Make a list of the biotech and pharmaceutical companies developing marijuana-based, or cannabis, treatments, and GW Pharmaceuticals PLC (GWPH​) is most certainly going to occupy the top spot. The U.K.-based biopharmaceutical company, founded in 1998, is involved in the development of medications using its exclusive cannabinoid product platform. The company is currently assessing the potential of cannabinoids for treating a number of central nervous system disorders—multiple sclerosis and epilepsy for instance—cancer, type 2 diabetes and neurodegenerative diseases. Here are the marijuana-based treatments that GW Pharma is currently working on.

Sativex (Nabiximols)

Sativex, GW Pharma’s first and its only commercially available cannabis-based medication, is an oromucosal spray—or mouth spray—currently indicated as a treatment for symptom improvement of moderate to severe spasticity due to multiple sclerosis in adult patients who haven’t responded sufficiently to other anti-spasticity treatments. The medication was derived from the cannabis plant and its active cannabinoids include tetrahydrocannabinol (THC) and cannabidiol (CBD). It was the first approved cannabis-based medication in the U.K.

Sativex is already being sold in 16 countries outside the U.S. The medication has received regulatory approval in 14 additional countries and the company anticipates commercial launches for the product in these countries over the next 12 months. According to the information provided by research firm Evaluate, Sativex had worldwide sales of $21 million in 2016.

GW Pharma had hopes of expanding Sativex’s label to include the treatment of cancer pain, but three clinical trials conducted in collaboration with Japanese drugmaker Otsuka, a co-developer for Sativex, failed in 2015. Since the failed trials, collaboration revenue from Otsuka has declined, leading to shrinking overall revenue for GW Pharma. On TTM basis, GWPH’s revenue has dropped by roughly 80% since the end of 2014.


After it became clear that Sativex wouldn’t make it as a treatment for cancer pain, GW Pharma shifted focus to another lead product candidate in Epidiolex. Epidiolex is a solution of pure-derived CBD, being developed for the treatment of a number of severe early-onset, treatment-resistant epilepsy syndromes. Dravet syndrome, Lennox-Gastaut syndrome (LGS), Tuberous Sclerosis Complex (TSC) and Infantile Spasms (IS) are some of the epilepsy syndromes that GW Pharma is targeting with Epidiolex.

GW Pharma currently has six pivotal phase III clinical trials for Epidiolex in all—two in Dravet syndrome, two in Lennox-Gastaut syndrome, one in infantile spasms and one in tuberous sclerosis complex.

Last year, the company announced a raft of positive results from the pivotal phase III trials in Dravet syndrome and Lennox-Gastaut syndrome. Physicians have also administered Epidiolex as part of an expanded access program, in which the FDA allows investigational drugs to be administered to patients with serious or urgently life-threatening diseases where therapeutic alternatives are nonexistent. Physicians reported that Epidiolex helped reduce total seizure, with about 47% of the 261 patients that enrolled in the expanded access program witnessing 50% or more reduction in total seizures.

Given the encouraging results, Epidiolex received an orphan drug designation from the European Medicines Agency (EMA) for the treatment of LGS in March. The company is also working on submitting a new drug application for Epidiolex in the U.S. and Europe this year.

If Epidiolex makes it to the market, analysts polled by Thomson Reuters expect the medication to hit about $1.6 billion in annual sales by 2023, according to Reuters. That’d be a huge addition to the $14.7 million revenue that the company generated last year. 

GWP42006 (CBDV)

GWP42006 is another product candidate from GW Pharma targeting the epilepsy space. Unlike Epidiolex that is cannabidiol based, GWP42006 has cannabidivarin (CBDV) as its primary cannabinoid. Scientists working with GW Pharma published a paper in the September 2012 edition of the British Journal of Pharmacology, citing that GWP42006 could potentially prevent more seizures with fewer of the side effects witnessed with existing antiepileptic drugs. The study also showed that GWP42006 could be more effective when combined with existing antiepileptic drugs.

GW Pharma is also evaluating GWP42006 as a potential treatment for autism spectrum disorders.

GWP42006 is currently in phase II trials for the treatment of epilepsy, while its use for the treatment of autism spectrum disorders is currently phase I clinical trials. GW Pharma expects to commence phase II trials for GWP42006 in autism spectrum disorders in the third quarter of the year.


GWP42003 is a CBD-based pipeline candidate for the treatment of Neonatal Hypoxic-Ischemic Encephalopathy (NHIE). NHIE is a severe brain injury that a child sustains due to deprivation of oxygen during birth. In the 2010 edition of the Early Human Development journal, researchers stated that NHIE occurs in 1.5 to 2.8 of every 1000 births in the U.S. According GW Pharma, 35% of NHIE patients are expected to die in early life, while the condition remains permanent in about 30% of NHIE patients. There are no existing FDA-approved medicines specifically for NHIE. GWP42003 received an orphan status and a fast track designation from the FDA in 2015. The EMA also awarded the pipeline candidate an orphan status in 2015. GW Pharma began phase I trials for the intravenous administration of GWP42003 in the fourth quarter of 2016.

GW Pharma is also trialing GWP42003 as a treatment for schizophrenia, a rare mental disorder that disturbs how a person feels, thinks and behave. GWP42003 as a treatment for schizophrenia in currently in phase II trials. (For related reading, see: First Medical Marijuana ETF Has Launched.)

Other Treatments

GW Pharma is also working on a treatment for recurrent glioblastoma multiforme, or GBM, a severe brain tumor. GBM represents about 46% of the 22,500 new cases of brain cancer reported in the U.S. yearly, according to the New England Journal of Medicine.

GW Pharma has given the codename GWP42002:GWP42003 to the product candidate for the treatment of GBM. The product candidate has received the orphan drug status from the FDA and is currently in phase II trials.