Please assess the completion status of the following clinical trial:

Trial Title: Efficacy and Safety of SPD503 in Combination With Psychostimulants

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

Eligibility Criteria:
Inclusion Criteria:~* Healthy subjects with ADHD currently taking a stable dose of psychostimulant for at least 4 weeks~* Aged 6-17 years with a sub-optimal~* Partial response to stimulants~* Subjects must be \< 95th percentile for BMI with weight \>= 55lbs and \<= 176lbs

- Gender: ALL
- Minimum Age: 6 Years
- Maximum Age: 17 Years
- Healthy Volunteers: f

Study Arms:
- SPD503-AM (Type: EXPERIMENTAL): SPD503 (Guanfacine Extended Release)
- SPD503-PM (Type: EXPERIMENTAL): SPD503 (Guanfacine Extended Release)
- Placebo (Type: PLACEBO_COMPARATOR): None

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