A clinical trial to compare satralizumab with placebo in people with autoimmune encephalitis

 1. Why is the Cielo clinical trial needed?

Acute encephalitis is a rare and debilitating disease of the brain caused by inflammation. Autoimmune encephalitis (AIE) includes disorders that are associated with an identifiable cause, such as autoantibodies. Autoantibodies are antibodies (a type of immune protein) that mistakenly attack healthy tissues and proteins. NMDAR AIE and LGI1 AIE are two of the most common types of AIE and are caused by the production of autoantibodies against NMDAR and LGI1 proteins, respectively.

There are currently no approved therapies for NMDAR AIE or LGI1 AIE, highlighting a significant need for further research into treatment for these specific types of AIE.

The purpose of this clinical trial is to assess the effectiveness and safety of satralizumab in patients with NMDAR AIE or LGI1 AIE.

2. How does the Cielo clinical trial work?

This clinical trial is recruiting people who have a health condition called NMDAR AIE or LGI1 AIE. People can take part if they are at least 12 years old and have been diagnosed with NMDAR AIE, or at least 18 years old and have been diagnosed with LGI1 AIE.

The purpose of this clinical trial is to compare the effects, good or bad, of satralizumab against placebo in people with NMDAR AIE or LGI1 AIE. People who take part in this clinical trial will receive either satralizumab or placebo.

Participants will be given the clinical trial treatment satralizumab OR placebo for 52 weeks. Participants will be seen by the clinical trial doctor every four weeks to be given their clinical trial treatment. These hospital visits will include checks to see how the participant is responding to the treatment and any side effects they may be having. Depending on whether participants choose to take part in an optional extension period of the trial (which will last for at least two years), their total time in the clinical trial may last for up to five years (including follow-up appointments). Participants are free to stop trial treatment and leave the clinical trial at any time.

3. What are the main endpoints of the Cielo clinical trial?

The main clinical trial endpoint (the main result that is measured in the trial to see if the medicine has worked) is the proportion of participants who show an improvement in their degree of disability or dependence when performing daily activities, after 24 weeks of treatment. 

The other clinical trial endpoints include the number and severity of adverse events (any unexpected medical problems that occur while receiving the treatment), and the time for participants to achieve seizure freedom (no seizures for at least six weeks). 

4. Who can take part in this clinical trial?

People can take part in this trial if they have been diagnosed with NMDAR AIE or LGI1 AIE, with symptoms that started no longer than nine months ago.

People may not be able to take part in this trial if they have a history of cancer or certain other medical conditions, or if they have been treated with particular medications. People who are pregnant or breastfeeding will not be able to take part in this clinical trial.

5. What treatment will participants be given in this clinical trial? 

Everyone who joins this clinical trial will be put into one of two groups randomly (like flipping a coin) and given either:

●          Satralizumab as a subcutaneous injection (involves inserting a needle under the skin of the abdomen or leg) at Weeks 0, 2 and 4, and then every four weeks until Week 52

●          OR placebo as a subcutaneous injection at Weeks 0, 2 and 4, and then every four weeks until Week 52.

Participants will have a 50% chance of being placed in either the satralizumab or placebo group.

This is a ‘placebo-controlled’ clinical trial, which means that one of the groups will be given a substance with no active ingredients (also known as a ‘placebo’); it looks like the drug being tested. Comparing results from the different groups helps the researchers know whether any changes seen are a result of the drug or occurring by chance.

This is also a double-blind trial, which means that neither the participant nor the clinical trial doctor can choose or know the group the participant is in, until the trial is over. This approach helps to prevent bias based on expectations about what will happen. However, the participant’s clinical trial doctor can find out which group the participant is in if their safety is at risk. If participants choose to enter the extension period of the clinical trial, they can choose to either continue with the original double-blinded treatment they were assigned to, receive satralizumab, or stop clinical trial treatment altogether but continue to attend clinical trial assessments.

6. Are there any risks or benefits in taking part in this clinical trial?

The safety or effectiveness of the experimental treatment or use may not be fully 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. Potential participants will be told about any risks and benefits of taking part in the clinical trial, as well as any additional procedures, tests, or assessments they will be asked to undergo. These will all 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). A potential participant should also discuss these with members of the research team and with their usual healthcare 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 drugs

Participants may have side effects (an unwanted effect of a drug or medical treatment) from the drugs used in this clinical trial. Side effects can be mild to severe and even life-threatening, and can vary from person to person.

Satralizumab

Potential participants will be told about the known side effects of satralizumab, and where relevant, also potential side effects based on human and laboratory studies or knowledge of similar drugs.

Satralizumab and placebo will be given by subcutaneous injection. Participants will be told about any known side effects of subcutaneous injections.

Potential benefits associated with the clinical trial

Participants' health may or may not improve from participation in the clinical trial, but the information that is collected may help other people who have a similar medical condition in the future.

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For more information about this clinical trial see the For Expert tab on the specific ForPatients page or follow this link to ClinicalTrials.gov: https://clinicaltrials.gov/ct2/show/NCT05503264