Spinal Muscular AtrophyPhase 2OPALNCT07047144
A Study to Evaluate How Apitegromab Works in Subjects Who Are Less Than 2 Years Old and Have Spinal Muscular Atrophy
A Phase 2 study testing Apitegromab, Nusinersen and Risdiplam in people with Spinal Muscular Atrophy and SMA, run by Scholar Rock, Inc. at 23 sites in 7 countries.
Trial summary
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… Read more about this study
- Who is it for?
- Ages Up to 2 years
- Conditions the study is for
- Spinal Muscular Atrophy, SMA, Spinal Muscular Atrophy Type 2
- What is being tested?
- Apitegromab, Nusinersen and Risdiplam
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 52 participants
- Where
- 23 sitesin 7 countries
- Study dates
- 15 Sep 2025to Mar 2029
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Up to 2 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Is <2 years old at the time of the informed consent
- Had a gestational age of ≥35 weeks and gestational body weight ≥2.0 kg at birth
- Has confirmed diagnosis of 5q autosomal recessive SMA
- Has confirmed presence of SMN2 gene copy(ies)
- 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)
- Body weight for age is no less than 1st percentile based on the WHO Child Growth Standards at the Screening Visit
- Has delayed motor milestones for age attributed to SMA at the discretion of the Investigator or a CHOP-INTEND score <55
Who cannot join
- Nutritional status that is not anticipated to be stable throughout the study or medical necessity for a gastric feeding tube, where most feeds are administered by this route
- Major orthopedic issues such as severe scoliosis or severe contractures or interventional procedure, including spine or hip surgery, which is considered to have the potential to substantially limit the ability of the subject to be evaluated on any motor function outcome measures, within 6 months before Screening or anticipated during the study
- Any other physical limitations (eg, the subject requires cast for contractures) that would prevent the subject from undergoing motor function outcome measures throughout the study.
Trial locations and contacts
23 sites in 7 countries. Contact the study team or a site near you to ask about taking part.
23 sites in 7 countries
United States12 sites, 12 recruiting
- Recruiting
Children's Healthcare of Atlanta
Atlanta, Georgia, 30329
Julia Hunt, 404-785-4677, julia.hunt@choa.org
- Recruiting
Children's Hospital Colorado
Aurora, Colorado, 80045
Hannah Kleiner, 720-222-1377, hannah.kleiner@childrenscolorado.org
- Recruiting
University of Texas Southwestern Medical Center
Dallas, Texas, 75207
Holly Lawrence, 214-456-9561, Holly.Lawrence@utsouthwestern.edu
- Recruiting
Neurology Rare Disease Center
Flower Mound, Texas, 75028
Jennifer Avelar, 972-999-1011, jennifer.avelar@neuromdcenter.com
- Recruiting
Cook Children's Medical Center
Fort Worth, Texas, 76104
Kayla Blough, 682-303-1489, kayla.blough@cookchildrens.org
- Recruiting
Helen DeVos Children's Hospital at Spectrum Health
Grand Rapids, Michigan, 49503
Rosa Sifontes-Escamilla, 616-486-6342, rosa.sifontes-escamilla@helendevoschildrens.org
- Recruiting
Texas Children's Hospital (TCH)-Clinical Care Center (CCC)
Houston, Texas, 77030
Kim Walker, 832-824-0253, Kim.Walker@bcm.edu
- Recruiting
University of Iowa
Iowa City, Iowa, 52242
Carrie Stephan, 319-356-2673, carrie-stephan@iowa.edu
- Recruiting
Children's Hospital of Orange County (CHOC)
Orange, California, 92868
Sabrine Serrano, 714-509-7926, Sabrina.serrano@choc.org
- Recruiting
Stanford Neuroscience Health Center (SNHC)
Palo Alto, California, 94304
Wendy Ao, 650-725-4341, NeuromuscularResearch@stanford.edu
- Recruiting
The Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, 19104
Karen Monono, 267-425-0158, mononok@chop.edu
- Recruiting
Phoenix Children's Hospital
