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Observational Study of Muscle Response to SMA Therapies

This observational study is looking at how muscles and nerve cells in people with Spinal Muscular Atrophy (SMA) respond to treatments like nusinersen (Spinraza®), onasemnogene abeparvovec (Zolgensma®), and risdiplam (Evrysdi®). Researchers want to see if a special type of MRI (magnetic resonance imaging) can reliably measure changes in muscle energy in people with SMA types 2 and 3. You could be eligible if you are 5 to 20 years old, have a confirmed SMA diagnosis with specific genetic markers, and meet certain functional criteria. The study aims to understand how these different SMA treatments affect muscle health over time. The status of this study is currently unclear.

Study design
This is an observational study with a planned enrollment of 24 participants. It is not testing a new drug, but rather observing patients who are already receiving SMA treatments.
What's involved
You would visit the clinic 3 times over one year. Each visit includes MRI scans, muscle ultrasound, nerve tests, muscle function tests, lung function tests, blood work, vital signs, and questionnaires about your quality of life.
Compensation
Not stated in the trial record.
Follow-up
Participants will be followed for 12 months, with assessments at baseline, 6 months, and 12 months.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06532474

Exploring the Physiologic, Pharmacodynamic, and Clinical Responses of Skeletal Muscle in Patients With Spinal Muscular Atrophy Treated With SMN-Directed Therapies

Recruiting
Not specifiedAges 5–20Observational
St. Jude Children's Research Hospital
~24 participants
Updated 2026-07-09 on ClinicalTrials.gov

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Feasibility of performing MR functional imaging in SMA patients
Measured over At baseline and at 6 months (+/- 14 days)
+5 more outcomes measured

Conditions

Spinal Muscular Atrophy

Explore related trials

Spinal Muscular AtrophySMN1 GeneSMN2 Gene

Where it's being run

1 sites across 1 states
Tennessee1

Study leadership

  • Richard Finkel, MD · PRINCIPAL_INVESTIGATOR · St. Jude Children's Research Hospital

Who to contact

Jean Laboe, RN
[email protected]
901-595-1693
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Genetic confirmation of SMA with homozygous deletion of SMN1 or compound heterozygous deletion/mutation of SMN1
Two, three, or four copies of SMN2
Age 5 to 20 years
Non-ambulatory participants: maximum function sitting or standing with support, HFMSE score at screening between 10 and 45 points.
Ambulatory participants: minimum function of independent walking, able to walk unassisted a minimum of 100 meters at screening, HFMSE score at screening between 40 and 66.
SMN-directed therapy inclusion:
Current Evrysdi prescription (Group 1)
Must have Evrysdi prescription through their treating physician
If initiating combined therapy using Evrysdi with Spinraza or Zolgensma, must have not started Evrysdi treatment OR
Current Spinraza or Zolgensma prescription (Group 2)
For patients on Spinraza, must have been taking Spinraza for at least 12 months at screening (4 loading and 2 maintenance doses) and following the FDA-recommended dosing schedule
For patients on Zolgensma, must have been dosed at least one year prior to screening
Must have Spinraza or Zolgensma prescription through their treating physician OR
Changing from Spinraza or Zolgensma to Evrysdi (Group 3)
For patients on Spinraza, must have been taking Spinraza for at least 12 months at screening (4 loading and 2 maintenance doses) and following the FDA-recommended dosing schedule
For patients on Zolgensma, must have been dosed at least one year prior to screening
Must have voluntarily decided to switch therapies based on discussion with their treating physician
Must have Evrysdi prescription through their treating physician but have not yet initiated treatment OR
Have never received any SMN-directed therapies (Group 4)

Exclusion

Any chronic medical condition, planned surgery, or treatment with a medication which would impact safety or participation of the study at the investigator's discretion
Inability to perform reliably the motor function testing or the exercise testing in the MR scanner.
Fat fraction \> 35% in calf or bicep at screening MRI
Need for routine non-invasive ventilation support.
Non-oral nutritional support, e.g., gastrostomy tube feeding.
Any ferrous metal implants (e.g., spinal rods) that preclude testing in a MR scanner.

What this trial measures

  • Feasibility of performing MR functional imaging in SMA patientsAt baseline and at 6 months (+/- 14 days)

    MR functional imaging is considered feasible if ≥ 80% of MRI protocol eligible patients can complete 100% of imaging assessments at baseline and 6 months.

  • Reliability of performing MR functional imaging in SMA patientsAt baseline and at 6 months (+/- 14 days)

    MR functional imaging is considered reliable if the test-retest reliability is ≥ 0.80 for key imaging biomarkers.

  • Compare skeletal muscle oxidative phosphorylation bioenergetics in patients with SMA types 2 and 3 (phosphocreatine)At baseline and longitudinally at 6 (+/- 14 days) and 12 months (+/- 14 days)

    Real-time 31P MR spectroscopy and CrCEST MRI will be used to measure phosphocreatine within the muscles at rest, during an exercise protocol, and during post-exercise recovery to baseline. Both measure the recovery time in seconds.

  • Compare skeletal muscle oxidative phosphorylation bioenergetics in patients with SMA types 2 and 3 (creatine concentrations)At baseline and longitudinally at 6 (+/- 14 days) and 12 months (+/- 14 days)

    Real-time 31P MR spectroscopy and CrCEST MRI will be used to measure creatine concentrations within the muscles at rest, during an exercise protocol, and during post-exercise recovery to baseline. Both measure the recovery time in seconds.

  • Measure intramuscular fat fraction in major muscle extremity in patients with SMA types 2 and 3At baseline and longitudinally at 6 (+/- 14 days) and 12 months (+/- 14 days)

    Measurement of thickness of muscle compared to fat on MRI, measured in percentage.

  • Measure electrophysiological tests of motor neuron function to repetitive nerve stimulation in patients with SMA types 2 and 3At baseline and longitudinally at 6 (+/- 14 days) and 12 months (+/- 14 days)

    Electrophysiological testing: Compound motor action potential (CMAP, measured in millivolts), motor unit number estimate (MUNE, average 200-400 for most limb muscles), and repetitive stimulation at 3 Hz - right ulnar to abductor digiti minimus and right fibular/peroneal nerve to tibialis anterior muscle. A decrease of more than 40% in the amplitude of CMAP is considered abnormal.