A Phase 2 interventional study of Apitegromab and Nusinersen in Spinal Muscular Atrophy, SMA and Spinal Muscular Atrophy Type 2, sponsored by Scholar Rock, Inc.. Recruiting at 23 sites in 7 countries. Open to participants aged Up to 2 Years. Per ClinicalTrials.gov, last updated 2026-10-02.
Sponsored by Scholar Rock, Inc. · Phase 2, Interventional, and Treatment
This double-blind, Phase 2, multiple-dose study will be conducted to evaluate the PK/PD, efficacy, safety, and tolerability of apitegromab in subjects \<2 years old with 5q autosomal recessive SMA who have delayed motor milestones for their age attributed to SMA at the discretion of the Investigator or a Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) score \<55.
61 studies on the registry are indexed under Spinal Muscular Atrophies of Childhood; 18 are open to participants now.
This study's planned enrollment of 52 is above the median of 15 across 41 interventional studies indexed under Spinal Muscular Atrophies of Childhood.
Browse Spinal Muscular Atrophies of Childhood studies →Scholar Rock, Inc. is the lead sponsor of 9 studies on the registry; 3 are open to participants now.
Compared within Spinal Muscular Atrophies of Childhood, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Muscular Atrophy, Spinal. The counts are of registry records indexed under each term, refreshed daily. How we classify →
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients who are less than 2 years of age with SMA will receive apitegromab every 4 weeks by intravenous (IV) infusion during the 48-week Treatment Period. Patients must have been treated with an approved SMN1-targeted therapy (ie, onasemnogene abeparvovec-xioi) or are continuing to be treated with an approved SMN2-targeted therapy (ie, nusinersen or risdiplam).
Drug: Apitegromab · Drug: Nusinersen · Drug: Risdiplam
Patients who are less than 2 years of age with SMA will receive apitegromab every 4 weeks by intravenous (IV) infusion during the 48-week Treatment Period. Patients must have been treated with an approved SMN1-targeted therapy (ie, onasemnogene abeparvovec-xioi) or are continuing to be treated with an approved SMN2-targeted therapy (ie, nusinersen or risdiplam).
Drug: Apitegromab · Drug: Nusinersen · Drug: Risdiplam
Apitegromab is a fully human anti-proMyostatin monoclonal antibody (mAb) of the immunoglobulin G4 (IgG4)/lambda isotype that specifically binds to human pro/latent myostatin with high affinity inhibiting myostatin activation. SRK-015 will be administered every 4 weeks by intravenous (IV) infusion.
Also known as: SRK-015
Nusinersen is a current standard-of-care SMN therapy that targets the SMN2 gene. It will be administered intrathecally per the prescribing information.
Also known as: Spinraza
Risdiplam is a current standard-of-care SMN therapy that targets the SMN2 gene. It will be administered orally per the prescribing information.
Also known as: Evrysdi
Evaluate the PK of apitegromab in subjects <2 years old with SMA
Apitegromab concentrations in serum
Time frame: 52 Weeks
Evaluate the PD of apitegromab in subjects <2 years old with SMA
Total latent myostatin concentrations in serum
Time frame: 52 Weeks
Evaluate the motor function outcomes (ie, efficacy) due to apitegromab treatment
Change from baseline in the raw score of the Bayley Scale of Infant and Toddler Development, Fourth Edition - Gross Motor Subscale (BSID-4 GMS) at 48 weeks. BSID-4 GMS is a standardized assessment commonly used to evaluate development across 5 domains in infants and young children. It consists of 58 items, scored from 0 to 2 for each item, with higher scores indicating better gross motor development.
Time frame: 48 Weeks
Assess the safety and tolerability of apitegromab administered to subjects receiving an SMN therapy
Incidence of TEAEs and SAEs by severity
Time frame: 52 Weeks
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Apitegromab
Spinal Muscular Atrophies of Childhood →
Scholar Rock, Inc.