Please assess the completion status of the following clinical trial:

Trial Title: A Study of the Effectiveness and Safety of Topiramate Versus Placebo for Preventing Chronic Migraine Headaches

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

Eligibility Criteria:
Inclusion Criteria:~* Diagnosis of chronic migraine~* \>=15 headache days per month in past 30 days~* \>= 15 headache days, half of which need to be migraine headaches during the prospective baseline period~* MIDAS test score \>= 11 at Visit 1~* In generally good health~* If female, using birth control~* No abnormalities on neurological examination~Exclusion Criteria:~* Failed \> 2 adequate trials of migraine prevention medications~* Failed topiramate due to lack of effectiveness or adverse events~* Daily headaches of severe intensity during past 30 days~* Cluster, basilar, ophthalmoplegic, or hemiplegic migraines~* Migraines started after age 50~* Other pain greater than migraine pain~* Use of drugs to treat migraines for \> 4 days per week during the past month

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

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