheduled visit of the treatment period in the parent study

Part B: Completed study drug treatment in Part A or had study drug interruption(s) in Part A but completed study visits up to the last scheduled visit of the treatment period of Part A

Key Exclusion Criteria:

History of study drug intolerance in the parent study

Other protocol defined Inclusion/Exclusion criteria may apply.

Details on Vertex data sharing criteria and process for requesting access can be found at: https://www.vrtx.com/our-science/clinical-trials-data-sharing/