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RecruitingNCT07038200FORTITUDE-3Updated Jul 27, 2026

A Study to Evaluate Del-brax (Also Referred to as AOC 1020) in Participants With FSHD

A Phase 3 interventional study of AOC-1020 and Placebo in Facioscapulohumeral Muscular Dystrophy, FSHD and FSHD - Facioscapulohumeral Muscular Dystrophy, sponsored by Avidity Biosciences, Inc.. Recruiting at 46 sites in 10 countries. Open to participants aged 16 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-07-27.

Sponsored by Avidity Biosciences, Inc. · Phase 3, Interventional, and Treatment

Phase
Phase 3
Study type
Interventional
Enrollment
200
Allocation
Randomized
Ages
16 Years to 70 Years
Sex
All
01

Study summary

A Randomized, Double-blind, Placebo-controlled, Phase 3 Study to Evaluate the Efficacy and Safety of Intravenous AOC 1020 for the Treatment of Facioscapulohumeral Muscular Dystrophy (FSHD)

Read the detailed description

The study duration is approximately 22 months, consisting of a screening period of up to 6 weeks, a 78-week active treatment period, and a 12-week follow-up period (18 weeks from the last dose).

Participants will be randomized to receive an intravenous infusion of either delbrax or placebo at the clinical study site every 6 weeks for a total of 13 doses. The final dose will occur at Week 72, followed by a final assessment at Week 78.

After completion of the Week 78 visit, eligible participants will have the option to enroll in an open-label extension (OLE) study, pending regulatory approval. Participants who decline participation in the OLE will be followed for 12 weeks for safety.

An Independent Data Monitoring Committee (IDMC) comprising members independent and external to the Sponsor will review safety, tolerability, and efficacy (as needed) data of this study at regular intervals.

02

Conditions studied

  • Facioscapulohumeral Muscular Dystrophy
  • FSHD
  • FSHD - Facioscapulohumeral Muscular Dystrophy
  • FSHD1
  • FSHD2
  • Fascioscapulohumeral Muscular Dystrophy
  • Fascioscapulohumeral Muscular Dystrophy Type 1
  • Fascioscapulohumeral Muscular Dystrophy Type 2
  • Facioscapulohumeral Muscular Dystrophy 1
  • Facioscapulohumeral Dystrophy
  • Facio-Scapulo-Humeral Dystrophy
  • Facioscapulohumeral Muscular Dystrophy 2
  • Facioscapulohumeral Muscular Dystrophy Type 1 (FSHD1)
  • FSH Muscular Dystrophy
  • Landouzy Dejerine Dystrophy
  • Landouzy-Dejerine Muscular Dystrophy
  • Landouzy-Dejerine Syndrome

Keywords

  • Avidity
  • Avidity Biosciences
  • del-brax
  • del brax
  • delbrax
  • AOC1020
  • AOC 1020
  • delpacibart braxlosiran
  • FORTITUDE-3
  • FORTITUDE Phase 3
  • FORTITUDE
  • FORTITUDE 3
03

Who can participate

Ages eligible
16 Years to 70 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Clinical and genetic diagnosis of FSHD1 or FSHD2
  • Ability to walk independently at pre-specified walking speed (orthoses and ankle braces allowed) for at least 10 meters at screening
  • Adequate muscle strength based on QMT composite score

Exclusion criteria

Exclusion Criteria:

  • Breastfeeding, pregnancy, or intent to become pregnant during the study
  • Unwilling or unable to comply with contraceptive requirements
  • Abnormal lab values, conditions or diseases that would make the participant unsuitable for the study
  • Blood Pressure > 140/90 mmHg at Screening
  • Treatment with another investigational drug or biological agent within 1 month of Screening or 5 half-lives of the drug, whichever is longer
  • Treatment with an oligonucleotide within 9 months of Screening
04

Study design

Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
200 participants (estimated)

Study arms

  • Experimental
    Del-brax

    Del-brax (AOC 1020) will be administered 13 times

    Drug: AOC-1020

  • Placebo comparator
    Placebo

    Saline will be administered 13 times

    Drug: Placebo

Interventions

  • DrugAOC-1020

    Del-brax will be administered by intravenous (IV) infusion.