Phoenix, Arizona, 85016
Melony Valdez, 602-933-2017, mvaldez8@phoenixchildrens.com
Belgium3 sites, 3 recruiting
- Recruiting
UZ Gent
Ghent, East-Flanders, 9000
Elke De Vos, +32 9 3321954, elke.devos@uzgent.be
- Recruiting
UZ Leuven - Campus Gasthuisberg
Leuven, 3000
- Recruiting
CHR Citadelle
Liège, 4000
Italy3 sites, 3 recruiting
- Recruiting
Fondazione I.R.C.C.S. - Istituto Neurologico Carlo Besta
Milan, 20133
- Recruiting
Centro Clinico NeMO Milano - Fondazione Serena Onlus
Milan, 20162
- Recruiting
Fondazione Policlinico Universitario Agostino Gemelli IRCCS
Rome, 00168
Spain2 sites, 2 recruiting
- Recruiting
Hospital Sant Joan de Déu Barcelona
Barcelona, 08950
- Recruiting
Hospital Universitari i Politecnico La Fecnic La Fe
Valencia, 46026
France1 site, 1 recruiting
- Recruiting
Hopital Trousseau - I-Motion
Paris, 75012
Andreea Seferian, +003 317 1738050, a.seferian@institut-myologie.org
Netherlands1 site, 1 recruiting
- Recruiting
Universitair Medisch Centrum Utrecht
Utrecht, 3584 CX
United Kingdom1 site, 1 recruiting
- Recruiting
Leeds General Infirmary Children's Research Department
Leeds, West Yorkshire, LS1 3EX
Anne-Marie Childs, +44 11 3392 2160, paedonc.research@nhs.net
About this study
Official title: A Phase 2, Double-Blind Study to Evaluate the Pharmacokinetics, Pharmacodynamics, Efficacy, and Safety of Apitegromab in Subjects <2 Years Old With Spinal Muscular Atrophy (SMA)
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.
- Conditions
- Spinal Muscular Atrophy, SMA, Spinal Muscular Atrophy Type 2, Spinal Muscular Atrophy Type 3, Neuromuscular Manifestations, Anti-myostatin
- Being tested
- Apitegromab, Nusinersen, Risdiplam
- Medical subject headings
- Muscular Atrophy, Spinal, Spinal Muscular Atrophies of Childhood, Neuromuscular Manifestations
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ApitegromabDrug
Also called SRK-015
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.
NusinersenDrug
Also called Spinraza
Nusinersen is a current standard-of-care SMN therapy that targets the SMN2 gene. It will be administered intrathecally per the prescribing information.
RisdiplamDrug
Also called Evrysdi
Risdiplam is a current standard-of-care SMN therapy that targets the SMN2 gene. It will be administered orally per the prescribing information.
| Study group | Role | What they receive |
|---|---|---|
| Apitegromab low dose + SMN Therapy | Experimental | 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). Receives: Drug: Apitegromab; Drug: Nusinersen; Drug: Risdiplam |
| Apitegromab high dose + SMN Therapy | Experimental | 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). Receives: Drug: Apitegromab; Drug: Nusinersen; Drug: Risdiplam |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate the PK of apitegromab in subjects <2 years old with SMA
Apitegromab concentrations in serum
Measured: 52 Weeks
Evaluate the PD of apitegromab in subjects <2 years old with SMA
Total latent myostatin concentrations in serum
Measured: 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.
Measured: 48 Weeks
Secondary outcomes (1)
Assess the safety and tolerability of apitegromab administered to subjects receiving an SMN therapy
Incidence of TEAEs and SAEs by severity
Measured: 52 Weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jul 2025
- Study start15 Sep 2025
- Primary completionNov 2028 (estimated)
- Study completionMar 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Spinal Muscular AtrophyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 52 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Scholar Rock, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07047144
- Sponsor's protocol ID
- SRK-015-005
- Acronym
- OPAL
- Status last verified
- Oct 2026
- First submitted
- 16 Apr 2025
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
- Expanded access
- Available