A Study to Assess the Effect of ELX/TEZ/IVA on Glucose Tolerance in Participants With Cystic Fibrosis (CF)

Key Inclusion Criteria: * Heterozygous for F508del and an MF mutation (F/MF genotypes) * Forced expiratory volume in 1 second (FEV1) value ≥ 30% of predicted mean for age, sex, and height * Abnormal glucose tolerance determined by an OGTT as either: * Impaired glucose tolerance (IGT) defined as 2 hour post OGTT blood glucose level ≥140 to \<200 mg/dL (≥7.77 to \<11.10 mmol/L) and fasting blood glucose level \<126 mg/dL (\<7.00 mmol/L) * CF-related diabetes (CFRD) defined as either fasting hyperglycemia (blood glucose level ≥126 mg/dL \[≥7.00 mmol/L\] after an 8-hour fast) or 2-hour post OGTT blood glucose level ≥200 mg/dL (≥11.10 mmol/L) Key Exclusion Criteria: * Clinically significant liver cirrhosis with or without portal hypertension * Solid organ or hematological transplantation * Lung infection with organisms associated with a more rapid decline in pulmonary status * Type 1 or Type 2 diabetes * Duration of CFRD ≥5 years Other protocol defined Inclusion/Exclusion criteria may apply.