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Evaluating Higher Dose Nusinersen in Patients with Spinal Muscular Atrophy Previously Treated with Risdiplam

Verified siteInvestigationalNo placebo
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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 Spinal Muscular Atrophy (SMA). SMA is a genetic disease that affects the muscles, leading to weakness and movement difficulties. The study is evaluating a treatment called Nusinersen, which is also known by the code name BIIB058. Nusinersen is administered as a solution for injection directly into the spinal canal, a method known as intrathecal use. The purpose of this study is to assess how well a higher dose of Nusinersen works in improving motor function in patients with SMA who have previously been treated with another medication called Risdiplam.

Participants in this study will receive a higher dose of Nusinersen over a period of time. The study will monitor changes in their ability to use their upper limbs, as well as any side effects they may experience. The study will also track changes in clinical laboratory parameters, heart activity through an Electrocardiogram (ECG), vital signs, and oxygen levels in the blood. The study aims to provide valuable information on the effectiveness and safety of using a higher dose of Nusinersen in treating SMA.

This trial is designed to help understand if increasing the dose of Nusinersen can offer better outcomes for patients with SMA who have already been treated with Risdiplam. The study will continue for several years to gather comprehensive data on the long-term effects and benefits of this treatment approach.

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

    Initiation of treatment

    The study involves the administration of a medication called nusinersen, which is used to treat spinal muscular atrophy (SMA).

    The medication is given as a solution for injection through a method called intrathecal use, which means it is injected into the space around the spinal cord.

  2. Step 2

    Dosage and administration

    Two different dosages of nusinersen are used in the study: 28 mg and 50 mg.

    The specific dosage and frequency of administration will be determined by the study protocol and the healthcare team.

  3. Step 3

    Monitoring motor function

    The primary goal of the study is to evaluate changes in motor function after treatment with higher doses of nusinersen.

    This will be assessed using a tool called the Revised Upper Limb Module (RULM) score, which measures upper limb function.

  4. Step 4

    Monitoring safety and side effects

    Participants will be monitored for any adverse events or serious adverse events throughout the study period, which lasts up to Day 1695.

    Regular checks will be conducted to observe any changes in clinical laboratory parameters, electrocardiogram (ECG), vital signs, and pulse oximetry from the baseline.

  5. Step 5

    Study duration

    The study is expected to continue until July 22, 2027.

    Participants will be involved in the study for the entire duration, with regular assessments and follow-ups as outlined in the study protocol.

Who can join the trial?

12 criteria

  • Have a genetic confirmation of 5q Spinal Muscular Atrophy (SMA), which means a specific change in the SMN1 gene.
  • Be willing to stop taking a medication called risdiplam.
  • Be willing and able to start treatment with HD nusinersen.
  • Have a diagnosis of later-onset SMA, with symptoms starting after the age of 6 months.
  • Be between the ages of 15 and 50 at the time of giving consent to participate.
  • Weigh more than 20 kilograms (about 44 pounds).
  • Have received risdiplam treatment as follows:
    • If you have never taken nusinersen before, you must have been on risdiplam for at least 6 months before joining the study.
    • If you have taken nusinersen before, you must have stopped it for at least 16 months and have been on risdiplam for at least 12 months before joining the study.
    • Be able to perform certain physical tests that are suitable for your age as part of the study.
    • Have a RULM entry item A score of 3 or more. This is a score from a test that measures upper limb movement.
    • Have a RULM total score between 5 and 30 during the screening. This is a total score from the same test.
    • Be nonambulatory, which means not being able to walk 15 feet (about 4.57 meters) on your own without help.

Who cannot join the trial?

8 criteria

  • Participants who have not been previously treated with a medication called risdiplam cannot join the study. Risdiplam is a drug used to treat spinal muscular atrophy.
  • Individuals who have any other serious medical conditions that could interfere with the study cannot participate.
  • Participants who are unable to follow the study procedures or attend the required visits cannot be included.
  • People who are currently participating in another clinical trial cannot join this study.
  • Individuals who have had a recent surgery or are planning to have surgery during the study period cannot participate.
  • Participants who have a history of drug or alcohol abuse cannot be included in the study.
  • Women who are pregnant or breastfeeding cannot participate in the study.
  • Individuals who have an allergy or sensitivity to the study medication or its ingredients cannot join the study.
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Investigated drugs

  • Nusinersen

    is a medication used in the treatment of spinal muscular atrophy (SMA). In this study, a higher dose of nusinersen is being evaluated to see how it affects motor function in patients who have previously been treated with another medication called risdiplam. Nusinersen works by helping to increase the production of a protein that is important for the health and function of motor neurons, which are the nerve cells that control muscle movement.

  • Risdiplam

    is another medication used to treat spinal muscular atrophy (SMA). It is designed to help increase the levels of a protein that is crucial for the survival of motor neurons. Patients in this study have previously been treated with risdiplam before receiving the higher dose of nusinersen. The study aims to understand how switching from risdiplam to a higher dose of nusinersen affects the patients' motor abilities.

What is already known about the treatment

Nusinersen – Nusinersen is administered through an injection into the spinal canal, a method known as intrathecal injection. It is currently approved for use in treating spinal muscular atrophy (SMA) and is well-documented in medical literature for its effectiveness in improving motor function in patients with this condition. The medication works by increasing the production of a protein essential for motor neuron survival, which is deficient in individuals with SMA. Nusinersen is classified as an antisense oligonucleotide, a type of drug that targets specific RNA molecules to modify protein production.

Investigated diseases

Spinal Muscular Atrophy – Spinal Muscular Atrophy (SMA) is a genetic disorder characterized by the progressive loss of motor neurons, which are nerve cells in the spinal cord that control muscle movement. This leads to muscle weakness and atrophy, primarily affecting the muscles closest to the center of the body, such as those in the shoulders, hips, and back. The severity of the disease can vary, with some individuals experiencing significant physical limitations, while others may have milder symptoms. SMA is typically diagnosed in infancy or early childhood, but it can also manifest later in life. As the disease progresses, individuals may experience difficulties with activities such as walking, sitting, and breathing. The progression rate can differ among individuals, with some experiencing a rapid decline in motor function and others having a slower progression.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-505639-11-00Protocol code232SM303Estimated enrolment45 patientsSponsorBiogen Idec Research Limited

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