Efficacy and Safety of Losmapimod in Treating Subjects With Facioscapulohumeral Muscular Dystrophy (FSHD)


About this study

The purpose of this study is to evaluate the safety and effectiveness of losmapimod in treating patients with Facioscapulohumeral Muscular Dystrophy (FSHD) over 48 weeks.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

- Patients must be between 18 and 65 years of age, inclusive, at the time of consent

- Genetically confirmed diagnosis of FSHD 1 or FSHD 2.

- Clinical severity score of 2 to 4 (Ricci Score; Range 0-5), at screening. Patients who are wheelchair-dependent or dependent on walker or wheelchair for activities are not
permitted to enroll in the study.

- Screening total relative surface area (RSA) (Q1-Q4) without weight in the dominant upper extremities (UE) assessed by reachable workspace (RWS) ≥ 0.2 and ≤ 0.7.

- No contraindications to MRI.

Exclusion Criteria:

- Previously diagnosed cancer that has not been in complete remission for at least 5 years. Localized carcinomas of the skin and carcinoma in situ of the cervix that have been resected or ablated for cure are not exclusionary.

- Patients who are on drug(s) or supplements that may affect muscle function, as determined by the Investigator: patients must be on a stable dose of that drug(s) or supplement for at least 3 months prior to the first dose of study drug and remain on that stable dose for the duration of the study.

- Orally administered CYP3A4 substrates and MATE and OAT3 substrates are not permitted as concomitant therapy during the administration of losmapimod (defined as baseline
visit through end of study treatment).

- Known active opportunistic or life-threatening infections including HIV and hepatitis B or C.

- Known active or inactive tuberculosis infection.

- Acute or chronic history of liver disease.

- Known severe renal impairment.

- History of cardiac dysrhythmias requiring anti-arrhythmia treatment(s); or history or evidence of abnormal ECGs.

- Use of another investigational product within 30 days or 5 half-lives (whichever is longer) or currently participating in a study of an investigational device.

- Current or anticipated participation in a natural history study. Previous participation is allowed but patients cannot continue after enrollment in Study 1821-FSH-301.

- Known hypersensitivity to losmapimod or any of its excipients.

- Previous participation in a Fulcrum-sponsored FSHD losmapimod study (FIS-001-2019 or FIS-002-2019).

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 2/9/23. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Elie Naddaf, M.D.

Closed for enrollment

Contact information:

Jonathan Duff

(507) 538-0266


More information


  • Evaluate safety, tolerability, pharmacokinetics (PK) and target engagement (TE) of losmapimod in blood and muscle in facioscapulohumeral dystrophy (FSHD). Read More on PubMed
  • A depth-ranging sensor (Kinect) based upper extremity motion analysis system was applied to determine the spectrum of reachable workspace encountered in facioscapulohumeral muscular dystrophy (FSHD). Read More on PubMed
  • The purpose of this study was to establish safety and tolerability of a single intravenous (IV) infusion of a p38 mitogen-activated protein kinase inhibitor, losmapimod, to obtain therapeutic levels rapidly for a potential acute coronary syndrome indication. Pharmacokinetics (PK) following IV dosing were characterized, and pharmacokinetic/pharmacodynamic (PK/PD) relationships between losmapimod and phosphorylated heat shock protein 27 (pHSP27) and high-sensitivity C-reactive protein were explored. Read More on PubMed

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