Salanersen (BIIB115) for improving movement in people 15–60 with spinal muscular atrophy who are treatment‑naïve or previously on risdiplam

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This Phase 3 interventional study enrolls participants aged 15–60 with genetically confirmed 5q SMA and a baseline HFMSE score between 10 and 54, including both ambulatory and nonambulatory patients. Participants are split into two cohorts based on prior exposure to SMA therapy: treatment‑naïve or previously treated with risdiplam, and will receive salanersen with monitoring of motor function, safety, tolerability, and pharmacokinetics. The primary endpoint focuses on clinical efficacy for movement using standardized motor scales, while secondary endpoints capture adverse events and PK parameters. The protocol excludes prior myostatin inhibitor use and requires the ability to sit unassisted for at least 10 seconds and, for ambulatory participants, the capacity to complete a 6‑minute walk test at screening.

Why it matters

Who can join: the full rules

Key Inclusion Criteria:

* Participants aged 15 to 60 years, inclusive, at the time of informed consent
* Participants with genetic documentation of 5q Spinal Muscular Atrophy (SMA) (homozygous gene deletion or mutation or compound heterozygous mutation).
* Participants with clinical signs and symptoms consistent with SMA.
* Survival motor neuron 2 (SMN2) copy number ≥ 1.
* Participants with baseline Hammersmith Functional Motor Scale - Expanded (HFMSE) total score of ≥ 10 to ≤ 54.
* Participants who are able to sit without using support for at least 10 seconds.
* Participants with no prior treatment with myostatin inhibitors and a willingness to remain off concurrent myostatin inhibitor therapy for the duration of the study.
* Ambulatory and nonambulatory participants:

  * Ambulatory participants must be able to walk at least 10 meters independently without assistance and are willing and able to complete the 6 Minute Walk Test (6MWT) at Screening.
* For participants in the treatment-naïve cohort:

  * No prior treatment with an approved SMA Disease Modifying Therapy (DMT) or an investigational drug given for the treatment of SMA.
* For participants in the risdiplam-treated cohort:

  * Currently receiving risdiplam treatment and have been on once-daily 5 milligrams (mg) risdiplam treatment for at least 6 months prior to Screening.
  * Willing to stop risdiplam therapy for the duration of the study. The last dose of risdiplam must be taken the day before the first dose of salanersen.
  * No prior treatment with nusinersen, onasemnogene abeparvovec-xioi/onasemnogene abeparvovec-brve (OA), other approved DMTs for SMA or investigational drugs given for the treatment of SMA apart from risdiplam.

Key Exclusion Criteria:

* Respiratory insufficiency at Screening, defined by the medical necessity for invasive or noninvasive ventilation for \> 6 hours during a 24-hour period (except for nocturnal bilevel positive airway pressure).
* Medical necessity for a gastric feeding tube, where the majority of nutrition is provided by this route, as assessed by the site Investigator at Screening.
* History of brain or spinal cord disease or other contraindications (e.g., severe scoliosis) that would interfere with the lumbar puncture (LP) procedures, Cerebrospinal fluid (CSF) circulation, efficacy assessments, or safety assessments (including a history of hydrocephalus or implanted shunt for CSF drainage), as assessed by the Investigator.
* Hospitalization for surgery, a pulmonary event, or nutritional support within 2 months prior to Screening or plans to undergo elective procedures or surgeries at any time after signing the Informed Consent Form (ICF) through the end of the study. Note: If prior scoliosis surgery has been performed, it must be done at least 1 year prior to Screening.
* Presence of an active medical issue (e.g., infection, recent fracture) that would make the participant unsuitable for inclusion, as assessed by the Investigator.
* Current enrollment or a plan to enroll in any interventional clinical study in which an investigational treatment or approved therapy for investigational use is administered within 90 days or 5 half-lives of the treatment (if known), whichever is longer, prior to Screening. This includes neuromodulation therapy such as spinal cord stimulation.

Note: Other protocol-defined inclusion/exclusion criteria will apply.

Where it's running

• Stanford University Medical Center
  Palo Alto, California, United States Recruiting
• Childrens Hospital of the Kings Daughter Norfolk
  Norfolk, Virginia, United States Recruiting
• Peking Union Medical College Hospital
  Beijing, China Recruiting

Study contacts

• Study coordinator: US Biogen Clinical Trial Center
• Email: clinicaltrials@biogen.com
• Phone: 866-633-4636

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Pregnancy-time treatment of fetal SMA: a registry of mother-child outcomes

  This registry collects information on pregnancies where a fetus diagnosed with spinal muscular atrophy was treated with a disease‑modifying therapy in the womb to see how the pregnancy and baby fare after birth.

  Recruiting St. Jude Children's Research Hospital · Memphis, Tennessee · NCT07805278

• Intrathecal Zolgensma in spinal muscular atrophy patients in Japan

  This study tests the safety and real‑world effectiveness of intrathecal onasemnogene abeparvovec in SMA patients in Japan.

  Recruiting at 4 sites Novartis · Toyoake, Aichi-ken and 3 other locations · NCT07767890

• Spinal muscular atrophy patients get a single intrathecal gene therapy dose to see how it works in real-world U.S. settings

  This study tests whether a one-time intrathecal dose of ITVISMA® (onasemnogene abeparvovec-brve) is safe and effective for SMA patients in real-world U.S. clinical practice.

  Recruiting at 6 sites Phase 4 Novartis · Little Rock, Arkansas and 5 other locations · NCT07448610

• CuidAME: Spain's longitudinal registry for spinal muscular atrophy

  This project collects long-term clinical and treatment data from children and adults with genetically confirmed 5q spinal muscular atrophy in Spain to track outcomes over time.

  Recruiting Fundació Sant Joan de Déu · Esplugues de Llobregat · NCT07231549

• Apitegromab for infants under 2 with spinal muscular atrophy

  This trial will test whether adding apitegromab to approved SMA therapy helps infants under 2 with 5q SMA reach better motor milestones.

  Recruiting at 23 sites Phase 2 Scholar Rock, Inc. · Phoenix, Arizona and 22 other locations · NCT07047144

• Understanding fatigue in patients with spinal muscular atrophy treated with nusinersen

  This study is trying to see how nusinersen treatment affects fatigue in people with spinal muscular atrophy and how that fatigue impacts their daily activities.

  Recruiting Columbia University · New York, New York · NCT06955897

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.