A Study to Evaluate How Apitegromab Works in Subjects Who Are Less Than 2 Years Old and Have Spinal Muscular Atrophy

Conditions

• Anti-myostatin
• Neuromuscular Manifestations
• SMA
• Spinal Muscular Atrophy
• Spinal Muscular Atrophy Type 2
• Spinal Muscular Atrophy Type 3

Eligibility Criteria

Sex

ALL

Age

N/A - 2 Years

Healthy Volunteers

Not accepted

Interventions

• Apitegromab — DRUG
  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.
• Nusinersen — DRUG
  Nusinersen is a current standard-of-care SMN therapy that targets the SMN2 gene. It will be administered intrathecally per the prescribing information.
• Risdiplam — DRUG
  Risdiplam is a current standard-of-care SMN therapy that targets the SMN2 gene. It will be administered orally per the prescribing information.

Study Details

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.

Key Dates

Start date

Sep 15, 2025

Status verified

Apr 2026

Primary completion

Nov 30, 2028

Completion

Mar 31, 2029

Study Design

Enrollment

52 participants (estimated)

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Arms

• Experimental: Apitegromab low dose + SMN Therapy
  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).
• Experimental: Apitegromab high dose + SMN Therapy
  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).

Primary Outcome Measure

Evaluate the PK of apitegromab in subjects <2 years old with SMA [ Time Frame: 52 Weeks ]

Central Contacts

• Scholar Rock
  857-259-3860
  [email protected]

Locations (14)

Find similar trials in Phoenix, AZ

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