Epidiolex is a liquid formulation of pure plant-derived Cannabidiol (CBD) as a treatment for various orphan pediatric epilepsy syndromes. GW has been conducting pre-clinical research of CBD in epilepsy since 2007. This research has shown that CBD has significant anti-epileptiform and anticonvulsant activity using a variety of in vitro and in vivo models and that it has the ability to treat seizures in acute animal models of epilepsy with significantly fewer side effects than existing AEDs.
GW’s strategy for the development of Epidiolex within the field of childhood-onset epilepsy is to initially concentrate formal development efforts on four orphan indications: Dravet syndrome, LGS, TSC, and IS, each of which are severe infantile-onset, drug-resistant epilepsy syndromes. GW expects to further expand the potential market opportunity of Epidiolex by targeting additional orphan seizure disorders.
In addition to Epidiolex, our epilepsy product candidates also include GWP42006, which features CBDV as the primary cannabinoid. CBDV is distinct in chemical structure to CBD and has also shown anti-epileptic properties across a range of in vitro and in vivo models of epilepsy. In a paper published in the September 2012 issue of The British Journal of Pharmacology, GWP42006 strongly suppressed seizures in six different experimental models commonly used in epilepsy treatment. GWP42006 was also found to provide additional efficacy signals when combined with drugs currently used to control epilepsy. Genetic biomarkers for response have been identified.
We have completed a Phase 1 trial of GWP42006 in 66 healthy subjects. In this trial, GWP42006 was well tolerated even at the highest tested dose. There were no serious or severe adverse events reported, nor any withdrawals due to adverse events. We have commenced a Phase 2 trial of GWP42006 in 130 patients with epilepsy and expect results in 2017. As part of our agreement with the government of New South Wales in Australia, we expect an additional trial of GWP42006 to commence in 2016 in children with treatment-resistant epilepsy. We believe that GWP42006 has the potential for development in the field of pediatric epilepsy as well as the broader epilepsy market.
Autism Spectrum Disorders
Many of the pediatric intractable epilepsy conditions within the Epidiolex Expanded Access Program share considerable overlap with Autism Spectrum Disorders (ASD). Early clinical observations from treating physicians suggest a potential role for cannabinoids in addressing certain problems associated with ASD; they may be able to treat deficits in cognition, behavior and communication.
GW is working with investigators to gain clinical experience in the use of different cannabinoids for the treatment of Autism Spectrum Disorders and we have a number of ongoing initiatives to evaluate a range of cannabinoids in pre-clinical models of ASD, including an assessment of the effect of cannabinoids on cognitive and behavioral function in animal models of conditions characterized as being on the 'autism spectrum'. These animal models include both genetically determined abnormalities of neurobehaviour, and chemically-induced models, and include Rett syndrome and Fragile X among others.
We are evaluating a product containing a proprietary CBD:THC combination in the treatment of recurrent glioblastoma multiforme, or GBM, a particularly aggressive brain tumor which is considered a rare disease by the FDA and the European Medicines Agency.
A recent study carried out in collaboration with us by specialists at St George’s, University of London, was the first to show an effect on brain tumors when combining cannabinoids with irradiation. This research, published in Molecular Cancer Therapeutics, showed that tumor growth in mouse brain was significantly slowed when this combination of THC and CBD was used with irradiation and tumor inhibition was higher than observed with irradiation alone.
In 2014, we commenced an early proof of concept Phase 1b/2a clinical trial in 20 patients with recurrent GBM evaluating GWP42002:GWP42003 (THC/CBD) in combination with temozolomide, the current standard of care. This study is a two part study with an open-label phase to assess safety and tolerability followed by a double blind, randomized, placebo-controlled phase with patients randomized to receive active or placebo. The first phase, an open-label safety evaluation of GWP42002:GWP42003 comprising two cohorts of three patients each completing two cycles (months) of treatment is now complete. Safety data from these initial patient cohorts has been assessed by the independent safety monitoring board and their approval was given to proceed into a Phase 2a placebo-controlled phase. We have now completed recruitment of the 20 patient placebo-controlled 2a phase of the trial.
Neonatal Hypoxic-Ischemic Encephalopathy (NHIE)
NHIE is acute or sub-acute brain injury due to asphyxia caused during birth resulting from deprivation of oxygen during birth (hypoxia) as a result of a sentinel event such as ruptured placenta, parental shock and even increased heart rate. Hypoxic damage can occur to most of the infant’s organs, but brain damage is the most serious and least likely to heal, resulting in encephalopathy. This can later manifest itself as either mental retardation (including developmental delay and/or intellectual disability) or physical disabilities such as spasticity, blindness and deafness. The exact timing and underlying causes of these outcomes remains unknown but it is widely recognized that interventions need to be administered within six hours of hypoxic insult.
We are developing an intravenous CBD formulation in the treatment of NHIE. In April 2015, we received Orphan Drug Designation from the FDA for CBD for the treatment of NHIE in July 2015 and we received Orphan Drug Designation from the EMA for CBD for the treatment of perinatal asphyxia, an alternative term for the same condition. In addition, in July 2015 we received Fast Track Designation from the FDA.
Schizophrenia is a chronic disease that manifests through disturbances of perception, thought, cognition, emotion, motivation and motor activity. Over a lifetime, about 1% of the population will develop schizophrenia.
Our product, GWP42003, has shown notable anti-psychotic effects in accepted pre-clinical models of schizophrenia and importantly has also demonstrated the ability to reduce the characteristic movement disorders induced by currently available anti-psychotic agents.
In September 2015, we announced top line results from an exploratory Phase 2a placebo-controlled clinical trial of CBD in 88 patients with schizophrenia who had previously failed to respond adequately to first line anti-psychotic medications. We believe that the signals demonstrated in this trial, together with the safety profile, provide us with the prospect of new and distinct cannabinoid neuropsychiatric product pipeline opportunity, as the mechanism of CBD does not appear to rely on the dopamine D2 receptor augmentation of standard antipsychotics.
We are now analyzing the data to fully understand the appropriate next steps regarding product development in schizophrenia with future research likely focused on pediatric orphan neuropsychiatric indications.
Cerebral Palsy in Children
GW is currently conducting a study to assess the efficacy, safety and tolerability of Sativex as an adjunctive treatment to existing anti-spasticity medications in children aged 8 to 18 with spasticity due to cerebral palsy or traumatic central nervous system injury who have not responded adequately to existing anti-spasticity medications. This study is a randomized, double-blind, placebo-controlled study followed by a 24-week open label extension phase and is expected to enroll approximately 70 patients.