Please assess the completion status of the following clinical trial:

Trial Title: Sitagliptin Added-on to Insulin Study (0431-051)

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

Eligibility Criteria:
Inclusion Criteria:~* Patient has type 2 diabetes mellitus~* Patient is poorly controlled while on insulin or insulin and metformin~Exclusion Criteria:~* Patient has a history of type 1 diabetes mellitus or history of ketoacidosis~* Patient is taking oral antidiabetic agents other than metformin during the past 3 months~* Patient is currently on treatment with daily use of pre-prandial short-acting or rapid-acting insulin

- Gender: ALL
- Minimum Age: 21 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- 1 (Type: EXPERIMENTAL): sitagliptin
- 2 (Type: PLACEBO_COMPARATOR): Placebo

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