GW Pharmaceuticals has initiated the first US phase III clinical trial studying nabiximols for multiple sclerosis (MS) associated spasticity.

Outside the US, nabiximols is known as Sativex and is approved for use to treat MS spasticity in over 25 countries, including the UK. It is a ‘complex botanical medicine’ and is derived from extracts of the cannabis plant and administered as an oral spray.

In three previous European phase III studies, nabiximols was shown to be well-tolerated and provided continued reductions in patient-reported spasticity for individuals with MS.

According to GW, the phase III trial is one of five pivotal studies planned for the cannabidiol in MS spasticity, with the remaining studies in track to launch either later this year or in 2021.

GW expects that a positive result in any one of these five studies will enable an NDA submission to the US Food and Drug Administration (FDA), potentially as early as mid-2021. Currently, Sativex is not approved for any indication in the US.

“We are excited that the US phase III clinical program evaluating nabiximols in multiple sclerosis spasticity is now recruiting patients, after a delay due to COVID-19,” said Justin Gover, GW’s chief executive officer.

“Given the rigorous studies already conducted on the medicine outside of the US, and positive discussions with the FDA, we believe that we have a clear path to an NDA submission, potentially as soon as next year, and a significant second product opportunity for GW in the US.

“Now is the ideal time to develop nabiximols in the US as research shows a significant percentage of spasticity patients are today self-medicating using unapproved cannabis products to relieve their spasticity,” he added.