Ganaxolone missed its primary endpoint in the double-blind portion of the 1042-0603 study. Due to this outcome Marinus discontinued this extension study.

A follow-on, two-year open-label extension study of ganaxolone as add-on therapy in adult patients with drug-resistant partial-onset seizures

This study is a 2-year, open-label continuation for those patients benefiting from ganaxolone treatment after completing Protocol 1042-0603.

Inclusion Criteria:

• Subjects who have completed all scheduled clinical study visits in the previous protocol 1042-0603 and have shown a minimum 35% improvement in mean 28-day seizure frequency over the last three 28-day periods in study 1042-603 as compared to the baseline of study 1042-603.
• Subjects whose daily study drug compliance in Study 1042-0603 was 90% or greater, and for whom the investigator feels that the subject was compliant with the full dose as prescribed.
• Able to give informed consent in writing, or have a legally authorized representative able to do so, after being properly informed of the nature and risks of the study and prior to engaging in any study-related procedures.
• Currently being treated and maintained with a stable regimen of 1, 2, or 3 anti-epileptic drugs (AED) at a consistent dose for one month prior to study entry.
• Implanted Vagus Nerve Stimulator (VNS) is permitted and will not count towards the number of concomitant AEDs.
• Able and willing to maintain an accurate and complete daily written seizure calendar or has a caregiver who is able and willing to maintain an accurate and complete daily written seizure calendar.
• Able and willing to take drug with food twice daily. Ganaxolone must be administered with food.
• Sexually active women of childbearing potential (WCBP) must be using a medically acceptable method of birth control and have a negative pregnancy test at Visit 1 and at subsequent visits.

Exclusion Criteria:

• Have any medical condition that, in the investigator's judgment, is considered to be clinically significant and could potentially affect subject safety or study outcome
• Experienced a Serious Adverse Event or a moderate or severe medically important adverse event judged probably or definitely related to open-label ganaxolone in the previous study, 1042-0603
• Have Alanine transferase (ALT; SGPT) or Aspartate transferase (AST; SGOT) levels > 3 times upper limits of normal (ULN), or total bilirubin >1.5 time ULN during Study 1042-0603.
• Have a history of malignancy within the past 2 years, with the exception of basal cell carcinoma.
• Seizures secondary to illicit drug or alcohol use, infection, neoplasm, demyelinating disease, degenerative neurological disease, or central nervous system (CNS) disease deemed progressive, metabolic illness, or progressive degenerative disease.
• Have active suicidal plan/intent, or have had active suicidal thoughts in the past 6 months. Have a history of an actual suicide attempt in the last 5 years or more than 1 lifetime actual suicide attempt as classified by the Columbia-Suicide Severity Rating Scale (C-SSRS).
• Have a history of drug or alcohol abuse within the past 5 years. As with other AEDs, the use of alcohol is not advised.
• Are currently following or planning to follow a ketogenic diet.
• Current use of vigabatrin or ezogabine (retigabine; Potiga; Trobalt) is not permitted.
• Females who are pregnant, currently breastfeeding or planning to become pregnant during the study.
• Inability/unwillingness to withhold grapefruit and grapefruit juice from diet during the entire clinical trial.

Safety Population: All participants who signed informed consent and took one dose of study medication in this study.

Up to Week 104

Adverse events and Serious adverse events were collected in Safety Population.