Ganaxolone is a first-in-class synthetic neurosteroid being studied for the treatment of epilepsy, posttraumatic stress disorder and fragile-X syndrome.

Ganaxolone (3α-hydroxy-3β-methyl-5α-pregnan-20-one) is the 3β-methylated synthetic analog of the neurosteroid allopregnanolone, a metabolite of progesterone. In seizure disorders, extrasynaptic GABA A receptors where neurosteroids bind with high affinity have been implicated in maintaining GABA inhibitory tone counteracting neuronal hyperexcitation. Additionally, decreases in levels of allopregnanolone or neurosteroid binding site protein expression have been associated with several neuropsychiatric disorders: anxiety, posttraumatic stress disorder, depression, fragile-X syndrome, and Niemann-Pick disorder. In all of these disorders, administration of allopregnanolone in animal models or to human subjects has been shown to improve symptoms. An important distinction between allopregnanolone and ganaxolone is that while they share the same binding profile, ganaxolone does not appear to generate metabolites that have significant classical nuclear steroid hormone activity (For substance summary, please click here.) and therefore is not expected to have steroidal side effects. Ganaxolone has been administered to more than 900 healthy adult volunteers and patients in Phase 1 and Phase 2 studies. The results show ganaxolone to be well-tolerated and safe in adults, children and infants.

Marinus has invented proprietary nanoparticle formulations of ganaxolone [U.S. Patent # 7,858,609] which demonstrate enhanced bioavailability and stability as compared to previous efforts to formulate this water insoluble drug. Marinus has pending patent applications pertaining to the efficient manufacture of ganaxolone.