Please assess the completion status of the following clinical trial:

Trial Title: Safety Study of Ivacaftor in Subjects With Cystic Fibrosis

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE2
- Number of Arms: 4.0

Eligibility Criteria:
Inclusion Criteria:~* Weighing at least 40 kg~* Confirmed diagnosis of cystic fibrosis (CF) and G551D mutation in at least 1 allele~* Forced expiratory volume in 1 second (FEV1) of at least 40% of predicted normal for age, gender, and height~* Willing to remain on stable medication regimen for the duration of study participation~* No significant clinical laboratory abnormalities, not pregnant, and willing to use at least 2 highly effective birth control methods during Part 1 and 1 highly effective birth control method during Part 2 of the study~* No clinically significant abnormalities that would have interfered with the study assessments, as judged by the investigator~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~* Ongoing acute respiratory infection, pulmonary exacerbation, or changes in therapy for pulmonary disease within 14 days 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~* History of abnormal renal function (creatinine clearance \< 50 mL/min using Cockcroft-Gault equation)~* History of solid organ or hematological transplantation~* Pregnant or breast-feeding (for women)~* Ongoing participation in another therapeutic clinical trial, or prior participation in an investigational drug study without appropriate washout~* Concomitant use of any inhibitors or inducers of cytochrome P450 3A4 (CYP3A4)

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Ivacaftor Group A (Type: EXPERIMENTAL): Subjects in Part 1 who first received 25 mg or 75 mg of ivacaftor every 12 hours (q12h) for 14 days, then crossed over to receive the alternate dose for another 14 days.
- Ivacaftor Group B (Type: EXPERIMENTAL): Subjects in Part 1 who first received 75 mg or 150 mg of ivacaftor q12h for 14 days then crossed over to receive the alternate dose for another 14 days.
- Ivacaftor Group C (Type: EXPERIMENTAL): Subjects in Part 2 who received 150 mg or 250 mg of ivacaftor q12h for 28 days.
- Placebo (Type: PLACEBO_COMPARATOR): Subjects who received placebo in Part 1 and subjects who received placebo in Part 2.

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