A study to find out the best length of time between ocrelizumab doses for patients with relapsing remitting multiple sclerosis using a trial design with multiple groups and multiple stages

This study is looking for adults aged 18 or older who have been diagnosed with relapsing-remitting MS (RRMS) and are currently taking ocrelizumab. You'll need to have been on ocrelizumab for at least two years (four doses given six months apart) following UK guidelines.

Your level of disability from MS, as measured by a specific scale (called EDSS), needs to be within a certain range – from no disability up to someone who might need a walking aid for longer distances but can still walk. You also need to be willing to continue taking ocrelizumab and agree to have regular MRI scans.

There are some reasons why you might not be able to join. For example, if you've had an MS relapse or new changes on your brain scan (MRI) in the past year, or if you're taking other medicines that affect your immune system. You also wouldn't be able to join if you're pregnant, planning to become pregnant, or if there's any reason you can't have regular MRI scans.

If you join this study, you'll continue to receive ocrelizumab, but the timing of your doses might be different from the standard every six months. You'll have regular appointments at the clinic, which will include medical checks, blood tests, and important brain scans (MRIs) to see how your MS is responding to the treatment. These scans are a crucial part of the study.

The study will compare different groups, with each group receiving ocrelizumab on a different schedule. You won't know which schedule you're on, but your clinical team will be closely monitoring you. The total duration of your participation in the study will be determined by the researchers, but clinical trials usually involve a commitment of several years, including follow-up assessments.