Please assess the completion status of the following clinical trial:

Trial Title: A Phase 3 Study to Evaluate the Efficacy and Safety of Ivacaftor and VX-661 in Combination With Ivacaftor in Subjects Aged 12 Years and Older With Cystic Fibrosis, Heterozygous for the F508del-cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mutation

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: TRIPLE
- Phase: PHASE3
- Number of Arms: 3.0

Eligibility Criteria:
Inclusion Criteria:~* Heterozygous for F508del-CFTR and a second allele with a CFTR mutation predicted to have residual function~* Forced Expiratory Volume in 1 Second (FEV1) greater than or equal to (≥) 40 percent (%) and less than or equal to (≤) 90% of predicted normal for age, sex, and height during screening~* Sweat chloride value ≥60 millimole per liter (mmol/L) during screening OR as documented in the participant's medical record~* Stable CF disease as judged by the investigator~Exclusion Criteria:~* History of any comorbidity that, in the opinion of the investigator, might confound the results of the study or pose an additional risk in administering study drug to the participant~* An acute upper or lower respiratory infection, pulmonary exacerbation~* History of solid organ or hematological transplantation~* Ongoing or prior participation in an investigational drug study (including studies investigating VX-661, lumacaftor \[VX-809\], and/or ivacaftor) within 30 days of screening~* Pregnant and nursing females~* Sexually active participants of reproductive potential who are not willing to follow the contraception requirements

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

Study Arms:
- VX-661/Ivacaftor combination (Type: EXPERIMENTAL): None
- Ivacaftor monotherapy (Type: EXPERIMENTAL): None
- Placebo (Type: PLACEBO_COMPARATOR): None

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