    Also known as: Del-brax

  • DrugPlacebo

    Placebo will be administered by intravenous (IV) infusion.

    Also known as: Saline

05

What researchers measure

Primary outcomes

  1. Change from Baseline to Week 78 in Quantitative Muscle Testing (QMT) total composite score (PPN)

    Assessment of muscle strength using standardized quantitative measurements

    Time frame: Baseline through Week 78

Secondary outcomes

  1. Change from Baseline to Week 78 in 10MWRT

    Assessment of the time required to walk or run 10 meters as quickly and safely as possible

    Time frame: Baseline through Week 78

  2. Change from Baseline to Week 78 in Timed Up-and-Go (TUG)

    Assessment of functional mobility by measuring the time required to stand up from a chair, walk 3 meters, turn, return, and sit down

    Time frame: Baseline through Week 78

  3. Change from Baseline to Week 78 in Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Item Bank v2.0-Physical Function-Short Form 20a Questionnaire

    Assessment of patient-reported physical function using the PROMIS Physical Function Short Form 20a questionnaire

    Time frame: Baseline through Week 78

  4. Change from Baseline to Week 78 in PROMIS Fatigue

    Assessment of patient-reported fatigue using the PROMIS Fatigue questionnaire

    Time frame: Baseline through Week 78

  5. Change from Baseline to Week 78 in Worst Pain Numeric Rating Scale (NRS)

    Assessment of the severity and impact of fatigue over the previous 7 days using the self-reported PROMIS Fatigue Short Form 6a questionnaire

    Time frame: Baseline through Week 78

  6. Change from Baseline to Week 78 in Patient Global Impression of Severity/Change (PGI-S/PGI-C)

    Assessment of participant-reported disease severity and change in disease status using the Patient Global Impression of Severity/Change (PGI-S/PGI-C) scales

    Time frame: Baseline through Week 78

  7. Change from Baseline to Week 78 in Quality of Life in Neurological Disorders (NeuroQoL) Upper Extremity Function

    Assessment of health-related quality of life using the Quality of Life in Neurological Disorders (Neuro-QoL) questionnaire

    Time frame: Baseline through Week 78

  8. Change from Baseline to Week 78 in NeuroQoL Sleep Disturbance

    Assessment of participant-reported sleep disturbance using the Neuro-QoL Sleep Disturbance questionnaire

