Clinical Trials Undertaken Of New Treatment Option For Rare Form Of Epilepsy

A neuroactive steroid drug known as ganaxolone has been heralded as a new treatment option for a rare form of Epilepsy with positive clinical results so far.

The rare form of epilepsy known as PCDH19, a paediatric orphan indication of epilepsy, only affects a small number of people. With around 30,000 cases of the illness reported in the US, no approved therapies currently exist, which means there is a significant number of patients with unmet needs.

The only treatment options available for the disorder are off-label drugs such as benzodiazepines, levetiracetam, valproate, and phenytoin, which only work to alleviate the symptoms of this form of epilepsy. Current treatments have also been found to be ineffective in young children. However, ganaxolone is being touted as the next step as clinical trials have proven that the drug can help treat children.

The form of epilepsy is caused by an inherited mutation within the X chromosome and generally effects females. The illness is characterised by early onset and cluster seizures that can lead to behavioural disturbances along with sensory and cognition impairment.

Ganaxolone acts as a central nervous system (CNS) selective GABAA modulator and shows anticonvulsant activity. It was originally developed as a treatment for adults with drug-resistant focal onset seizures but failed in Phase III clinical trials.

In 2015 the drug was granted Orphan Drug Designation by the FDA passing through Phase II exploratory open label clinical trials with 64% of subjects (7 out of 11) showing seizure reduction compared to baseline with no ill effects. These were the first formal clinical trials carried out for PCDH19 epilepsy.

The drug is said to increase signalling at existing receptors, normalising GABA activity. This leads to a reduction in hyperactivity and other symptoms associated with the disorder. However, more research needs to be conducted in this area.

The trials of this drug are important due to the number of unmet cases, especially in children. If ganaxolone is approved it would be the first viable treatment to fit the needs of patients living with the illness, reducing paediatric seizures and improving both cognitive skills and quality of life.

November 2016