• 1\. Age ≥45 years to 75 years of age 2. Diagnosed with sIBM based on the ENMC IBM Research Diagnostic Criteria 3. Willing and able to comply with clinic visits and study-related procedures. 4. Provide informed consent signed by the study patient or legally acceptable representative.

• 5\. Able to understand and complete study-related questionnaires. 6. Able to ambulate at least 20 ft/6 meters with or without assistive device Once arising from the chair, the participant may use any walking device, i.e. walker/frame, cane, crutches, or braces. They cannot be supported by another person and cannot use furniture or walls for support.

• 7\. If female, the subject must be: (a) surgically sterilized via hysterectomy, bilateral oophorectomy, or bilateral tubal ligation. or (b) of childbearing potential and using a birth control method, such as:

• •Combined (estrogen and progestogen-containing) hormonal. contraception associated with inhibition of ovulation:

• o Oral

⁃ Intravaginal

⁃ Transdermal

• Progestogen-only hormonal contraception associated with inhibition of ovulation:

⁃ Oral

⁃ Injectable

⁃ Implantable

‣ • Intrauterine device

‣ • Intrauterine hormone-releasing system

‣ • Bilateral tubal occlusion

∙ Vasectomized partner

∙ Sexual abstinence or of non-childbearing potential (i.e., no menses for ≥12 consecutive months without any other underlying medical cause) The subject must agree to continue using her selected method of birth control with her sexual partner during the study and for 120 days after study completion.

• 8\. If male, the subject must have had a vasectomy or must use a reliable method of birth control with their partner or maintain total abstinence from sexual intercourse. The subject must agree to continue using his selected method of birth control with his sexual partner during the study and for 120 days after the study completion.