    Time frame: Baseline through Week 78

  9. Change from Baseline to Week 78 in DUX4-regulated plasma KHDC1L

    Assess of changes from baseline in circulating PD biomarkers relevant to FSHD

    Time frame: Baseline through Week 78

  10. Change from Baseline to Week 78 in Serum CK

    Assess of changes from baseline in circulating PD biomarkers relevant to FSHD

    Time frame: Baseline through Week 78

06

Study locations

28 of 46 sites recruiting
  • University of California Irvine
    Orange, California 92868, United States
    Active, not recruiting
  • Stanford University
    Palo Alto, California 94304, United States
    Active, not recruiting
  • University of Colorado
    Denver, Colorado 80045, United States
    Active, not recruiting
  • University of Florida
    Gainesville, Florida 32608, United States
    Active, not recruiting
  • University of Iowa
    Iowa City, Iowa 52242, United States
    Active, not recruiting
  • Kansas University Medical Center
    Kansas City, Kansas 66205, United States
    Active, not recruiting
  • Kennedy Krieger Institute
    Baltimore, Maryland 21205, United States
    Active, not recruiting
  • University of Massachusetts
    Worcester, Massachusetts 01655, United States
    Active, not recruiting
  • University of Rochester Medical Center
    Rochester, New York 14642, United States
    Active, not recruiting
  • Duke University
    Durham, North Carolina 27708, United States
    Active, not recruiting
  • Ohio State University
    Columbus, Ohio 43221, United States
    Active, not recruiting
  • University of Pennsylvania
    Philadelphia, Pennsylvania 19104, United States
    Active, not recruiting
  • University of Texas Health Science Center at San Antonio
    San Antonio, Texas 78229, United States
    Active, not recruiting
  • Virginia Commonwealth University
    Richmond, Virginia 23298, United States
    Active, not recruiting
  • University of Calgary - Cumming School of Medicine
    Calgary, Alberta, Canada
    Recruiting
  • University of Alberta Hospital
    Edmonton, Alberta, Canada
    Recruiting
  • The Ottawa Hospital
    Ottawa, Ontario, Canada
    Recruiting
  • Genge Partners Inc
    Montreal, Quebec, Canada
    Recruiting
  • Aarhus University Hospital
    Aarhus, Denmark
    Not yet recruiting
  • Rigshospitalet
    Copenhagen, Denmark
    Recruiting
  • Centre de Reference des Maladies Neuromusculaires et de la SLA - AP-HM Hopital de La Timone
    Marseille, France
    Not yet recruiting
  • CHU de Montpellier - Hopital Gui de Chauliac
    Montpellier, France
    Not yet recruiting
  • CHU de Nice - Hopital Pasteur 2 - Centre de reference des Maladies Neuromusculaires
    Nice, France
    Not yet recruiting
  • AP-HP Hopital Pitie-Salpetriere
    Paris, France
    Recruiting
  • Universitaetsklinikum Bonn
    Bonn, Germany
    Recruiting
  • Georg-August-Universitaet Goettingen Stiftung oeffentlichen Rechts Universitaetsmedizin Goettingen
    Göttingen, Germany
    Recruiting
  • Klinikum der Ludwig-Maximilians-Universitaet Muenchen
    München, Germany
    Recruiting
  • Universitaetsklinikum Ulm
    Ulm, Germany
    Recruiting
  • Fondazione Serena ETS - Centro Clinico NeMO Milano
    Milan, Italy
    Recruiting
  • Azienda Ospedaliero Universitaria Pisana
    Pisa, Italy
    Recruiting
  • Azienda Ospedaliero-Universitaria Sant'Andrea
    Roma, Italy
    Recruiting
  • Fondazione Policlinico Universitario A. Gemelli IRCCS - Universita Cattolica del Sacro Cuore
    Roma, Italy
    Recruiting
  • National Hospital Organization Osaka Toneyama Medical Center
    Osaka, Japan
    Recruiting
  • The University of Osaka Hospital
    Osaka, Japan
    Recruiting
  • National Hospital Organization Sendai Nishitaga Hospital
    Sendai, Japan
    Recruiting
  • National Center of Neurology and Psychiatry
    Tokyo, Japan
    Recruiting
  • Academisch Ziekenhuis Leiden
    Leiden, Netherlands
    Recruiting
  • Stichting Radboud Universitair Medisch Centrum
    Nijmegen, Netherlands
    Recruiting
  • Hospital Universitari de Bellvitge
    Barcelona, Spain
    Recruiting
  • Hospital Universitario Vall d'Hebron
    Barcelona, Spain
    Recruiting
  • Hospital Universitario Donostia
    San Sebastián, Spain
    Recruiting
  • Hospital Universitari i Politecnic La Fe
    Valencia, Spain
    Recruiting
  • National Hospital for Neurology & Neurosurgery
    London, United Kingdom
    Recruiting
  • St. George's University Hospitals NHS Foundation Trust
    London, United Kingdom
    Recruiting
  • Royal Victoria Infirmary
    Newcastle upon Tyne, United Kingdom
    Recruiting
  • Royal Hallamshire Hospital
    Sheffield, United Kingdom
    Recruiting
07

References and documents

Individual participant data

Plan to share: Undecided

08

Registry details

Key details

Study ID
NCT07038200
Lead sponsor
Avidity Biosciences, Inc.
Responsible party
Sponsor
First posted
Jun 26, 2025
Start date
Jun 10, 2025
Primary completion
May 2028 (estimated)
Completion
Jul 2028 (estimated)
Last update
Jul 27, 2026

Study contacts

Avidity Biosciences, Inc., A Novartis Company
Contact
novartis.email@novartis.com
1-888-669-6682
Avidity Biosciences, Inc., A Novartis Company
Contact
novartis.email@novartis.com
+41613241111

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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