Tests salanersen in babies with spinal muscular atrophy before symptoms appear
Tests salanersen in newborn babies with genetic spinal muscular atrophy and no symptoms yet.
Plain-language title generated from the registry record
Registry title: A Study to Learn About Salanersen's (BIIB115) Effects on Movement and Its Safety When Given Before Symptoms Appear in Babies With Genetically Diagnosed Spinal Muscular Atrophy (SMA)
Key facts
- Where
- Guangzhou, Shanghai, and Zhengzhou, ChinaSee the 3 sites
- Phase
- Phase 3
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for babies up to 42 days old who have a genetic diagnosis of spinal muscular atrophy (SMA) but no symptoms yet, and who have had no SMA treatment.
- Age
- Babies up to 42 days old at the first dose.
- Sex
- Boys and girls can both join.
- Disease stage
- Genetically confirmed 5q SMA with 2 or 3 copies of the SMN2 gene, and no clear signs or symptoms of SMA yet.
- Earlier treatment
- No earlier approved SMA disease-modifying treatment (such as nusinersen, onasemnogene abeparvovec-xioi or risdiplam), no myostatin inhibitor, and no investigational SMA drug.
- Biomarker or test result
- Homozygous deletion or mutation, or compound heterozygous mutation, of the SMN1 gene (5q SMA); 2 or 3 SMN2 copies; ulnar CMAP amplitude of 2 millivolt (mV) or more at screening and before the first dose.
Main reasons for not taking part
- Signs or symptoms that strongly suggest SMA at screening or Day 1 before dosing
- No reflexes (areflexia) at the biceps, knee or ankle
- Low oxygen levels (hypoxemia) as defined in the record
- Neonatal respiratory distress syndrome that needed surfactant or invasive ventilation
- Any reason that raises the risk of complications from lumbar puncture or safety checks
Read by machine on 9 November 2026.
Where in China
- Guangzhou Woman and Children's Medical Center_GuangzhouGuangzhou, ChinaTaking people
- Childrens Hospital of Fudan University_ShanghaiShanghai, ChinaTaking people
- The Third Affiliated Hospital of Zhengzhou University - North CampusZhengzhou, ChinaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Biogen
- Trial code
- NCT07221669EU 2025-524054-34-00
- Record updated
- 23 October 2026
- Original description
In this study, researchers will learn more about the effects and safety of BIIB115, also known as salanersen.Read full original descriptionShow less
An Open-Label Study to Assess the Efficacy and Safety of Multiple Doses of Salanersen (BIIB115) Delivered Intrathecally to Treatment-Naïve, Presymptomatic Infants With Genetically Diagnosed Spinal Muscular Atrophy
In this study, researchers will learn more about the effects and safety of BIIB115, also known as salanersen.
Specifically, researchers will learn more about how salanersen works in babies who have been diagnosed with SMA through genetic testing but have not yet started showing signs or symptoms. Most people with SMA have changes in a gene called survival motor neuron 1, also known as SMN1. These changes lower the amount of SMN protein in their bodies. Without enough of this protein, motor neurons and muscles cannot work properly. A similar gene called SMN2 can help replace some of the lost SMN protein in the body. Salanersen works by helping the SMN2 gene to make more SMN protein.
In this study, participants will have either 2 SMN2 copies or 3 SMN2 copies. The higher the copy number, the less severe the participant's SMA is.
The main goal of this study is to see if starting salanersen before signs or symptoms appear can prevent signs or symptoms of SMA or make them less severe. Researchers will use different tests to learn if motor symptoms are changing, including the World Health Organization (WHO) motor milestones.
The main questions researchers want to answer in this study are:
* How many participants with 2 copies of the SMN2 gene can sit without support at 12 months? * How many participants with 3 copies of the SMN2 gene can walk alone at 18 months?
Researchers will also learn more about:
* The effects on participants' motor symptoms and how many new movement milestones participants achieve. * How many participants stay free of SMA symptoms * How much salanersen gets into the fluid surrounding the brain and spinal cord. * How much salanersen gets into the blood. * How many participants have adverse events or serious adverse events. Adverse events are health problems that may or may not be caused by the study drug.
This study will be done as follows:
* First, participants will be screened to check if they can join the study. The screening period will be up to 28 days. * This is an "open label" study. This is a study in which the participants, study doctor, and site staff know which study drug participants are receiving. In this study, all participants will receive salanersen through an intrathecal injection, or one that is given into the fluid surrounding the brain and spinal cord. * There will be 2 parts in this study. During Part 1, participants will receive 2 doses of salanersen, about 12 months apart from each other. Part 1 will last up to 25 months. * During Part 2, participants will continue to receive salanersen. They will receive up to 3 doses, 12 months apart from each other. Part 2 will last up to 36 months. * During Part 1, participants will have up to 11 clinic visits and up to 3 phone calls. During Part 2, participants will have up to 7 clinic visits and up to 12 phone calls.
Inclusion: -≤42 days of age at first dose of salanersen; Genetic documentation of 5q SMA homozygous gene deletion or mutation or compound heterozygous mutation; Two or three copies of the survival motor neuron 2 (SMN2) gene; Ulnar compound muscle action potential (CMAP) amplitude ≥2 millivolt (mV) at Screening and Day 1 predose; Body weight ≥3rd percentile for age based on World Health Organization (WHO) Child Growth Standards at the time of informed consent.
Exclusion: Any prior treatment with an approved SMA disease-modifying therapy (e.g., nusinersen, onasemnogene abeparvovec-xioi [OA], and/or risdiplam), a myostatin inhibitor therapy, or an investigational drug given for the treatment of SMA; Note: Other protocol-defined inclusion/exclusion criteria will apply; Diagnosis of neonatal respiratory distress syndrome necessitating surfactant replacement therapy or invasive ventilatory support; Any reason, anatomical or otherwise (including hematology/coagulation laboratory results), that presents increased risk of complication from the LP procedures or safety assessments; Any clinical signs or symptoms at Screening or Day 1 predose that are, in the opinion of the Investigator, strongly suggestive of SMA; Areflexia on neurologic examination at biceps, knee, or ankle at Screening or Day 1 Predose; Hypoxemia (oxygen saturation <96% awake or asleep without any supplemental oxygen or respiratory support, or for altitudes >1000 meters (m), oxygen saturation of <92% awake or asleep without any supplemental oxygen or respiratory support).