The purpose of the study is to examine the clinical safety, tolerability, and efficacy of clobazam (Onfi) when it replaces the pre-existing clonazepam therapy in patients with refractory epilepsy.

The study is designed to answer frequently asked questions when clinicians replace existing 1,4-benzodiazepine to Onfi, as follows:

1. What should be the optimal equivalent doses for conversion?
2. How quickly should it be converted?
3. Would there be significant improvement of seizure control?
4. Should we expect difference in tolerability? If so, what are common adverse events?
5. Would the tolerance to the therapeutic effect differ with Onfi after conversion?

Inclusion Criteria:

• Subject has a confirmed diagnosis of medically refractory epilepsy with or without secondary generalization for at least 12 months prior to the initial study visit.
• Currently taking stable dosing regimen of clonazepam (0.5-4mg daily) for seizure control.
• Takes at least one additional Anti-epileptic drug besides benzodiazepine.
• Age 18-70 years, inclusive.
• In opinion of investigator, can be safely treated with Onfi.
• Minimum of 2 seizures, but no more than 24 complex partial or generalized seizures, during the 8-week baseline period prior to study entry.
• Able to communicate effectively with study personnel and considered reliable, able, willing, and cooperative with regard to complying with protocol-defined requirements, including completion of study diary.

Exclusion Criteria:

• Clinically relevant current illness or history of that may interfere with the subject's ability to complete the study as determined by the investigator.
• History of status epilepticus within 6 months prior to the initial study visit.
• History of suicidal attempts or suicidal ideation within 12 months of initial visit.