GW’s pipeline in the field of epilepsy currently includes two product candidates: CBD (Epidiolex® in the US) and GWP42006 (CBDV).
Cannabidiol (Epidiolex® )
GW’s liquid formulation of pure plant-derived cannabidiol (CBD) is being investigated 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 three orphan indications: Dravet syndrome, LGS, and TSC, 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 for development.
In addition to CBD oral solution, 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 evaluating 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 2a placebo-controlled study to evaluate the efficacy and safety of GWP42006 in 162 patients with epilepsy. In the trial’s preliminary top-line results, both active and placebo arms showed similar reductions in focal seizures of approximately 40 percent. In the trial, GWP42006 was generally well tolerated. We believe that GWP42006 has the potential for development in the field of epilepsy and the Company expects to continue exploring potential development opportunities for this compound in the field of epilepsy.
Autism Spectrum Disorders
Many of the childhood-onset intractable epilepsy conditions within the CBD expanded access program share considerable overlap with ASDs and these conditions often fall within the orphan disease space. Initial clinical observations from treating physicians suggest a potential role for cannabinoids in addressing problems associated with ASDs such as deficits in cognition, behavior, and communication.
GW has evaluated the cannabinoids CBD and CBDV in both general and syndromic pre-clinical models of ASDs yielding promising signals on cognitive and social functioning endpoints as well as repetitive behaviors. These animal models include both genetically determined and chemically-induced models of neurobehavioral abnormalities, and include Rett syndrome and Fragile X syndrome among others.
GW is expanding its clinical evaluation in Rett Syndrome to now include GW’s CBD oral solution. The Company believes, based on promising pre-clinical data and observations from the Company’s pivotal and expanded access studies, that CBD offers potential in treating ASDs and considers that Epidiolex offers the most rapid development path for patients that suffer from this very challenging condition.
We are evaluating a product containing a proprietary CBD:THC combination in the treatment of recurrent glioblastoma, 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 February 2017, GW completed a placebo-controlled Phase 2 study of a combination of CBD and THC in 21 patients with recurrent glioblastoma multiforme, or GBM, the most common and most aggressive brain cancer. This study evaluated a number of safety and exploratory efficacy endpoints and showed that patients with documented recurrent glioblastoma treated with CBD:THC as add-on therapy to dose-intense temozolomide had an 83 percent one-year survival compared with 44 percent for patients on placebo (plus dose-intense temozolomide) (p=0.042). Median survival time for the CBD:THC group was greater than 662 days compared with 369 days in the placebo group. Two year survival was 50 percent for patients treated with CBD:THC +TMZ versus 22 percent for patients treated with placebo + TMZ. Median survival time for the CBD:THC group was greater than 662 days compared with 369 days in the placebo group. In this study, CBD:THC was generally well tolerated.
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.
GW has received Orphan Drug Designation and Fast Track Designation from the FDA for CBD for the treatment of NHIE. GW has also received Orphan Drug Designation from the EMA for CBD for the treatment of perinatal asphyxia, an alternate term that describes the same condition. Under an IND, GW has completed a Phase 1 trial of GWP42003 in healthy volunteers for an intravenous CBD formulation in the treatment of NHIE. GW plans to consult with FDA on the most appropriate design for an efficacy and safety study in neonates.
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.
GW’s cannabinoids have shown notable anti-psychotic effects in pre-clinical models of schizophrenia and in September 2015, we announced positive 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. GW is evaluating appropriate next steps regarding product development in schizophrenia with future research likely focused on pediatric orphan neuropsychiatric indications.
GW Sativex MS Trials
GW has sponsored clinical trials studying the effect of Sativex on symptoms of MS including; spasticity, neuropathic pain and bladder control. In all of these trials, patients remained on their existing medication during the course of the trial. All symptom relief obtained from Sativex in these trials was over and above any effect achieved by the patients' existing treatments. All completed and published trials are listed below:
Michael G. Serpell, William Notcutt, Christine Collin. J Neurol 2013;260:285-295.
Notcutt W, Langford R, Davies P, Ratcliffe S, Potts R. Mult Scler. 2012 Feb;18(2):219-28.
A. Hilliard, C. Stott, S.Wright, G. Guy, G. Pryce, S. Al-Izki, C. Bolton, and G. Giovannoni. International Scholarly Research Network ISRN Neurology Volume 2012;2012:802649.
A randomized, double-blind, placebo-controlled, parallel-group, enriched-design study of nabiximols* (Sativex® ), as add-on therapy, in subjects with refractory spasticity caused by multiple sclerosis.
Novotna A, Mares J, Ratcliffe S, Novakova I, Vachova M, Zapletalova O, Gasperini C, Pozzilli C, Cefaro L, Comi G, Rossi P, Ambler Z, Stelmasiak Z, Erdmann A, Montalban X, Klimek A, Davies P; Sativex Spasticity Study Group. Eur J Neurol. 2011 Sep;18(9):1122-31
Wade DT, Collin C, Stott C, Duncombe P. MS 2010;16 (6), 707-714
Collin C, Ehler E, Waberzinek G, Alsindi Z, Davies P, Powell K, Notcutt W, O'Leary C, Ratcliffe S, Nováková I, Zapletalova O, Piková J, Ambler Z. Neurological Research, 2010; 32(5), 451-459
Collin C, Davies P, Mutiboko IK, Ratcliffe S. European Journal of Neurology. 2007;14:290-6.
Wade DT, Makela PM, House H, Bateman C, Robson P. Mult Scler. 2006 Oct;12(5):639-45.
Perras C. Issues Emerg Health Technol. 2005 Sep(72):1-4.
Wade DT, Makela P, Robson P, House H, Bateman C. Multiple Sclerosis. 2004;10:1-8.
Kavia RB, De Ridder D, Constantinescu CS, Stott CG, Fowler CJ. Mult Scler. 2010 Nov;16(11):1349-59.
Brady CM, DasGupta R, Dalton C, et al. Mult Scler. 2004;10(4):425-33
Barnes MP. Expert Opin Pharmacother. 2006 Apr;7(5):607-15.
William G. Notcutt. Prim Health Care Res Dev. 2012 Jul 12:1-8.
S. Wright, P. Ducombe and D.G. Altman. Trials 2012; 13:189. DOI:10.1186/1745-1625-13-189.