Long-Term Safety & Efficacy of Apitegromab in Patients With SMA Who Completed Previous Trials of Apitegromab

Recruitment Status
ACTIVE, NOT RECRUITING
(See Contacts and Locations)Verified April 2025 by Scholar Rock, Inc.
Sponsor
Scholar Rock, Inc.
Information Provided by (Responsible Party)
Scholar Rock, Inc.
Clinicaltrials.gov Identifier
NCT05626855
Other Study ID Numbers:
SRK-015-004
First Submitted
November 6, 2022
First Posted
November 24, 2022
Last Update Posted
May 24, 2025
Last Verified
April 2025

ClinicalTrials.gov processed this data on May 2025. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

Condition or DiseaseIntervention/Treatment
Spinal Muscular AtrophySpinal Muscular Atrophy Type 3Spinal Muscular Atrophy Type 2SMANeuromuscular DiseasesMuscular AtrophyAtrophyMuscular Atrophy, SpinalNeuromuscular ManifestationsAnti-myostatin
Drug: Apitegromab

Study Design

Study TypeInterventional
Actual Enrollment238 participants
Design AllocationN/A
Interventional ModelSingle Group Assignment
MaskingNone (Open Label)
Primary PurposeTreatment
Official TitleAn Open-Label, Multicenter, Extension Trial to Evaluate the Long-Term Safety and Efficacy of Apitegromab in Patients With Type 2 and Type 3 Spinal Muscular Atrophy Who Completed Previous Investigational Trials of Apitegromab
Study Start DateApril 16, 2023
Actual Primary Completion Date5mos 2w from now
Actual Study Completion Date2yrs 11mos from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Treatment Period
Patients who are ≥2 years of age with Type 2 and Type 3 SMA will receive apitegromab 20 mg/kg every 4 weeks by intravenous (IV) infusion during the 104-week Treatment Period
Drug: Apitegromab
Apitegromab (SRK-015) is an investigational, fully human immunoglobulin G4 monoclonal antibody that specifically binds to human proforms (i.e., inactive precursor forms) of myostatin, pro- and latent- myostatin, with high affinity, inhibiting activation of myostatin, a negative regulator of muscle growth and strength.

Outcome Measures

Primary Outcome Measures
  1. Evaluate the long-term safety and tolerability of apitegromab in patients with Type 2 and Type 3 SMA
    Incidence of TEAEs and SAEs by severity
Secondary Outcome Measures
  1. Evaluate the long-term efficacy of apitegromab by assessing changes in motor function outcome measures at prespecified time points
    Hammersmith Functional Motor Scale Expanded (HFMSE) total score at prespecified time points (excludes ambulatory patients)
  2. Evaluate the long-term efficacy of apitegromab by assessing changes in motor function outcome measures at prespecified time points
    Revised Upper Limb Module (RULM) total score at prespecified time points (excludes ambulatory patients)
  3. Evaluate the long-term efficacy of apitegromab by assessing changes in motor function outcome measures at prespecified time points
    Number of World Health Organization (WHO) motor development milestones attained at prespecified time points (excludes ambulatory patients)
  4. Evaluate the long-term efficacy of apitegromab by assessing changes in motor function outcome measures at prespecified time points
    Revised Hammersmith Scale (RHS) total score
  5. Evaluate the long-term efficacy of apitegromab by assessing changes in motor function outcome measures at prespecified time points
    Results for 6-Minute Walk Test
  6. Evaluate the long-term efficacy of apitegromab by assessing changes in motor function outcome measures at prespecified time points
    30-Second Sit-to-Stand
  7. Further evaluate the immunogenicity of apitegromab
    Presence or absence of antidrug antibody (ADA) against apitegromab in serum from blood samples

Eligibility Criteria

Ages Eligible for Study(Child, Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
Inclusion Criteria
Patients have completed the Phase 2 TOPAZ (Study SRK-015-002) trial or the Phase 3 SAPPHIRE (Study SRK-015-003) trial. (For TOPAZ, completed is defined as completion of Visit EC14 in Extension Period C or participating in TOPAZ at the time the trial is ended. For SAPPHIRE, completed is defined as completion of Visit 14 or participating in SAPPHIRE at the time the trial is ended)
Estimated life expectancy \>2 years from the Baseline Visit (Day 1)
Able to receive study drug infusions and provide blood samples through the use of a peripheral IV or a long-term IV access device that the patient has placed for reasons independent from the trial
Able to adhere to the requirements of the protocol, including travel to the trial site and completing all trial procedures and trial visits
Females of childbearing potential must have a negative pregnancy test at the Baseline Visit and agree to use at least 1 highly effective method of contraception throughout the trial and for 20 weeks after the last dose of apitegromab
Exclusion Criteria
Patient permanently discontinued study treatment during the feeder trial (i.e., TOPAZ or SAPPHIRE)
Nutritional status that was not stable over the past 6 months and is not anticipated to be stable throughout the trial or medical necessity for a gastric/nasogastric feeding tube, where the majority of feeds are given by this route, as assessed by the Investigator
Patient is currently enrolled in any investigational drug trial other than TOPAZ or SAPPHIRE
Prior history of severe hypersensitivity reaction or intolerance to SMN-targeted therapies
Prior history of severe hypersensitivity reaction or intolerance to apitegromab
Use of chronic daytime noninvasive ventilatory support for \>16 hours daily in the 2 weeks before dosing, or anticipated to regularly receive such daytime ventilator support chronically throughout the trial
Any acute or comorbid condition interfering with the well-being of the patient at the patient's last visit in TOPAZ or SAPPHIRE, (including active systemic infection, the need for acute treatment, or inpatient observation due to any reason). After resolution of the condition, the patient can be enrolled in the trial if they meet all the other eligibility criteria.
Pregnant or breastfeeding
Any other condition or clinically significant laboratory result or ECG value that, in the opinion of the Investigator, may compromise safety or compliance, would preclude the patient from successful completion of the trial, or interfere with the interpretation of the results

