Trial to Evaluate the Effect of Nabiximols Oromucosal Spray on Clinical Measures of Spasticity in Participants With Multiple Sclerosis

Inclusion Criteria: Screening (Visit 1) * Has had a diagnosis with any disease subtype of multiple sclerosis (MS), by revised 2017 McDonald criteria, for at least 12 months prior to Visit 1 and is expected to remain stable for the duration of the trial * Has a Modified Ashworth Scale (MAS) untransformed score of at least 2 in 2 or more of 6 muscle groups (right knee flexors, left knee flexors, right knee extensors, left knee extensors, right plantar flexors, or left plantar flexors) at Visit 1 * Currently receiving optimized treatment with at least 1 oral antispasticity drug (baclofen, tizanidine, and/or dantrolene) that has been stable for at least 30 days prior to Visit 1. Despite optimization, the participant does not have adequate relief of spasticity symptoms, including muscle spasms. Optimization of antispasticity medications is defined as having reached the most efficacious and best tolerated dose according to the relevant local prescribing information. The participant must be willing to maintain the same antispasticity medication and not plan to initiate a new course of physiotherapy for the duration of the trial. * If currently receiving an approved MS disease-modifying therapy, it must be at a stable dose for at least 3 months prior to Visit 1 and is expected to remain stable for the duration of the trial. * If currently receiving dalfampridine or fampridine, it must be at a stable dose for at least 3 months prior to Visit 1 and is expected to remain stable for th…