The trial is testing whether Mavenclad could benefit upper limb movement in MS patients.

The MS Society has announced that the 100th patient has joined the world-first phase 2 clinical trial, ChariotMS, for advanced multiple sclerosis (MS).

The trial has been testing whether Mavenclad (cladribine) can help people living with MS maintain the use of their arms and hands.

Estimated to affect around 130,000 people in the UK, MS is a lifelong condition that affects the brain and spinal cord and can lead to problems with vision, arm or leg movement, sensation or balance.

Funded by the MS Society, ChariotMS is the first ever trial of a potential disease modifying therapy (DMT) that focuses on people with advanced MS, both primary and secondary progressive, with no upper age limit.

Already licensed as a DMT, Mavenclad is used to treat highly active relapsing MS which targets immune activity in the brain to stop the immune system from mistakenly damaging the protective coating around the nerves.

Aiming to enrol 200 patients, the trial has been recruiting those with an Expanded Disability Status Scale score of 6.5 to 8.5, meaning they cannot walk further than 20 metres with two crutches or are unable to walk at all but have some movement in their arms and hands.

Patients will be randomly assigned to orally take either Mavenclad or a placebo over the course of two years.

Using the Nine Hole Peg Test, researchers will measure how hand and arm function changes over time in patients living with the condition to determine whether the drug is effective.

Additionally, they will collect MRI scans of patients involved in the study to see whether Mavenclad has an effect on lesions in the brain.

If successful, Mavenclad could become the first DMT to protect upper limb function and “would unquestionably improve the quality of life of people with MS, helping them to live more independent lives,” said Dr Clare Walton, head of research at the MS Society.