Contacts and Locations

Sponsors and CollaboratorsScholar Rock, Inc.
Locations
Phoenix Childrens Hospital | Phoenix Arizona, United States, 85016UCSD Altman Clinical and Translational Research | La Jolla California, United States, 92037Children's Hospital Los Angeles | Los Angeles California, United States, 90027Stanford Neuroscience Health Center | Palo Alto California, United States, 94304Children's Hospital Colorado | Aurora Colorado, United States, 80045Nemours Biomedical Research | Orlando Florida, United States, 32827Lurie Children's Hospital of Chicago | Chicago Illinois, United States, 60611University of Iowa | Iowa City Iowa, United States, 52242University of Kansas Medical Center | Fairway Kansas, United States, 66205Johns HopkinsHospital | Baltimore Maryland, United States, 21287Boston Children's Hospital | Boston Massachusetts, United States, 02115Helen DeVos Children's Hospital | Grand Rapids Michigan, United States, 49503Gillette Children's Specialty Healthcare | Saint Paul Minnesota, United States, 55101Washington University Medical Campus | St Louis Missouri, United States, 63110Columbia University Medical Center | New York New York, United States, 10032Wake Forest University School of Medicine | Winston-Salem North Carolina, United States, 27157Nationwide Children's Hospital | Columbus Ohio, United States, 43215Oregon Health & Science University | Portland Oregon, United States, 97239The Children's Hospital of Philadelphia | Philadelphia Pennsylvania, United States, 19104St. Jude Children's Research Hospital | Memphis Tennessee, United States, 38105University of Texas Southwestern - Pediatric Neurology | Dallas Texas, United States, 75207University of Utah | Salt Lake City Utah, United States, 84112Children's Specialty Group PLLC (Children's Hospital of The King's Daughters) | Newport News Virginia, United States, 23606Seattle Children's Hospital | Seattle Washington, United States, 98115University of Wisconsin Hospital | Madison Wisconsin, United States, 53792UZ Gent | Ghent , Belgium, 9000UZ Leuven | Leuven , Belgium, 3000CHR Citadelle | Liège , Belgium, 4000CHRU de Lille - Hpital Jeanne de Flandre | Lille , France, 59037Hopital Trousseau - I-Motion | Paris , France, 75012CHU Toulouse Hopital des Enfants | Toulouse , France, 31059Universitätskinderklinik Bonn, Abteilung für Neuropädiatrie und SPZ | Bonn , Germany, 53127Universitatsklinikum Essen | Essen , Germany, 45147Universitatsklinikum Freiburg | Freiburg im Breisgau , Germany, 79106Klinikum der Universitat Munchen, Dr. von Haunersches Kinderspital, Abteilung fur Kinderneurologie und Entwicklungsneurologie | Munchen, Bayern , Germany, 80337Istituto Giannina Gaslini, Centro Traslazionale di Miologia e Patologie Neurodegenerative | Genova , Italy, 16147UOC NEUROLOGIA E MALATTIE NEUROMUSCOLARI A.O.U Policlinico G. Martino | Messina , Italy, 98125Carlo Besta Neurological Research Institute | Milan , Italy, 20133NeuroMuscular Omnicentre | Milan , Italy, 20162Fondazione Policlinico Universitario A. Gemelli | Roma , Italy, 106UMC Utrecht | Utrecht , Netherlands, 3508Uniwersyteckie Centrum Kliniczne | Gdansk , Poland, 80-211Uniwersytecki Szpital Kliniczny w Poznaniu, Oddział Kliniczny Neurologii Dzieci i Młodzieży | Poznan , Poland, 60-355Instytut Pomnik - Centrum Zdrowia Dziecka | Warsaw , Poland, 04-730Hospital Sant Joan de Deau | Barcelona , Spain, 08950Hospital Universitari i Politecnic La Fe | Valencia , Spain, 46026Leeds Children's Hospital Clinical Research | Leeds , United Kingdom, LS1 3EXGreat Ormond Street Hospital for Children | London , United Kingdom, WC1N 1EHUniversity of Oxford | Oxford , United Kingdom, OX3 0ER