A clinical trial to test the safety of RO7121932 at different dose levels in people living with multiple sclerosis; determine how well it is tolerated by trial participants; measure how the body absorbs, distributes, and gets rid of it; and find out what effects, good or bad, RO7121932 has on trial participants.

1. Why is the B-Shuttle clinical trial needed?
RO7121932 (Study Drug) is being developed for the possible treatment of MS. The Study Drug combines an antibody with a “brain shuttle” module, which delivers it to the brain (see here for more information on how the brain shuttle acts as a shuttle and delivers the Study Drug to the brain). Antibodies act like your body’s immune system and attach themselves to certain cells to attack germs and other illnesses in your body. The Study Drug attaches to certain types of white blood cells (B cells) and reduces their number to stop your immune system from attacking the myelin around the nerve cells. Since B cells are also found in the brain, attaching the antibody to the “brain shuttle” will allow us to also decrease this B-cell population. These B cells, especially those in the brain, are thought to play a role in MS.

2. How does the B-Shuttle clinical trial work?
This clinical trial is recruiting people who have a health condition called multiple sclerosis (MS), but have not experienced a relapse or new MRI activity for 12 months. People with relapsing (RMS) and progressive (PMS) are eligible. More information can be found in section 4.

The purpose of this clinical trial is to test the safety of RO7121932 at different doses and to understand the way the body processes RO7121932. 

If you are eligible, you will be given one dose of the Study Drug (RO7121932). After doing some tests to confirm you are suitable for the trial, you will come into the clinical unit for the Study Drug administration and stay for two nights so that your health can be monitored. After leaving the clinical unit on the third day, there will be at least 10 outpatient hospital visits (six times in the first month and then four times, once per month over the next four months; the duration will vary depending on the procedures that will be performed). These hospital visits will include checks to see how you are responding to the treatment and any side effects you may be having. In total, the time commitment for you is approximately 24 weeks. You are free to leave the clinical trial at any time.

3. What are the main endpoints of the B-Shuttle clinical trial?
The main clinical trial endpoint (the main results that are measured in the trial to see if the Study Drug has worked) are 

• side effects - how often, how bad they are and why they might have occurred 
• blood and urine results - reviewing trends in certain tests to see if the Study Drug is causing changes in your body 
• vital signs (pulse rate, blood pressure) and electrocardiogram (ECG, measurements of your heart rhythm) - reviewing trends in changes after the Study Drug has been taken. 
  
• Changes in suicide risk

The other clinical trial endpoints are measuring how the body absorbs, distributes, and gets rid of the Study Drug in blood and spinal fluid; and finding out what effects, good or bad, RO7121932 has on trial participants.

4. Who can take part in this clinical trial?
You can take part in this trial if you:

• Are aged 18 to 55 years, inclusive.
• Have non-active (have not experienced a relapse or new MRI activity for 12 months) MS: relapsing MS (RMS) or progressive MS (PMS).
• Have an Expanded Disability Status Scale score ≤ 6.0 at Screening. 
• Are not on any therapy for controlling MS symptoms or are not planning on starting any MS therapy for the whole trial duration.

You may not be able to take part in this trial if you:

• Have any other disorders of the brain that may mimic MS.
• Have active or uncontrolled infections, including exhibiting symptoms consistent with severe acute respiratory syndrome coronavirus 2  (SARS-CoV-2) within 6 weeks prior the start of the participation in the trial.
• Have a current diagnosis of epilepsy.
• Have any illness or major diseases that in the Doctor's judgment may affect interpretation of trial results or patient safety.
• Have received previous treatment with B cell-depleting therapies (e.g., rituximab, ocrelizumab, or ofatumumab), alemtuzumab, daclizumab, cladribine, mitoxantrone, cyclophosphamide, total body irradiation, bone marrow transplantation and bone marrow stem cell transplantation.
• Are currently receiving or have taken natalizumab in the last two years.
• Have received treatment with Botox for limb spasticity within 24 weeks before Screening.
• Have had a drug or alcohol addiction within the past year.
• Have a history of cancer within 10 years prior to Screening.
• Received a live or live-attenuated vaccine within 6 weeks prior to the start of the trial. Influenza and/or COVID-19 vaccination is permitted if the inactivated vaccine formulation is administered.

5. What treatment will participants be given in this clinical trial?
In this trial, 6 different dose levels of the Study Drug (RO7121932) are planned to be tested, one per cohort as indicated in the diagram below. Everyone who joins this clinical trial will be given a single dose of RO7121932, as an intravenous infusion (via a tube linked to a small needle in your vein). After each cohort is complete, the test results will be reviewed. The next cohort will start at a higher dose level after the previous dose level has been shown to be safe and well tolerated in previous participants. 

In each dose group (cohort), only one participant (called sentinel) will receive the Study Drug at first. If this is assessed to be safe, and at least 36 hours have gone by since the sentinel participant in this dose group has received the Study Drug, the remaining participants of the same dose group will receive the Study Drug.

6. Are there any risks or benefits in taking part in this clinical trial?
The safety or effectiveness of the Study Drug is not known at the time of the trial. Most trials involve some risks to the participant, although it may not be greater than the risks related to routine medical care or the natural progression of the health condition. You will be told about any risks and benefits of taking part in the clinical trial, as well as any additional procedures, tests, or assessments you will be asked to undergo. These will be described in an informed consent document (a document that provides people with the information they need to make a decision to volunteer for a clinical trial). Potential participants should also discuss these with members of the research team and with their usual health care provider. Anyone interested in taking part in a clinical trial should know as much as possible about the trial and feel comfortable asking the research team any questions about the trial.

Risks associated with the clinical trial Study Drug (RO7121932)
RO7121932 has not yet been tested in humans.  For this reason, the side effects (an unwanted effect of a drug or medical treatment) of this drug are not known at this time. Side effects can be mild to severe and even life threatening, and can vary from person to person. You will be told about the potential side effects, based on laboratory studies or knowledge of similar drugs. 

RO7121932 will be given by intravenous infusion (involves inserting a needle into the vein of your arm). You will be told about any known side effects of intravenous infusion or risks associated with study procedures.

Potential benefits associated with the clinical trial
There is no guarantee that you will receive any benefits from this study, and taking part in this study may or may not cause your health to improve. Because this is an investigational therapy being used in a dose-ranging first-in-human trial, you will receive a dose that is not expected to have much, if any, effectiveness on treating or preventing progression of your disease. Information from this study may help doctors learn more about the Study Drug and the treatment of MS. This information may benefit other patients with MS or a similar condition in the future.