Please assess the completion status of the following clinical trial:

Trial Title: Study of Ivacaftor in Cystic Fibrosis Subjects Aged 12 Years and Older With the G551D Mutation

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE3
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Confirmed diagnosis of cystic fibrosis (CF) and G551D mutation in at least 1 allele~* Forced expiratory volume in 1 second (FEV1) of 40% to 90% (inclusive) of predicted normal for age, gender, and height at Screening.~* No clinically significant abnormalities that would have interfered with the study assessments, as judged by the investigator~* Willing to use highly effective birth control methods during the study~Exclusion Criteria:~* History of any illness or condition that might confound the results of the study or pose an additional risk in administering study drug to the subject~* Acute respiratory infection, pulmonary exacerbation, or changes in therapy for pulmonary disease within 4 weeks of Day 1 of the study~* History of alcohol, medication or illicit drug abuse within one year prior to Day 1~* Abnormal liver function ≥ 3x the upper limit of normal~* Abnormal renal function at Screening~* History of solid organ or hematological transplantation~* Pregnant, planning a pregnancy, breast-feeding, or unwilling to follow contraception requirements~* Ongoing participation in another therapeutic clinical study or prior participation in an investigational drug study within 30 days prior to Screening~* Use of inhaled hypertonic saline treatment~* Concomitant use of any inhibitors or inducers of cytochrome P450 3A4 (CYP 3A4)

- Gender: ALL
- Minimum Age: 12 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Placebo (Type: PLACEBO_COMPARATOR): Subjects who received placebo every 12 hours (q12h) for up to 48 weeks.
- 150 mg Ivacaftor q12h (Type: EXPERIMENTAL): Subjects who received 150 mg of ivacaftor q12h for up to 48 weeks.

Based on this trial design, predict the completion outcome and termination type (if applicable).