Spinal Muscular Atrophy (SMA) Clinical Trials and Treatments

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by mutations in the SMN1 gene, resulting in deficiency of survival motor neuron (SMN) protein. SMN protein is essential for survival and function of motor neurons in the anterior horn of the spinal cord. Without adequate SMN, motor neurons degenerate, causing progressive muscle weakness and atrophy beginning proximally (hip and shoulder muscles) and advancing distally.

The most common symptoms of Spinal Muscular Atrophy include Progressive muscle weakness starting proximally, Difficulty with motor milestones in infants, Hypotonia and loss of muscle tone, Feeding and swallowing difficulties, Breathing difficulties, especially when lying down, among others. Spinal Muscular Atrophy affects approximately 1 in 10,000 to 14,000 births; 1 in 25 people are carriers. Symptoms can range from mild to severe and may vary between individuals.

Trial Friend lists all active clinical trials for Spinal Muscular Atrophy from ClinicalTrials.gov, with eligibility criteria translated into plain English. Patients can filter by trial phase and recruitment status, search by location, and use the Match Me tool to score trials against their profile. SMA now has two separate kinds of treatment, and the distinction matters when you are weighing trials. SMN-targeted therapies protect motor neurons and include Spinraza, Evrysdi, the one-time gene therapy Zolgensma, given by IV infusion to children under 2, and Itvisma (onasemnogene abeparvovec-brve), a one-time gene therapy injected into the spinal fluid (intrathecal) that the FDA approved in November 2025 for patients 2 years and older.

Yes. As of September 2026, Trial Friend lists 5 FDA-approved drugs used to treat Spinal Muscular Atrophy: Spinraza (nusinersen), first approved in 2016; Zolgensma (onasemnogene abeparvovec), first approved in 2019; Evrysdi (risdiplam), first approved in 2020; Itvisma (onasemnogene abeparvovec-brve), first approved in 2025; and Isembyld (apitegromab), first approved in 2026.

Each has its own page with what the label covers, side effects and how it is given, and the Treatments section of this page adds any further approved drugs found in FDA labeling data.

Spinal Muscular Atrophy is caused by variants in the SMN1 and SMN2 genes. Most cases are a homozygous SMN1 deletion; SMN2 copy number modifies severity and guides treatment decisions.

It is inherited in an autosomal recessive pattern: both parents are usually unaffected carriers, and each pregnancy has a 1 in 4 chance of an affected child. The condition affects approximately 1 in 10,000 to 14,000 births; 1 in 25 people are carriers. Genetic testing confirms the diagnosis.

Yes. Genetic testing for Spinal Muscular Atrophy looks at the SMN1 and SMN2 genes. Most cases are a homozygous SMN1 deletion; SMN2 copy number modifies severity and guides treatment decisions.

It is inherited in an autosomal recessive pattern: both parents are usually unaffected carriers, and each pregnancy has a 1 in 4 chance of an affected child.

A confirmed variant establishes the diagnosis and is often required to enroll in gene-specific trials. The labs currently offering the test are listed in the Genetic Testing section of this page, pulled live from the NIH Genetic Testing Registry. A genetic counselor can help interpret the result and decide which relatives should be tested.

Eligibility for Spinal Muscular Atrophy clinical trials depends on factors like age, diagnosis, treatment history, and overall health. Each trial sets its own inclusion and exclusion criteria. Trial Friend translates these requirements from medical language into plain English so patients can review them more easily. The Match Me tool can score your profile against active trials to help identify studies that may be a fit.

Participating in a Spinal Muscular Atrophy clinical trial typically involves scheduled visits, medical tests, and close monitoring by a research team. Depending on the study phase, you may receive an investigational treatment, a placebo, or the current standard of care. Trials may last from a few weeks to several years. Study participation is voluntary, and you can withdraw at any time.