Please assess the completion status of the following clinical trial:

Trial Title: Immuno & Safety Study of GSK Biologicals' Thio or Preservative Free Hepatitis B Vaccine in Subjects Aged 11-15 Yrs

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: NONE
- Phase: PHASE3
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Subjects have participated in primary study HBV-280~* Written informed consent will be obtained from each subject and/ or parent or guardian of the subject before the blood-sampling visit of each year

- Gender: ALL
- Minimum Age: 13 Years
- Maximum Age: 20 Years
- Healthy Volunteers: t

Study Arms:
- 2-Dose Engerix (Type: EXPERIMENTAL): subjects received 2 doses of adult (thiomersal-free) HBV formulation, one at 0 and 6 months, respectively and placebo (physiological saline) at 1 month.
- 3-Dose Engerix (Type: ACTIVE_COMPARATOR): subjects received 3 doses of paediatric (preservative-free) HBV formulation one at 0, 1 and 6 months, respectively.

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