Key Inclusion Criteria:  Participant has one of the following genotypes:  Homozygous for F508del; Heterozygous for F508del and a gating (F/G) mutation; Heterozygous for F508del and a residual function (F/RF) mutation; At least 1 other TCR CFTR gene mutation identified as responsive to ELX/TEZ/IVA and no F508del mutation Forced expiratory volume in 1 second (FEV1) value >=40% and <=90% of predicted mean for age, sex, and height for participants currently receiving CFTR protein modulator therapy; FEV1 >=40% and <=80% for participants not currently receiving CFTR protein modulator therapy  Key Exclusion Criteria:  History of solid organ or hematological transplantation Hepatic cirrhosis with portal hypertension, moderate hepatic impairment (Child Pugh Score 7 to 9), or severe hepatic impairment (Child Pugh Score 10 to 15) Lung infection with organisms associated with a more rapid decline in pulmonary status Pregnant or breast-feeding females  Other protocol defined Inclusion/Exclusion criteria may apply