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Study on the Safety and Efficacy of CLS12311 and Autologous Red Blood Cells for Patients with Relapsing Remitting Multiple Sclerosis

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as Relapsing Remitting Multiple Sclerosis (RRMS), which is a type of multiple sclerosis characterized by periods of new or increasing symptoms followed by periods of partial or complete recovery. The study is testing a new treatment called CLS12311, which is a type of cell therapy. This treatment involves using a special form of red blood cells that are coupled with peptides, which are small proteins. The goal is to see if this treatment can help reduce the number of new lesions, or damaged areas, in the brain that are associated with inflammation in patients with RRMS.

The purpose of the study is to assess the safety and effectiveness of CLS12311 in patients with RRMS. The study will be conducted in two parts. In the first part, the focus will be on understanding how safe and tolerable the treatment is for patients. In the second part, the study will also look at how well the treatment works in reducing new brain lesions, which are detected using magnetic resonance imaging (MRI). Patients will receive the treatment through an intravenous infusion, which means it will be delivered directly into a vein.

Throughout the study, researchers will monitor patients for any side effects and changes in their condition. The study will also explore how the treatment affects certain immune cells and markers in the blood, which can provide insights into how the treatment works. The study is expected to continue until 2027, with recruitment of participants starting in 2024. This research aims to provide new insights into potential treatments for RRMS and improve the understanding of how this condition can be managed more effectively.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes a review of medical history and a baseline MRI scan to identify new brain lesions.

    Eligibility criteria include being diagnosed with relapsing-remitting multiple sclerosis (RRMS) according to the 2017 McDonald criteria, aged between 18 and 55, and having a disease duration of less than 10 years.

  2. Step 2

    Baseline period

    During the baseline period, additional MRI scans are performed to establish the number of new brain lesions. This helps in determining the patient's qualification for Part B of the study.

    Patients must have at least two new brain lesions on two MRI scans during this period to qualify for Part B.

  3. Step 3

    Treatment phase

    The treatment involves the administration of autologous uncoupled red blood cells (RBCs) through intravenous infusion. The active substance is referred to as CLS12311.

    The treatment phase is divided into two parts: Part A focuses on safety and tolerability, while Part B also assesses the efficacy of the treatment in reducing new brain lesions.

  4. Step 4

    Monitoring and follow-up

    Throughout the treatment phase, regular monitoring is conducted to assess safety and efficacy. This includes tracking any adverse events and changes in disease activity through clinical evaluations and MRI scans.

    The primary goal is to evaluate the safety and tolerability of CLS12311, as well as its effectiveness in reducing new brain lesions.

  5. Step 5

    End of study

    The study is expected to conclude by March 2027. At the end of the study, a final assessment is conducted to evaluate the overall outcomes of the treatment.

    Participants are informed of the results and any potential next steps based on the findings of the study.

Who can join the trial?

10 criteria

  • Must have **Relapsing Remitting Multiple Sclerosis (RRMS)** according to the 2017 McDonald criteria.
  • Must be between **18 and 55 years old**.
  • Must have had the disease for **less than 10 years** since diagnosis.
  • Must have an **EDSS score** between 0 and 5.5. The EDSS is a scale used to measure disability in people with multiple sclerosis.
  • For Part B, must have had **at least 1 relapse** or new brain lesions in the past 12 months.
  • Must be either untreated or have stopped therapy for a certain period. Patients should not be eligible for approved therapies or have chosen not to receive them after being informed.
  • Sexually active women who can have children must agree to use a **highly effective method of birth control** during the treatment and for at least 4 weeks after the last dose.
  • Men must agree to use **condoms** during the treatment and for at least 4 weeks after the last dose unless they are surgically sterile.
  • Must have received the **basic COVID-19 vaccination**, which means two doses of a two-dose vaccine, or one dose of a single-dose vaccine, or a combination of vaccination and infection.
  • For Part B, must have **2 or more new brain lesions** on two MRI scans during the baseline phase. An MRI is a type of scan that creates detailed images of the inside of the body.

Who cannot join the trial?

5 criteria

  • Patients who do not have Relapsing Remitting Multiple Sclerosis (RRMS) cannot participate. RRMS is a type of multiple sclerosis where symptoms come and go.
  • Patients who are not within the specified age range for the study cannot participate. The age range is not specified here, but it is important for eligibility.
  • Patients who are not willing to undergo brain magnetic resonance imaging (MRI) cannot participate. An MRI is a scan that uses magnets and radio waves to create pictures of the inside of the body.
  • Patients who are part of a vulnerable population, which may include groups like children or pregnant women, cannot participate unless specified otherwise.
  • Patients who do not meet other specific health criteria set by the study cannot participate. These criteria are not detailed here but are important for safety and accuracy.
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Investigated drugs

CLS12311 is an investigational therapy being studied for its safety and effectiveness in patients with relapsing-remitting multiple sclerosis (RRMS). This therapy involves using the patient's own red blood cells, which are coupled with specific peptides. The goal is to see if this treatment can reduce the number of new lesions in the brain, which are indicators of inflammation and disease activity in RRMS.

What is already known about the treatment

CLS12311 – This medication is administered through autologous peptide-coupled red blood cells, which are introduced into the patient's body. It is currently being studied in clinical trials for its safety and effectiveness in treating Relapsing Remitting Multiple Sclerosis (RRMS). The main therapeutic indication is to reduce the number of new lesions in the brain, as seen on MRI scans, which are indicative of inflammatory disease activity in RRMS. At the molecular level, the mechanism of action involves modulating the immune response to decrease inflammation. It is classified pharmacologically as an immunomodulatory agent.

Investigated diseases

Relapsing Remitting Multiple Sclerosis (RRMS) – This is a form of multiple sclerosis characterized by episodes of new or increasing neurological symptoms, known as relapses, followed by periods of partial or complete recovery. During these relapses, inflammation damages the protective covering of nerve fibers in the central nervous system, leading to symptoms such as fatigue, numbness, vision problems, and difficulty with coordination and balance. The disease progresses with alternating periods of relapses and remissions, where symptoms may improve or disappear entirely. Over time, some individuals may experience a gradual worsening of symptoms, even during remission phases. The frequency and severity of relapses can vary widely among individuals. RRMS is the most common form of multiple sclerosis at the time of diagnosis.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase ITrial ID2023-510127-30-00Protocol codeMSB-IG-H-2101Estimated enrolment12 patientsSponsorCellerys AG

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