Conditions: Migraine
Keywords: Topiramate Migraine
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 387
Healthy volunteers: no

Brief summary:
The purpose of this study is to determine a recommended dose of topiramate in participants with migraine (type of severe headache that occurs periodically and is often associated with nausea, vomiting, and constipation or diarrhea), to verify the superiority (statistically more effective) of the drug to placebo (an inactive substance that is compared with a drug to test whether the drug has a real effect in a clinical trial), and to assess if a same therapeutic effect can be observed between this study and overseas Caucasian clinical studies.

Detailed description:
This study is a multicenter (more than 1 site), placebo-controlled (compared to placebo), randomized (participants assigned study drug by chance), double-blind (neither the participant nor the physician know the assigned study drug), parallel-group comparison (comparison for each group at the same time) study. The study period consists of 4 phases: the observation phase, double-blind phase, exit period and follow-up period. After the double-blind phase, the participants will be transferred to the continuous treatment study. The observation phase which is started after informed consent consists of the washout period (non-treatment period with migraine preventive medication: at least 2 weeks) and baseline determination period (at least 4 weeks). The participants who complete the observation phase and meet the inclusion criteria will be randomly assigned to the topiramate 50 milligram (mg) group, topiramate 100-mg group or placebo group after registration. The double-blind phase consists of the titration period (dose-escalation, 4 weeks) and fixed-dose period (18 weeks). In the titration period, starting from 1 topiramate 25-mg tablet or 1 topiramate 25-mg placebo tablet once daily (1 tablet in the evening), the dose will be increased by 1 tablet every week up to twice daily (2 tablets in the morning, 2 tablets in the evening). After that, the twice-daily treatment (2 tablets in the morning, 2 tablets in the evening) will be continued for 7 days from Day 22 to Day 28. In the fixed-dose period, the topiramate 25-mg tablets or topiramate 25-mg placebo tablets at the same dose as that in the final treatment in titration period will be continued. The participants who are not transferred to the continuous treatment study after completion of the double-blind phase or after discontinuation during the double-blind phase will be transferred to the exit period (up to 1 week).The participants who complete the exit period will be transferred to the follow-up period, and a follow-up of the participant's safety and headache symptoms such as the migraine period rate will be conducted for 4 weeks after the completion of investigational treatment. Meanwhile, the participants who complete the double-blind phase or those who discontinue the study at Week 4 or later in the fixed-dose period during the double-blind phase due to lack of efficacy and give consent to transfer to the continuous treatment study will be transferred to the transfer period (up to 3 weeks) under blind conditions.

Arms:
arm 1: In titration period, topiramate 25 milligram (mg) tablet will be given once daily in evening orally for 7 days; then topiramate 25 mg tablet twice daily orally from Day 8 to Day 14; then topiramate 25 mg tablet twice daily along with matching placebo tablet once daily in the evening orally from Day 15 to Day 21; then topiramate 25 mg tablet along with matching placebo tablet twice daily orally from Day 22 to Day 28 and will be continued further for 18 weeks in the fixed dose period. arm 2: In titration period, topiramate 25 mg tablet will be given once daily in the evening orally for 7 days; then topiramate 25 mg tablet twice daily orally from Day 8 to Day 14; then topiramate 25 mg tablet twice daily (1 tablet in the morning and 2 tablets in the evening) orally from Day 15 to Day 21; then 2 topiramate 25 mg tablets twice daily orally from Day 22 to Day 28 and will be continued further for 18 weeks in the fixed dose period. arm 3: In titration period, matching placebo tablet will be given once daily in evening orally for 7 days; followed by matching placebo tablet twice daily orally from Day 8 to Day 14; followed by matching placebo tablet twice daily (1 tablet in the morning and 2 tablets in the evening) orally from Day 15 to Day 21; followed by 2 matching placebo tablets twice orally from Day 22 to Day 28 and will becontinued further for 18 weeks in the fixed dose period.

Interventions: intervention 1: Topiramate intervention 2: Placebo
Intervention descriptions: intervention 1: In the titration period, topiramate 25-mg tablet once daily orally for 1 week, the dose will be increased by 1 tablet every week up to twice daily for a total of 4 weeks so that the total daily dose given is 50 mg or 100mg. The dose given in the final titration week will be continued for further 18 weeks (fixed dose period). intervention 2: In the titration period, matching placebo tablet once daily orally for 1 week, the dose will be increased by 1 tablet every week up to twice daily for a total of 4 weeks. The dose given in the final titration week will be continued for further 18 weeks (fixed dose period).

Protocol document: