Key Inclusion Criteria:  Heterozygous for F508del and a minimal function mutation (F/MF genotype) Forced expiratory volume in 1 second (FEV1) value >=40% and <=90% of predicted mean for age, sex, and height for participants currently receiving ELX/TEZ/IVA therapy; FEV1 >=40% and <=80% for participants not currently receiving ELX/TEZ/IVA  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